| 1. |
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| 2. |
- Balleyguier, Corinne, et al.
(författare)
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Staging of uterine cervical cancer with MRI : guidelines of the European Society of Urogenital Radiology
- 2011
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 21:5, s. 1102-1110
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To design clear guidelines for the staging and follow-up of patients with uterine cervical cancer, and to provide the radiologist with a framework for use in multidisciplinary conferences. Methods: Guidelines for uterine cervical cancer staging and follow-up were defined by the female imaging subcommittee of the ESUR (European Society of Urogenital Radiology) based on the expert consensus of imaging protocols of 11 leading institutions and a critical review of the literature. Results: The results indicated that high field Magnetic Resonance Imaging (MRI) should include at least two T2-weighted sequences in sagittal, axial oblique or coronal oblique orientation (short and long axis of the uterine cervix) of the pelvic content. Axial T1-weighted sequence is useful to detect suspicious pelvic and abdominal lymph nodes, and images from symphysis to the left renal vein are required. The intravenous administration of Gadolinium-chelates is optional but is often required for small lesions (< 2 cm) and for follow-up after treatment. Diffusion-weighted sequences are optional but are recommended to help evaluate lymph nodes and to detect a residual lesion after chemoradiotherapy. Conclusions: Expert consensus and literature review lead to an optimized MRI protocol to stage uterine cervical cancer. MRI is the imaging modality of choice for preoperative staging and follow-up in patients with uterine cervical cancer.
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| 3. |
- Beets-Tan, Regina G. H., et al.
(författare)
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Magnetic resonance imaging for the clinical management of rectal cancer patients : recommendations from the 2012 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting
- 2013
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 23:9, s. 2522-2531
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Tidskriftsartikel (refereegranskat)abstract
- To develop guidelines describing a standardised approach regarding the acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for clinical staging and restaging of rectal cancer. A consensus meeting of 14 abdominal imaging experts from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) was conducted following the RAND-UCLA Appropriateness Method. Two independent (non-voting) chairs facilitated the meeting. Two hundred and thirty-six items were scored by participants for appropriateness and classified subsequently as appropriate or inappropriate (defined by a parts per thousand yen 80 % consensus) or uncertain (defined by < 80 % consensus). Items not reaching 80 % consensus were noted. Consensus was reached for 88 % of items: recommendations regarding hardware, patient preparation, imaging sequences, angulation, criteria for MRI assessment and MRI reporting were constructed from these. These expert consensus recommendations can be used as clinical guidelines for primary staging and restaging of rectal cancer using MRI. These guidelines recommend standardised imaging for staging and restaging of rectal cancer. The guidelines were constructed through consensus amongst 14 abdominal imaging experts. Consensus was reached by in 88 % of 236 items discussed.
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| 4. |
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| 5. |
- Bertl, Kristina, et al.
(författare)
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Radiological assessment of the inferior alveolar artery course in human corpse mandibles
- 2014
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Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 25:4, s. 1148-1153
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: CT assessment of the entire course of the inferior alveolar artery (IAA) within the mandibular canal. Methods: After contrast medium injection (180 or 400 mg/ml iodine concentration) into the external carotid arteries of 15 fresh human cadaver heads, the main IAA’s position in the canal (cranial, buccal, lingual or caudal) was assessed in dental CT images of partially edentulous mandibles. Results: The course of the main IAA could be followed at both iodine concentrations. The higher concentration gave the ex- pected better contrast, without creating artefacts, and improved visibility of smaller arteries, such as anastomotic sections, dental branches and the incisive branch. The main IAA changed its position in the canal more often than so far known (mean 4.3 times, SD 1.24, range 2–7), but with a similar bilateral course. A cranial position was most often detected (42 %), followed by lingual (36 %), caudal (16 %) and buccal ( 6 %). Conclusions: With this non-invasive radiologic method, the entire course of the main IAA in the mandibular canal could be followed simultaneously with other bone structures on both sides of human cadaver mandibles. This methodology allows one to amend existing anatomical and histological data, which are important for surgical interventions near the mandibular canal.
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| 7. |
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| 8. |
- Dahlqvist Leinhard, Olof, 1978-, et al.
