Deep learning denoising reconstruction for improved image quality in fetal cardiac cine MRI.

Purpose: This study aims to evaluate deep learning (DL) denoising reconstructions for image quality improvement of Doppler ultrasound (DUS)-gated fetal cardiac MRI in congenital heart disease (CHD). Methods: Twenty-five fetuses with CHD (mean gestational age: 35 ± 1 weeks) underwent fetal cardiac MRI at 3T. Cine imaging was acquired using a balanced steady-state free precession (bSSFP) sequence with Doppler ultrasound gating. Images were reconstructed using both compressed sensing (bSSFP CS) and a pre-trained convolutional neural network trained for DL denoising (bSSFP DL). Images were compared qualitatively based on a 5-point Likert scale (from 1 = non-diagnostic to 5 = excellent) and quantitatively by calculating the apparent signal-to-noise ratio (aSNR) and contrast-to-noise ratio (aCNR). Diagnostic confidence was assessed for the atria, ventricles, foramen ovale, valves, great vessels, aortic arch, and pulmonary veins. Results: Fetal cardiac cine MRI was successful in 23 fetuses (92%), with two studies excluded due to extensive fetal motion. The image quality of bSSFP DL cine reconstructions was rated superior to standard bSSFP CS cine images in terms of contrast [3 (interquartile range: 2-4) vs. 5 (4-5), P < 0.001] and endocardial edge definition [3 (2-4) vs. 4 (4-5), P < 0.001], while the extent of artifacts was found to be comparable [4 (3-4.75) vs. 4 (3-4), P = 0.40]. bSSFP DL images had higher aSNR and aCNR compared with the bSSFP CS images (aSNR: 13.4 ± 6.9 vs. 8.3 ± 3.6, P < 0.001; aCNR: 26.6 ± 15.8 vs. 14.4 ± 6.8, P < 0.001). Diagnostic confidence of the bSSFP DL images was superior for the evaluation of cardiovascular structures (e.g., atria and ventricles: P = 0.003). Conclusion: DL image denoising provides superior quality for DUS-gated fetal cardiac cine imaging of CHD compared to standard CS image reconstruction.

CT-derived Epicardial Adipose Tissue Inflammation Predicts Outcome in Patients Undergoing Transcatheter Aortic Valve Replacement.

PURPOSE: Inflammatory changes in epicardial (EAT) and pericardial adipose tissue (PAT) are associated with increased overall cardiovascular risk. Using routine, preinterventional cardiac CT data, we examined the predictive value of quantity and quality of EAT and PAT for outcome after transcatheter aortic valve replacement (TAVR). MATERIALS AND METHODS: Cardiac CT data of 1197 patients who underwent TAVR at the in-house heart center between 2011 and 2020 were retrospectively analyzed. The amount and density of EAT and PAT were quantified from single-slice CT images at the level of the aortic valve. Using established risk scores and known independent risk factors, a clinical benchmark model (BMI, Chronic kidney disease stage, EuroSCORE 2, STS Prom, year of intervention) for outcome prediction (2-year mortality) after TAVR was established. Subsequently, we tested whether the additional inclusion of area and density values of EAT and PAT in the clinical benchmark model improved prediction. For this purpose, the cohort was divided into a training (n=798) and a test cohort (n=399). RESULTS: Within the 2-year follow-up, 264 patients died. In the training cohort, particularly the addition of EAT density to the clinical benchmark model showed a significant association with outcome (hazard ratio 1.04, 95% CI: 1.01-1.07; P =0.013). In the test cohort, the outcome prediction of the clinical benchmark model was also significantly improved with the inclusion of EAT density (c-statistic: 0.589 vs. 0.628; P =0.026). CONCLUSIONS: EAT density as a surrogate marker of EAT inflammation was associated with 2-year mortality after TAVR and may improve outcome prediction independent of established risk parameters.

Locoregional Therapies for Primary and Metastatic Breast Cancer: AJR Expert Panel Narrative Review.

Minimally invasive locoregional therapies have a growing role in the multidisciplinary treatment of primary and metastatic breast cancer. Factors contributing to the expanding role of ablation for primary breast cancer include earlier diagnosis, when tumors are small, and increased longevity of patients whose condition precludes surgery. Cryoablation has emerged as the leading ablative modality for primary breast cancer owing to its wide availability, the lack of need for sedation, and the ability to monitor the ablation zone. Emerging evidence suggests that in patients with oligometastatic breast cancer, use of locoregional therapies to eradicate all disease sites may confer a survival advantage. Evidence also suggests that transarterial therapies-including chemoembolization, chemoperfusion, and radioembolization-may be helpful to some patients with advanced liver metastases from breast cancer, such as those with hepatic oligoprogression or those who cannot tolerate systemic therapy. However, the optimal modalities for treatment of oligometastatic and advanced metastatic disease remain unknown. Finally, locoregional therapies may produce tumor antigens that in combination with immunotherapy drive anti-tumor immunity. Although key trials are ongoing, additional prospective studies are needed to establish the inclusion of interventional oncology in societal breast cancer guidelines to support further clinical adoption and improved patient outcomes.

