| 1. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Added diagnostic utility of CT perfusion and CT angiography in acute ischemic stroke. Evaluation of three different patient categories
- 2009
-
Ingår i: Functional Neurology. - 0393-5264. ; 24:2, s. 93-98
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with a clinical picture of acute ischemic stroke are a heterogeneous group. The aim of this study was to evaluate the added utility of CT perfusion (CTP) and CT angiography (CTA) in the workup of three different categories of acute ischemic stroke patients. Fifty patients (61 +/- 05 years old) were included in this retrospective analysis. Twenty-nine patients had transient ischemic attacks (TIAs) (Group I), 15 were not eligible for treatment with thrombolysis (Group II) and six showed no improvement after thrombolysis (Group III). CTP and CTA provided additional information, not revealed by plain CT, in all the Group II patients and in one third of the patients belonging to the other groups. The final diagnoses were TIA (n=23), thromboembolic cerebral infarctions (n=22), carotid artery dissection (n=4) and metastases (n=1). Of the 29 patients admitted with TIA, only 22 patients still had this diagnosis on discharge from the stroke unit. Given the risk of impending stroke, it would be important to include these modalities in the initial workup of TIA.
|
|
| 2. |
- Abul-Kasim, Kasim
(författare)
-
Adolescent Idiopathic Scoliosis. The Role of Low Dose Computed Tomography.
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Continuous implementation of new operative methods for correction and stabilization of spinal deformities in young patients with AIS demands a detailed morphological analysis of the vertebral column. CT spine according to protocols available in daily clinical practice means high radiation dose to these young individuals. All examinations included in this thesis were performed on a 16-slice CT scanner. Examination of the chest phantom in paper I showed that the radiation dose of the spine (including 15 vertebrae) was 20 times lower than that of routinely used protocols for CT examination of the spine in children (0.38 mSv vs 7.76 mSv). In paper II the radiation dose and the impact of dose reduction on image quality were evaluated in 113 consecutive examinations with low-dose spine CT and compared with that of 127 CTs after trauma and 15 CTs performed according to a previously used ANV-protocol of a limited part of the vertebral column. The effective dose of the low-dose spine CT (0.01 mSv/cm scan length) was 20 times lower than that of the standard CT for trauma (0.20 mSv/cm scan length). The absorbed doses to the breasts, genital organs, and thyroid gland in the low-dose spine CT was 8, 265, and 22 times lower than the corresponding doses in CT for trauma. This significant dose reduction conveyed no impact on image quality with regard to answering the clinical questions at issue for the preoperative CTs and for the postoperative CTs after posterior corrective surgery. In paper III the low-dose CT showed to be a reliable method in the evaluation of screw placement in patients with AIS after posterior scoliosis surgery with titanium implants, using the new grading system for screw misplacement. Our proposed grading system for screw misplacement has shown to be feasible, practical, and easy to perform and is in line with the general agreement about the harmlessness of misplacement with minor pedicle breach. In paper IV the evaluation of the clinical and radiological outcome of 49 patients with AIS operated on with titanium “all-pedicle screw construct” showed an overall misplacement rate of 17 %. No evidence of neurovascular complications was reported. In parity with most of the reports in the literature the lateral- and medial cortical perforation were the most common types of screw misplacement (8 % and 6.1 % respectively).
|
|
| 3. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Advanced radiological work-up as an adjunct to decision in early reconstructive surgery in brachial plexus injuries
- 2010
-
Ingår i: Journal of Brachial Plexus and Peripheral Nerve Injury. - : BioMed Central. - 1749-7221. ; 5, s. 14-
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundAs neurophysiologic tests may not reveal the extent of brachial plexus injury at the early stage, the role of early radiological work-up has become increasingly important. The aim of the study was to evaluate the concordance between the radiological and clinical findings with the intraoperative findings in adult patients with brachial plexus injuries.MethodsSeven consecutive male patients (median age 33; range 15-61) with brachial plexus injuries, caused by motor cycle accidents in 5/7 patients, who underwent extensive radiological work-up with magnetic resonance imaging (MRI), computed tomography myelography (CT-M) or both were included in this retrospective study. A total of 34 spinal nerve roots were evaluated by neuroradiologists at two different occasions. The degree of agreement between the radiological findings of every individual nerve root and the intraoperative findings was estimated by calculation of kappa coefficient (К-value). Using the operative findings as a gold standard, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the clinical findings and the radiological findings were estimated.ResultsThe diagnostic accuracy of radiological findings was 88% compared with 65% for the clinical findings. The concordance between the radiological findings and the intraoperative findings was substantial (К = 0.76) compared with only fair (К = 0.34) for the clinical findings. There were two false positive and two false negative radiological findings (sensitivity and PPV of 0.90; specificity and NPV of 0.87).ConclusionsThe advanced optimized radiological work-up used showed high reliability and substantial agreement with the intraoperative findings in adult patients with brachial plexus injury.
|
|
| 4. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Combined Clinical and Radiological Prognostic Model in Acute Ischemic Stroke
- 2010
-
Ingår i: Acta Neurologica Belgica. - 2240-2993. ; 110:3, s. 239-245
-
Tidskriftsartikel (refereegranskat)abstract
- We sought to propose and test the validity of a comprehensive prognostic model in middle cerebral artery-stroke treated with Intravenous thrombolysis. A total of 127 consecutive patients (aged 70 +/- 12 years; 54% males) were included in this retrospective study. Variables included in our prognostic model were: NIHSS on admission (1-3 points), occurrence of hyperdense middle cerebral artery sign and early ischemic signs on baseline CT (1 point each). NIHSS at 24 hours (0-3 points), posttreatment hemorrhage (1 point), and infarct volume (0-4 points). The score range teas 1-13, with higher values suggest unfavorable prognosis. Our prognostic score was correlated with the modified Rankin scale (mRS) at 3 months after stroke [correlation coefficient of 0.62, P < 0.001] and can thus help early prediction of the functional outcome. Logistic regression showed that NIHSS at 24 hours and EICs on baseline CT were independent predictor of our prognostic score (adjusted odds ratio of 4.1 and 5). Adopting a cut-off value of prognostic score <= 3 for favorable prognosis and >= 7 for unfavorable prognosis helped to predict the need for institutionalization and the functional outcome with higher accuracy and predictive values compared with using scores only based on NIHSS.
|
|
| 5. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Curve length, curve form, and location of lower-end vertebra as a means of identifying the type of scoliosis.
- 2010
-
Ingår i: Journal of Orthopaedic Surgery. - 2309-4990. ; 18:1, s. 1-5
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine if the curve length, curve form, and location of the lower-end vertebra can identify the type of scoliosis. METHODS: Standing posteroanterior and lateral radiographs of 78 women and 27 men with scoliosis aged 8 to 32 years were retrospectively analysed. Parameters measured were (1) the curve length (the number of vertebrae in the main curve), (2) the curve form (C-form, inverted C-form, or S-form), (3) the curve apex (the vertebral body at the apex of each curve), (4) the site of the scoliosis (thoracic, thoracolumbar, or lumbar), and (5) the location of the lower-end vertebra. RESULTS: Only 3 (4%) of 77 patients with idiopathic scoliosis had a curve length of >8 vertebrae, compared with 19 (90%) of 21 patients with neuromuscular/neuropathic scoliosis (p<0.001, Fisher's exact test). 14 (18%) of the patients with idiopathic scoliosis had an S-form curve, compared with none in those with neuromuscular/neuropathic or congenital/osteogenic scoliosis (p=0.035, Fisher's exact test). No patient with idiopathic scoliosis had the lower- end vertebra located at L5, compared with 8 (38%) patients with neuromuscular scoliosis (p<0.001, Fisher's exact test). The criteria for neuromuscular/neuropathic scoliosis (a curve length of >8 vertebrae, a C-form or inverted C-form curve, and a lower-end vertebra located at L4 or L5) had 81% specificity, 76% sensitivity, 100% positive and 93% negative predictive values. CONCLUSION: These criteria may help identify patients with neuromuscular/neuropathic scoliosis for further investigation by magnetic resonance imaging or computed tomography before they undergo corrective surgery.
|
|
| 6. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Differentialdiagnoser
- 2010
-
Bok (övrigt vetenskapligt/konstnärligt)
|
|
| 7. |
|
|
| 8. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Dural ectasia in adolescent idiopathic scoliosis: quantitative assessment on magnetic resonance imaging.