(författare)
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Quantifying differences in hepatic uptake of the liver specific contrast agents Gd-EOB-DTPA and Gd-BOPTA : a pilot study
- 2012
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Ingår i: European Radiology. - : Springer Berlin/Heidelberg. - 0938-7994 .- 1432-1084. ; 22:3, s. 642-653
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To develop and evaluate a procedure for quantifying the hepatocyte-specific uptake of Gd-BOPTA and Gd-EOB-DTPA using dynamic contrast-enhanced (DCE) MRI. Methods Ten healthy volunteers were prospectively recruited and 21 patients with suspected hepatobiliary disease were retrospectively evaluated. All subjects were examined with DCE-MRI using 0.025 mmol/kg of Gd-EOB-DTPA. The healthy volunteers underwent an additional examination using 0.05 mmol/kg of Gd-BOPTA. The signal intensities (SI) of liver and spleen parenchyma were obtained from unenhanced and enhanced acquisitions. Using pharmacokinetic models of the liver and spleen, and an SI rescaling procedure, a hepatic uptake rate, K Hep, estimate was derived. The K Hep values for Gd-EOB-DTPA were then studied in relation to those for Gd-BOPTA and to a clinical classification of the patient’s hepatobiliary dysfunction. Results K Hep estimated using Gd-EOB-DTPA showed a significant Pearson correlation with K Hep estimated using Gd-BOPTA (r = 0.64; P < 0.05) in healthy subjects. Patients with impaired hepatobiliary function had significantly lower K Hep than patients with normal hepatobiliary function (K Hep = 0.09 ± 0.05 min-1 versus K Hep = 0.24 ± 0.10 min−1; P < 0.01). Conclusions A new procedure for quantifying the hepatocyte-specific uptake of T 1-enhancing contrast agent was demonstrated and used to show that impaired hepatobiliary function severely influences the hepatic uptake of Gd-EOB-DTPA. Key Points • The liver uptake of contrast agents may be measured with standard clinical MRI. • Calculation of liver contrast agent uptake is improved by considering splenic uptake. • Liver function affects the uptake of the liver-specific contrast agent Gd-EOB-DTPA. • Hepatic uptake of two contrast agents (Gd-EOB-DTPA, Gd-BOPTA) is correlated in healthy individuals. • This method can be useful for determining liver function, e.g. before hepatic surgery
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| 9. |
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| 10. |
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| 11. |
- Fisichella, Valeria A, 1974, et al.
(författare)
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Evaluation of image quality and lesion perception by human readers on 3D CT colonography: comparison of standard and low radiation dose
- 2010
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Ingår i: European Radiology. - 1432-1084. ; 20:3, s. 630-9
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: We compared the prevalence of noise-related artefacts and lesion perception on three-dimensional (3D) CT colonography (CTC) at standard and low radiation doses. METHODS: Forty-eight patients underwent CTC (64 x 0.625 mm collimation; tube rotation time 0.5 s; automatic tube current modulation: standard dose 40-160 mA, low dose 10-50 mA). Low- and standard-dose acquisitions were performed in the supine position, one after the other. The presence of artefacts (cobblestone and snow artefacts, irregularly delineated folds) and the presence of polyps were evaluated by five radiologists on 3D images at standard dose, the original low dose and a modified low dose, i.e. after manipulation of opacity on 3D. RESULTS: The mean effective dose was 3.9 +/- 1.3 mSv at standard dose and 1.03 +/- 0.4 mSv at low dose. The number of images showing cobblestone artefacts and irregularly delineated folds at original and modified low doses was significantly higher than at standard dose (P < 0.0001). Most of the artefacts on modified low-dose images were mild. No significant difference in sensitivity between the dose levels was found for polyps >/=6 mm. CONCLUSIONS: Reduction of the effective dose to 1 mSv significantly affects image quality on 3D CTC, but the perception of >/=6 mm lesions is not significantly impaired.
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| 12. |
- Jackowski, Christian, 1975-, et al.
(författare)
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Magnetic resonance imaging goes postmortem: noninvasive detection and assessment of myocardial infarction by postmortem MRI
- 2011
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; Jan;21:1, s. 70-78
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate the performance of postmortem magnetic resonance imaging (pmMRI) in identification and characterization of lethal myocardial infarction in a non-invasive manner on human corpses.MATERIALS AND METHODS: Before forensic autopsy, 20 human forensic corpses were examined on a 1.5-T system for the presence of myocardial infarction. Short axis, transversal and longitudinal long axis images (T1-weighted; T2-weighted; PD-weighted) were acquired in situ. In subsequent autopsy, the section technique was adapted to short axis images. Histological investigations were conducted to confirm autopsy and/or radiological diagnoses.RESULTS: Nineteen myocardial lesions were detected and age staged with pmMRI, of which 13 were histologically confirmed (chronic, subacute and acute). Six lesions interpreted as peracute by pmMRI showed no macroscopic or histological finding. Five of the six peracute lesions correlated well to coronary pathology, and one case displayed a severe hypertrophic alteration.CONCLUSION: pmMRI reliably demonstrates chronic, subacute and acute myocardial infarction in situ. In peracute cases pmMRI may display ischemic lesions undetectable at autopsy and routine histology. pmMRI has the potential to substantiate autopsy and to counteract the loss of reliable information on causes of death due to the recent disappearance of the clinical autopsy.
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| 13. |
- Jensen, Kristin, et al.
