The value of non-enhanced MRI in the evaluation of patients with suspected idiopathic inflammatory myopathy.

INTRODUCTION/AIMS: The performance of magnetic resonance imaging (MRI) for diagnosing suspected idiopathic inflammatory myopathy (IIM) remains controversial. Furthermore, the role of contrast-enhanced magnetic resonance imaging (CE-MRI) sequences is unclear. The aim of this study was to evaluate the sensitivity and specificity of a non-enhanced magnetic resonance imaging (NE-MRI) protocol compared to a CE-MRI protocol in adult patients with confirmed IIM. METHODS: This study retrospectively enrolled patients with suspected IIM who underwent MRI of the upper thigh between 2008 and 2020. The protocol consisted of a T1-weighted (T1w) sequence, a turbo inversion recovery magnitude (TIRM) sequence and a contrast-enhanced T1-weighted sequence (CE-T1w). After randomly stratifying patients into a group with only the T1w and TIRM sequences available and another group with additional availability of CE-T1w, three blinded readers assessed the presence of IIM based on characteristic imaging features. Confirmation of the diagnosis was determined based on the 2017 ACR/EULAR criteria. RESULTS: Of the 80 patients (mean age 49.0 ± 21.1 years; 42 female, 38 male) included, 54 (67.5%) had a positive diagnosis of IIM. Cumulated sensitivity and specificity for MRI to detect IIM was 87.1% and 83.3% in the NE-MRI group versus 87.0% and 63.0% in the CE-MRI group. The group differences for sensitivity and specificity were non-significant for each of the three readers, respectively (p ≥ .081). DISCUSSION: NE-MRI detects suspected IIM with high diagnostic accuracy and performs equivalently to CE-MRI. Therefore, it may be appropriate to omit the use of contrast agents in MRI scans performed for suspected IIM.

Dual-Energy CT muscle fat fraction as a new imaging biomarker of body composition and survival predictor in critically ill patients.

OBJECTIVE: To analyze changes in the muscular fat fraction (FF) during immobilization at the intensive care unit (ICU) using dual-energy CT (DECT) and evaluate the predictive value of the DECT FF as a new imaging biomarker for morbidity and survival. METHODS: Immobilized ICU patients (n = 81, 43.2% female, 60.3 ± 12.7 years) were included, who received two dual-source DECT scans (CT1, CT2) within a minimum interval of 10 days between 11/2019 and 09/2022. The DECT FF was quantified for the posterior paraspinal muscle by two radiologists using material decomposition. The skeletal muscle index (SMI), muscle radiodensity attenuation (MRA), subcutaneous-/ visceral adipose tissue area (SAT, VAT), and waist circumference (WC) were assessed. Reasons for ICU admission, clinical scoring systems, therapeutic regimes, and in-hospital mortality were noted. Linear mixed models, Cox regression, and intraclass correlation coefficients were employed. RESULTS: Between CT1 and CT2 (median 21 days), the DECT FF increased (from 20.9% ± 12.0 to 27.0% ± 12.0, p = 0.001). The SMI decreased (35.7 cm2/m2 ± 8.8 to 31.1 cm2/m2 ± 7.6, p < 0.001) as did the MRA (29 HU ± 10 to 26 HU ± 11, p = 0.009). WC, SAT, and VAT did not change. In-hospital mortality was 61.5%. In multivariable analyses, only the change in DECT FF was associated with in-hospital mortality (hazard ratio (HR) 9.20 [1.78-47.71], p = 0.008), renal replacement therapy (HR 48.67 [9.18-258.09], p < 0.001), and tracheotomy at ICU (HR 37.22 [5.66-245.02], p < 0.001). Inter-observer reproducibility of DECT FF measurements was excellent (CT1: 0.98 [0.97; 0.99], CT2: 0.99 [0.96-0.99]). CONCLUSION: The DECT FF appears to be suitable for detecting increasing myosteatosis. It seems to have predictive value as a new imaging biomarker for ICU patients. CLINICAL RELEVANCE STATEMENT: The dual-energy CT muscular fat fraction appears to be a robust imaging biomarker to detect and monitor myosteatosis. It has potential for prognosticating, risk stratifying, and thereby guiding therapeutic nutritional regimes and physiotherapy in critically ill patients. KEY POINTS: The dual-energy CT muscular fat fraction detects increasing myosteatosis caused by immobilization. Change in dual-energy CT muscular fat fraction was a predictor of  in-hospital morbidity and mortality. Dual-energy CT muscular fat fraction had a predictive value superior to established CT body composition parameters.

Quantification of Liver Iron Overload with MRI: Review and Guidelines from the ESGAR and SAR.

