3D black-blood 3T-MRI for the diagnosis of abdominal large vessel vasculitis.

OBJECTIVES: To assess the value of a T1-3D black-blood turbo spin echo (TSE) sequence for the diagnosis of abdominal large vessel vasculitis (LVV). MATERIALS AND METHODS: The study included 20 patients with abdominal LVV and 17 controls, who underwent a 3T-MRI scan using a modified T1-3D volumetric isotropic TSE acquisition and a segmented T1-3D turbo field echo sequence (T1-mVISTA/T1-eTHRIVE). Two radiologists independently analyzed the aorta for concentric contrast enhancement, concentric wall thickening, image quality, and flow artifact intensity (CCE/CWT/IQ/FAI; 4-point scales). The mean aortic wall thickness (MAWT) in post-contrast T1-mVISTA was compared between patients and controls. RESULTS: IQ of T1-mVISTA was rated good to excellent in 91.5% of 282 evaluated vessel segments with no or minor FAI present in 85.5%. The inter-observer reproducibility for the identification of CCE/CWT on T1-mVISTA was 0.92 and 0.93 (p < 0.001). The distribution of segmental inflammation in T1-mVISTA significantly correlated with T1-eTHRIVE (CCE, κ = 0.768; CWT, κ = 0.715; p < 0.001), resulting in a sensitivity, specificity, and positive predictive value of 100%, 81.3%, and 83.3%. The MAWT significantly differed between patients and controls (3.29 ± 0.81 vs. 2.24 ± 0.45 mm; p < 0.001). CONCLUSIONS: T1-mVISTA enables the evaluation of the MAWT and allows the detection of abdominal LVV. KEY POINTS: • 3D T1w-mVISTA accurately depicted the large abdominal vessels. • 3D T1w-mVISTA enables accurate measurements of the abdominal aortic wall thickness. • 3D T1w-mVISTA is useful for the detection of abdominal LVV.

Contrast-enhanced modified 3D T1-weighted TSE black-blood imaging can improve detection of infectious and neoplastic meningitis.

OBJECTIVES: To evaluate the diagnostic value of a contrast-enhanced 3D T1-weighted-modified volumetric isotropic turbo spin-echo acquisition sequence (T1-mVISTA) in comparison with a conventional 3D T1-weighted magnetization-prepared rapid gradient-echo (T1-MP-RAGE) sequence for the detection of meningeal enhancement in patients with meningitis. METHODS: Thirty patients (infectious meningitis, n = 12; neoplastic meningitis, n = 18) and 45 matched controls were enrolled in this retrospective case-control study. Sets of randomly selected T1-mVISTA and T1-MP-RAGE images (both with 0.8-mm isotropic resolution) were read separately 4 weeks apart. Image quality, leptomeningeal and dural enhancement, grading of visual contrast enhancement, and diagnostic confidence were compared using the Kruskal-Wallis rank sum test. RESULTS: Image quality was rated to be good to excellent in 75 out of 75 cases (100%) for T1-mVISTA and 74 out of 75 cases (98.7%) for T1-MP-RAGE. T1-mVISTA detected significantly more patients with leptomeningeal enhancement (p = 0.006) compared with T1-MP-RAGE (86.7 vs. 50.0%, p < 0.001), each with specificity of 100%. Similarly, sensitivity of T1-mVISTA for the detection of dural and/or leptomeningeal enhancement was also significantly higher compared with that of T1-MP-RAGE (96.7 vs. 80.0%, p = 0.025) without significant differences regarding specificity (97.8 vs. 95.6%, p = 0.317). No significant differences were found for dural enhancement alone. Diagnostic confidence in T1-mVISTA was significantly higher (p = 0.01). Visual contrast enhancement was tendentially higher in T1-mVISTA. CONCLUSIONS: T1-mVISTA may be an adequate and probably better alternative to T1-MP-RAGE for detection of leptomeningeal diseases. KEY POINTS: • Black-blood T1-mVISTA showed a significant higher sensitivity for the detection of leptomeningeal enhancement compared with MP-RAGE without losses regarding specificity. • Diagnostic confidence was assessed significantly higher in T1-mVISTA. • T1-mVISTA should be considered a supplement or an alternative to T1-MP-RAGE in patients with suspected leptomeningeal diseases.

Simple Endoscopic Score of Crohn Disease and Magnetic Resonance Enterography in Children: Report From ImageKids Study.

