| 1. |
- Abul-Kasim, Kasim, et al.
(författare)
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Intradural spinal tumors: current classification and MRI features
- 2008
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 50:4, s. 301-314
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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.
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| 2. |
- Alemany Ripoll, Montserrat, et al.
(författare)
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Detection and appearance of intraparenchymal haematomas of the brain at 1.5 T with spin-echo, FLAIR and GE sequences : poor relationship to the age of the haematoma
- 2004
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 46:6, s. 435-43
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Tidskriftsartikel (refereegranskat)abstract
- The specific appearance of blood related to time at T1- and T2-weighted spin-echo (SE) sequences is generally accepted; thus, these sequences are classically used for estimating the age of haematomas. Magnetic resonance imaging at 1.5 T, including T1- and T2-weighted SE fluid-attenuated inversion recovery (FLAIR) and T2*-weighted gradient-echo (GE) sequences, was performed on 82 intraparenchymal haematomas (IPHs) and 15 haemorrhagic infarcts (HIs) in order to analyse the appearance at different stages and with different sequences, and to investigate how reliably the age of hematomas can be estimated. The IPHs had been previously detected by CT, were spontaneous ( n=72) or traumatic ( n=10) in origin and were of different sizes (2 mm to 7 cm) and ages (from 7.5 h to 4 years after acute haemorrhagic event). The age of the lesion was calculated from the moment when clinical symptoms started or the traumatic event occurred. The 15 patients with HIs were patients with ischaemic stroke in whom there was either a suspicion of haemorrhagic transformation on CT, or haemorrhage was detected as an additional finding on MR performed for other indications. Patients with conditions that could affect the SI of blood, such as anticoagulant therapy or severe anaemia, were excluded. The signal intensity pattern of the lesions was analysed and related to their ages without prior knowledge of the clinical data. All lesions were detected with T2*-weighted GE. T1-weighted SE missed 13 haematomas and T2-weighted SE and FLAIR sequences missed five. Haemorrhagic transformation was missed in three infarcts by T1-, T2-weighted SE and FLAIR. The signal pattern on FLAIR was identical to that on T2-weighted SE. For all sequences, a wide variety of signal patterns, without a clear relationship to the age of the haematomas, was observed. There was a poor relationship between the real MR appearance of IPHs and the theoretical appearance on SE sequences. T2*-weighted GE was effective for detecting small bleedings but was not useful for estimating the age of a lesion. The FLAIR does not provide any more information than T2-weighted SE.
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| 3. |
- Andersson, Henrik, et al.
(författare)
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Comparison of image quality between a novel mobile CT scanner and current generation stationary CT scanners
- 2023
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 65:3, s. 503-512
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Point-of-care imaging with mobile CT scanners offers several advantages, provided that the image quality is satisfactory. Our aim was to compare image quality of a novel mobile CT to stationary scanners for patients in a neurosurgical intensive care unit (ICU). Methods: From November 2020 to April 2021, all patients above 18 years of age examined by a mobile CT scanner at a neurosurgical ICU were included if they also had a stationary head CT examination during the same hospitalization. Quantitative image quality parameters included attenuation and noise in six predefined regions of interest, as well as contrast-to-noise ratio between gray and white matter. Subjective image quality was rated on a 4-garde scale, by four radiologists blinded to scanner parameters. Results: Fifty patients were included in the final study population. Radiation dose and image attenuation values were similar for mobCT and stationary CTs. There was a small statistically significant difference in subjective quality rating between mobCT and stationary CT images. Two radiologists favored the stationary CT images, one was neutral, and one favored mobCT images. For overall image quality, 14% of mobCT images were rated grade 1 (poor image quality) compared to 8% for stationary CT images. Conclusion: Point-of-care brain CT imaging was successfully performed on clinical neurosurgical ICU patients with small reduction in image quality, predominantly affecting the posterior fossa, compared to high-end stationary CT scanners.
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| 4. |
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| 5. |
- Autti, Taina, et al.
(författare)
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MRI of neuronal ceroid lipofuscinosis : II. Postmortem MRI and histopathological study of the brain in 16 cases of neuronal ceroid lipofuscinosis of juvenile or late infantile type
- 1997
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 39:5, s. 371-7
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Tidskriftsartikel (refereegranskat)abstract
- Postmortem MRI was carried out on the formalin-fixed brains of 14 patients with juvenile (JNCL) and two with late infantile neuronal ceroid lipofuscinosis, one of variant and the other of classical type. Two patients with JNCL had also undergone MRI during life. After MRI, specimens for histopathological analysis were taken from standard areas of the cerebral cortex, deep nuclei and white matter. The signal intensity of the periventricular white matter was usually higher than that of the peripheral white matter, a finding which correlated with the severe periventricular loss of myelin and gliosis observed histologically. The signal intensity was usually lower in the thalamus than in the putamen; in some patients the signal intensity of the thalamus was equal to or even lower than that of the white matter. However, myelin loss, gliosis, the storage process or neuronal loss in the thalamus did not correlate with the MRI findings. Since in one patient with JNCL the ante- and postmortem MRI did not differ basically, it appears probable that the periventricular changes detected in vivo on MRI are due to the severe loss of myelin and gliosis observed in this study. However, changes resulting from the fixation process must be considered, when postmortem and in vivo MRI are correlated.