Accumulation of excess iron in the body, or systemic iron overload, results from a variety of causes. The concentration of iron in the liver is linearly related to the total body iron stores and, for this reason, quantification of liver iron concentration (LIC) is widely regarded as the best surrogate to assess total body iron. Historically assessed using biopsy, there is a clear need for noninvasive quantitative imaging biomarkers of LIC. MRI is highly sensitive to the presence of tissue iron and has been increasingly adopted as a noninvasive alternative to biopsy for detection, severity grading, and treatment monitoring in patients with known or suspected iron overload. Multiple MRI strategies have been developed in the past 2 decades, based on both gradient-echo and spin-echo imaging, including signal intensity ratio and relaxometry strategies. However, there is a general lack of consensus regarding the appropriate use of these methods. The overall goal of this article is to summarize the current state of the art in the clinical use of MRI to quantify liver iron content and to assess the overall level of evidence of these various methods. Based on this summary, expert consensus panel recommendations on best practices for MRI-based quantification of liver iron are provided.

Work expectations, their fulfillment, and exhaustion among radiologists of all career levels: what can be learned from the example of Germany.

OBJECTIVES: To evaluate work expectations of radiologists at different career levels, their fulfillment, prevalence of exhaustion, and exhaustion-associated factors. METHODS: A standardized digital questionnaire was distributed internationally to radiologists of all career levels in the hospital and in ambulatory care via radiological societies and sent manually to 4500 radiologists of the largest German hospitals between December 2020 and April 2021. Statistics were based on age- and gender-adjusted regression analyses of respondents working in Germany (510 out of 594 total respondents). RESULTS: The most frequent expectations were "joy at work" (97%) and a "good working atmosphere" (97%), which were considered fulfilled by at least 78%. The expectation of a "structured residency within the regular time interval" (79%) was more frequently judged fulfilled by senior physicians (83%, odds ratio (OR) 4.31 [95% confidence interval (95% CI) 1.95-9.52]), chief physicians (85%, 6.81 [95% CI 1.91-24.29]), and radiologists outside the hospital (88%, 7.59 [95% CI 2.40-24.03]) than by residents (68%). Exhaustion was most common among residents (physical exhaustion: 38%; emotional exhaustion: 36%), in-hospital specialists (29%; 38%), and senior physicians (30%; 29%). In contrast to paid extra hours, unpaid extra hours were associated with physical exhaustion (5-10 extra hours: OR 2.54 [95% CI 1.54-4.19]). Fewer opportunities to shape the work environment were related to a higher probability of physical (2.03 [95% CI 1.32-3.13]) and emotional (2.15 [95% CI 1.39-3.33]) exhaustion. CONCLUSIONS: While most radiologists enjoy their work, residents wish for more training structure. Ensuring payment of extra hours and employee empowerment may help preventing burnout in high-risk groups. KEY POINTS: • Most important work expectations of radiologists who work in Germany are "joy at work," a "good working atmosphere," "support for further qualification," and a "structured residency within the regular time interval," with the latter containing potential for improvement according to residents. • Physical and emotional exhaustion are common at all career levels except for chief physicians and for radiologists who work outside the hospital in ambulatory care. • Exhaustion as a major burnout criterion is associated with unpaid extra hours and reduced opportunities to shape the work environment.

Gender differences and cooperation in medical authorships - an analysis of the recent ten years in five key medical disciplines.

BACKGROUND: Career prospects in academic medicine are strongly linked to scientific authorship and this marker has been widely used as an indicator of gender equity in academia. However, direct comparisons of medical disciplines regarding their proportion of female physicians (FP) in different countries are missing. This study examines the gender parity and gender cooperation using first authorships (FA) and senior authorships (SA) of scientific publications in five medical disciplines and six different OECD countries over a 10-year time-trend. METHODS: Articles from three high-impact journals in each of the medical discipline radiology, urology, surgery, gynecology, and pediatrics from the years 2007/8 and 2017/18 were retrospectively reviewed. The gender and affiliation location of the FA and SA of original research articles and reviews were assigned and compared with the proportion of in each discipline for the United States of America, Canada, United Kingdom, France, Germany, and Japan. Mantel-Haenszel test and multinomial logistic regression models were used to calculate differences in proportions of women authors and FP and to assess trends and proportions of FA and SA. RESULTS: 30,803 articles were evaluated. Equally, with rising proportions of FP in all disciplines, the number of women authors increased across years. The shares of women FAs were either significantly higher (urology/surgery/gynecology) or balanced (pediatrics/radiology) compared to the proportion of FP. In contrast, the shares of women SA were balanced only in disciplines with a low proportion of FP (urology and surgery) and otherwise reduced. Women same-gender cooperation was as common as men same-gender cooperation and preferred over a women-led mixed gender cooperation in disciplines where this seemed to be practicable due to the high proportions of FP. CONCLUSION: In contrast to FA, a significant disparity persists in SA, particularly in disciplines with a high proportion of FP. The discrepancy between FA and SA may reflect, among others, dropout from an academic career in early or mid-academic levels, for example, due to structural inequality; together with the findings on gender preference in authorship collaborations, this may inform future strategies for promoting equal career advancement for women physicians.