OBJECTIVES: We aimed to explore the ability of magnetic resonance enterography (MRE) to impute the simple endoscopic score of Crohn disease (SES-CD) in children with CD, in whom failure of ileal intubation is common and may impair SES-CD calculation in clinical studies. METHODS: This is a substudy of the prospective ImageKids study in which children with CD underwent ileocolonoscopy (scored by SES-CD) and MRE (scored on a 100 mm visual analogue scale [VAS] and by MaRIA). Mucosal healing (MH) was defined as SES-CD <3, MRE-VAS <20 mm, and/or MaRIA <7. RESULTS: A total of 237 children (22 centers, age 11.5 ±â€Š3.3 years), were enrolled. Ileal intubation has failed in 40 of 237 (17%). The agreement between SES-CD and MRE was 75% (k = 0.508, P < 0.001) in the ileum, and 68% to 85% in the colonic segments (k = 0.21-0.50, P < 0.001). The sensitivity and specificity of ileal MRE-VAS for MH were 91.7% (95% confidence interval 0.84-0.96) and 53.1% (95% confidence interval 0.43-0.63), respectively. The ileal MaRIA score (calculated in 33/40) was higher in the children without ileal intubation than in the others (20.5 ±â€Š7.1 vs 15.1 ±â€Š10.8, respectively, P = 0.0018). In 7% (16/237) of children, isolated active ileal disease would have been missed when considering SES-CD only. A multivariable model predicted the ileal SES-CD subscore from the MaRIA: SES-CDileum = 1.145 + 0.169 × MaRIAileum rounded to the nearest whole number (R = 0.17). Applying this model to the children without ileal intubation revealed that 29 of 33 (88%) had ileal disease; 8 of 29 patients (28%) with normal colonic SES-CD had imputed ileal SES-CD ≥3. CONCLUSIONS: MRE is useful for imputing the ileal disease in pediatric clinical studies, overcoming the problem of ileal nonintubation.

Muscle MRI in patients with dysferlinopathy: pattern recognition and implications for clinical trials.

BACKGROUND AND OBJECTIVE: Dysferlinopathies are a group of muscle disorders caused by mutations in the DYSF gene. Previous muscle imaging studies describe a selective pattern of muscle involvement in smaller patient cohorts, but a large imaging study across the entire spectrum of the dysferlinopathies had not been performed and previous imaging findings were not correlated with functional tests. METHODS: We present cross-sectional T1-weighted muscle MRI data from 182 patients with genetically confirmed dysferlinopathies. We have analysed the pattern of muscles involved in the disease using hierarchical analysis and presented it as heatmaps. Results of the MRI scans have been correlated with relevant functional tests for each region of the body analysed. RESULTS: In 181 of the 182 patients scanned, we observed muscle pathology on T1-weighted images, with the gastrocnemius medialis and the soleus being the most commonly affected muscles. A similar pattern of involvement was identified in most patients regardless of their clinical presentation. Increased muscle pathology on MRI correlated positively with disease duration and functional impairment. CONCLUSIONS: The information generated by this study is of high diagnostic value and important for clinical trial development. We have been able to describe a pattern that can be considered as characteristic of dysferlinopathy. We have defined the natural history of the disease from a radiological point of view. These results enabled the identification of the most relevant regions of interest for quantitative MRI in longitudinal studies, such as clinical trials. CLINICAL TRIAL REGISTRATION: NCT01676077.

3D-black-blood 3T-MRI for the diagnosis of thoracic large vessel vasculitis: A feasibility study.

OBJECTIVES: To evaluate the feasibility of T1w-3D black-blood turbo spin echo (TSE) sequence with variable flip angles for the diagnosis of thoracic large vessel vasculitis (LVV). METHODS: Thirty-five patients with LVV, diagnosed according to the current standard of reference, and 35 controls were imaged at 3.0T using 1.2 × 1.3 × 2.0 mm3 fat-suppressed, T1w-3D, modified Volumetric Isotropic TSE Acquisition (mVISTA) pre- and post-contrast. Applying a navigator and peripheral pulse unit triggering (PPU), the total scan time was 10-12 min. Thoracic aorta and subclavian and pulmonary arteries were evaluated for image quality (IQ), flow artefact intensity, diagnostic confidence, concentric wall thickening and contrast enhancement (CWT, CCE) using a 4-point scale. RESULTS: IQ was good in all examinations (3.25 ± 0.72) and good to excellent in 342 of 408 evaluated segments (83.8 %), while 84.1 % showed no or minor flow artefacts. The interobserver reproducibility for the identification of CCE and CWT was 0.969 and 0.971 (p < 0.001) with an average diagnostic confidence of 3.47 ± 0.64. CCE and CWT were strongly correlated (Cohen's k = 0.87; P < 0.001) and significantly more frequent in the LVV-group (52.8 % vs. 1.0 %; 59.8 % vs. 2.4 %; P < 0.001). CONCLUSIONS: Navigated fat-suppressed T1w-3D black-blood MRI with PPU-triggering allows diagnosis of thoracic LVV. KEY POINTS: • Cross-sectional imaging is frequently applied in the diagnosis of LVV. • Navigated, PPU-triggered, T1w-3D mVISTA pre- and post contrast takes 10-12 min. • In this prospective, single-centre study, T1w-3D mVISTA accurately depicted large thoracic vessels. • T1w-3D mVISTA visualized CWT/CCW as correlates of mural inflammation in LVV. • T1w-3D mVISTA might be an alternative diagnostic tool without ionizing radiation.