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| 6. |
- Autti, Taina, et al.
(författare)
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MRI of neuronal ceroid lipofuscinosis : I. Cranial MRI of 30 patients with juvenile neuronal lipofuscinosis
- 1996
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Ingår i: Neuroradiology. - 0028-3940 .- 1432-1920. ; 38:5, s. 476-82
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Tidskriftsartikel (refereegranskat)abstract
- We studied 30 patients with juvenile neuronal ceroid lipofuscinosis (JNCL). The patients (aged 6-25 years) and 43 age-matched healthy volunteers underwent MRI. After visual assessment, the signal intensity was measured on T2-weighted images in numerous locations. The thickness of the cortex and corpus callosum and the dimensions of the brain stem were measured. Mild to moderate cerebral atrophy was found in 14 of 30 patients, most of them over 14 years of age; 5 older patients had mild to moderate cerebellar atrophy. There was reduction in the size of the corpus callosum and brain stem. The thalamus, caudate nucleus and putamen appeared to give low signal in patients from the ages of 7, 11 and 11 years, respectively. In contrast, the signal intensity measured from the thalamus in these patients showed only a slight (insignificant) decrease compared with controls. The most significant alteration, an increase in measured signal intensity, was found in the white matter (P < 0.0001), even in the youngest patients. The MRI findings correlated significantly with decreased intelligence, speech disturbances and motor problems. Although MRI findings in JNCL do not appear very specific and the visual changes develop relatively late, the absence of pathological MRI findings in the very early stage of the disease may play a part in differential diagnosis of the different types of NCL. Furthermore, the MRI findings may be used in assessing severity and prognosis, particularly in young patients.
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| 7. |
- Bajic, Dragan, et al.
(författare)
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Hippocampal development at gestation weeks 23 to 36 : An ultrasound study on preterm neonates
- 2010
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 52:6, s. 489-494
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: During fetal development, the hippocampal structures fold around the hippocampal sulcus into the temporal lobe. According to the literature, this inversion should be completed at gestation week (GW) 21. Thereafter, the hippocampal shape should resemble the adult shape. However, incomplete hippocampal inversion (IHI) is found in 19% of the common population. The aim of this study was to study fetal hippocampal development by examining neonates born preterm. METHODS: We analyzed cranial ultrasound examinations, performed as a part of the routine assessment of all preterm infants, over a 3-year period and excluded the infants with brain pathology. The final material consisted of 158 children born <35 GW. A rounded form (the ratio between the horizontal and vertical diameters of the hippocampal body <25 GW and >/=25 GW was statistically highly significant (p < 0.001). The frequency of bilateral IHI was highest in the youngest age group. In the other groups, the left-sided IHI was the most common. CONCLUSION: In about 50% of the neonates, hippocampal inversion is not completed up to GW 24; but from 25 GW onwards, the frequency and laterality of IHI is similar to that in the adult population.
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| 8. |
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| 9. |
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| 10. |
- Burtscher, I M, et al.
(författare)
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Proton magnetic resonance spectroscopy in brain tumours: clinical applications
- 2001
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 43:5, s. 345-352
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Forskningsöversikt (refereegranskat)abstract
- Parallel to the rapid development of clinical MRI, MR spectroscopy (MRS) has, after starting as an analytical tool used in chemistry and physics, evolved to a noninvasive clinical examination. Most common neuroradiological diagnostic indications for MRS are functional inborn errors, neonatal hypoxia, ischaemia, metabolic diseases, white matter and degenerative diseases, epilepsy, inflammation, infections and intracranial neoplasm. Compared to CT and MRI, well-established morphological diagnostic tools, MRS provides information on the metabolic state of brain tissue. We review the clinical impact of MRS in diagnosis of tumours and their differentiation from non-neoplastic lesions.
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| 11. |
- Canto Moreira, Nuno, et al.
(författare)
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Measurements of the normal fetal brain at gestation weeks 17 to 23 : a MRI study
- 2011
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 53:1, s. 43-48
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: To obtain measurements of the normal fetal brain before 24 weeks of gestation (GW), a deadline for medical decisions on fetal viability in a large number of countries. METHODS: We retrospectively reviewed 70 normal MR examinations of fetuses aged GW 17 to 23. The fronto-occipital diameter, the cerebral bi-parietal diameter, the transverse cerebellar diameter, the vermian height, and antero-posterior diameter were measured. RESULTS: The median, maximum, and minimum values for each parameter were displayed for each individual GW. CONCLUSION: The recorded data might contribute to a better assessment of fetal health by providing normal boundaries for the brain growth.
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| 12. |
- Canto Moreira, Nuno, et al.
(författare)
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The ear in fetal MRI : what can we really see?