Gender trends in authorships and publication impact in Academic Radiology-a 10-year perspective.

OBJECTIVES: To analyze the development of publication numbers of female authors in high-, medium-, and low-impact radiological journals. METHODS: In this bibliometric analysis, gender of the first (FA) and senior author (SA) was assigned to all original research articles and reviews, published in 10 high-, medium-, and low-impact radiological journals in 2007/8 and 2017/18. The adjusted event rate (AER) and adjusted odds ratio (AOR) were calculated using mixed logistic and multinomial logistic regression models to assess and compare female publications according to impact factor, journal, author position, and combination. RESULTS: The proportion of female FA and female SA in N = 6979 (2007/2008) and N = 7383 (2017/2018) articles increased to 29.1% and 16.1% in 2017/2018, respectively. While most female authorships were continuously observed in medium-impact journals, the strongest increase occurred for both female FA (AOR 2.0; p < .0001) and SA (AOR 2.1; p < .0001) in low-impact journals. Female SA published significantly more often in a low- (AOR 1.5) or medium- (AOR 1.8) than in a high-ranking journal. Among the high-ranking journals, female FA published most frequently in European Radiology (32.4%; 95% CI [29.3-35.8]; p < .0001), female SA in Investigative Radiology (15.9%; 95% CI [13.7-18.4]; p < .0001). Male same-sex authorships decreased (AOR 0.9), but remained at least twice as common as all-female or mixed authorships. CONCLUSION: The increase in female authorship is reflected in all impact areas. Female FA and SA increased most in low-ranking journals but are most common in medium-ranking journals. Female SA remain rare, especially in high impact journals. KEY POINTS: • Compared to the proportion of female radiologists worldwide, female senior authors are underrepresented in all impact areas, in particular in high-impact journals. • Among the included high-ranking radiological journals, female first authors and senior authors were strongest represented in European Radiology and Investigative Radiology, while across all impact areas they mostly published in medium-ranking journals. • Female author combinations were more frequent in low- and medium- than in high-ranking journals, whereas male author combinations remained more common than female senior author collaborations in all impact areas.

Fetal dynamic magnetic resonance imaging using Doppler ultrasound gating for the assessment of the aortic isthmus: A feasibility study.

INTRODUCTION: Cardiovascular magnetic resonance imaging (MRI) is established in cardiac evaluation in postnatal life, but its application to the fetus has been hampered by technical limitations. We aimed to investigate the feasibility of dynamic MRI of the fetal aortic isthmus using a magnetic resonance-compatible Doppler ultrasound device for cardiac gating. MATERIAL AND METHODS: This prospective study included 19 fetuses at a median gestational age of 32.3 weeks (range 26-38 weeks). Imaging of the fetal aortic isthmus was assessed by (a) dynamic steady-state free precession MRI using a magnetic resonance-compatible Doppler ultrasound device for cardiac gating and (b) echocardiography. Diameters of the aortic isthmus were compared by two blinded observers. Magnetic resonance image quality was assessed independently by two observers using a four-point scale (1 = low quality, 4 = high quality). Furthermore, we performed four-dimensional flow MRI of the fetal aorta in three of these fetuses. RESULTS: The Doppler ultrasound device for cardiac gating allowed successful dynamic MRI examinations of the aortic isthmus in 18/19 (95%) fetuses. Evaluation of the fetal aortic isthmus was possible by both MRI (15/18, 83%) and echocardiography (16/18, 89%) (P < .05). Diameters of the aortic isthmus were concordant for MRI (3.8 ± 0.9 mm) and echocardiography (4.0 ± 1.1 mm), with a variability of 10.8% (bias -2.3%, 95% limits of agreement -23.9% to 19.3%). Overall magnetic resonance image quality was good (score 4 in 67% and score 3 in 23%) with good inter-observer agreement (κ = 0.75; 95% CI 0.5-1). Fetal four-dimensional flow MRI allowed visualization of aortic flow dynamics. CONCLUSIONS: Doppler ultrasound-gating allows dynamic MRI of the fetal aorta with the potential to serve as a complementary imaging tool in cases where echocardiography is inconclusive.

CT Findings of Upper Urinary Tract Lesions in IgG4-Related Disease: Comparison With Urothelial Carcinoma.