Increase of Intra-abdominal Adipose Tissue in Pediatric Crohn Disease.

BACKGROUND AND OBJECTIVE: Recent evidence points toward an active immunological role of intra-abdominal adipose tissue in Crohn disease (CD). We quantified the abdominal adipose tissue compartments using magnetic resonance imaging (MRI) in 27 pediatric patients with CD compared with 14 controls undergoing MRI examination for other reasons. METHODS: Total (TAAT), subcutaneous (SCAT) and intra-abdominal (IAAT) adipose tissue areas were measured by semiautomatic segmentation on a transverse slice centered on the umbilicus (mean ±â€Šstandard deviation in square centimeter) using standard T1-weighted sequences. IAAT/TAAT and IAAT/height ratios were calculated and analyzed for associations with disease duration, phenotype, or therapy. RESULTS: Patients with CD (median age 15.0 years, range 7.7-17.9, 18/27 boys, median disease duration 29 months, range 0-136) compared to controls (median age 13.9 years, range 3.3-17.8, 4/14 boys) had higher IAAT area (42.3 ±â€Š21.0 vs 28.7 ±â€Š11.6, P = 0.0494) but similar SCAT and TAAT areas (104.6 ±â€Š72.8 vs 96.5 ±â€Š50.8, P = 0.8170 and 146.9 ±â€Š87.3 vs 125.3 ±â€Š61.5, P = 0.7417, respectively). IAAT/TAAT ratio was higher in patients with CD compared to controls (0.32 ±â€Š0.10 vs 0.24 ±â€Š0.04, P = 0.0081). Patients with disease duration >2 years (n = 14) had higher IAAT/TAAT ratio than those with shorter disease and controls (0.35 ±â€Š0.10 vs 0.28 ±â€Š0.08, P = 0.0288 and 0.24 ±â€Š0.04, P = 0.0009, respectively). In these patients, increased IAAT/height ratio was associated with complicated disease (P = 0.043, r = 0.573). No association was found between IAAT/TAAT ratio and actual disease activity or therapy. CONCLUSIONS: IAAT is increased in pediatric CD and correlates with disease duration. Assessment of IAAT accumulation may be considered in future MRI scores for inflammation and bowel damage in CD and during follow-up of different therapeutic interventions.

Perianal Pediatric Crohn Disease Is Associated With a Distinct Phenotype and Greater Inflammatory Burden.

OBJECTIVES: Data on the outcomes of children with perianal Crohn disease (pCD) are limited, although its presence is often used for justifying early use of biologics. We aimed to assess whether pCD in children is associated with more severe outcomes as found in adults. METHODS: Data were extracted from the ImageKids database, a prospective, multicenter, longitudinal cohort study. The study enrolled 246 children at disease onset or thereafter. All patients underwent comprehensive clinical, endoscopic, and radiologic evaluation at enrollment; 98 children had repeat evaluation at 18 months. RESULTS: Of the 234 included patients (mean age 14.2 ±â€Š2.4 years; 131 [56%] boys), 57 (24%) had perianal findings, whereas only 21 (9%) had fistulizing perianal disease. Children with pCD had reduced weight and height z scores compared with non-pCD patients (-0.9 vs -0.35, P = 0.03 and -0.68 vs -0.23, respectively; P = 0.04), higher weighted pediatric CD activity index (32 [interquartile range 16-50] vs 20 [8-37]; P = 0.004), lower serum albumin (3.6 ±â€Š0.7 vs 4.5 ±â€Š0.8, P = 0.016), and higher magnetic resonance enterography global inflammatory score (P = 0.04). Children with pCD had more rectal (57% vs 38%, P = 0.04), and jejunal involvement (31% vs 11% P = 0.003) and a higher prevalence of granulomas (64% vs 23%, P = 0.0001). Magnetic resonance enterography-based damage scores did not differ between groups. Patients with skin tags/fissures only, had similar clinical, endoscopic, and radiologic characteristics as patients with no perianal findings. CONCLUSIONS: Pediatric patients with pCD with fistulizing disease have distinct phenotypic features and a predisposition to a greater inflammatory burden.