- 2011
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 53:12, s. 1001-1008
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The aim of this study was to investigate the ability to depict the components of the ear on brain-oriented fetal MRI studies. METHODS: Retrospective evaluation of the ear in MRI studies was performed post-mortem in 16 fetuses ranging from 15 to 22 gestation weeks (GW), and in 122 examinations in vivo of fetuses ranging from 20 to 38 GW. The cochlea, vestibular apparatus, middle ear, and external auditory canal were separately graded according to the components that were delineated. RESULTS: The components of the inner and middle ear were fully delineated in 100% of the post-mortem examinations, but the external auditory canals were only seen in only 25%. In the in vivo group, the imaging detail was much lower. Cochlear turns could be identified in 75% of the fetuses, the vestibule and the lateral semicircular canals in 72% andossicles in 70%. Before 25 GW, the ability to identify these individual parts was 50%, 30%, and 33%, respectively, and above it was 89%, 93%, and 90% . In most cases, the external auditory canals could only be seen after 29 GW. CONCLUSION: In fetal MRI studies in vivo, it is possible to depict the components of the ear in the majority of the fetuses, in such a manner as to exclude major malformations. However, MRI might not provide enough detail to rule out pathology of the ear before 25 GW, this being a critical age for pregnancy management in many countries.
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| 13. |
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| 14. |
- Correia de Verdier, Maria, et al.
(författare)
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Normal ranges and test-retest reproducibility of flow and velocity parameters in intracranial arteries measured with phase-contrast magnetic resonance imaging
- 2016
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 58:5, s. 521-531
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The purpose of the present study was to investigate normal ranges and test-retest reproducibility of phase-contrast MRI (PC-MRI)-measured flow and velocity parameters in intracranial arteries.METHODS: Highest flow (HF), lowest flow (LF), peak systolic velocity (PSV), and end diastolic velocity (EDV) were measured at two dates in the anterior (ACA), middle (MCA), and posterior (PCA) cerebral arteries of 30 healthy volunteers using two-dimensional PC-MRI at 3 T. Least detectable difference (LDD) was calculated.RESULTS: In the left ACA, HF was (mean (range, LDD)) 126 ml/min (36-312, 59 %), LF 61 ml/min (0-156, 101 %), PSV 64 cm/s (32-141, 67 %), and EDV 35 cm/s (18-55, 42 %); in the right ACA, HF was 154 ml/min (42-246, 49 %), LF 77 ml/min (0-156, 131 %), PSV 75 cm/s (26-161, 82 %), and EDV 39 cm/s (7-59, 67 %). In the left MCA, HF was 235 ml/min (126-372, 35 %), LF 116 ml/min (42-186, 48 %), PSV 90 cm/s (55-183, 39 %), and EDV 46 cm/s (20-66, 28 %); in the right MCA, HF was 238 ml/min (162-342, 44 %), LF 120 ml/min (72-216, 48 %), PSV 88 cm/s (55-141, 35 %), and EDV 45 cm/s (26-67, 23 %). In the left PCA, HF was 108 ml/min (42-168, 54 %), LF 53 ml/min (18-108, 64 %), PSV 50 cm/s (24-77, 63 %), and EDV 28 cm/s (14-40, 45 %); in the right PCA, HF was 98 ml/min (30-162, 49 %), LF 49 ml/min (12-84, 55 %), PSV 47 cm/s (27-88, 59 %), and EDV 27 cm/s (16-41, 45 %).CONCLUSION: PC-MRI-measured flow and velocity parameters in the main intracranial arteries have large normal ranges. Reproducibility is highest in MCA.
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| 15. |
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| 16. |
- Cronqvist, Mats, et al.
(författare)
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Diffusion and perfusion MRI in patients with ruptured and unruptured intracranial aneurysms treated by endovascular coiling: complications, procedural results, MR findings and clinical outcome.
- 2005
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 47:11, s. 855-873
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Tidskriftsartikel (refereegranskat)abstract
- Our purpose was to evaluate treatment safety as well as complications frequency and management in endovascular coiling of intracerebral aneurysms using MR diffusion and perfusion imaging. In this prospective study, 77 MR examinations were performed in conjunction with 43 procedures in 40 patients, 14 patients presented with ruptured and 26 with unruptured aneurysms. Mean time interval between treatment and post-procedure MRI was 29 and 25 h for the ruptured and unruptured aneurysm group, respectively. Peri-procedural complications, including five major events and five minor transient events, occurred in 10/43 procedures (23%), necessitating thrombolytic therapy in two patients and angioplasty in one, all three within the unruptured aneurysm group. Fifty-one new lesions were found on post-treatment DWI and 47 of them were regarded as of ischemic origin. Most lesions were small (< 3 mm), ipsilateral to the treated aneurysm and asymptomatic (37/40 patients). Sixty-seven percent of the lesions were found in the ruptured and 33% in the unruptured aneurysm group. The ischemic lesions did occur more frequently in patients treated for aneurysm of large neck size and according to the remodelling technique. The overall morbidity and mortality rates were 14.6 and 7.3% whereas morbidity and mortality rates related to the technique were only 2.6 and 0%, respectively. Silent embolism seems to be more common than clinically evident and partially related to patient presentation, heparinazation and treatment strategy. The capability to depict early complications and analyse their potential causes by using MR with DWI has been of great importance in our modification and improvement of therapeutic protocols, evaluations and strategies.
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| 17. |
- Cronqvist, Mats, et al.