(författare)
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Comparing five different iterative reconstruction algorithms for computed tomography in an ROC study
- 2014
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 24:12, s. 2989-3002
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to evaluate lesion conspicuity achieved with five different iterative reconstruction techniques from four CT vendors at three different dose levels. Comparisons were made of iterative algorithm and filtered back projection (FBP) among and within systems. An anthropomorphic liver phantom was examined with four CT systems, each from a different vendor. CTDIvol levels of 5 mGy, 10 mGy and 15 mGy were chosen. Images were reconstructed with FBP and the iterative algorithm on the system. Images were interpreted independently by four observers, and the areas under the ROC curve (AUCs) were calculated. Noise and contrast-to-noise ratios (CNR) were measured. One iterative algorithm increased AUC (0.79, 0.95, and 0.97) compared to FBP (0.70, 0.86, and 0.93) at all dose levels (p < 0.001 and p = 0.047). Another algorithm increased AUC from 0.78 with FBP to 0.84 (p = 0.007) at 5 mGy. Differences at 10 and 15 mGy were not significant (p-values: 0.084-0.883). Three algorithms showed no difference in AUC compared to FBP (p-values: 0.008-1.000). All of the algorithms decreased noise (10-71 %) and improved CNR. Only two algorithms improved lesion detection, even though noise reduction was shown with all algorithms. aEuro cent Iterative reconstruction algorithms affected lesion detection differently at different dose levels. aEuro cent One iterative algorithm improved lesion detectability compared to filtered back projection. aEuro cent Three algorithms did not significantly improve lesion detectability. aEuro cent One algorithm improved lesion detectability at the lowest dose level.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Kristiansson, Mattias, et al.
(författare)
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Ultralow contrast medium doses at CT to diagnose pulmonary embolism in patients with moderate to severe renal impairment: a feasibility study.
- 2010
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 20, s. 1321-1330
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To analyse 80-kVp 16-MDCT in patients with clinically suspected pulmonary embolism (PE) and diminished renal function after a reduction in dose of contrast medium (CM) from 200 to 150 mg I/kg. METHODS: Fifty patients with suspected PE and glomerular filtration rate (GFR) less than 50 mL/min underwent 80-kVp 16-MDCT with 150 mg I/kg. Mean density/image noise (1 standard deviation) was measured in a region of interest in the left pulmonary artery (LPA) and a lower lobe segmental artery (LLSA), and the contrast-to-noise ratio (CNR) was calculated. The values of LPA and LLSA were averaged. RESULTS: Median values/2.5-97.5 percentiles were: age 84/67-96 years, weight 65/43-84 kg, GFR 36/21-45 mL/min, CM dose 9.6/6.4-12 g of iodine, PA density 353/164-495 HU and CNR 11/4.4-20. PE incidence was 16%, and 8% and 12% of the examinations were regarded suboptimal by observer 1 and 2, respectively. Density/CNR values were within ranges reported for common 120-kVp MDCT protocols. None of 32 patients with plasma-creatinine follow-up within 1 week experienced a rise of more than 44.2 mumol/L and none of 50 patients had oliguria/anuria or dialysis. None of 40 patients with a negative CT/no anticoagulation had thromboembolism during follow-up. CONCLUSION: 80-kVp MDCT combined with individualised ultralow CM doses may provide satisfactory diagnostic quality, which should be to the benefit of patients at risk of contrast medium-induced nephropathy.
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| 18. |
- Lidén, Mats, et al.
(författare)
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Making renal stones change size : impact of CT image post processing and reader variability
- 2011
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 21:10, s. 2218-2225
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The objectives of this study were to quantify the impact of image post-processing parameters on the apparent renal stone size, and to quantify the intra- and inter-reader variability in renal stone size estimation. Methods Fifty CT datasets including a renal or ureteral stone were included retrospectively during a prospective inclusion period. Each of the CT datasets was post-processed in different ways regarding slice thickness, slice increment and window setting. In the first part of the study a single reader repeated size estimations for the renal stones using different post-processing parameters. In the intra-reader variability experiment one reader reported size estimations for the same images with a one-week interval. The inter-reader variability data were obtained from 11 readers reporting size estimations for the same renal stones. Results The apparent stone size differed according to image post-processing parameters with the largest mean differences seen with regard to the window settings experiment (1.5 mm, p < 0.001) and slice thickness (0.8 mm, p < 0.001). Changes in parameters introduced a bias and a pseudo-random variability. The inter-reader variability was considerably larger than the intra-reader variability. Conclusion Our results indicate a need for the standardisation of making measurements on CT images.
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| 19. |
- Lidén, Mats, 1976-, et al.
(författare)
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Urinary stone size estimation : a new segmentation algorithm-based CT method
- 2012
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Ingår i: European Radiology. - New York, USA : Springer. - 0938-7994 .- 1432-1084. ; 22:4, s. 731-737
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Tidskriftsartikel (refereegranskat)abstract
- The size estimation in CT images of an obstructing ureteral calculus is important for the clinical management of a patient presenting with renal colic. The objective of the present study was to develop a reader independent urinary calculus segmentation algorithm using well-known digital image processing steps and to validate the method against size estimations by several readers. Fifty clinical CT examinations demonstrating urinary calculi were included. Each calculus was measured independently by 11 readers. The mean value of their size estimations was used as validation data for each calculus. The segmentation algorithm consisted of interpolated zoom, binary thresholding and morphological operations. Ten examinations were used for algorithm optimisation and 40 for validation. Based on the optimisation results three segmentation method candidates were identified. Between the primary segmentation algorithm using cubic spline interpolation and the mean estimation by 11 readers, the bias was 0.0 mm, the standard deviation of the difference 0.26 mm and the Bland-Altman limits of agreement 0.0 +/- 0.5 mm. The validation showed good agreement between the suggested algorithm and the mean estimation by a large number of readers. The limit of agreement was narrower than the inter-reader limit of agreement previously reported for the same data. The size of kidney stones is usually estimated manually by the radiologist. An algorithm for computer-aided size estimation is introduced. The variability between readers can be reduced. A reduced variability can give better information for treatment decisions.