- 2010
-
Ingår i: European Spine Journal. - : Springer Science and Business Media LLC. - 0940-6719 .- 1432-0932. ; Apr 7, s. 754-759
-
Tidskriftsartikel (refereegranskat)abstract
- To our knowledge, the assessment of dural sac diameters in patients with adolescent idiopathic scoliosis (AIS) is not reported in the literature. The aim of this study was to find out if, dural ectasia occurs more frequently among patients with AIS, to define cut-off values for dural sac ratio and test the validity of such values. A total of 126 spine MRIs (79 patients with AIS and 47 control subjects) were included in this retrospective analysis (age range 7-25 years, 62% were females). Dural sac diameter (DSD) and vertebral body diameter (VBD) were estimated and dural sac ratio (DSR = DSD/VBD) was calculated at T5 and L3. DSR at T5 and L3 were 0.69 +/- 0.12, and 0.52 +/- 0.10, respectively, in patients with AIS compared with 0.62 +/- 0.11, and 0.44 +/- 0.07, respectively, in controls (P = 0.001 at T5 and <0.001 at L3). Our estimated cut-off values for DSR were 0.84 and 0.58 at T5 and L3, respectively. This resulted in 100% sensitivity compared with 74% when using the cut-off values proposed by Oosterhof et al. No statistically significant association was found between the occurrence of dural sac enlargement in patients with AIS and the severity of scoliotic deformity, the apical vertebral rotation, epidural fat thickness, occurrence of pain, neurological deficit, atypical scoliosis or rapid curve progression. Females were affected more frequently than males. As dural sac enlargement means thinning of the pedicles, we believe that the findings of this study have important clinical implications on the preoperative workup of AIS.
|
|
| 9. |
|
|
| 10. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Extensive central nervous system involvement in Merkel cell carcinoma : a case report and review of the literature
- 2011
-
Ingår i: Journal of Medical Case Reports. - : Springer Science and Business Media LLC. - 1752-1947. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Merkel cell carcinoma is a rare malignant cutaneous neoplasm that is locally invasive and frequently metastasizes to lymph nodes, liver, lungs, bone and brain. The incidence of Merkel cell carcinoma has increased in the past three decades.CASE PRESENTATION: A 65-year-old Caucasian man presented with a sudden onset of severe headache and a three-month history of balance disturbance. Magnetic resonance imaging revealed a large meningeal metastasis. The radiologic workup showed retroperitoneal and inguinal lymph node metastases. Biopsy of the inguinal lymph nodes showed metastases of Merkel cell carcinoma. Biopsy from three different suspected skin lesions revealed no Merkel cell carcinoma, and the primary site of Merkel cell carcinoma remained unknown. Leptomeningeal metastases, new axillary lymph node metastases, and intraspinal (epidural and intradural) metastases were detected within six, seven and eight months, respectively, from the start of symptoms despite treating the intracranial metastasis with gamma knife and the abdominal metastases with surgical dissection and external radiotherapy. This indicates the aggressive nature of the disease.CONCLUSION: To the best of our knowledge, this is the first report in the literature of an intracranial meningeal metastasis of Merkel cell carcinoma treated with gamma knife and of intraspinal intradural metastases of Merkel cell carcinoma. Despite good initial response to radiotherapy, recurrence and occurrence of new metastases are common in Merkel cell carcinoma.
|
|
| 11. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Hyperdense middle cerebral artery sign in multidetector computed tomography: Definition, occurrence, and reliability analysis.
- 2009
-
Ingår i: Neurology India. - : Medknow. - 0028-3886. ; 57:2, s. 143-150
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The hyperdense middle cerebral artery sign (HMCAS) is one of the early changes seen on the computed tomography in acute ischemic stroke of MCA territory. Aims: To evaluate the reliability of subjective evaluation of HMCAS on CT performed at multidetector CT (MDCT) and evaluated in the Picture Archiving Communication Systems, to define objective criteria for HMCAS and to find out if there are any predictors for the occurrence of HMCAS. Materials and Methods: CTs of 121 consecutive patients (mean age of 70 years) treated with thrombolytic therapy were retrospectively evaluated by two neuroradiologists both subjectively and objectively with respect to HMCAS. Results: HMCAS was subjectively found in 32% of study population. The interobserver and intraobserver agreement were substantial (K value of 0.69 and 0.80, respectively) and increased to almost perfect (Kvalue of 0.86) when the reader provided with clinical information. The HMCAS was found twice as often in male patients. Patients with HMCAS were three years younger than those whose baseline CT did not show HMCAS. A 100% sensitivity achieved when objective criteria were defined as combination of MCA attenuation >/= 46HU and MCA ratio > 1.2 (using oval ROIs) and MCA attenuation >/= 50 HU and MCA ratio of > 1.4 (using pixel sized ROIs). Conclusion: Performing CT examinations on MDCT and assessment of the images in PACS might have contributed to improvement of the reliability of evaluating HMCAS on CT by enabling an objective evaluation of this sign with measurements of attenuation value in the course of MCA using oval or pixel sized ROIs as well as estimation of MCA ratio .
|
|
| 12. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Hyperdense middle cerebral artery sign is an ominous prognostic marker despite optimal workflow.
- 2010
-
Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 122, s. 132-139
-
Tidskriftsartikel (refereegranskat)abstract
- Abul-Kasim K, Brizzi M, Petersson J. Hyperdense middle cerebral artery sign is an ominous prognostic marker despite optimal workflow. Acta Neurol Scand: DOI: 10.1111/j.1600-0404.2009.01277.x. (c) 2009 The Authors Journal compilation (c) 2009 Blackwell Munksgaard.Objectives - To evaluate the association between the hyperdense middle cerebral artery sign (HMCAS) and the functional outcome on one hand, and different predictors such as the National Institutes of Health Stroke Scale (NIHSS), infarct size, ASPECTS Score, intracerebral hemorrhage, and mortality on the other hand. Material and methods - Retrospective analysis of 120 patients with MCA-stroke treated with intravenous thrombolysis. We tested the association between HMCAS and NIHSS, infarct volume, ASPECTS, outcome, level of consciousness, different recorded time intervals, and the day/time of admission. Results - Seventy-four percentage of patients treated with thrombolysis developed cerebral infarction. All patients with HMCAS (n = 39) sustained infarction and only 31% showed favorable outcome compared with 62% and 60%, respectively among patients without HMCAS (P < 0.001 and P = 0.002). There was statistically significant association between functional outcome and HMCAS (P = 0.002), infarct volume, NIHSS, and ASPECTS (P < 0.001). The time to treatment was 12 min shorter in patients who developed infarction (P = 0.037). Independent predictors for outcome were NIHSS and the occurrence of cerebral infarction on computed tomography for the whole study population, and infarct volume for patients who sustained cerebral infarction. Conclusions - Despite optimal workflow, patients with HMCAS showed poor outcome after intravenous thrombolysis. The results emphasize the urgent need for more effective revascularization therapies and neuroprotective treatment in this subgroup of stroke patients.
|
|
| 13. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Increased rod stiffness improves the degree of deformity correction by segmental pedicle screw fixation in adolescent idiopathic scoliosis.