(författare)
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Diffusion- and perfusion-weighted MRI in therapeutic neurointerventional procedures
- 2001
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 43:8, s. 662-671
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Tidskriftsartikel (refereegranskat)abstract
- We describe three patients in whom we used MRI, including diffusion- and perfusion-weighted imaging (DWI, PWI) in conjunction with endovascular therapy. Two had intracranial aneurysms and one an arteriovenous malformation (AVM). The aneurysms were treated by coil embolisation or detachable balloons for proximal artery occlusion; the AVM was obliterated by intranidal glue injection. All patients had transient or permanent neurological deficits after treatment. The MRI techniques and interventional procedures are described and the DWI and PWI patterns found are correlated with the clinical features. We discuss how the information gained from MRI may increase our understanding of procedure-related complications and its potential impact on our therapeutic interventions, in order to prevent or limit the clinical consequences of such events.
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| 18. |
- Davide, Brotto, et al.
(författare)
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Oculo-auriculo-vertebral spectrum : going beyond the first and second pharyngeal arch involvement
- 2017
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Ingår i: Neuroradiology. - Berlin : Springer. - 0028-3940 .- 1432-1920. ; 59:3, s. 305-316
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Intracranial vascular, bone, and brain abnormalities might be observed in oculo-auriculo-vertebral spectrum (OAVS) patients even though these structures do not derive embryologically from the first and second pharyngeal arches. This neuroimaging study investigated their type, frequency and phenotype correlations among OAVS patients.Methods: Thirty-five OAVS patients (mean-age 4.8 ± 6.0 years; age range 0.3-30, 14 females) underwent head CT (all patients) and brain MRI (32 patients); 19 patients had a more severe phenotype (Goldenhar syndrome). Internal carotid artery hypoplasia/agenesia and abnormal course, brain abnormalities, internal acoustic canal stenosis/aplasia, cochlear-vestibular malformations, facial nerve bony canal anomalies, and oval window atresia were recorded.Results: Nine of 35 (26%) OAVS patients showed internal carotid artery anomalies; 18/32 (56%) had protean brain MRI abnormalities, ranging from tegmental cap anomaly to mild ventriculomegaly, which were associated with Goldenhar syndrome (p < 0.001) and concomitant cranial nerve abnormalities (p = 0.004); 11/35 (31%) disclosed cochlear-vestibular abnormalities including Michel deformity, common cavity, cochlear hypoplasia, and incomplete partition type-1 that were associated with Goldenhar syndrome (p = 0.01) and ipsilateral VIII cranial nerve abnormalities (p < 0.001); 16/35 (46%, 23 sides) presented facial nerve bony canal abnormalities that were associated with Goldenhar syndrome (p < 0.001) and ipsilateral VII cranial nerve (p < 0.001) and cochlear-vestibular (p < 0.001) abnormalities; and 23/31 (74%, 31 sides) showed oval window atresia, always with concomitant ossicular chain dysplasia.Conclusions: Intracranial vascular, bone, and brain abnormalities in OAVS patients are strikingly common and heterogeneous. As their detection might impact significantly on clinical and surgical management of affected patients, accurate neuroimaging investigations should be included in the diagnostic work-up of OAVS.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- F., Durmo, et al.
(författare)
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Multivoxel 1H MR spectroscopy biometrics for preoprerative differentiation between brain tumors
- 2018
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 60:S2, s. 444-444
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Konferensbidrag (refereegranskat)abstract
- Purpose To investigate multivoxel proton Magnetic Resonance Spectroscopy (1HMRS) biometrics for preoperative differentiation and prognosis of patients with brain metastases (MET), low-(LGG) and high grade glioma (HGG). Methods Thirty-five patients (15 HGG, 9 LGG and 11 MET) were included. Proton Magnetic Resonance Spectroscopy Imaging(1H-MRSI) data was assessed and neurochemical profiles for metabolites (NAA+NAAG, Cr+PCr, Glu+Gln (Glx), Lac, Ins, GPC+PCho) and total Lipids (tLip) and macromolecule (tMM) signals were estimated. Concentrations were reported as either absolute or ratios to total choline (tCho=GPC+PCho) and creatine (tCr=Cr+PCr) levels. Voxels of interest (VOIs) in a MRSI matrix were labelled accordingly to contrast-enhancing/nonenhancing lesional, edema, ipsi- or contralateral healthy appearing tissue and the metabolite averages were reported for each tissue type. Multi-biometric analysis with logistic regression, ROC- and Kaplan-Meier survival analysis was performed in SPSS v.24 and postprocessing with LC Model. Results Across HGG/LGG/MET; the average Ins/tCho was shown to be prognostic for overall survival (OS): with low values (≤1.29) in affected hemisphere predicting worse OS than high values (>1.29), (Log Rank
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| 23. |
- F., Durmo, et al.