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| 20. |
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| 21. |
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| 22. |
- Neri, Emanuele, et al.
(författare)
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The second ESGAR consensus statement on CT colonography.
- 2013
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 23:3, s. 720-729
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To update quality standards for CT colonography based on consensus among opinion leaders within the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). MATERIAL AND METHODS: A multinational European panel of nine members of the ESGAR CT colonography Working Group (representing six EU countries) used a modified Delphi process to rate their level of agreement on a variety of statements pertaining to the acquisition, interpretation and implementation of CT colonography. Four Delphi rounds were conducted, each at 2months interval. RESULTS: The panel elaborated 86 statements. In the final round the panelists achieved complete consensus in 71 of 86 statements (82%). Categories including the highest proportion of statements with excellent Cronbach's internal reliability were colon distension, scan parameters, use of intravenous contrast agents, general guidelines on patient preparation, role of CAD and lesion measurement. Lower internal reliability was achieved for the use of a rectal tube, spasmolytics, decubitus positioning and number of CT data acquisitions, faecal tagging, 2D vs. 3D reading, and reporting. CONCLUSION: The recommendations of the consensus should be useful for both the radiologist who is starting a CTC service and for those who have already implemented the technique but whose practice may need updating. KEY POINTS : • Computed tomographic colonography is the optimal radiological method of assessing the colon • This article reviews ESGAR quality standards for CT colonography • This article is aimed to provide CT-colonography guidelines for practising radiologists • The recommendations should help radiologists who are starting/updating their CTC services.
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| 23. |
- Norén, Bengt, et al.
(författare)
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Separation of advanced from mild hepatic fibrosis by quantification of the hepatobiliary uptake of Gd-EOB-DTPA
- 2013
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Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 23:1, s. 174-181
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo apply dynamic contrast-enhanced (DCE) MRI on patients presenting with elevated liver enzymes without clinical signs of hepatic decompensation in order to quantitatively compare the hepatocyte-specific uptake of Gd-EOB-DTPA with histopathological fibrosis stage.MethodsA total of 38 patients were prospectively examined using 1.5-T MRI. Data were acquired from regions of interest in the liver and spleen by using time series of single-breath-hold symmetrically sampled two-point Dixon 3D images (non-enhanced, arterial and venous portal phase; 3, 10, 20 and 30 min) following a bolus injection of Gd-EOB-DTPA (0.025 mmol/kg). The signal intensity (SI) values were reconstructed using a phase-sensitive technique and normalised using multiscale adaptive normalising averaging (MANA). Liver-to-spleen contrast ratios (LSC_N) and the contrast uptake rate (KHep) were calculated. Liver biopsy was performed and classified according to the Batts and Ludwig system.ResultsArea under the receiver-operating characteristic curve (AUROC) values of 0.71, 0.80 and 0.78, respectively, were found for KHep, LSC_N10 and LSC_N20 with regard to severe versus mild fibrosis. Significant group differences were found for KHep (borderline), LSC_N10 and LSC_N20.ConclusionsLiver fibrosis stage strongly influences the hepatocyte-specific uptake of Gd-EOB-DTPA. Potentially the normalisation technique and KHep will reduce patient and system bias, yielding a robust approach to non-invasive liver function determination.
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| 24. |
- Nyman, Ulf, et al.
(författare)
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Are intravenous injections of contrast media really less nephrotoxic than intra-arterial injections?
- 2012
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 22:6, s. 1366-1371
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Tidskriftsartikel (refereegranskat)abstract
- We oppose the opinion that the intra-arterial administration of iodine-based contrast media (CM) appears to pose a greater risk of contrast medium-induced nephropathy (CIN) than intravenous administration since 1) in intra-arterial coronary procedures and most other intra-arterial angiographic examinations, CM injections are also intravenous relative to the kidneys, 2) there is a lack of comparative trials studying the risk of CIN between intra-arterial and intravenous procedures with matched risk factors and CM doses, 3) a bias selection of patients with fewer risk factors may explain the seemingly lower rate of CIN after CT in comparison with coronary interventions, 4) the rate of CIN following intra-arterial coronary procedures may also be exaggerated owing to other causes of acute kidney failure, such as haemodynamic instability and microembolisation, 5) roughly the same gram-iodine/GFR ratio (a parts per thousand 1:1) as a limit of relatively safe CM doses has preliminarily been found for both intravenous CT and intra-arterial coronary procedures and 6) the substantially higher injected intravenous CM dose rate during CT relative to an intra-arterial coronary procedure might actually pose a higher risk of CIN following CT. Key Points Most intra-arterial injections of contrast media are intravenous relative to the kidneys. No evidence that intravenous CM injections should be less nephrotoxic than intra-arterial. Considerably higher dose rates of CM are used for CT relative to intra-arterial procedures. Higher dose rates may pose higher nephrotoxic risk for intravenous based CT studies.