OBJECTIVE. IgG4-related disease is characterized by extensive infiltration of IgG4-positive plasma cells and fibrosis in various organs. The objective of this study is to investigate CT findings of IgG4-related lesions involving the upper urinary tract and compare them with those of urothelial carcinomas. MATERIALS AND METHODS. This study reviewed pretreatment CT images of 13 consecutive patients with IgG4-related disease with upper urinary tract lesions and 80 consecutive patients with urothelial carcinomas. The findings assessed were laterality, location, growth pattern, margins, internal structure, presence of calcification and lipid component, enhancement pattern, and extraurinary findings. RESULTS. Bilaterality (p < 0.0001), an extramural growth pattern (p < 0.0001), a greater number of affected segments (p = 0.04), and a gradual dynamic enhancement pattern (p < 0.001) were significantly more frequent in patients with IgG4-related disease. With regard to extraurinary findings, paraaortic fat stranding (p = 0.03), presacral fat stranding (p < 0.001), fat stranding of the pelvic walls (p < 0.001), and aortic involvement (p < 0.001) were seen more frequently in patients with IgG4-related disease; on the other hand, there was no statistically significant difference in terms of frequency of pancreatic involvement. Hydronephrosis and renal involvement were seen more frequently in patients with urothelial carcinoma, although the difference was not statistically significant. CONCLUSION. CT findings suggestive of IgG4-related upper urinary tract lesions in comparison with urothelial carcinoma are bilateral and have a longer urinary tract involvement and exhibit an extramural growth pattern, ill-defined margins, a gradual enhancement pattern, aortic involvement, and fat stranding in the paraaortic, presacral, or pelvic wall areas.

Increased urinary bladder volume improves the detectability of urinary stones at the ureterovesical junction in non-enhanced computed tomography (NECT).

OBJECTIVES: To evaluate the influence of the urinary bladder volume on the detectability of urolithiasis at the ureterovesical junction (UVJ) using a low-dose CT (LD-CT) with iterative reconstruction (IR) and a standard-dose CT (SD-CT) without IR in a large cohort. METHODS: Four hundred patients (278 males (69.5%), mean 44.6 ± 14.7 years) with urolithiasis at the UVJ were investigated either by an LD-CT with IR (n = 289, 72%) or an SD-CT without IR (n = 111, 28%) protocol. The detectability of distal urolithiasis was assessed by a dichotomous assessment (definite or questionable) by two radiologists in consensus and by a quantitative analysis of the signal density distribution across a line drawn parallel to the distal ureter. Based on the resulting graph, minimum/maximum density values and mean/maximum upslopes and downslopes were derived and calculated automatically. In all patients, the total bladder volume was calculated by a slice-by-slice approach on axial CT images. RESULTS: Patients with definite stones showed significantly higher urinary bladder volumes compared to patients with questionable stones in both LD-CT and SD-CT (p < 0.01). These results were independent of stones' length and patients' BMI values. Using cutoffs of 92 ml for LD-CT and 69 ml for SD-CT, high positive predictive values/accuracy rates of 96%/85% (LD-CT) and 98%/86% (SD-CT) were observed to identify definite urinary stones. CONCLUSIONS: Urinary bladder volume has a significant impact on the detectability of distal urolithiasis. Moderate bladder filling by pre-CT hydration with subsequent CT scan at the time of high urge to void increases the detectability of urinary stones at the UVJ in clinical routine. KEY POINTS: • Urinary bladder volume significantly affects the detectability of distal urolithiasis • Higher bladder volumes are associated with improved detectability of distal urinary stones • Oral pre-CT hydration for urolithiasis is easily applicable and cost-effective.

Glenoid and rotator interval dimension in patients older than 40 years after traumatic anterior shoulder dislocation.

INTRODUCTION: The number of patients above 40 years suffering an anterior shoulder dislocation for the first time has recently increased. This study investigated the role of glenoid version, inclination and rotator interval dimension in patients older than 40 years with an anterior shoulder dislocation. We hypothesize that the rotator interval plays a more important role than the osseus alignment in older patients. MATERIALS AND METHODS: Patients aged older than 40 years with a traumatic shoulder dislocation were compared with patients who had undergone magnetic resonance imaging (MRI) for a different reason. The MRIs of 61 dislocation group patients were compared with MRIs of 73 comparison group patients. Two shoulder surgeons measured glenoid version, inclination, height and width, rotator interval (RI) height, base (width) and area. The study and comparison group consisted of 61 patients with a mean age of 59 ± 9 years and 73 patients with a mean age of 57 ± 12, respectively. RESULTS: The mean glenoid version of the dislocation group was - 4.9° ± 4.4° (retroversion) and mean inclination was 9.8° ± 8° (reclination). Mean rotator interval base, height and the rotator interval area was 46 ± 6 mm, 14 ± 5 mm and 33 ± 14 mm2, respectively. The comparison group had a mean glenoid version of - 5.4° ± 5.4° and a mean inclination of 10.8° ± 6.2°. The rotator interval base was 41 ± 6 mm, the height was 16 ± 4 mm and the area was 34 ± 11 mm2. The between-group differences were statistically significant for rotator interval height and base (p < 0.0001). A significant difference was revealed for the height-width ratio of the glenoid (p = 0.0001). CONCLUSIONS: In patients older than 40 years who have suffered anterior shoulder dislocation, the shape of the glenoid rather than its spatial position is of significance. A wide and high rotator interval promotes anterior shoulder dislocation in these patients.