(författare)
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Mutlimodality MR imaging for differentiation between brain tumor lesions
- 2016
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 58:Suppl 1, s. 53-54
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Konferensbidrag (refereegranskat)abstract
- Purpose: Applying diffusion and perfusion metrics for evaluation of low-(LGG), high grade glioma (HGG) and metastases (MET) for differential diagnosis. Materials and Method: 43 patients (18HGG, 10 LGG, and 15MET) were included. MR data for tumour volume, perilesional edema, rCBF-, rCBV-, FLAIR-, FA-, ADC-maps were quantified by regions of interest (ROI). Measures of different parameters, and ratios, using contralateral white matter as denominator, were performed. A binary logistic regression model was constructed for multi-parametric analysis and ROCanalysis. Results: Significant difference was found for nADCt, rCBF, rCBV between LGG and HGG, nADCe between HGG and MET, and Ev, Ev-Tv ratio, nADCt, nADCe, rCBF, rCBV between LGG and MET. ROCanalysis for HGG compared to LGG showed 80 % sensitivity and 81.2 % specificity for nADCt, 100 % sensitivity and 100 % specificity for rCBF and 80 % sensitivity and 90 % specificity for rCBV. ROC-curves betweenMETand LGG showed sensitivity and specificity for Ev 73.3 % and 90 %, Ev-Tv ratio 80 % and 100 %, nADCt 90 % and 86.7 %, nADCe 80 % and 90 %, rCBF 93.3 % and 100 %, and rCBV 60 % and 100 %. Combining Ev, Ev-Tv ratio, nADCt, nADCe and rCBV between METand LGG gave 93.3%sensitivity and 100%specificity. Combining nADCt and rCBV between HGG and LGG 86.7 % sensitivity and 100 % specificity. Conclusion: Multi-parametric imaging protocols is an advantage for preoperative distinction of LGG, HGG and MET.
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| 24. |
- Falk, Anna, et al.
(författare)
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Discrimination between glioma grades II and III in suspected low-grade gliomas using dynamic contrast-enhanced and dynamic susceptibility contrast perfusion MR imaging : a histogram analysis approach
- 2014
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 56:12, s. 1031-1038
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionPerfusion magnetic resonance imaging (MRI) can be used in the pre-operative assessment of brain tumours. The aim of this prospective study was to identify the perfusion parameters from dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) perfusion imaging that could best discriminate between grade II and III gliomas.MethodsMRI (3 T) including morphological ((T2 fluid attenuated inversion recovery (FLAIR) and T1-weighted (T1W)+Gd)) and perfusion (DCE and DSC) sequences was performed in 39 patients with newly diagnosed suspected low-grade glioma after written informed consent in this review board-approved study. Regions of interests (ROIs) in tumour area were delineated on FLAIR images co-registered to DCE and DSC, respectively, in 25 patients with histopathological grade II (n = 18) and III (n = 7) gliomas. Statistical analysis of differences between grade II and grade III gliomas in histogram perfusion parameters was performed, and the areas under the curves (AUC) from the ROC analyses were evaluated.ResultsIn DCE, the skewness of transfer constant (k trans) was found superior for differentiating grade II from grade III in all gliomas (AUC 0.76). In DSC, the standard deviation of relative cerebral blood flow (rCBF) was found superior for differentiating grade II from grade III gliomas (AUC 0.80).ConclusionsHistogram parameters from k trans (DCE) and rCBF (DSC) could most efficiently discriminate between grade II and grade III gliomas.
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Finnsson, Johannes, et al.
(författare)
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1H-MR spectroscopy of adult-onset autosomal dominant leukodystrophy with autonomic symptoms
- 2013
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 55:8, s. 933-939
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Tidskriftsartikel (refereegranskat)abstract
- Adult-onset ADLD with autonomic symptoms is a rare disease with a clinical course somewhat similar to chronic progressive MS but with different imaging findings consisting of extensive white matter changes in the cerebrum and cerebellar peduncles. Patients usually present in the fourth to sixth decade with autonomic symptoms, manifesting later symptoms from the pyramidal tracts and ataxia. Here, we present magnetic resonance spectroscopy (MRS) findings in this disease. Fourteen subjects, from two non-related families, with genetic linkage to the disease were studied with magnetic resonance imaging and single-voxel MRS. Clinically, they ranged from asymptomatic to wheelchair-using. Their results were compared to those of age- and sex-matched healthy controls. One MRS was excluded due to suboptimal quality. The remaining 13 subjects manifested characteristic evidence of pathology on MRI, 11 of them exhibited extensive changes. The metabolite concentrations of total Cr, total Cho, and total NAA measured in millimolars, using internal water as a reference, were significantly lower in these 11 subjects compared to controls, and we found linear correlations between all these metabolite levels. When total Cr was used as a reference, we found no difference between subjects and controls. No lactate was detected. The decreased metabolite concentrations measured using internal water as a reference are most likely due to increased water content in the tissues, diluting all metabolites to a similar degree. This is also in agreement with the high signal intensity exhibited in the white matter on T2-weighted MR images and with the reported histopathological findings of vacuolated myelin.
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| 29. |
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| 31. |
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Fragata, Isabel, et al.