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| 25. |
- Nyman, Ulf, et al.
(författare)
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Iodine contrast iso-attenuating with diagnostic gadolinium doses in CTA and angiography results in ultra-low iodine doses. A way to avoid both CIN and NSF in azotemic patients?
- 2011
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 21, s. 326-336
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To establish iodine (I) contrast medium (CM) doses iso-attenuating with gadolinium (Gd) CM doses regarded diagnostic in CTA and percutaneous catheter-angiography/vascular interventions (PCA/PVI) in azotemic patients. METHODS: CT Hounsfield units (HU) were measured in 20-mL syringes containing 0.01/0.02,/0.05/0.1 mmol/mL of iodine or gadolinium atoms and placed in phantoms. Relative contrast were measured in 20-mL syringes filled with iohexol at 35/50/70/90/110/140 mg I/mL and 0.5 M gadodiamide using radiofluoroscopy (RF), digital radiography (DX) and x-ray angiography (XA) systems. Clinical doses of Gd-CM at CTA/PCA/PVI were reviewed. RESULTS: At CT 91-116 and 104-125 mg I/mL in the chest and abdominal phantoms, respectively, were iso-attenuating with 0.5 M Gd at 80-140 kVp. At RF/DX/XA systems 35-90 mg I/mL were iso-attenuating with 0.5 M gadodiamide at 60-115 kVp. Clinically, 60 mL 91-125 mg I/mL (5.5-7.5 gram-iodine) at 80-140 kVp CTA and 60 mL of 35-90 mg I/mL (2.1-5.4 gram-iodine) at 60-115 kVp PCA/PVI would be iso-attenuating with 60 mL 0.5 M Gd-CM (=0.4 mmol Gd/kg in a 75-kg person). CONCLUSIONS: Meticulous examination technique and judicious use of ultra-low I-CM doses iso-attenuating with diagnostic Gd-CM doses in CTA and PCA/PVI may minimise the risk of nephrotoxicity in azotemic patients, while there is no risk of NSF.
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| 26. |
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| 27. |
- Ragnehed, Mattias, 1976-, et al.
(författare)
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Visual Grading of 2D and 3D fMRI compared to image based descriptive measures
- 2010
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Ingår i: European Radiology. - Berlin / Heidelberg : Springer. - 0938-7994 .- 1432-1084. ; 20:3, s. 714-724
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Tidskriftsartikel (refereegranskat)abstract
- A prerequisite for successful clinical use of functional Magnetic Resonance Imaging (fMRI) is the selection of an appropriate imaging sequence. In this paper, 2D and 3D fMRI sequences were compared using different image quality assessment methods. Descriptive image measures, such as activation volume and temporal signal-to-noise ratio (TSNR), were compared with results from Visual Grading Characteristics (VGC) analysis of the fMRI results. It was found that significant differences in activation volume and TSNR were not directly reflected by differences in VGC scores. The results suggest that better performance on descriptive image measures is not always an indicator of improved diagnostic quality of the fMRI results. In conclusion, in addition to descriptive image measures, it is important to include measures of diagnostic quality when comparing different fMRI data acquisition methods.
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| 28. |
- Sandborg, Michael, 1961-, et al.
(författare)
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Local skin and eye lens equivalent odses in interventional neuroradiology
- 2010
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 20:3, s. 725-733
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Tidskriftsartikel (refereegranskat)abstract
- Purpose To assess patient skin and eye lens doses in interventional neuroradiology and to assess both stochastic and deterministic radiation risks. Methods Kerma–area product (P KA) was recorded and skin doses measured using thermoluminescence dosimeters. Estimated dose at interventional reference point (IRP) was compared with measured absorbed doses. Results The average and maximum fluoroscopy times were 32 and 189 min for coiling and 40 and 144 min for embolisation. The average and maximum P KA for coiling were 121 and 436 Gy cm2, respectively, and 189 and 677 Gy cm2 for embolisation. The average and maximum values of the measured maximum absorbed skin doses were 0.72 and 3.0 Sv, respectively, for coiling and 0.79 and 2.1 Sv for embolisation. Two out of the 52 patients received skin doses in excess of 2 Sv. The average and maximum doses to the eye lens (left eye) were 51 and 515 mSv (coiling) and 71 and 289 mSv (embolisation). Conclusion The ratio between the measured dose and the dose at the IRP was 0.44 ± 0.18 mSv/mGy indicating that the dose displayed by the x-ray unit overestimates the maximum skin dose but is still a valuable indication of the dose. The risk of inducing skin erythema and lens cataract during our hospital procedures is therefore small.
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| 29. |
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| 30. |
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| 31. |
- Svensson, Anders, et al.