Recommendations on the use of magnetic resonance imaging in PSC-A position statement from the International PSC Study Group.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disorder characterized by inflammation and fibrosis of the intra- and/or extrahepatic bile ducts. Magnetic resonance imaging (MRI) is a noninvasive imaging modality that can be used to diagnose PSC and detect disease related complications. Quantitative MRI technologies also have the potential to provide valuable prognostic information. Despite the potential of this imaging technology, the clinical application of MRI in the care of PSC patients and imaging standards vary across institutions. Moreover, a unified position statement about the role of MRI in the care of PSC patients, quality imaging standards, and its potential as a research tool is lacking. CONCLUSION: Members of the International PSC Study Group and radiologists from North America and Europe have compiled the following position statement to provide guidance regarding the application of MRI in the care of PSC patients, minimum imaging standards, and future areas of research. (Hepatology 2017;66:1675-1688).

Diagnostic prediction of complicated appendicitis by combined clinical and radiological appendicitis severity index (APSI).

OBJECTIVES: To develop a routinely applicable severity index for the management of acute appendicitis in adults using combined clinical and radiological parameters and retroperitoneal space planes (RSP). METHODS: Two hundred consecutive patients with histologically proven acute appendicitis and available presurgical CT scans were analysed retrospectively. Two radiologists assessed all CT scans for morphologic sings of appendicitis and six RSP. Clinical parameters were age, body temperature, C-reactive protein (CRP), white blood cell count, and duration of symptoms. Radiological parameters were appendix diameter and wall thickness, periappendiceal fat stranding and fluid, intraluminal and extraluminal air, thinning of appendiceal wall, caecal wall thickening, appendicolith and abscess formation. RESULTS: One hundred and three patients (51%) had histologically proven complicated appendicitis. Based on three clinical (age ≥52 years, body temperature ≥37.5°C, duration of symptoms ≥48 h) and four computed tomography (CT) findings (appendix diameter ≥14 mm, presence of periappendiceal fluid, extraluminal air, perityphlitic abscess), the APSI was developed using regression coefficients of multivariate logistic regression analyses with a maximum of 10 points. A score of ≥4 points predicted complicated appendicitis with a positive predictive value of 92% and a negative predictive value of 83%. Substantial to excellent interobserver agreement was found for the four radiological parameters of the APSI [intraclass correlation coefficient (ICC), 0.78-0.83]. The RSP evaluation presented no added value for the diagnosis of complicated appendicitis. CONCLUSIONS: Using APSI, an accurate and simple prediction of complicated appendicitis in adults was possible. The RSP count was not useful for the diagnosis of complicated appendicitis. KEY POINTS: • Appendicitis severity score provides an accurate and simple prediction of complicated appendicitis • Appendicitis severity score ≥4 accurately predicted complicated appendicitis (PPV 92%;NPV 83%) • Evaluation of retroperitoneal space planes was not useful in diagnosing complicated appendicitis.

Postmortem MR diffusion-weighted imaging of the liver: time-behavior of the hepatic apparent diffusion coefficient in the early death interval.

OBJECTIVE: The objective of this study is to assess postmortem changes of the hepatic apparent diffusion coefficient (ADC) at multiple time points in the time interval of 16 hours postmortem in comparison to in vivo controls and to literature data. MATERIAL AND METHODS: Hepatic diffusion-weighted imaging (DWI) was repeatedly performed at 1.5 Tesla (b values 50, 400, and 800 s/mm2) in 2-hourly steps within 16 hours postmortem in 19 cases (male to female 13:6, mean age 68.5 ± 12.2 years) and 5 in vivo controls. The core body temperature was measured rectally prior to every scan. Mean ADC values were calculated from regions of interest (ROIs) and compared to in vivo healthy controls and to literature data of normal liver parenchyma. Spearman rank correlation and Levenberg-Marquardt algorithm were used to assess a relationship between postmortem core body temperature and ADC values. RESULTS: Mean hepatic ADC values were significantly lower in postmortem cases than in in vivo controls (52.0 ± 15.0 · 10-5 mm2/s vs. 111.0 ± 15.7 · 10-5 mm2/s, p < 0.0001). The ex vivo liver ADC correlated inversely to calculated liver temperature (-3.5 ± 0.8) · 10-5 mm2/s/°C, r = -0.44, p < 0.0001. At low calculated liver temperature (< 30 °C), the ADC described an average increase of (22 ± 10) · 10-5 mm2/s/°C. CONCLUSION: Hepatic ADC values show a characteristic change in the immediate 16 hours postmortem, which is influenced by the postmortem liver temperature change. With the knowledge of characteristic postmortem liver changes, diffusion-weighted imaging could be added to conventional postmortem MRI for virtual autopsy.