(författare)
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Evolution of diffusion tensor imaging parameters after acute subarachnoid haemorrhage : a prospective cohort study
- 2017
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 59:1, s. 13-21
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Few studies assessed diffusion tensor imaging (DTI) changes in the acute phase of subarachnoid haemorrhage (SAH). We prospectively evaluated DTI parameters in the acute phase of SAH and 8-10 days after and analysed whether changes could be related to SAH severity or to the development of delayed cerebral ischemia (DCI).METHODS: Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) changes over time were assessed in a prospective cohort of patients with acute SAH. Two MRI studies were performed at <72 h (MRI-1) and 8-10 days (MRI-2). DTI parameters were recorded in 15 ROIs. Linear mixed regression models were used.RESULTS: Forty-two patients were included. Subtle changes in DTI parameters were found between MRI-1 and MRI-2. At the posterior limb of internal capsule (PLIC), a weak evidence of a 0.02 mean increase in FA (p = 0.064) and a 17.55 × 10(-6) mm(2)/s decrease in ADC (p = 0.052) were found in MRI-2. Both FA and ADC changed over time at the cerebellum (increase of 0.03; p = 0.017; decrease of 34.73 × 10(-6) mm(2)/s; p = 0.002, respectively). Patients with DCI had lower FA values on MRI-1 and lower ADC on MRI-2, although not reaching statistical significance, compared to non-DCI patients. DTI parameters on MRI-1 were not correlated to clinical admission scales.CONCLUSION: ADC and FA values show subtle changes over time in acute SAH at the PLIC and cerebellum although not statistically associated with the severity of SAH or the occurrence of DCI. However, DTI changes occurred mainly in DCI patients, suggesting a possible role of DTI as a marker of DCI.
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| 36. |
- Fransson, Veronica, et al.
(författare)
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Image quality of spectral brain computed tomography angiography using halved dose of iodine contrast medium
- 2023
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Ingår i: Neuroradiology. - 0028-3940. ; 65:9, s. 1333-1342
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Reduction in iodinated contrast medium (CM) dose is highly motivated. Our aim was to evaluate if a 50% reduction of CM, while preserving image quality, is possible in brain CT angiography (CTA) using virtual monoenergetic images (VMI) on spectral CT. As a secondary aim, we evaluated if VMI can salvage examinations with suboptimal CM timing. Methods: Consecutive patients older than 18 years without intracranial stenosis/occlusion were included. Three imaging protocols were used: group 1, full CM dose; group 2, 50% CM dose suboptimal timing; and group 3, 50% CM dose optimized timing. Attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured in the internal carotid artery, M2 segment of the middle cerebral artery, and white matter for conventional images (CI) and VMI (40–200 keV). Qualitative image quality for CI and VMI (50 and 60 keV) was rated by 4 experienced reviewers. Results: Qualitatively and quantitatively, VMI (40–60 keV) improved image quality within each group. Significantly higher attenuation and CNR was found for group 3 VMI 40–50 keV, with unchanged SNR, compared to group 1 CI. Group 3 VMI 50 keV also received significantly higher rating scores than group 1 CI. Group 2 VMI (40–50 keV) had significantly higher CNR compared to group 3 CI, but the subjective image quality was similar. Conclusion: VMI of 50 keV with 50% CM dose increases qualitative and quantitative image quality over CI with full CM dose. Using VMI reduces non-diagnostic examinations and may salvage CTA examinations deemed non-diagnostic due to suboptimal timing.
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| 37. |
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| 38. |
- Geijer, Bo, et al.
(författare)
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Diffusion-weighted imaging of brain metastases: their potential to be misinterpreted as focal ischaemic lesions.
- 2002
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 44:7, s. 568-573
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Tidskriftsartikel (refereegranskat)abstract
- Small focal ischaemic brain lesions are said to be easy to identify in the acute stage and to differentiate from older lesions using diffusion-weighted imaging (DWI). Brain metastases are common and the aim of this study was to evaluate the risk of misinterpretation as ischaemic lesions in a standard MRI protocol for clinical stroke. Of 26 patients investigated with MRI for possible metastases, 12 did have metastatic brain lesions, including most of the common tumours. On a 1.5 tesla imager, we obtained DWI, plus T2- and T1-weighted images, the latter before and after triple-dose contrast medium. Well-circumscribed brain lesions with a decreased apparent diffusion coefficient and a slightly or moderately increased signal on T2-weighted images were found in patients with metastases from a small-cell bronchial carcinoma and a pulmonary adenocarcinoma. The same features were also found in metastases from a breast carcinoma but the lesions were surrounded by oedema. With a standard DWI protocol, the features of common brain metastases may overlap with those of small acute and subacute ischaemic lesions.
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| 39. |
- Geijer, Bo, et al.
(författare)
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Persistent high signal on diffusion-weighted MRI in the late stages of small cortical and lacunar ischaemic lesions
- 2001
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 43:2, s. 115-122
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Tidskriftsartikel (refereegranskat)abstract
- Diffusion-weighted imaging (DWI) is very sensitive to early brain infarcts. However, the late stages have been insufficiently studied. Infarcts in small vessel disease are often multiple and of different ages, and differentiation between new and old lesions might be difficult. We have therefore studied the change with time in DWI of small (< 3 ml) ischaemic lesions. We imaged 21 patients with an acute lacunar syndrome and a lesion visible on early DWI. They all had three MRI examinations 12-58 h (early), 7-16 and 54-144 days after the onset of stroke; 10 patients with high DWI signal on the third examination had a fourth examination 12-28 months after the stroke. MRI was performed at 1.5 T, using echo-planar DWI with 7 b-values from 0 to 1200 x 10(6) s/m2 and conventional T2-weighted imaging. After 7-16 days 18 of 21 lesions gave high signal on DWI, and 12/16 measurable lesions had a decreased apparent diffusion coefficient (ADC). After 54-144 days ten lesions still gave high DWI signal and two still had an ADC below normal. On the fourth examination there was no remaining high DWI signal and all ADC were higher than normal.