(författare)
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Automatic individualized contrast medium dosage during hepatic computed tomography by using computed tomography dose index volume (CTDIvol)
- 2014
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 24:8, s. 1959-1963
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Tidskriftsartikel (refereegranskat)abstract
- To compare hepatic parenchymal contrast media (CM) enhancement during multi-detector row computed tomography (MDCT) and its correlation with volume pitch-corrected computed tomography dose index CTDIvol) and body weight (BW). One hundred patients referred for standard three-phase thoraco-abdominal MDCT examination were enrolled. BW was measured in the CT suite. Forty grams of iodine was administered intravenously (iodixanol 320 mg I/ml at 5 ml/s or iomeprol 400 mg I/ml at 4 ml/s) followed by a 50-ml saline flush. CTDIvol presented by the CT equipment during the parenchymal examination was recorded. The CM enhancement of the liver was defined as the attenuation HU of the liver parenchyma during the hepatic parenchymal phase minus the attenuation in the native phase. Liver parenchymal enhancement was negatively correlated to both CTDIvol (r = -0.60) and BW (r = -0.64), but the difference in correlation between those two was not significant. CTDIvol may replace BW when adjusting CM doses to body size. This makes it potentially feasible to automatically individualize CM dosage by CT. aEuro cent CTDI (vol) is related to liver CM enhancement in the parenchymal phase. aEuro cent CTDI (vol) provides comparable information to body weight (BW). aEuro cent CTDI (vol) may be used when automatically adjusting CM dose for patient size.
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| 32. |
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| 33. |
- Thomas, Marianna S, et al.
(författare)
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Test-retest reliability of automated whole body and compartmental muscle volume measurements on a wide bore 3T MR system
- 2014
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Ingår i: European Radiology. - : Springer Berlin/Heidelberg. - 0938-7994 .- 1432-1084. ; 24:9, s. 2279-2291
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:To measure the test-retest reproducibility of an automated system for quantifying whole body and compartmental muscle volumes using wide bore 3 T MRI.MATERIALS AND METHODS:Thirty volunteers stratified by body mass index underwent whole body 3 T MRI, two-point Dixon sequences, on two separate occasions. Water-fat separation was performed, with automated segmentation of whole body, torso, upper and lower leg volumes, and manually segmented lower leg muscle volumes.RESULTS:Mean automated total body muscle volume was 19·32 L (SD9·1) and 19·28 L (SD9·12) for first and second acquisitions (Intraclass correlation coefficient (ICC) = 1·0, 95 % level of agreement -0·32-0·2 L). ICC for all automated test-retest muscle volumes were almost perfect (0·99-1·0) with 95 % levels of agreement 1.8-6.6 % of mean volume. Automated muscle volume measurements correlate closely with manual quantification (right lower leg: manual 1·68 L (2SD0·6) compared to automated 1·64 L (2SD 0·6), left lower leg: manual 1·69 L (2SD 0·64) compared to automated 1·63 L (SD0·61), correlation coefficients for automated and manual segmentation were 0·94-0·96).CONCLUSION:Fully automated whole body and compartmental muscle volume quantification can be achieved rapidly on a 3 T wide bore system with very low margins of error, excellent test-retest reliability and excellent correlation to manual segmentation in the lower leg.KEY POINTS:• Sarcopaenia is an important reversible complication of a number of diseases. • Manual quantification of muscle volume is time-consuming and expensive. • Muscles can be imaged using in and out of phase MRI. • Automated atlas-based segmentation can identify muscle groups. • Automated muscle volume segmentation is reproducible and can replace manual measurements.
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| 34. |
- Thomsen, Henrik S., et al.
(författare)
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Nephrogenic systemic fibrosis and gadolinium-based contrast media: updated ESUR Contrast Medium Safety Committee guidelines
- 2013
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 23:2, s. 307-318
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Tidskriftsartikel (refereegranskat)abstract
- To update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media. Topics reviewed include the history, clinical features and prevalence of nephrogenic systemic fibrosis and the current understanding of its pathophysiology. The risk factors for NSF are discussed and prophylactic measures are recommended. The stability of the different gadolinium-based contrast media and the potential long-term effects of gadolinium in the body have also been reviewed. aEuro cent Clinical features, risk factors and prevention of nephrogenic systemic fibrosis are reviewed aEuro cent Patients with GFR below 30 ml/min/1.73 m (2) have increased risk of developing NSF aEuro cent Low stability gadolinium contrast media show the strongest association with NSF aEuro cent Following guidelines regarding gadolinium contrast agents minimises the risk of NSF aEuro cent Potential long-term harm from gadolinium accumulation in the body is discussed.
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| 35. |
- Timberg, Pontus, et al.
(författare)
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Investigation of viewing procedures for interpretation of breast tomosynthesis image volumes: a detection-task study with eye tracking.