The diagnostic value of 18F-FDG PET and MRI in paediatric histiocytosis.

PURPOSE: To analyse the diagnostic value of (18)F-FDG PET and MRI for the evaluation of active lesions in paediatric Langerhans cell histiocytosis. METHODS: We compared 21 (18)F-FDG PET scans with 21 MRI scans (mean time interval 17 days) in 15 patients (11 male, 4 female, age range 4 months to 19 years) with biopsy-proven histiocytosis. Primary criteria for the lesion-based analysis were signs of vital histiocyte infiltrates (bone marrow oedema and contrast enhancement for MRI; SUV greater than the mean SUV of the right liver lobe for PET). PET and MR images were analysed separately and side-by-side. The results were validated by biopsy or follow-up scans after more than 6 months. RESULTS: Of 53 lesions evaluated, 13 were confirmed by histology and 40 on follow-up investigations. The sensitivity and specificity of PET were 67 % and 76 % and of MRI were 81 % and 47 %, respectively. MRI showed seven false-positive bone lesions after successful chemotherapy. PET showed five false-negative small bone lesions, one false-negative lesion of the skull and three false-negative findings for intracerebral involvement. PET showed one false-positive lesion in the lymphoid tissue of the head and neck region and two false-positive bone lesions after treatment. Combined PET/MR analysis decreased the number of false-negative findings on primary staging, whereas no advantage over PET alone was seen in terms of false-positive or false-negative results on follow-up. CONCLUSION: Our retrospective analysis suggests a pivotal role of (18)F-FDG PET in lesion follow-up due to a lower number of false-positive findings after chemotherapy. MRI showed a higher sensitivity and is indispensable for primary staging, evaluation of brain involvement and biopsy planning. Combined MRI/PET analysis improved sensitivity by decreasing the false-negative rate during primary staging indicating a future role of simultaneous whole-body PET/MRI for primary investigation of paediatric histiocytosis.

High ¹²³I-MIBG uptake in neuroblastic tumours indicates unfavourable histopathology.

PURPOSE: Scintigraphy using (123)I-metaiodobenzylguanidine ((123)I-MIBG) is widely used for the detection of neuroblastic tumours. The aim of this study was to identify a possible correlation between the uptake intensity on (123)I-MIBG SPECT and histopathology of neuroblastic tumours. METHODS: (123)I-MIBG SPECT examinations were performed in 55 paediatric patients with neuroblastic tumour and compared to histopathology after surgical resection or biopsy at a mean of 2 weeks after SPECT. For each lesion International Neuroblastoma Pathology Classification System (INPC) stage, mitosis karyorrhexis index (MKI), location and a semiquantitative tumour-to-liver count-rate ratio (TLCRR) were determined. Also, the presence or absence of MYCN amplification, p1 deletion, urine catecholamine and neuron-specific enolase blood levels at the time of scanning were recorded. RESULTS: In the 55 patients, 61 lesions were evaluated with (123)I-MIBG SPECT and corresponding histopathological findings were reviewed (11 ganglioneuroma, 11 ganglioneuroblastoma and 39 neuroblastoma). TLCRR was significantly higher in the neuroblastoma group (mean TLCRR 2.7) than in the ganglioneuroblastoma group (mean TLCRR 1.0) and ganglioneuroma group (mean TLCRR 0.7) at the time of primary diagnosis (p < 0.001) and at follow-up (p = 0.039). Intense (123)I-MIBG uptake was found in tumour tissue with a high mitotic activity (MKI-high or MKI-intermediate) after treatment. Four ganglioneuromas (36 %), three ganglioneuroblastomas (27 %) and six neuroblastomas (15 %) were (123)I-MIBG-negative. CONCLUSION: In paediatric patients with peripheral neuroblastic tumours, strong (123)I-MIBG uptake indicates unfavourable histopathology. High uptake was seen in neuroblastomas and in tumours with a high mitotic activity.

Nuclear medicine and multimodality imaging of pediatric neuroblastoma.