- 2011
-
Ingår i: Scoliosis. - : Springer Science and Business Media LLC. - 1748-7161. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There are limited reports in literature studying the impact of rod diameter and stiffness on the degree of deformity correction in patients with AIS. AIMS: The aims of this study were to evaluate the 3-dimentional deformity correction achieved by segmental pedicle screw fixation in patients with adolescent idiopathic scoliosis, and to find out if learning or the change to stiffer rods had any positive impact on deformity correction. STUDY DESIGN: Retrospective study. METHODS: Plain radiographs and low-dose spine CTs of 116 consecutive patients (aged 15.9 ± 2.8 years) operated during the period 2005-2009 (group 1: patients operated autumn 2005-2006; group 2: 2007; group 3: 2008; group 4: 2009) were retrospectively evaluated. RESULTS: There was no statistically significant difference between the correction of the Cobb angle (P = 0.425) or lower end vertebra tilt (P = 0.298) in patients operated during the first versus the remaining periods of the study. No restoration of the sagittal kyphosis was reported in the first period compared with 5.9° in the last study period (P < 0.001). The correction of vertebral rotation was also improved from 4.2° to 7.8° (P < 0.001) for the same periods. For the whole study population, there was statistically significant correlation between the order of the operation (patient number) and the restoration of sagittal kyphosis (r = -0.344, P = 0.001), and the correction of vertebral rotation (r = 0.370, P < 0.001), but not for the Cobb angle or LEVT. However, there was no significant difference in restoration of sagittal kyphosis and the vertebral rotation in the first 17 patients compared with the last 17 patients operated with rods of 5.5 mm diameter (P = 0.621, and 0.941, respectively), indicating that rod stiffness had more impact on the deformity correction than did learning. CONCLUSIONS: This study showed that rod stiffness had more impact on the deformity correction than did learning.
|
|
| 14. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Interobserver and intraobserver agreement in the evaluation of CT perfusion in ischemic stroke
- 2009
-
Ingår i: Functional Neurology. - 0393-5264. ; 24:3, s. 139-145
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge of interrater reliability in the evaluation of perfusion computed tomography (CTP) studies is very limited even though the method is widely used in the workup of acute stroke. The aims of this study were to estimate the inter- and intraolbserver agreement in the evaluation of CTP data and to evaluate the feasibility of the method. The CTP data of 20 consecutive patients (50% were females) aged 68 +/- 11 years with different categories of acute ischemic stroke were included in this retrospective analysis. Perfusion studies were evaluated independently by six radiologists on two different occasions. The overall inter- and intraolbserver agreement was substantial, showing a K value of 0.65 (95% confidence interval 0.39-0.91). The time required for the post-processing and interpretation ranged from 37 to 460 seconds. Evaluation of manually post-processed CTP data according to the maximum slope model appears to be reliable. Experience and also a short training period increase the reliability of the method and reduce the time needed for delivery of the results to the treating clinician.
|
|
| 15. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Intracranial manifestations in SAPHO syndrome: the first case report in literature.
- 2012
-
Ingår i: Rheumatology International. - : Springer Science and Business Media LLC. - 1437-160X .- 0172-8172. ; 32:6, s. 1797-1799
-
Tidskriftsartikel (refereegranskat)abstract
- A 41-year-old woman with SAPHO syndrome presented with numbness of her left arm followed by a generalized seizure. Computed tomography and magnetic resonance imaging of the brain revealed a small ring enhancing lesion in the right parietal lobe with adjacent meningeal thickening and enhancement. Surgical removal and histopathology showed evidence of severe chronic sterile inflammation and no malignant cell. Symptoms recurred and a lesion were again detected on radiological follow-up, but improvement occurred following treatment with antibiotics and biphosphonate, achieving a low inflammatory activity, reduction in CNS lesions and relative clinical well-being. This is a first report in literature about the central nervous system involvement in a patient with SAPHO syndrome.
|
|
| 16. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Intradural spinal tumors: current classification and MRI features
- 2008
-
Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 50:4, s. 301-314
-
Tidskriftsartikel (refereegranskat)abstract
- The differential diagnosis of intradural spinal tumors is primarily based on location, but the clinical presentation, age, and gender of the patient are also important factors in determining the diagnosis. This comprehensive review focuses on the current classification, clinical symptoms, and MRI features of the more common intradural extramedullary and intramedullary neoplastic lesions. This review does not include extradural lesions.
|
|
| 17. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Low-dose computed tomography of the paranasal sinuses: radiation doses and reliability analysis.
- 2011
-
Ingår i: American Journal of Otolaryngology. - : Elsevier BV. - 1532-818X .- 0196-0709. ; 32, s. 47-51
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The study aimed to (1) optimize the radiation doses of computed tomography (CT) of paranasal sinuses, (2) compare the radiation doses of different CT protocols with that of plain radiography, and (3) evaluate the reliability of low-dose CT in the detection of pathology and characterization of the detected pathology. MATERIALS AND METHODS: A head phantom was examined with different scan parameters to define a cutoff value to which the radiation dose can be reduced without negative impact on image quality. Kruskal-Wallis test and Wilcoxon W test were performed to compare the effective doses of the plain radiography in 30 patients with that of 3 different CT protocols in a total of 90 patients. The interobserver and intraobserver agreement in the detection of pathologic findings and in characterization of the pathology was estimated by calculating kappa value. RESULTS: The effective doses of plain radiography and low-dose CT were 0.098 and 0.045 mSv, respectively (P < .001). The effective dose of standard CT of sinuses (0.371 mSv) was 3.8 times higher than that of plain radiography and 8.2 times higher than that of low-dose CT (P < .001). The interobserver and intraobserver agreement on CT with regard to detection of pathology and pathology characterization was almost perfect (kappa values 0.81-1) compared to fair (kappa values 0.38-0.39) in plain radiography. CONCLUSIONS: The here proposed low-dose CT means significant dose reduction and is a reliable method in the investigation of the paranasal sinuses.
|
|
| 18. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Low-dose helical computed tomography (CT) in the perioperative workup of adolescent idiopathic scoliosis.
- 2009
-
Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 19, s. 610-618
-
Tidskriftsartikel (refereegranskat)abstract
- The study aims were to estimate the radiation dose in patients examined with low dose spine CT and to compare it with that received by patients undergoing standard CT for trauma of the same region, as well as to evaluate the impact of dose reduction on image quality. Radiation doses in 113 consecutive low dose spine CTs were compared with those in 127 CTs for trauma. The inter- and intraobserver agreement in measurements of pedicular width, and vertebral rotation, measurements of signal-to-noise ratio and assessment of hardware status were the indicators in the evaluation of image quality. The effective dose of the low dose spine CT (0.37 mSv) was 20 times lower than that of a standard CT for trauma (13.09 mSv). This dose reduction conveyed no impact on image quality. This low dose spine CT protocol allows detailed evaluation that is necessary for preoperative planning and postoperative evaluation.
|
|
| 19. |
- Abul-Kasim, Kasim
(författare)
-
LOW-DOSE SPINE CT: OPTIMISATION AND CLINICAL IMPLEMENTATION.