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| 40. |
- Geijer, Bo, et al.
(författare)
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The value of b required to avoid T2 shine-through from old lucunar infarcts in diffusion-weighted imaging
- 2001
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 43:7, s. 511-517
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Tidskriftsartikel (refereegranskat)abstract
- Multiple small infarcts of different ages are common in small-vessel disease. Diffusion-weighted imaging (DWI) is a powerful method for discriminating new from chronic lesions. This can be done on the diffusion-weighted images provided that b is sufficiently high. Our purpose was to determine that critical value of b. We reviewed DWI from a previous study of acute, mainly lacunar strokes, and selected 18 old lacunar infarcts, well defined on uncoded images with b 0 s/m2 (i. e., T2-weighted images) but invisible on DWI with b 1,200 x 10(6) s/m2. We used a 1.5 tesla imager and single-shot echo-planar technique. We had seven separate acquisitions with echo time 123 ms and b in steps between 0 and 1,200 x 10(6) s/m2. Two neuroradiologists blinded to the selection of lesions carried out two different lesion-detection procedures, thereby testing each lesion four times, giving a total of 72 tests of b values. The results were consistent, indicating a level for detection of 800 x 10(6) s/m2 in two tests, 400-600 x 10(6) s/m2 in 65 tests and at lower values in the remainder. For imagers up to 1.5 tesla, at long repetition times and an echo time up to 120 ms T2-shine through of old lacunar infarcts can be avoided using b of 1,000 x 10(6) s/m2.
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| 41. |
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| 42. |
- Haller, Sven, et al.
(författare)
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Caffeine impact on working memory-related network activation patterns in early stages of cognitive decline
- 2017
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Ingår i: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 59:4, s. 387-395
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Recent evidence indicates that caffeine may have a beneficial effect on cognitive decline and dementia. The current investigation assessed the effect of acute caffeine administration on working memory during the earliest stage of cognitive decline in elderly participants. Methods The study includes consecutive 45 elderly controls and 18 individuals with mild cognitive impairment (MCI, 71.6 +/- 4.7 years, 7 females). During neuropsychological follow-up at 18 months, 24 controls remained stable (sCON, 70.0 +/- 4.3 years, 11 women), while the remaining 21 showed subtle cognitive deterioration (dCON, 73.4 +/- 5.9 years, 14 women). All participants underwent an established 2-back working task in a crossover design of 200 mg caffeine versus placebo. Data analysis included task-related general linear model and functional connectivity tensorial independent component analysis. Results Working memory behavioral performances did not differ between sCON and dCON, while MCI was slower and less accurate than both control groups (p < 0.05). The dCON group had a less pronounced effect of acute caffeine administration essentially restricted to the right hemisphere (p < 0.05 corrected) and reduced default mode network (DMN) deactivation compared to sCON (p < 0.01 corrected). Conclusion dCON cases are characterized by decreased sensitivity to caffeine effects on brain activation and DMN deactivation. These complex fMRI patterns possibly reflect the instable status of these cases with intact behavioral performances despite already existing functional alterations in neocortical circuits.
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| 43. |
- Haller, Sven, et al.
(författare)
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MR skin signal loss effect/artifact
- 2018
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 60:6, s. 661-662
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Tidskriftsartikel (refereegranskat)
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| 44. |
- Haller, Sven, et al.
(författare)
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MRI detection of cerebral microbleeds : size matters
- 2019
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 61:10, s. 1209-1213
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Cerebral microbleeds (CMB) play an important role as an imaging biomarker notably in vascular and neurodegenerative diseases. Current clinical brain MRI underestimates the number of CMB with respect to histopathology. It is expected that small CMBs are more likely to be false-negatives, yet this has not been demonstrated and the average size of false-negative and true-positive CMBs have not been established.METHODS: The radiologic-histopathologic correlation study was approved by the local review board and included 42 consecutive cases (mean age at death, 80.7 ± 10.0 years; 23 females and 19 men) between 12 January 2012 and 10 December 2012 having undergone brain autopsy. Postmortem SWI (susceptibility-weighted imaging) images were acquired on a clinical 3T system using parameters similar to clinical routine. The detection of CMB on postmortem MRI was compared with corresponding histopathological slices.RESULTS: Postmortem MRI detected 23 true-positive CMB. Histopathology additionally detected 68 CMBs (false-negative MRI CMBs). The average size true-positive MRI CMBs had on histopathology was 3.6 ± 7.1 mm3. The average size false-negative MRI CMBs was significantly smaller (p < 0.05), measuring 0.3 ± 1.2 mm3 on histopathology.CONCLUSION: Size matters. As expected, the average size of true-positive MRI CMB was around 10 times larger as compared with false-negative MRI CMB. Evidently, in addition to size, other factors will influence the detectability of CMB, including iron content, ratio of Fe2+/Fe3+, spatial configuration, and location, yet this remains to be elucidated in future studies.