Dynamic fetal cardiovascular magnetic resonance imaging using Doppler ultrasound gating.

BACKGROUND: Fetal cardiovascular magnetic resonance (CMR) imaging may provide a valuable adjunct to fetal echocardiography in the evaluation of congenital cardiovascular pathologies. However, dynamic fetal CMR is difficult due to the lack of direct in-utero cardiac gating. The aim of this study was to investigate the effectiveness of a newly developed Doppler ultrasound (DUS) device in humans for fetal CMR gating. METHODS: Fifteen fetuses (gestational age 30-39 weeks) were examined using 1.5 T CMR scanners at three different imaging sites. A newly developed CMR-compatible DUS device was used to generate gating signals from fetal cardiac motion. Gated dynamic balanced steady-state free precession images were acquired in 4-chamber and short-axis cardiac views. Gating signals during data acquisition were analyzed with respect to trigger variability and sensitivity. Image quality was assessed by measuring endocardial blurring (EB) and by image evaluation using a 4-point scale. Left ventricular (LV) volumetry was performed using the single-plane ellipsoid model. RESULTS: Gating signals from the fetal heart were detected with a variability of 26 ± 22 ms and a sensitivity of trigger detection of 96 ± 4%. EB was 2.9 ± 0.6 pixels (4-chamber) and 2.5 ± 0.1 pixels (short axis). Image quality scores were 3.6 ± 0.6 (overall), 3.4 ± 0.7 (mitral valve), 3.4 ± 0.7 (foramen ovale), 3.6 ± 0.7 (atrial septum), 3.7 ± 0.5 (papillary muscles), 3.8 ± 0.4 (differentiation myocardium/lumen), 3.7 ± 0.5 (differentiation myocardium/lung), and 3.9 ± 0.4 (systolic myocardial thickening). Inter-observer agreement for the scores was moderate to very good (kappa 0.57-0.84) for all structures. LV volumetry revealed mean values of 2.8 ± 1.2 ml (end-diastolic volume), 0.9 ± 0.4 ml (end systolic volume), 1.9 ± 0.8 ml (stroke volume), and 69.1 ± 8.4% (ejection fraction). CONCLUSION: High-quality dynamic fetal CMR was successfully performed using a newly developed DUS device for direct fetal cardiac gating. This technique has the potential to improve the utility of fetal CMR in the evaluation of congenital pathologies.

Feasibility of peripheral nerve MR neurography using diffusion tensor imaging adapted to skeletal muscle disease.

Background Diffusion tensor imaging (DTI) of peripheral nerves may provide additional information about nerve involvement in muscular disorders, but is considered difficult due to different optimal scan parameters tailored to magnetic resonance (MR) signal properties of muscle and neural tissues. Purpose To assess the feasibility of sciatic nerve DTI using two different approaches of region of interest (ROI)-localization in DTI scans with b-values 500 s/mm2, in participants with muscular disorders and in controls. Material and Methods DTI of the thigh was conducted on a 3T system in ten patients (6 men, 4 women; mean age =54 ± 15 years) with neuromuscular disorders and ten controls. T1-weighted (T1W) images were co-registered to fractional anisotropy (FA) color-encoded images. The apparent diffusion coefficient (ADC), FA, and fiber track length (FTL) were analyzed by two operators using a freehand ROI and a single-point ROI covering the sciatic nerve. Interclass correlation coefficient (ICC) and Bland-Altman analysis were used for evaluation of inter-operator and inter-technical agreement, respectively. Results Three-dimensional visualization of sciatic nerve fiber was achievable using both techniques. The ICC of DTI metrics showed excellent inter-operator agreement both in patients and controls. Bland-Altman analysis revealed good agreement of both techniques. A maximum FTL was achieved using the single-point ROI technique, but with a lower inter-operator agreement (ICC = 0.99 vs. 0.83). The ADC and maximum FTL were significantly decreased in patients compared to controls. Conclusion Both ROI localization techniques are feasible to analyze the sciatic nerve in the setting of muscular disease. A maximum FTL is reached using the single-point ROI, however, at the cost of lower inter-operator agreement.

MRI-based quantitative susceptibility mapping (QSM) and R2* mapping of liver iron overload: Comparison with SQUID-based biomagnetic liver susceptometry.