- 2010
-
Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 139, s. 169-172
-
Tidskriftsartikel (refereegranskat)abstract
- Spinal deformities affect young individuals predominantly girls who are usually subjected to regular and intensive radiological investigation especially before and after corrective surgery. Optimisation of spine computed tomography (CT) and the implementation of the low-dose CT in the work-up of spinal deformities were presented. The presented low-dose CT here means providing the operating surgeons with essential information about 15 vertebral bodies (almost 36-cm long region of the vertebral column). The mean effective dose of the low-dose CT was 0.37 mSv without any negative impact on image quality with regard to answering the clinical questions at issue. Tube current modulation (angular and longitudinal) has contributed to 19 % of the total dose reduction and soft tissue algorithm has helped to reduce the artefacts from the metal implants in the postoperative CTs.
|
|
| 20. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Measurement of vertebral rotation in adolescent idiopathic scoliosis with low-dose CT in prone position - method description and reliability analysis
- 2010
-
Ingår i: Scoliosis. - : Springer Science and Business Media LLC. - 1748-7161. ; 5, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- Background: To our knowledge there is no report in the literature on measurements of vertebral rotation with low-dose computed tomography (CT) in prone position.Aims: To describe and test the reliability of this new method, compare it with other methods in use and evaluate the influence of body position on the degree of vertebral rotation measured by different radiological methods.Study design: Retrospective study.Methods: 25 consecutive patients with adolescent idiopathic scoliosis scheduled for surgery (17 girls, 8 boys) aged 15 ± 2 years (mean ± SD) were included in the analysis of this study. The degree of the vertebral rotation was in all patients measured according to the method of Perdriolle on standing plain radiographs and on supine CT scanogram, and according to the method of Aaro and Dahlborn on axial CT images in prone position and on magnetic resonance imaging (MRI) in supine position. The measurements were done by one neuroradiologist at two different occasions. Bland and Altman statistical approach was used in the reliability assessment.Results: The reliability of measuring vertebral rotation by axial CT images in prone position was almost perfect with an intraclass correlation coefficient of 0.95, a random error of the intraobserver differences of 2.3°, a repeatability coefficient of 3.2° and a coefficient of variation of 18.4%. Corresponding values for measurements on CT scanogram were 0.83, 5.1°, 7.2°, and 32.8%, respectively, indicating lower reliability of the latter modality and method. The degree of vertebral rotation measured on standing plain radiographs, prone CT scanogram, axial images on CT in prone position and on MRI in supine position were 25.7 ± 9.8°, 21.9 ± 8.3°, 17.4 ± 7.1°, and 16.1 ± 6.5°, respectively. The vertebral rotation measured on axial CT images in prone position was in average 7.5% larger than that measured on axial MRI in supine position.Conclusions: This study has shown that measurements of vertebral rotation in prone position were more reliable on axial CT images than on CT scanogram. The measurement of vertebral rotation on CT (corrected to the pelvic tilt) in prone position imposes lower impact of the recumbent position on the vertebral rotation than did MRI in supine position. However, the magnitude of differences is of doubtful clinical significance.
|
|
| 21. |
- Abul-Kasim, Kasim, et al.
(författare)
-
MRI Findings in Spinal MRI of 306 Children with Scoliosis. A Comprehensive Retrospective Analysis.
- 2008
-
Ingår i: The Neuroradiology Journal. ; 21:5, s. 672-677
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to analyze the MRI findings and assess the prevalence of different associated structural abnormalities in children with scoliosis and to determine if the age of onset is a possible indicator of intraspinal pathology. This is a retrospective analysis of 663 consecutive MR examinations (319 patients). Thirteen patients with known intraspinal tumors were excluded and a total of 306 patients aged 2-18 years with scoliosis were subjected for analysis. The scoliosis was regarded as idiopathic in 62% of patients. Among the remaining 38% the most commonly seen abnormality was syrinx and Chiari malformations. There was no statistically significant difference in the occurrence of syrinx only or syrinx associated with Chiari I malformation in patients younger than ten years and those older than ten years. MRI examination is an essential part of the work up of scoliosis in the pediatric population especially before any corrective surgery. This study and a review of the current literature suggest there is no clinical marker that would definitely serve as an indicator of the presence of intraspinal pathology in these patients.
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
- Abul-Kasim, Kasim
(författare)
-
Neuroimaging in patients with dysphagia
- 2017
-
Ingår i: Dysphagia. - Cham : Springer International Publishing. - 0942-5373 .- 2197-4187. ; , s. 497-506
-
Bokkapitel (refereegranskat)abstract
- With increasing availability of computed tomography (CT) and magnetic resonance imaging (MRI), patients with dysphagia are nowadays often investigated with these modalities in order to localize a possible site of injury causing dysphagia. However, these radiological modalities often reveal some abnormalities especially in elderly patients, and the correlation of these findings with clinical symptoms needs therefore a good knowledge about the anatomy of different structures involved in swallowing. Beside description of these different anatomical structures and the most common pathological conditions that cause dysphagia, this chapter is also enriched with illustrative radiological images, often at the axial plane that radiologists are familiar with.
|
|
| 25. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Neuroradiologi
- 2009
-
Bok (populärvet., debatt m.m.)abstract
- Neuroradiologi är den första läroboken i sitt slag i Skandinavien och erbjuder en heltäckande inblick i diagnostiken av sjukdomar inom hjärna, rygg samt huvud- och halsregion med neuroanatomi och differentialdiagnostik, illustrerat med ett unikt bildmaterial. Bokens första tre delar innefattar 150, 80 respektive 80 diagnoser. De diagnoser som inte ryms i de första tre delarna hittar man i bokens fjärde del (Del IV, Neuroencyklopedi). I denna del finns en kort sammanfattad beskrivning av olika sällsynta diagnoser, syndrom och anatomiska begrepp. Del V och VI omfattar över hundra differentialdiagnoser med mycket detaljerad och deskriptiv neuroanatomi. Boken som innehåller 4 267 bilder är upplagd som en uppslagsbok, vilket underlättar för läsaren att hitta den sökta diagnosen. Under varje diagnosrubrik finns en kortfattad beskrivning av etiologi, patologi, klinik, behandling och prognos samt detaljerad beskrivning av de radiologiska fynden. Neuroradiologi är en lättläst lärobok i neuroradiologi. Just neuroradiologi utgör en mycket stor del av såväl den akuta som den planerade radiologiska verksamheten och är under snabb utveckling med kontinuerlig introduktion av nya metoder. Boken vänder sig i första hand till radiologer och neuroradiologer, inte minst de som är under utbildning. Flera andra kliniska specialister såsom neurologer, neurokirurger, ortopeder, öronläkare, allmänläkare kommer att ha gott stöd av boken. Övrig vårdpersonal kan ha stor nytta av boken som ett uppslagsverk.
|
|
| 26. |
|
|
| 27. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Optimization of Radiation Exposure and Image Quality of the Cone-beam O-arm Intraoperative Imaging System in Spinal Surgery.
- 2012
-
Ingår i: Journal of Spinal Disorders and Techniques. - 1539-2465. ; 25:1, s. 52-58
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Retrospective study. OBJECTIVES: To optimize the radiation doses and image quality for the cone-beam O-arm surgical imaging system in spinal surgery. SUMMARY OF BACKGROUND: Neurovascular compromise has been reported after screw misplacement during thoracic pedicle screw insertion. The use of O-arm with or without navigation system during spinal surgery has been shown to lower the rate of screw misplacement. The main drawback of such imaging surgical systems is the high radiation exposure. METHODS: Chest phantom and cadaveric pig spine were examined on the O-arm with different scan settings: 2 were recommended by the O-arm manufacturer (120 kV/320 mAs, and 120 kV/128 mAs), and 3 low-dose settings (80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs). The radiation doses were estimated by Monte Carlo calculations. Objective evaluation of image quality included interobserver agreement in the measurement of pedicular width in chest phantom and assessment of screw placement in cadaveric pig spine. RESULTS: The effective dose/cm for 120 kV/320 mAs scan was 13, 26, and 69 times higher than those delivered with 80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs scans, respectively. Images with 60 kV/40 mAs were unreliable. Images with 80 kV/80 mAs were considered reliable with good interobserver agreement when measuring the pedicular width (random error 0.38 mm and intraclass correlation coefficient 0.979) and almost perfect agreement when evaluating the screw placement (κ value 0.86). CONCLUSIONS: The radiation doses of the O-arm system can be reduced 5 to 13 times without negative impact on image quality with regard to information required for spinal surgery.
|
|
| 28. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Patients with adolescent idiopathic scoliosis of Lenke type-1 curve exhibit specific pedicle width pattern.