Neuroblastoma is an embryonic tumor of the peripheral sympathetic nervous system and is metastatic or high risk for relapse in nearly 50% of cases. Therefore, exact staging with radiological and nuclear medicine imaging methods is crucial for defining the adequate therapeutic choice. Tumor cells express the norepinephrine transporter, which makes metaiodobenzylguanidine (MIBG), an analogue of norepinephrine, an ideal tumor specific agent for imaging. MIBG imaging has several disadvantages, such as limited spatial resolution, limited sensitivity in small lesions and the need for two or even more acquisition sessions. Most of these limitations can be overcome with positron emission tomography (PET) using [F-18]2-fluoro-2-deoxyglucose [FDG]. Furthermore, new tracers, such as fluorodopa or somatostatin receptor agonists, have been tested for imaging neuroblastoma recently. However, MIBG scintigraphy and PET alone are not sufficient for operative or biopsy planning. In this regard, a combination with morphological imaging is indispensable. This article will discuss strategies for primary and follow-up diagnosis in neuroblastoma using different nuclear medicine and radiological imaging methods as well as multimodality imaging.

Diagnostic value of combined ¹8F-FDG PET/MRI for staging and restaging in paediatric oncology.

PURPOSE: The present study compares the diagnostic value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and MRI to combined/registered (18)F-FDG PET/MRI for staging and restaging in paediatric oncology. METHODS: Over 8 years and 2 months, 270 (18)F-FDG PET and 270 MRI examinations (mean interval 5 days) were performed in 132 patients with proven (n = 117) or suspected (n = 15) malignant disease: solid tumours (n = 64), systemic malignancy (n = 53) and benign disease (n = 15). A total of 259 suspected tumour lesions were analysed retrospectively during primary diagnosis and 554 lesions during follow-up. Image analysis was performed separately on each modality, followed by analysis of combined and registered (18)F-FDG PET/MRI imaging. RESULTS: A total of 813 lesions were evaluated and confirmed by histopathology (n = 158) and/or imaging follow-up (n = 655) after 6 months. In the separate analysis of (18)F-FDG PET and MRI, sensitivity was 86 %/94 % and specificity 85 %/38 %. Combined/registered (18)F-FDG PET/MRI led to a sensitivity of 97 %/97 % and specificity of 81 %/82 %. False-positive results ((18)F-FDG PET n = 69, MRI n = 281, combined (18)F-FDG PET/MRI n = 85, registered (18)F-FDG PET/MRI n = 80) were due to physiological uptake or post-therapeutic changes. False-negative results ((18)F-FDG PET n = 50, MRI n = 20, combined (18)F-FDG PET/MRI n = 11, registered (18)F-FDG PET/MRI n = 11) were based on low uptake or minimal morphological changes. Examination-based evaluation during follow-up showed a sensitivity/specificity of 91 %/81 % for (18)F-FDG PET, 93 %/30 % for MRI and 96 %/72 % for combined (18)F-FDG PET/MRI. CONCLUSION: For the detection of single tumour lesions, registered (18)F-FDG PET/MRI proved to be the methodology of choice for adequate tumour staging. In the examination-based evaluation, MRI alone performed better than (18)F-FDG PET and combined/registered imaging during primary diagnosis. At follow-up, however, the examination-based evaluation demonstrated a superiority of (18)F-FDG PET alone.

Development and Validation of a Pediatric MRI-Based Perianal Crohn Disease (PEMPAC) Index-A Report from the ImageKids Study.

BACKGROUND: As part of the prospective multicenter ImageKids study, we aimed to develop and validate the pediatric MRI-based perianal Crohn disease (PEMPAC) index. METHODS: Children with Crohn disease with any clinical perianal findings underwent pelvic magnetic resonance imaging at 21 sites globally. The site radiologist and 2 central radiologists provided a radiologist global assessment (RGA) on a 100 mm visual analog scale and scored the items selected by a Delphi group of 35 international radiologists and a review of the literature. Two weighted multivariable statistical models were constructed against the RGA. RESULTS: Eighty children underwent 95 pelvic magnetic resonance imaging scans; 64 were used for derivation and 31 for validation. The following items were included: fistula number, location, length and T2 hyperintensity; abscesses; rectal wall involvement; and fistula branching. The last 2 items had negative beta scores and thus were excluded in a contending basic model. In the validation cohort, the full and the basic models had the same strong correlation with the RGA (r = 0.75; P < 0.01) and with the adult Van Assche index (VAI; r = 0.93 and 0.92; P < 0.001). The correlation of the VAI with the RGA was similar (r = 0.77; P < 0.01). The 2 models and the VAI had a similar ability to differentiate remission from active disease (area under the receiver operating characteristic curve, 0.91-0.94). The PEMPAC index had good responsiveness to change (area under the receiver operating characteristic curve, 0.89; 95% confidence interval, 0.69-1.00). CONCLUSIONS: Using a blended judgmental and mathematical approach, we developed and validated an index for quantifying the severity of perianal disease in children with CD. The adult VAI may also be used with confidence in children.