PURPOSE: We aimed to determine the agreement between quantitative susceptibility mapping (QSM)-based biomagnetic liver susceptometry (BLS) and confounder-corrected R2* mapping with superconducting quantum interference device (SQUID)-based biomagnetic liver susceptometry in patients with liver iron overload. METHODS: Data were acquired from two healthy controls and 22 patients undergoing MRI and SQUID-BLS as part of routine monitoring for iron overload. Magnetic resonance imaging was performed on a 3T system using a three-dimensional multi-echo gradient-echo acquisition. Both magnetic susceptibility and R2* of the liver were estimated from this acquisition. Linear regression was used to compare estimates of QSM-BLS and R2* to SQUID-BLS. RESULTS: Both QSM-BLS and confounder-corrected R2* were sensitive to the presence of iron in the liver. Linear regression between QSM-BLS and SQUID-BLS demonstrated the following relationship: QSM-BLS = (-0.22 ± 0.11) + (0.49 ± 0.05) · SQUID-BLS with r2 = 0.88. The coefficient of determination between liver R2* and SQUID-BLS was also r2 = 0.88. CONCLUSION: We determined a strong correlation between both QSM-BLS and confounder-corrected R2* to SQUID-BLS. This study demonstrates the feasibility of QSM-BLS and confounder-corrected R2* for assessing liver iron overload, particularly when SQUID systems are not accessible. Magn Reson Med 78:264-270, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Left atrial active contractile function parameters assessed by cardiac MR are sensitive to myocardial iron.

PURPOSE: To determine the impact of myocardial iron overload on left atrial (LA) volume and function using MR in patients with systemic iron overload. MATERIALS AND METHODS: Thirty-eight patients with systemic iron overload disease and 10 controls underwent 1.5 Tesla MR performing steady state free precession short-axis cine-series of the LA. Three-dimensional-volumetry was assessed to calculate LA volumes and function. Parameters were indexed (i) to body surface area. The myocardial transverse relaxation rate R2* was determined in the ventricular septum using a multi-echo GRE sequence (breathhold; electrocardiography triggered; 12 echoes; echo time = 1.3-25.7 ms). RESULTS: Significantly decreased active atrial emptying fraction (AAEF) (23% [95%-range, 7-34] versus 36% [95%-range, 14-49], P = 0.009), active atrial emptying volume (AAEVi) (5.5 mL/m2 [95%-range, 2-11] versus 11.9 mL/m2 [95%-range, 3-23], P = 0.008), and active peak emptying rate (APERi) (46 mL/s/m2 [95%-range, 29-69] versus 75 mL/s/m2 [95%-range, 45-178], P < 0.001) were found for patients with myocardial iron overload (R2* > 40 s-1 ) compared with patients with normal myocardial iron levels (R2* < 40 s-1 ). Receiver operating characteristics (ROC) analysis revealed higher potential to indicate myocardial iron overload for the AAEF (area under the ROC curve [AUC] = 0.84; P < 0.0001), APERi (AUC = 0.87; P < 0.0001), and AAEVi (AUC = 0.80; P < 0.0001) compared with LA ejection fraction (LAEF) (AUC = 0.68; P = 0.02) with equal sensitivities and specificities of 82% (AAEF), 79% (APERi), 73% (AAEVi), and 57% (LAEF). CONCLUSION: MR parameters of active LA contractile function were associated with myocardial iron overload. This cross-sectional study suggests impaired active LA contractile function to be sensitive to myocardial iron toxicity. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:535-541.

Diffusion-weighted imaging of the kidneys in haemolytic uraemic syndrome.

OBJECTIVES: To evaluate the kidneys of patients with haemolytic uraemic syndrome (HUS) using diffusion-weighted imaging (DWI) and Doppler ultrasound (US) compared with healthy controls. MATERIALS AND METHODS: Fifteen patients (mean age 33.3 years; three male; 12 female) with diarrhoea-positive HUS and 15 healthy volunteers were prospectively evaluated with DWI and Doppler US. A total apparent diffusion coefficient (ADCTOT), and ADCs predominantly reflecting microperfusion (ADCLOW) and diffusion (ADCHIGH) were calculated. Doppler US evaluated renal vascularity and flow. RESULTS: When compared with controls, kidneys affected by HUS showed reduced cortical ADC values (ADCTOT 1.79±0.22 vs. 2.04±0.1x10-3 mm2/s, P 0.001), resulting in either low corticomedullary differences (11/15 patients) or an inverted corticomedullary pattern (4/15 patients). Reduction of cortical ADC values was associated with a decrease of cortical vascularity on Doppler US (ADCTOT, P<0.001; ADCLOW, P 0.047). Kidneys with complete absence of the cortical vasculature on Doppler US (four patients) also demonstrated limited diffusion (ADCHIGH, P 0.002). Low glomerular filtration rate, requirement for haemodialysis during hospitalization, and longer duration of haemodialysis were associated with decreased cortical diffusivity (ADCTOT: P 0.04, 0.007, and <0.001, respectively). CONCLUSION: DWI shows qualitative and quantitative abnormalities in kidneys affected by HUS, thereby extending the non-invasive assessment of renal parenchymal damage. KEY POINTS: • In HUS, DWI is feasible for functional characterization of kidney involvement. • Kidneys affected by HUS showed reduced cortical diffusivity. • Decreased cortical diffusivity was associated with lower kidney function. • Requirement and duration of haemodialysis was linked to degree of cortical alterations.