- 2012
-
Ingår i: European Spine Journal. - : Springer Science and Business Media LLC. - 0940-6719 .- 1432-0932. ; 21, s. 57-63
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Study aim was to find out if patients with Lenke type 1 curve exhibit smaller pedicles and specific pedicle width pattern compared with individuals with no scoliosis. MATERIALS AND METHODS: 4,828 pedicle width measurements (T1-L5) in 61 consecutive patients with adolescent idiopathic scoliosis of Lenke type 1 curve, 61 control subjects, and 20 patients with Lenke type 5 curve, were retrospectively performed by an experienced neuroradiologist. RESULTS: Among patients with Lenke type 1 curve, the differences between the width of right and left upper thoracic pedicles were statistically significant; smallest at right T4 (2.6 mm). At scoliotic apex, the pedicles on the concave (left) side were significantly smaller than those on the convex (right) side; smallest at left T7 (3.2 mm). Among patients with Lenke type 1 curve, 97% had pedicle width <4 mm. CONCLUSIONS: Our study showed that patients with Lenke type 1 curve exhibit smaller pedicles and asymmetric pedicle width compared with control subjects.
|
|
| 29. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Perfusion weighted MR imaging may differentiate primary CNS-lymphoma from other homogeneously enhancing brain tumors.
- 2008
-
Ingår i: The Neuroradiology Journal. - 1971-4009. ; 21:5, s. 637-644
-
Tidskriftsartikel (refereegranskat)abstract
- Primary central nervous system lymphoma (PCNSL), glioblastoma multiforme (GBM) and metastases may be difficult to differentiate based on conventional imaging alone. The aim of this study was to investigate the value of perfusion weighted imaging (PWI) in differentiating homogeneously enhancing PCNSL from homogeneously enhancing GBM and metastases. Seven consecutive patients presenting with homogeneously enhancing intraaxial tumors on MRI were retrospectively analyzed. All seven patients (three immunocompetent patients with PCNSL, three with GBM, and one with cerebral metastases) were examined with identical MR-sequences including PWI. The relative regional Cerebral Blood Volume (rrCBV) and the rrCBV ratio (rrCBVratio) were calculated. In lymphomas rrCBVratio was 0.93 ± 0.42 (mean ± SD) compared with 7.93 ± 1.44 in GBM and metastases. All lymphomas had rrCBVratio < 1.43 while all GBM and metastases had rrCBVratio > 1.43 (Fischer exact test; p < 0.001). PWI may be a valuable method in differentiating homogenously enhancing PCNSL from GBM and metastases.
|
|
| 30. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Radiation dose optimization in CT planning of corrective scoliosis surgery. A phantom study.
- 2008
-
Ingår i: The Neuroradiology Journal. ; 21:3, s. 374-382
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to explore the possibility of obtaining a helical CT scan of a long segment of vertebral column, optimally reduce the radiation dose, compare the radiation dose of the low dose helical CT with that of some of the CT protocols used in clinical practice and finally assess the impact of such a dose reduction on the image quality. A chest phantom was examined with a 16-slice CT scanner. Six scans were performed with different radiation doses. The lowest radiation dose which had no impact on image quality with regard to the information required for surgical planning of patients with scoliosis, was 20 times lower than that of routinely used protocol for CT examination of the spine in children (0.38 mSv vs 7.76 mSv). Patients with scoliosis planned for corrective spinal surgery can be examined with low dose helical CT scan. The dose reduction systems (DRS) available in modern CT scanners contribute to dose reduction and should be used.
|
|
| 31. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Radiological and clinical outcome of screw placement in adolescent idiopathic scoliosis: evaluation with low-dose computed tomography.
- 2010
-
Ingår i: European Spine Journal. - : Springer Science and Business Media LLC. - 0940-6719 .- 1432-0932. ; 19:1, s. 96-104
-
Tidskriftsartikel (refereegranskat)abstract
- Posterior corrective surgery using "all pedicle screw construct" carries risk of neurovascular complications. The study aims were to assess the screw placement in patients with adolescent idiopathic scoliosis using CT with low-radiation dose, and to evaluate the clinical outcome in patients with misplaced pedicle screws. CTs of 49 consecutive patients (873 screws, 79% thoracic) were retrospectively evaluated by two independent radiologists. A new grading system was developed to distinguish between lateral, medial and anterior cortical perforations, endplate perforation and foraminal perforation. The grading system is based on whether the cortical violation is partial or total rather than on mm-basis. The overall rate of screw misplacement was 17% (n = 149): 8% were laterally placed and 6.1% were medially placed. The rates of anterior cortical, endplate and foraminal perforation were 1.5, 0.9, and 0.5%, respectively. Lateral cortical perforation was more frequent in the thoracic spine (P = 0.005), whereas other types of misplacement including medial cortical perforation were more frequent on the left and the concave side of scoliotic curves (P = 0.002 and 0.003). No neurovascular complications were reported. The association between the occurrence of screw misplacement and the Cobb angle was statistically significant (P = 0.037). Misplacements exceeding half screw diameter should be classified as unacceptable. Low-dose CT implies exposing these young individuals to a significantly lower radiation dose than do other protocols used in daily clinical practice. We recommend using low-dose CT and the grading system proposed here in the postoperative assessment of screw placement.
|
|
| 32. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Reliability of Low-Radiation Dose CT in the Assessment of Screw Placement After Posterior Scoliosis Surgery, Evaluated With a New Grading System
- 2009
-
Ingår i: Spine. - 0362-2436. ; 34:9, s. 941-948
-
Tidskriftsartikel (refereegranskat)abstract
- Study Design. A retrospective study. Objective. To evaluate the reliability of computed tomography (CT) with low radiation dose in the assessment of implant status in patients with adolescent idiopathic scoliosis (AIS). Summary of Background Data. The use of all-pedicle screw construct in scoliosis corrective surgery continues to gain increasing popularity since their introduction 1994 although their use in the thoracic spine carries a potential risk for neurovascular complications. CT is the method widely used to evaluate screw placement. Methods. Retrospective analysis of 46 consecutive low-dose spine CT in patients with AIS after posterior corrective surgery. Status of 809 titanium screws (642 thoracic) was evaluated. The degree of interobserver and intraobserver agreements about implant status was used as an indicator of the reliability of the low-dose spine CT in the assessment of accuracy of pedicle screw insertion. A new grading system has been developed for this purpose. Five types of misplacement have been evaluated: lateral, medial, and anterior cortical perforations; end-plate perforation; and foraminal perforation. Results. The analysis has shown a substantial interobserver and intraobserver agreements (kappa: 0.69 and 0.76, respectively) in differentiating pedicle screws with acceptable placement from screws with partial or total cortical perforation. None of the examinations was subjectively classified as unreliable. Conclusion. The study has shown that low-dose spine CT is a reliable method in evaluating screw placement in patients with AIS after posterior scoliosis surgery with titanium implants, using the here proposed grading system. The new grading system of screw misplacement was feasible and in line with the general agreement about the harmlessness of misplacement with minor pedicle breach. The reliability of low-dose spine CT in evaluation of lateral and medial cortical perforations was substantial. To reduce the radiation load, the postoperative assessment of titanium implants should be performed with low-dose CT.