¹²³I-MIBG scintigraphy/SPECT versus ¹8F-FDG PET in paediatric neuroblastoma.

PURPOSE: To analyse different uptake patterns in (123)I-MIBG scintigraphy/SPECT imaging and (18)F-FDG PET in paediatric neuroblastoma patients. METHODS: We compared 23 (123)I-MIBG scintigraphy scans and 23 (18)F-FDG PET scans (mean interval 10 days) in 19 patients with a suspected neuroblastic tumour (16 neuroblastoma, 1 ganglioneuroblastoma, 1 ganglioneuroma and 1 opsomyoclonus syndrome). SPECT images of the abdomen or other tumour-affected regions were available in all patients. Indications for (18)F-FDG PET were a (123)I-MIBG-negative tumour, a discrepancy in (123)I-MIBG uptake compared to the morphological imaging or imaging results inconsistent with clinical findings. A lesion was found by (123)I-MIBG scintigraphy and/or (18)F-FDG PET and/or morphological imaging. RESULTS: A total of 58 suspicious lesions (mean lesion diameter 3.8 cm) were evaluated and 18 were confirmed by histology and 40 by clinical follow-up. The sensitivities of (123)I-MIBG scintigraphy and (18)F-FDG PET were 50% and 78% and the specificities were 75% and 92%, respectively. False-positive results (three (123)I-MIBG scintigraphy, one (18)F-FDG PET) were due to physiological uptake or posttherapy changes. False-negative results (23 (123)I-MIBG scintigraphy, 10 (18)F-FDG PET) were due to low uptake and small lesion size. Combined (123)I-MIBG scintigraphy/(18)F-FDG PET imaging showed the highest sensitivity of 85%. In 34 lesions the (123)I-MIBG scintigraphy and morphological imaging findings were discrepant. (18)F-FDG PET correctly identified 32 of the discrepant findings. Two bone/bone marrow metastases were missed by (18)F-FDG PET. CONCLUSION: (123)I-MIBG scintigraphy and (18)F-FDG PET showed noticeable differences in their uptake patterns. (18)F-FDG PET was more sensitive and specific for the detection of neuroblastoma lesions. Our findings suggest that a (18)F-FDG PET scan may be useful in the event of discrepant or inconclusive findings on (123)I-MIBG scintigraphy/SPECT and morphological imaging.

PET/CT in malignant melanoma: contrast-enhanced CT versus plain low-dose CT.

PURPOSE: The aim of this study was to evaluate the diagnostic value of contrast-enhanced CT (CECT) versus non-enhanced low-dose CT (NECT) in the staging of advanced malignant melanoma with (18)F-fluordeoxyglucose (FDG) positron emission tomography (PET)/CT. METHODS: In total, 50 (18)F-FDG PET/CT examinations were performed in 50 patients with metastasized melanoma. For attenuation correction, whole-body NECT was performed followed by diagnostic CECT with contrast agent. For the whole-body PET, (18)F-FDG was applied. Criteria for evaluation were signs of vital tumour tissue (extent of lesions, contrast enhancement, maximum standardized uptake value >2.5). Findings suspicious for melanoma were considered lesions. NECT, CECT and (18)F-FDG PET were evaluated separately, followed by combined analysis of PET/NECT and PET/CECT. Findings were verified histologically and/or by follow-up (>6 months). RESULTS: Overall, 232 lesions were analysed, and 151 proved to be metastases. The sensitivity of NECT, CECT, PET, PET/NECT and PET/CECT was 62, 85, 90, 97 and 100%, and specificity was 52, 63, 88, 93 and 93%, respectively. Compared to CECT, NECT obtained additional false-negative results: lymph node (n = 19) and liver/spleen metastases (n = 9). Misinterpreted physiological structures mainly caused additional false-positive findings (n = 17). In combined analysis of PET/NECT, six false-positive [other tumours (n = 2), inflammatory lymph nodes (n = 2), inflammatory lung lesion (n = 1), blood vessel (n = 1)] and five false-negative findings [liver (n = 3), spleen (n = 1), lymph node metastases (n = 1)] remained. On PET/CECT, six false-positive [inflammatory lymph nodes (n = 3), other tumours (n = 2), inflammatory lung lesion (n = 1)] and no false-negative findings occurred. However, additional false findings on PET/NECT (6 of 232) did not change staging compared to PET/CECT. CONCLUSION: Our results indicate that it is justified to perform PET/NECT instead of PET/CECT for melanoma staging.

Delineation of upper urinary tract segments at MDCT urography in patients with extra-urinary mass lesions: retrospective comparison of standard and low-dose protocols for the excretory phase of imaging.