- 2013
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 23:4, s. 997-1005
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To evaluate the efficiency of different methods of reading breast tomosynthesis (BT) image volumes. METHODS: All viewing procedures consisted of free scroll volume browsing and three were combined with initial cine loops at three different frame rates (9, 14 and 25 fps). The presentation modes consisted of vertically and horizontally orientated BT image volumes. Fifty-five normal BT image volumes in mediolateral oblique view were collected. In these, simulated lesions were inserted, creating four unique image sets, one for each viewing procedure. Four observers interpreted the cases in a free-response task. Time efficiency, visual attention and search were investigated using eye tracking. RESULTS: Horizontally orientated BT image volumes were read faster than vertically when using free scroll browsing only and when combined with fast cine loop. Cine loops at slow frame rates were ruled out as inefficient. CONCLUSIONS: In general, horizontally oriented BT image volumes were read more efficiently. All viewing procedures except for slow frame rates were promising when assuming equivalent detection performance. KEY POINTS : • Breast tomosynthesis is increasingly used for breast cancer detection • There is a benefit in reading breast tomosynthesis image volumes presented horizontally • Align image content to visual field, especially for dynamic 3D images • Reading at slow frame rates was considered inefficient.
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| 36. |
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| 37. |
- van Tiel, J., et al.
(författare)
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Reproducibility of 3D delayed gadolinium enhanced MRI of cartilage (dGEMRIC) of the knee at 3.0 T in patients with early stage osteoarthritis
- 2013
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 23:2, s. 496-504
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Tidskriftsartikel (refereegranskat)abstract
- To assess the reproducibility of 3D delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) at 3 T in early stage knee osteoarthritis (OA) patients. In 20 patients, 3D dGEMRIC at 3 T was acquired twice within 7 days. To correct for patient motion during acquisition, all images were rigidly registered in 3D. Eight anatomical cartilage ROIs were analysed on both images of each patient. Capability of dGEMRIC to yield T1 maps that reproducibly distinguish spatial differences in cartilage quality was assessed in two ROIs within a single slice in each patient. Reproducibility was assessed using ICCs and Bland-Altman plots. ICCs ranged from 0.87 to 0.95, indicating good reproducibility. T1 maps revealed reproducible spatial differences in cartilage quality (ICC 0.79). Based on the Bland-Altman plots, we defined a threshold of 95 ms to determine if a change in dGEMRIC outcome in longitudinal research was statistically significant. 3D knee dGEMRIC at 3 T combined with 3D image registration is a highly reproducible measure of cartilage quality in early stage OA. Therefore, dGEMRIC may be a valuable tool in the non-invasive evaluation of cartilage quality changes in longitudinal research in patients with early stage OA and focal cartilage defects. aEuro cent Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) can assess osteoarthritis aEuro cent dGEMRIC yields highly reproducible T1 values in early stage osteoarthritic patients aEuro cent A threshold was established to determine significant changes in dGEMRIC outcomes aEuro cent dGEMRIC can be used to evaluate cartilage quality in longitudinal research.
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| 38. |
- Vult von Steyern, Kristina, et al.
(författare)
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Description and validation of a scoring system for tomosynthesis in pulmonary cystic fibrosis.
- 2012
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 22:12, s. 2718-2728
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To design and validate a scoring system for tomosynthesis (digital tomography) in pulmonary cystic fibrosis. METHODS: A scoring system dedicated to tomosynthesis in pulmonary cystic fibrosis was designed. Three radiologists independently scored 88 pairs of radiographs and tomosynthesis examinations of the chest in 60 patients with cystic fibrosis and 7 oncology patients. Radiographs were scored according to the Brasfield scoring system and tomosynthesis examinations were scored using the new scoring system. RESULTS: Observer agreements for the tomosynthesis score were almost perfect for the total score with square-weighted kappa >0.90, and generally substantial to almost perfect for subscores. Correlation between the tomosynthesis score and the Brasfield score was good for the three observers (Kendall's rank correlation tau 0.68, 0.77 and 0.78). Tomosynthesis was generally scored higher as a percentage of the maximum score. Observer agreements for the total score for Brasfield score were almost perfect (square-weighted kappa 0.80, 0.81 and 0.85). CONCLUSIONS: The tomosynthesis scoring system seems robust and correlates well with the Brasfield score. Compared with radiography, tomosynthesis is more sensitive to cystic fibrosis changes, especially bronchiectasis and mucus plugging, and the new tomosynthesis scoring system offers the possibility of more detailed and accurate scoring of disease severity. KEY POINTS : • Tomosynthesis is more sensitive than conventional radiography for pulmonary cystic fibrosis changes. • The radiation dose from chest tomosynthesis is low compared with computed tomography. • Tomosynthesis may become useful in the regular follow-up of patients with cystic fibrosis.
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| 39. |
- Wenger, Andrea, et al.