|
|
| 33. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Spinal Cord Injuries
- 2010
-
Ingår i: Trauma to the spinal cord.. - 9781608760022 ; , s. 483-499
-
Bokkapitel (refereegranskat)abstract
- Spinal cord injury can be classified as traumatic and non-traumatic. The traumatic spinal cord injuries (SCI) are caused by motor vehicle accidents (56 %), falls (14 %), firearm and violence-related (16.6 %) and sports injuries (7 %) [1]. Injuries after falls and minor trauma are more commonly seen in elderly patients as they more often have spondylosis and osteoporosis. Violence is more common in urban populations while sports injuries are common in young individuals. About 68 % of children involved in spinal cord injuries caused by motor vehicle accidents were not wearing a seatbelt. Almost 80% of patients with spinal cord injury had multiple injuries [2]. Associated injuries include other bone fractures(29.3 %) and brain injury (11.5 %) [3]. Other causes of spinal cord injuries are non-traumatic and include the following: vascular disorders, degenerative disorders, spinal tumors, infectious and inflammatory conditions of the vertebral column with secondary SCI as well as iatrogenic injuries after spinal injections and epidural catheter. Three possible mechanisms are believed to be involved in the development of spinal cord injuries [4]: (a) damage from direct trauma, (b) compression or transaction of neural elements by bone fragments, intraspinal hematoma, foreign bodies, or protruded disk, or (c) ischemia from damage of the spinal arteries or from venous congestion. As small arteries are disrupted by trauma, spinal cord swelling occurs within minutes after the trauma with resultant venous congestion and secondary ischemia. Cell death occurs days to weeks after the injury with involvement of the oligodendrocytes not only at the site of injury but also at several levels away from the injury site [5]. Following the primary spinal cord injury, a cascade of secondary injuries usually are initiated [6] resulting in: (a) vascular changes—ischemia, hemorrhage, and thrombosis [7], (b) Disturbance of electrolyte balance with accumulation of intracellular sodium resulting in edema [8], (c) accumulation of neurotransmitters and toxins edema [8], (d) inflammation [9], and (e) apoptosis.
|
|
| 34. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Spinal Epidural Lipomatosis: A Common Imaging Feature in Scheuermann Disease.
- 2012
-
Ingår i: Journal of Spinal Disorders and Techniques. - 1539-2465. ; 25:7, s. 356-361
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Retrospective study. OBJECTIVES: To find out if spinal epidural lipomatosis (SEL) occurs more commonly among patients with Scheuermann disease than in the general population. SUMMARY AND BACKGROUND: On the basis of our own radiologic and operative observation, SEL seems to occur frequently in patients with Scheuermann disease. METHODS: Magnetic resonance imaging of 87 individuals (72% male, average age 19±6 y) from 2 centers (29 consecutive patients with Scheuermann disease and 58 controls) were retrospectively evaluated by 2 neuroradiologists. Spinal epidural fat (EF) at seventh thoracic vertebra (EF7), maximum EF (EFmax), dural sac diameter at T7 and at the level of maximum EF (DS7 and DSmax) were measured. EF ratios at T7 (EFR7) and at maximum EF (EFRmax) were calculated as EF/DS. Body mass index (BMI) for study population and kyphosis severity for the patients were recorded. Mann-Whitney, Spearman correlation, and χ tests were performed dependent on the variable in question. RESULTS: EF7, DS7, EFmax, EFR7, and EFRmax was significantly higher among patients with Scheuermann disease (EFmax 5.7±2.4 mm) than among controls (EFmax 3.8±1.1 mm), P<0.001. Twelve patients with Scheuermann disease (41%) fulfilled our proposed criteria for the diagnosis of SEL (EFmax>6 mm+EFRmax>0.51) compared with 2 (3%) among controls (P<0.001). Patients with Scheuermann disease exhibited higher BMI than controls (24.9±5 kg/m vs. 22.9±4 kg/m, P=0.138). Logistic regression showed that the occurrence of SEL among patients with Scheuermann disease was independent of BMI (P=0.880). The degree of kyphosis in patients with Scheuermann's disease (62±20°) was correlated to the amount of the EF. CONCLUSIONS: As SEL occurs more frequently among patients with Scheuermann disease, spine magnetic resonance imaging should be routinely performed to screen each of these patients to avoid impending neurological injury during surgery, especially in those exhibiting SEL.
|
|
| 35. |
- Abul-Kasim, Kasim, et al.
(författare)
-
The Neuroanatomic Localization of Epstein-Barr Virus Encephalitis May Be a Predictive Factor for Its Clinical Outcome: A Case Report and Review of 100 Cases in 28 Reports.
- 2009
-
Ingår i: Journal of Child Neurology. - : SAGE Publications. - 1708-8283 .- 0883-0738. ; 24, s. 720-726
-
Tidskriftsartikel (refereegranskat)abstract
- Encephalitis is one of the manifestations of infection with Epstein-Barr virus with clinical outcome varying from complete recovery to death. A 16-year-old boy with Epstein-Barr virus encephalitis with global cortical and subcortical gray matter involvement and a full clinical recovery is reported. The case inspired a literature review which yielded 100 cases of Epstein-Barr virus encephalitis subjected to radiological investigation and published in 28 reports. Cerebellum and basal ganglia were reported to be equally involved by Epstein-Barr virus infection, next to cerebral hemisphere. Patients with isolated hemispheric gray or white matter involvement were reported to achieve good recovery while almost half of the patients with thalamic involvement developed sequelae. The highest mortality rate was among patients with isolated brain stem involvement. In conclusion, neuroanatomic distribution of the radiological abnormalities in Epstein-Barr virus encephalitis may be useful as a prognostic marker.
|
|
| 36. |
- Abul-Kasim, Kasim, et al.
(författare)
-
The rate of screw misplacement in segmental pedicle screw fixation in adolescent idiopathic scoliosis.
- 2011
-
Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 82, s. 50-55
-
Tidskriftsartikel (refereegranskat)abstract
- Background and purpose There are no reports in the literature on the influence of learning on the pedicle screw insertion. We studied the effect of learning on the rate of screw misplacement in patients with adolescent idiopathic scoliosis treated with segmental pedicle screw fixation. Method We retrospectively evaluated low-dose spine computed tomography of 116 consecutive patients (aged 16 (12-24) years, 94 females) who were operated during 4 periods over 2005-2009 (group 1: patients operated autumn 2005-2006; group 2: 2007; group 3: 2008; and group 4: 2009). 5 types of misplacement were recorded: medial cortical perforation, lateral cortical perforation, anterior cortical perforation of the vertebral body, endplate perforation, and perforation of the neural foramen. Reslts 2,201 pedicle screws were evaluated, with an average of 19 screws per patient. The rate of screw misplacement for the whole study was 14%. The rate of lateral and medial cortical perforation was 7% and 5%. There was an inverse correlation between the occurrence of misplacement and the patient number, i.e. the date of operation (r = -0.35; p < 0.001). The skillfulness of screw insertion improved with reduction of the rate of screw misplacement from 20% in 2005-2006 to 11% in 2009, with a breakpoint at the end of the first study period (34 patients). Interpretation We found a substantial learning curve; cumulative experience may have contributed to continued reduction of misplacement rate.
|
|
| 37. |
- Abul-Kasim, Kasim, et al.
(författare)
-
The Value of Contrast Administration in the MRI Evaluation of Scoliosis in Pediatric Population.
- 2008
-
Ingår i: The Neuroradiology Journal. ; 21:6, s. 844-847
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- The aim of this study was to analyze the added utility of contrast administration for spine MRI in children with scoliosis. A retrospective review of 663 consecutive contrast-enhanced spine MRI performed in 319 patients as part of the work up of scoliosis in children 2-18 years with clinically suspected or known scoliosis over a seven year period. Those patients with known tumors (13 patients) being evaluated for scoliosis were excluded from the study. In 306 patients with scoliosis and no history of tumor pathologic contrast enhancement was seen in seven (2%) patients. Lack of enhancement helped to characterize benign lesions in 31 (10%) of the patients. Although MRI is often recommended to exclude intraspinal pathology in pediatric patients with scoliosis, the need for contrast enhanced imaging is very limited and contrast medium should not be administered unless questionable pathology is detected on noncontrast MR spine imaging.
|
|
| 38. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Tonsillar ectopia in idiopathic scoliosis: does it play a role in the pathogenesis and prognosis or is it only an incidental finding?