PURPOSE: Excretory-phase CT urography (CTU) may replace excretory urography in patients without urinary tumors. However, radiation exposure is a concern. We retrospectively compared upper urinary tract (UUT) delineation in low-dose and standard CTU. MATERIAL AND METHODS: CTU (1-2 phases, 120 KV, 4 × 2.5 mm, pitch 0.875, i.v. non-ionic contrast media, iodine 36 g) was obtained with standard (14 patients, n = 27 UUTs, average 175.6 mAs/slice, average delay 16.8 min) or low-dose (26 patients, n = 86 UUTs, 29 mAs/slice, average delay 19.6 min) protocols. UUT was segmented into intrarenal collecting system (IRCS), upper, middle, and lower ureter (UU,MU,LU). Two independent readers (R1,R2) graded UUT segments as 1-not delineated, 2-partially delineated, 3-completely delineated (noisy margins), 4-completely delineated (clear margins). Chi-square statistics were calculated for partial versus complete delineation and complete delineation (clear margins), respectively. RESULTS: Complete delineation of UUT was similar in standard and low-dose CTU (R1, p > 0.15; R2, p > 0.2). IRCS, UU, and MU clearly delineated similarly often in standard and low-dose CTU (R1, p > 0.25; R2, p > 0.1). LU clearly delineated more often in standard protocols (R1, 18/6 standard, 38/31 low-dose, p > 0.1; R2 18/6 standard, 21/48 low-dose, p < 0.05). CONCLUSIONS: Low-dose CTU sufficiently delineated course of UUT and may locate obstruction/dilation, but appears unlikely to find intraluminal LU lesions.

Measurement of total and visceral fat mass in young adult women: a comparison of MRI with anthropometric measurements with and without bioelectrical impedance analysis.

OBJECTIVE: MRI is established for measurement of body fat mass (FM) and abdominal visceral adipose tissue (VAT). Anthropometric measurements and bioelectrical impedance analysis (BIA) have been proposed as surrogates to estimation by MRI. Aim of this work is to assess the predictive value of these methods for FM and VAT measured by MRI. METHODS: Patients were selected from cohort study PPS-Diab (prediction, prevention and subclassification of Type 2 diabetes). Total FM and VAT were quantified by MRI and BIA together with clinical variables like age, waist and hip circumference and height. Least-angle regressions were utilized to select anthropometric and BIA parameters for their use in multivariable linear regression models to predict total FM and VAT. Bland-Altman plots, Pearson correlation coefficients, Wilcoxon signed-rank tests and univariate linear regression models were applied. RESULTS: 116 females with 35 ± 3 years and a body mass index of 25.1 ± 5.3 kg/m2 were included into the analysis. A multivariable model revealed weight (ß = 0.516, p < 0.001), height (ß = -0.223, p < 0.001) and hip circumference (ß = 0.156, p = 0.003) as significantly associated with total FM measured by MRI. A additional multivariable model also showed a significant predictive value of FMBIA (ß = 0.583, p < 0.001) for FM. In addition, waist circumference (ß = 0.054, p < 0.001), weight (ß = 0.016, p = 0.031) in one model and FMBIA (ß = 0.026, p = 0.018) in another model were significantly associated with VAT quantified by MRI. However, deviations reached more than 5 kg for total FM and more than 1 kg for VAT. CONCLUSION: Anthropometric measurements and BIA show significant association with total FM and VAT. ADVANCES IN KNOWLEDGE: As these measurements show significant deviations from the absolute measured values determined by MRI, MRI should be considered the gold-standard for quantification.

Childhood-Onset Epileptic Encephalopathy Associated With Isolated Focal Cortical Dysplasia and a Novel TSC1 Germline Mutation.

Tuberous sclerosis complex (TSC) is an autosomal-dominant inheritable neurocutaneous disease due to mutations within the TSC1 and TSC2 genes. Many patients present with West syndrome, a severe epilepsy syndrome characterized by the triad of infantile spasms, an interictal electroencephalogram (EEG) pattern termed hypsarrhythmia (continuous slow activity with an amplitude higher than 300 µV and multiregional spikes/polyspikes/sharp waves) and developmental regression. In this study, we report on a previously healthy patient with positive family history of epilepsy with new-onset epileptic encephalopathy at the age of 9 years. Clinical signs alone were not sufficient to establish the diagnosis of TSC but epilepsy panel screening revealed a novel frameshift mutation (c.90delA; p.Glu31Argfs*12) within the TSC1 gene. Segregation gene analysis detected the same mutation in the mother. Cranial magnetic resonance imaging (MRI) studies from the index patient and his mother revealed a similar pattern of isolated subcortical white matter lesions resembling most likely focal cortical dysplasia (FCD) type IIb. In summary, in these 2 related patients, a novel TSC1 frameshift mutation was associated with an isolated FCD type IIb in the absence of further CNS abnormalities usually encountered in patients with TSC, fostering our understanding of the broad mutation spectra in the TSC1 gene and the close relationship between cortical tubers and FCD type IIb.