(författare)
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Relationship of 3D meniscal morphology and position with knee pain in subjects with knee osteoarthritis: a pilot study
- 2012
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 22:1, s. 211-220
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Tidskriftsartikel (refereegranskat)abstract
- To explore whether quantitative, three-dimensional measurements of meniscal position and size are associated with knee pain using a within-person, between-knee study design. We studied 53 subjects (19 men, 34 women) from the Osteoarthritis Initiative, with identical radiographic OA grades in both knees, but frequent pain in one and no pain in the other knee. The tibial plateau and menisci were analyzed using coronally reconstructed double echo steady-state sequence with water excitation (DESSwe) MRI. The medial meniscus covered a smaller proportion of the tibial plateau (-5%) and displayed greater extrusion of the body (+15%) in painful than in painless knees (paired t-test; p < 0.05). The external margin of the lateral meniscus showed greater extrusion of the body in painful knees (+22%; p = 0.03), but no significant difference in the position of its internal margin or tibial coverage. Medial or lateral extrusion a parts per thousand yen3 mm was more frequent in painful (n = 23) than in painless knees (n = 12; McNemar's test; p = 0.02). No significant association was observed between meniscal size and knee pain. These data suggest a relationship between extrusion of the meniscal body, as measured with quantitative MRI, and knee pain in subjects with knee OA. Further studies need to confirm these findings and their clinical relevance. Meniscal segmentation provides quantitative measures of meniscal size/position Between-knee, within-person approaches can explore potential sources of knee pain Meniscal extrusion may be a potential source of knee pain.
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| 40. |
- West, Janne, 1982-, et al.
(författare)
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Novel whole brain segmentation and volume estimation using quantitative MRI
- 2012
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Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 22:5, s. 998-1007
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Brain segmentation and volume estimation of grey matter (GM), white matter (WM) and cerebro-spinal fluid (CSF) are important for many neurological applications. Volumetric changes are observed in multiple sclerosis (MS), Alzheimer's disease and dementia, and in normal aging. A novel method is presented to segment brain tissue based on quantitative magnetic resonance imaging (qMRI) of the longitudinal relaxation rate R(1), the transverse relaxation rate R(2) and the proton density, PD. METHODS: Previously reported qMRI values for WM, GM and CSF were used to define tissues and a Bloch simulation performed to investigate R(1), R(2) and PD for tissue mixtures in the presence of noise. Based on the simulations a lookup grid was constructed to relate tissue partial volume to the R(1)-R(2)-PD space. The method was validated in 10 healthy subjects. MRI data were acquired using six resolutions and three geometries. RESULTS: Repeatability for different resolutions was 3.2% for WM, 3.2% for GM, 1.0% for CSF and 2.2% for total brain volume. Repeatability for different geometries was 8.5% for WM, 9.4% for GM, 2.4% for CSF and 2.4% for total brain volume. CONCLUSION: We propose a new robust qMRI-based approach which we demonstrate in a patient with MS. KEY POINTS : • A method for segmenting the brain and estimating tissue volume is presented • This method measures white matter, grey matter, cerebrospinal fluid and remaining tissue • The method calculates tissue fractions in voxel, thus accounting for partial volume • Repeatability was 2.2% for total brain volume with imaging resolution <2.0 mm.
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| 41. |
- Wilczek, M L, et al.
(författare)
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Digital X-ray radiogrammetry of hand or wrist radiographs can predict hip fracture risk-a study in 5,420 women and 2,837 men
- 2013
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Ingår i: European Radiology. - : Springer Verlag (Germany). - 0938-7994 .- 1432-1084. ; 23:5, s. 1383-1391
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Tidskriftsartikel (refereegranskat)abstract
- To assess whether digital X-ray radiogrammetry (DXR) analysis of standard clinical hand or wrist radiographs obtained at emergency hospitals can predict hip fracture risk. less thanbrgreater than less thanbrgreater thanA total of 45,538 radiographs depicting the left hand were gathered from three emergency hospitals in Stockholm, Sweden. Radiographs with insufficiently included metacarpal bone, fractures in measurement regions, foreign material or unacceptable positioning were manually excluded. A total of 18,824 radiographs from 15,072 patients were analysed with DXR, yielding a calculated BMD equivalent (DXR-BMD). Patients were matched with the national death and inpatient registers. Inclusion criteria were age a parts per thousand yen 40 years, no prior hip fracture and observation time andgt; 7 days. Hip fractures were identified via ICD-10 codes. Age-adjusted hazard ratio per standard deviation (HR/SD) was calculated using Cox regression. less thanbrgreater than less thanbrgreater than8,257 patients (65.6 % female, 34.4 % male) met the inclusion criteria. One hundred twenty-two patients suffered a hip fracture after their radiograph. The fracture group had a significantly lower DXR-BMD than the non-fracture group when adjusted for age. The HR/SD for hip fracture was 2.52 and 2.08 in women and men respectively. The area under the curve was 0.89 in women and 0.84 in men. less thanbrgreater than less thanbrgreater thanDXR analysis of wrist and hand radiographs obtained at emergency hospitals predicts hip fracture risk in women and men. less thanbrgreater than less thanbrgreater thanKey Points less thanbrgreater than less thanbrgreater thanDigital X-ray radiogrammetry of emergency hand/wrist radiographs predicts hip fracture risk. less thanbrgreater than less thanbrgreater thanDigital X-ray radiogrammetry (DXR) predicts hip fracture risk in both women and men. less thanbrgreater than less thanbrgreater thanOsteoporosis can potentially be identified in patients with suspected wrist fractures. less thanbrgreater than less thanbrgreater thanDXR can potentially be used for selective osteoporosis screening.
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