- 2009
-
Ingår i: Scoliosis. - : Springer Science and Business Media LLC. - 1748-7161. ; 4, s. 1-7
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: There is an ongoing controversy about the significance of tonsillar ectopia among patients with idiopathic scoliosis (IS). AIM: To find out if tonsillar ectopia occurs more frequently among patients with IS and if it plays any etiological or prognostic role in IS. STUDY DESIGN: Retrospective study. METHODS: Retrospective analysis of 155 consecutive spine MRIs (79 patients with IS and 76 controls; aged 7-25 years; 55% were female) with regard to the position of the cerebellar tonsils in relation to foramen magnum and the sagittal diameter of foramen magnum. All images were evaluated independently by two neuroradiologists. Interobserver and intraobserver reliability analysis was performed by calculation of kappa-value, intraclass correlation coefficient, and systematic and random errors. The occurrence of tonsillar ectopia among patients with IS and controls was estimated and the association of tonsillar ectopia with different predictors has been tested. Statistical significance was set to P
|
|
| 39. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Transient ischemic attack with deceptive presentation
- 2009
-
Ingår i: Acta Neurologica Belgica. - 2240-2993. ; 109:4, s. 333-335
-
Tidskriftsartikel (refereegranskat)abstract
- A patient with an initial diagnosis of TIA presented with a deceptive course of events and unfavorable outcome. Only a non-enhanced brain CT was performed initially. Hemodynamic studies were clone later on and revealed internal carotid artery (ICA) dissection on CT-angiography and evidence of irreversible ischemic changes on perfusion studies indicating that the ischemic process presumably was ongoing since the initial ischemic episode. Efforts to define patients with TIA with risk of developing major stroke are ongoing. We hereby exhort for more effort to include hemodynamic studies as early as possible in the radiological work-up of TIA.
|
|
| 40. |
- Abul-Kasim, Kasim, et al.
(författare)
-
Vertebral Hemangiomas : Prevalence, New Classification and Natural History. Magnetic Resonance Imaging-Based Retrospective Longitudinal Study
- 2023
-
Ingår i: Neuroradiology Journal. - : SAGE Publications. - 1971-4009 .- 2385-1996. ; 36:1, s. 23-30
-
Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: To determine the prevalence of vertebral hemangiomas (VHs), establish a new classification of VHs based on their MRI-signal pattern, and study their natural history. Methods: MRI of 1000 consecutive patients who underwent at least two MRI with an interval of at least 3 years. Growth rate and change of MRI-signal pattern during the follow-up period were the parameters included in studying the natural history of VHs. Results: The prevalence of VHs was 41%. VHs were classified as type I–IV with fat-rich VHs (type I), constituted 79% of all VHs. VHs were more common among females 43% versus males 39%, p =.22. The most affected vertebra was L1. Occurrence rates for cervical (1%), thoracic (7%), and lumbar spine (10%) differed significantly (p <.001). The prevalence of VHs increased with age regardless of gender or spinal part involved (p <.001). Only 26% of VHs changed their size and 4% changed their signal during the average follow-up of 7 years. All VHs were slowly growing lesions (average expected growth of <3 mm/10 years). No significant difference between growth rate of VHs type I (0.25 mm/year) and other types of VHs. None of the VHs that were initially reported as “metastases cannot be rule out” showed alarming change in signal or size. Conclusions: VH can be classified into four types based on their MRI-signal pattern. Regardless of their type, VHs are slowly growing lesions. The presence of typical morphological pattern should enable radiologists to confidently differentiate them from vertebral metastases.
|
|
| 41. |
- Aho Fält, Tobias, et al.
(författare)
-
Simulated Dose Reduction for Abdominal CT With Filtered Back Projection Technique: Effect on Liver Lesion Detection and Characterization
- 2019
-
Ingår i: American Journal of Roentgenology: diagnostic imaging and related sciences. - 0361-803X. ; 212:1, s. 84-93
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE. Previous studies have shown the possibility to reduce radiation dose in abdominal CT by 25–50% without negatively affecting detection of liver lesions. How radiation dose reduction affects characterization of liver metastases is not as well known. The objective of this study was to investigate how different levels of simulated dose reduction affect the detection and characterization of liver lesions, primarily hypovascular metastases. A secondary objective was to analyze the relationship between the lesion size and contrast-to-noise ratio (CNR) and the detection rate.MATERIALS AND METHODS. Thirty-nine patients (19 with metastases and 20 without) were retrospectively selected. The following radiation dose levels (DLs) were simulated: 100% (reference level), 75%, 50%, and 25%. Five readers were asked to mark liver lesions and rate the probability of malignancy on a 5-grade Likert scale. Noninferiority analysis using the jackknife free-response ROC (JAFROC) method was performed as well as direct comparison of detection rates and grades.RESULTS. JAFROC analysis showed noninferior detection and characterization of metastases at DL75 as compared with DL100. However, the number of benign lesions and false-positive localizations rated as “suspected malignancy” was significantly higher at DL75.CONCLUSION. Radiation dose can be reduced by 25% without negatively affecting diagnosis of hypovascular liver metastases. Characterization of benign lesions, however, is impaired at DL75, which may lead to unnecessary follow-up examinations. Finally, increased image noise seems to affect the detection of small lesions to a degree that cannot be explained solely by the reduction in CNR.
|
|
| 42. |
|
|
| 43. |
- Askaner, Krister, et al.
(författare)
-
Differentiation of Brain Metastases due to Primary Malignancy and Glioblastomas using Dynamic Susceptibility Contrast-Enhanced MR at 3T
- 2017
-
Konferensbidrag (refereegranskat)abstract
- Purpose:To find out differences in cerebral blood volume (CBV) maps derived from dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSCE-MRI) in glioblastomas and cerebral metastases. The main purpose was to compare CBV maps between metastases with different primary malignancies. Furthermore the metastasis group was compared with the glioblastoma group.Method:Conventional imaging and DSCE-MRI using 3T MRI system was performed in 114 patients, 38 glioblastomas and 76 metastases, 32 lung, 12 breast, 12 melanoma, 10 gastrointestinal (GI), and 10 other. CBV values were measured in the solid tumor area, peritumoral edema, area adjacent to peritumoral edema, and in normal apparent white matter in contralateral semioval center. The four subgroups of metastases were compared with one-way ANOVA to determine differences in CBV of significance. CBV values in glioblastomas and metastases were then statistically compared using paired t-test. Receiver -operating characteristic analysis was used to determine optimal cut-off values when parameters showed statistical differences.Results:There were no significantly differences in CBV between the four subgroups of metastases. CBV in the peritumoral edema significantly differentiated metastases from glioblastomas, p=0.0001. CBV cutoff value of 2.3 yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 87, 87, 71, and 91% respectively. Conclusions:Differentiation of glioblastomas and metastases is possible using DSCE-MRI. No statistically significant differences regarding CBV between metastases from lung, breast, melanoma, and GI were detected.
|
|
| 44. |
|
|
| 45. |
- Bibic, Adnan, et al.
(författare)
-
Measurement of vascular water transport in human subjects using time-resolved pulsed arterial spin labelling.