Thallium-201 Uptake of Giant Cell Tumor: One Step Toward the Differential Diagnosis to Atypically Presenting Osteosarcoma.

OBJECTIVE: The radiologic differential diagnosis of giant cell tumors (GCTs) is challenging because there is a risk of misdiagnosis of GCTs as malignant lesions such as atypically presenting osteosarcomas (OSs). This study aims to assess the feasibility of 201Tl scintigraphy for the differential diagnosis of GCT and atypical OS. MATERIALS AND METHODS: Thallium-201 scintigraphy scans obtained between January 2006 and October 2015 of patients with histologically proven GCT (23 patients [male-to-female ratio, 15:8]; median age, 33.0 years; age range, 20-61 years) and patients with atypically presenting OS (20 patients [male-to-female ratio, 11:9]; median age, 30.0 years; age range, 12-69 years) were retrospectively reviewed. Morphologic classification of osseous lesions was performed on radiographs and CT scans. The 201Tl scintigraphy-based tumor-to-background contrast (TBC) and washout rate (WR) were calculated on early phase and delayed phase scans. The laboratory parameters lactate dehydrogenase (LDH), C-reactive protein (CRP), and alkaline phosphatase were obtained. Statistical significance was estimated using the Mann-Whitney U test. Cutoff values were calculated for early phase TBC and delayed phase TBC. RESULTS: Twenty-two of 23 GCTs were detected on the initial radiographs, whereas only six of 20 atypical OSs were detected on the initial radiographs. The early phase TBC was increased in GCT (median, 2.59; range, 0.51-12.26) compared with atypical OS (median, 1.68; range, 0.90-6.45) (p = 0.07). The delayed phase TBC was increased in GCT (median, 1.65; range, 0.22-5.26) compared with atypical OS (median, 0.96; range, 0.39-3.76) (p = 0.02). The median WR was not significantly decreased in GCT. The cutoff value for the early phase TBC was 3.90, and the cutoff value for the delayed phase TBC was 1.64; these cutoff values for early and delayed phase TBC yielded a sensitivity of 80.0% and a specificity of 47.8% and 52.2% respectively. Serum LDH (mean: atypical OS vs GCT, 215.5 vs 170.5 U/L, respectively; p = 0.01), alkaline phosphatase (median: 355.0 vs 252.0 U/L; p = 0.03), and CRP (median: 0.21 vs 0.09 mg/dL; p = 0.04) values were significantly increased in atypical OS compared with GCT. CONCLUSION: The intense 201Tl uptake of GCT in combination with laboratory OS biomarkers facilitate the differential diagnosis of GCT and atypically presenting OS.

Isolated syndesmotic injuries in acute ankle sprains: diagnostic significance of clinical examination and MRI.

PURPOSE: Acute ankle sprains are frequently accompanied by syndesmotic injuries. These injuries are often overlooked in clinical examinations. The aim of this study was (1) to evaluate the incidence of syndesmotic injuries in acute ankle sprains using MRI, (2) to determine the accuracy of common clinical diagnostic tests, (3) to analyse their inter-rater reliability, and (4) to evaluate the role of clinical symptoms in the diagnosis of syndesmotic injuries. METHODS: A total of 100 patients with acute ankle sprain injury without associated fractures in plane radiographs were enrolled. The clinical assessment was performed by two independent examiners. Local findings, ankle ligament palpation, squeeze test, external rotation test, Drawer test, Cotton test, and the crossed-leg test (two examiners) were compared with MRI results (read by two blinded radiologists) as a reference standard. RESULTS: Ninety-six participants (57% male) met the inclusion criteria. MRI detected a ruptured anterior inferior tibiofibular ligament (AITFL) in 14 patients (15%); 9 partial tears and 5 complete tears were evident. Evidence of pain at rest was found to predict syndesmotic injuries most accurately (p = 0.039). The palpation test over the proximal fibula produced the highest inter-rater correlation (κ = 0.65), but the lowest sensitivity for syndesmotic injuries of 8%. All other clinical tests demonstrated moderate to fair inter-rater reliabilities (κ = 0.37-0.52). Low sensitivity values were found with all clinical tests (13.9-55.6%). CONCLUSION: In this study, clinical examination was insufficient to detect syndesmotic injuries in acute ankle sprains. MRI scanning revealed a syndesmotic lesion in 15% of patients. MRI scanning should be recommended in patients with ongoing pain at rest following ankle sprains. LEVEL OF EVIDENCE: I.