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| 45. |
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| 46. |
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| 47. |
- Haller, Sven, et al.
(författare)
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The R-AI-DIOLOGY checklist : a practical checklist for evaluation of artificial intelligence tools in clinical neuroradiology
- 2022
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Ingår i: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 64:5, s. 851-864
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Forskningsöversikt (refereegranskat)abstract
- Artificial intelligence (AI)-based tools are gradually blending into the clinical neuroradiology practice. Due to increasing complexity and diversity of such AI tools, it is not always obvious for the clinical neuroradiologist to capture the technical specifications of these applications, notably as commercial tools very rarely provide full details. The clinical neuroradiologist is thus confronted with the increasing dilemma to base clinical decisions on the output of AI tools without knowing in detail what is happening inside the "black box" of those AI applications. This dilemma is aggravated by the fact that currently, no established and generally accepted rules exist concerning best clinical practice and scientific and clinical validation nor for the medico-legal consequences in cases of wrong diagnoses. The current review article provides a practical checklist of essential points, intended to aid the user to identify and double-check necessary aspects, although we are aware that not all this information may be readily available at this stage, even for certified and commercially available AI tools. Furthermore, we therefore suggest that the developers of AI applications provide this information.
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| 48. |
- Hansson, Boel, et al.
(författare)
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Decrease of 7T MR short-term effects with repeated exposure
- 2024
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Ingår i: NEURORADIOLOGY. - 0028-3940 .- 1432-1920.
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Although participants in 7 T magnetic resonance (MR) studies tolerate ultra-high field (UHF) well, subjectively experienced short-term effects, such as dizziness, inconsistent movement, nausea, or metallic taste, are reported. Evidence on subjectively experienced short-term effects in multiple exposures to UHF MR is scarce. The purpose of this study is to investigated experience of short-term effects, and occurrence of motion in healthy subjects exposed to seven weekly 7 T MR examinations.Methods A questionnaire on short-term effects was completed by participants in an fMRI motor skill study. Seven UHF MR examinations were conducted over 7 weeks (exposure number: 1 to 7). Changes of experienced short-term effects were analyzed. Motion in fMRI images was quantified.Results The questionnaire was completed 360 times by 67 participants after one to seven 7T MR examinations. Logistic mixed model analysis showed a significant association between dizziness, inconsistent movement, nausea, and headache and the examination numbers (p<0.03). Exposure to repeated examinations had no significant effect on peripheral nerve stimulation (PNS) or motion of the subjects. The overall experience of a 7T examination improved significantly (p<0.001) with increasing examination numbers.Conclusion During multiple 7T examinations, subjects adapt to the strong static field. The short-term effects dizziness, inconsistent movement, nausea, and headache decrease over time as the MR sessions continue and experienced comfort increases. There was no significant difference in motion during the multiple fMRI examinations.
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| 49. |
- Hedderich, Dennis M, et al.
(författare)
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Artificial intelligence tools in clinical neuroradiology : essential medico-legal aspects
- 2023
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Ingår i: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 65, s. 1091-1099
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Forskningsöversikt (refereegranskat)abstract
- Commercial software based on artificial intelligence (AI) is entering clinical practice in neuroradiology. Consequently, medico-legal aspects of using Software as a Medical Device (SaMD) become increasingly important. These medico-legal issues warrant an interdisciplinary approach and may affect the way we work in daily practice. In this article, we seek to address three major topics: medical malpractice liability, regulation of AI-based medical devices, and privacy protection in shared medical imaging data, thereby focusing on the legal frameworks of the European Union and the USA. As many of the presented concepts are very complex and, in part, remain yet unsolved, this article is not meant to be comprehensive but rather thought-provoking. The goal is to engage clinical neuroradiologists in the debate and equip them to actively shape these topics in the future.
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| 50. |
- Hedner, Ulla, et al.
(författare)
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Recombinant factor VIIa (rFVIIa): its potential role as a hemostatic agent
- 2007
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 49:10, s. 789-793
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Forskningsöversikt (refereegranskat)abstract
- Recombinant activated coagulation factor VII (rFVIIa) was developed for the treatment of patients with hemophilia who have developed inhibitors against the factor they are missing. Hemophilia is a serious bleeding disorder and patients with hemophilia develop repeated spontaneous CNS, joint and muscle bleeding. Any trauma, even mild events, may cause life-threatening bleeding, and without treatment, these patients have a life expectancy of about 16 years. Thus, hemophilia can be regarded as a model of severe bleeding, and an agent capable of inducing hemostasis in severe hemophilia independent of the hemophilia proteins (FVIII or FIX) may also be effective in patients without hemophilia who experience serious bleeds. The availability of rFVIIa stimulated research on the role of FVII and tissue factor (TF) in the hemostatic process. As a result, a picture partly different from the one suggested by previous models [1, 2] has emerged. These previous models basically neglected the role of cells and cell membranes. The importance of platelets and platelet membrane phospholipids in hemostasis has been demonstrated, and the new concept of the hemostatic process, focusing on cell surfaces, has been outlined.
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