- 2015
-
Ingår i: NMR in Biomedicine. - : Wiley. - 0952-3480. ; 28:8, s. 1059-1068
-
Tidskriftsartikel (refereegranskat)abstract
- Most approaches to arterial spin labelling (ASL) data analysis aim to provide a quantitative measure of the cerebral blood flow (CBF). This study, however, focuses on the measurement of the transfer time of blood water through the capillaries to the parenchyma (referred to as the capillary transfer time, CTT) as an alternative parameter to characterise the haemodynamics of the system. The method employed is based on a non-compartmental model, and no measurements need to be added to a common time-resolved ASL experiment. Brownian motion of labelled spins in a potential was described by a one-dimensional general Langevin equation as the starting point, and as a Fokker-Planck differential equation for the averaged distribution of labelled spins at the end point, which takes into account the effects of flow and dispersion of labelled water by the pseudorandom nature of the microvasculature and the transcapillary permeability. Multi-inversion time (multi-TI) ASL data were acquired in 14 healthy subjects on two occasions in a test-retest design, using a pulsed ASL sequence and three-dimensional gradient and spin echo (3D-GRASE) readout. Based on an error analysis to predict the size of a region of interest (ROI) required to obtain reasonably precise parameter estimates, data were analysed in two relatively large ROIs, i.e. the occipital lobe (OC) and the insular cortex (IC). The average values of CTT in OC were 260 ± 60 ms in the first experiment and 270 ± 60 ms in the second experiment. The corresponding IC values were 460 ± 130 ms and 420 ± 139 ms, respectively. Information related to the water transfer time may be important for diagnostics and follow-up of cerebral conditions or diseases characterised by a disrupted blood-brain barrier or disturbed capillary blood flow. Copyright © 2015 John Wiley & Sons, Ltd.
|
|
| 46. |
- Blomstergren, Adam, et al.
(författare)
-
Evaluation of reproducibility in MRI quantitative volumetric assessment and its role in the prediction of overall survival and progression-free survival in glioblastoma
- 2019
-
Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 60:4, s. 516-525
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Residual tumor volume (RTV) and extent of resection (EOR) have previously been shown to affect survival in glioblastoma (GB) patients. Quantitative radiological assessment (QRA) of these factors could potentially affect clinical decision-making in the postoperative period. Purpose: The first aim was to evaluate the reproducibility of different volume estimation methods of RTV and EOR by comparing QRA with subjective visual estimation and with objective volume estimations. The second aim was to clarify whether QRA of RTV and EOR would provide accuracy in predicting progression-free survival (PFS) and overall survival (OS) in GB patients. Material and Methods: Seventy GB patients were studied retrospectively. Reproducibility of QRA was compared to conventional visual analysis. Intra-rater agreement between two repeated measurements of 25 patients was calculated. QRA for RTV and EOR was made for the entire study population. Survival analysis was performed by multivariate cox-regression analysis. Results: QRA of RTV and EOR gave superior intra-rater agreement compared to subjective evaluation. Multivariate survival analysis showed prognostic significance on 18 months PFS (hazard ratio [HR] = 0.44, P = 0.003) and OS (HR = 0.42, P = 0.012) at RTV < 1.6 mL and with EOR > 96% on PFS (HR = 2.152, P = 0.005) but not on OS (HR = 1.92, P = 0.053). Conclusion: QRA of tumor volumes is more robust compared to standard evaluation methods. Since EOR and RTV are correlated to the prognosis in GB, quantitative analysis of tumor volumes could aid decision-making and patient management postoperatively.
|
|
| 47. |
- Brink, Rob C., et al.
(författare)
-
Three-dimensional pelvic incidence is much higher in (thoraco)lumbar scoliosis than in controls
- 2019
-
Ingår i: European spine journal. - Heidelberg : Springer. - 0940-6719 .- 1432-0932. ; 28:3, s. 544-550
-
Tidskriftsartikel (refereegranskat)abstract
- PurposeThe pelvic incidence (PI) is used to describe the sagittal spino-pelvic alignment. In previous studies, radiographs were used, leading to less accuracy in establishing the three-dimensional (3D) spino-pelvic parameters. The purpose of this study is to analyze the differences in the 3D sagittal spino-pelvic alignment in adolescent idiopathic scoliosis (AIS) subjects and non-scoliotic controls.MethodsThirty-seven female AIS patients that underwent preoperative supine low-dose computed tomography imaging of the spine, hips and pelvis as part of their general workup were included and compared to 44 non-scoliotic age-matched female controls. A previously validated computerized method was used to measure the PI in 3D, as the angle between the line orthogonal to the inclination of the sacral endplate and the line connecting the center of the sacral endplate with the hip axis.ResultsThe PI was on average 46.8° ± 12.4° in AIS patients and 41.3° ± 11.4° in controls (p = 0.025), with a higher PI in Lenke type 5 curves (50.6° ± 16.2°) as compared to controls (p = 0.042), whereas the Lenke type 1 curves (45.9° ± 12.2°) did not differ from controls (p = 0.141).ConclusionLenke type 5 curves show a significantly higher PI than controls, whereas the Lenke type 1 curves did not differ from controls. This suggests a role of pelvic morphology and spino-pelvic alignment in the pathogenesis of idiopathic scoliosis. Further longitudinal studies should explore the exact role of the PI in the initiation and progression of different AIS types.
|
|
| 48. |
- Brizzi, Marco, et al.
(författare)
-
Early do-not-resuscitate orders in intracerebral haemorrhage; frequency and predictive value for death and functional outcome. A retrospective cohort study
- 2012
-
Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : Springer Science and Business Media LLC. - 1757-7241. ; 20
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: In former studies from North America early Do-Not-Resuscitate orders (DNR orders) in patients with intracerebral haemorrhage (ICH) had negative prognostic impact on mortality. The influence of DNR orders on functional outcome and whether DNR orders are grounded on relevant patient characteristics is unknown. We aimed to determine the frequency and predictive factors of DNR-orders and its association to prognosis, in ICH patients, in Scandinavia. Methods: In 197 consecutive ICH patients admitted to Skane University Hospital, Malmo, Sweden, between January 2007 and June 2009, information of the presence of DNR orders within 48 hours, clinical and radiological characteristics was retrieved by review of patient medical journal and computed tomography scans. Determinants of DNR-orders, one-month case fatality and bad functional outcome (modified Rankin Scale, grade 4-6) were assessed by logistic regression analysis. Results: DNR orders were made in 41% of the cases. After adjustment for confounding factors, age >= 75 years (Odds Ratio (95% confidence interval) 4.2(1.8-9.6)), former stroke (5.1(1.9-3.1)), Reaction Level Scale grade 2-3 and 4 (7.0(2.8-17.5) and (4.1(1.2-13.5), respectively) and intraventricular haemorrhage (3.8(1.6-9.4)) were independent determinants of early DNR orders. Independent predictors of one-month case fatality was age >= 75 years (3.7(1.4-9.6)) volume >= 30 ml (3.5(1.3-9.6)) and DNR orders (3.5(1.5-8.6)). Seizure (6.0(1.04-34.2) and brain stem hemorrhage (8.0(1.1-58.4)) were related to bad functional outcome, whereas early DNR order was not (3.5(0.99-12.7)). Conclusions: Well known prognostic factors are determinants for DNR orders, however DNR orders are independently related to one-month case fatality. In addition to improvements of the local routines, we welcome a change of attitude with an enhanced awareness of the definition of, and a more careful approach with respect to DNR orders.
|
|
| 49. |
|
|
| 50. |
- Dahlin, Lars, et al.
(författare)
-
Compression of the lower trunk of the brachial plexus by a cervical rib in two adolescent girls : case reports and surgical treatment.
- 2009
-
Ingår i: Journal of Brachial Plexus and Peripheral Nerve Injury. - : BioMed Central. - 1749-7221. ; 4, s. 14-
-
Tidskriftsartikel (refereegranskat)abstract
- Presence of a cervical rib in children is extremely rare, particularly when symptoms of compression of the lower trunk of the brachial plexus occur. We present two cases with such a condition, where two young girls, 11 and 16 years of age were treated by resection of the cervical rib after a supraclavicular exploration of the lower trunk of the brachial plexus. The procedure led to successful results, objectively verified with tests in a work simulator, at one year follow-up.
|
|