Multiple Sclerosis: Improved Detection of Active Cerebral Lesions With 3-Dimensional T1 Black-Blood Magnetic Resonance Imaging Compared With Conventional 3-Dimensional T1 GRE Imaging.

OBJECTIVES: The aim of this study was to assess the diagnostic accuracy of a modified high-resolution whole-brain three-dimensional T1-weighted black-blood sequence (T1-weighted modified volumetric isotropic turbo spin echo acquisition [T1-mVISTA]) in comparison to a standard three-dimensional T1-weighted magnetization-prepared rapid gradient echo (MP-RAGE) sequence for detection of contrast-enhancing cerebral lesions in patients with relapsing-remitting multiple sclerosis (MS). MATERIALS AND METHODS: After institutional review board approval and informed consent, 22 patients (8 men; aged 31.0 ± 9.2 years) with relapsing-remitting MS were included in this monocentric prospective cohort study.Contrast-enhanced T1-mVISTA and MP-RAGE, both with 0.8 mm resolution, were performed in all patients. In a substudy of 12 patients, T1-mVISTA was compared with a T1-mVISTA with 1.0 mm resolution (T1-mVISTA_1.0). Reference lesions were defined by an experienced neuroradiologist using all available sequences and served as the criterion standard. T1-mVISTA, T1-mVISTA_1.0, and MP-RAGE sequences were read in random order 4 weeks apart. Image quality, visual contrast enhancement, contrast-to-noise-ratio (CNR), diagnostic confidence, and lesion size were assessed and compared by Wilcoxon and Mann-Whitney U tests. RESULTS: Eleven of 22 patients displayed contrast-enhancing lesions. Visual contrast enhancement, CNR, and diagnostic confidence of contrast-enhancing MS lesions were significantly increased in T1-mVISTA compared with MP-RAGE (P < 0.001). Significantly more contrast-enhancing lesions were detected with T1-mVISTA than with MP-RAGE (71 vs 39, respectively; P < 0.001). With MP-RAGE, 25.6% of lesions were missed in the initial reading, whereas only 4.2% of lesions were missed with T1-mVISTA. Increase of the voxel volume from 0.8 mm to 1.0 mm isotropic in T1-mVISTA_1.0 did not affect the detectability of lesions, whereas scan time was decreased from 4:43 to 1:55 minutes. CONCLUSIONS: Three-dimensional T1-mVISTA improves the detection rates of contrast-enhancing cerebral MS lesions compared with conventional 3D MP-RAGE sequences by increasing CNR of lesions and might, therefore, be useful in patient management.

No Correlation of Pancreatic Fat and ß-Cell Function in Young Women With and Without a History of Gestational Diabetes.

Context: Pancreatic steatosis may contribute to ß-cell dysfunction in type 2 diabetes (T2D), but data are controversial. Women who had gestational diabetes mellitus (GDM) are at high risk for developing T2D. Objective: To examine the association of pancreatic fat content with early/first-phase insulin secretion (as markers of ß-cell function). Design: Cross-sectional analysis of a subcohort of the monocentric, prospective cohort study titled Prediction, Prevention, and Subclassification of Type 2 Diabetes. Setting: Ludwig Maximilians University Hospital, Munich, Germany. Participants: Ninety-seven women, 3 to 16 months after pregnancy [41 normoglycemic women post-GDM, 19 women post-GDM with pathological glucose metabolism, and 37 normoglycemic women after a normoglycemic pregnancy (controls)]. Main Outcome Measures: Correlation of MRI-measured pancreatic fat content with early insulin release in an oral glucose tolerance test (OGGT) [insulin increment within the first 30 minutes of the OGTT (IR30)] and first-phase insulin response (FPIR) in an intravenous glucose tolerance test (n = 65), both adjusted for insulin sensitivity index (ISI). Results: Pancreatic fat content did not correlate with IR30 and FPIR adjusted for ISI. It correlated positively with body mass index, waist circumference, liver fat, and intraabdominal fat volume. Conclusion: Pancreatic fat content does not correlate with ß-cell function in a cohort of young women with different degrees of T2D risk.