[Imaging of the pelvic floor (MR defecography) : The surgeon's perspective]. / Bildgebung des Beckenbodens (MR-Defäkographie) : Die Sicht der Chirurgie.

BACKGROUND: Magnetic resonance defecography (MRD) plays a central role in diagnosing pelvic floor functional disorders by visualizing the entire pelvic floor along with pelvic organs and providing functional assessment of the defecation process. A shared understanding between radiology and surgery regarding indications and interpretation of findings is crucial for optimal utilization of MRD. OBJECTIVES: This review aims to explain the indications for MRD from a surgical perspective and elucidate the significance of radiological findings for treatment. It intends to clarify for which symptoms MRD is appropriate and which criteria should be followed for standardized results. This is prerequisite to develop interdisciplinary therapeutic approaches. MATERIALS AND METHODS: A comprehensive literature search was conducted, including current consensus guidelines. RESULTS: MRD can provide relevant findings in the diagnosis of fecal incontinence and obstructed defecation syndrome, particularly in cases of pelvic floor descent, enterocele, intussusception, and pelvic floor dyssynergia. However, rectocele findings in MRD should be interpreted with caution in order to avoid overdiagnosis. CONCLUSION: MRD findings should never be considered in isolation but rather in conjunction with patient history, clinical examination, and symptomatology since morphology and functional complaints may not always correlate, and there is wide variance of normal values. Interdisciplinary interpretation of MRD results involving radiology, surgery, gynecology, and urology, preferably in the context of pelvic floor conferences, is recommended.

Long-Term Clinical Outcome of Abdomino-Thoracic Lymphatic Interventions of Traumatic and Non-Traumatic Lymphatic Leakage in Adults.

The aim of this study was to retrospectively evaluate the long-term results of lymphatic interventions in adults with abdomino-thoracic lymphatic pathologies. Management of abdomino-thoracic chylous effusions in adults undergoing X-ray-lymphangiography with or without lymph-vessel embolization (LVE) from 2010-2018 was reviewed. Patients underwent lymphangiography alone when imaging showed normal findings or lymphatic obstruction without leakage or reflux; otherwise, LVE was performed (leakage, reflux, obstruction with leakage or reflux, lymphatic masses). Technical and clinical success, complications, and long-term outcomes were assessed. 78 patients (47 male, median age 56.3 years) were treated for chylous effusions (60.3% traumatic, 39.7% non-traumatic). Lymphangiography showed leakage (48.7%), reflux (14.1%), obstruction (28.2%), lymphatic masses (5.1%), and normal findings (3.8%). Embolization was performed in 49/78 (62.8%) cases. Overall, treatment was clinically successful in 74.4% (mean follow-up of 28 months), with significant differences between LVE and lymphangiography (91.8% vs. 44.8%; p < 0.001), traumatic and non-traumatic etiologies (89.4% vs. 51.6%; p < 0.001), and leakage locations (p = 0.003). The clinical success of LVE did not differ between leakage etiologies or locations. Complications occurred in 5 patients (2/5 needed treatment). Patients survived significantly longer after successful treatment (2679 vs. 927 days; p = 0.044) and without malignancy (3214 vs. 1550 days; p = 0.043). Lymphatic interventions are safe and effective. LVE should be attempted whenever feasible, as success is high (>90%). Successful intervention has a positive effect on patient survival.

Deep Learning Super-Resolution Reconstruction for Fast and Motion-Robust T2-weighted Prostate MRI.

Background Deep learning (DL) reconstructions can enhance image quality while decreasing MRI acquisition time. However, DL reconstruction methods combined with compressed sensing for prostate MRI have not been well studied. Purpose To use an industry-developed DL algorithm to reconstruct low-resolution T2-weighted turbo spin-echo (TSE) prostate MRI scans and compare these with standard sequences. Materials and Methods In this prospective study, participants with suspected prostate cancer underwent prostate MRI with a Cartesian standard-resolution T2-weighted TSE sequence (T2C) and non-Cartesian standard-resolution T2-weighted TSE sequence (T2NC) between August and November 2022. Additionally, a low-resolution Cartesian DL-reconstructed T2-weighted TSE sequence (T2DL) with compressed sensing DL denoising and resolution upscaling reconstruction was acquired. Image sharpness was assessed qualitatively by two readers using a five-point Likert scale (from 1 = nondiagnostic to 5 = excellent) and quantitatively by calculating edge rise distance. The Friedman test and one-way analysis of variance with post hoc Bonferroni and Tukey tests, respectively, were used for group comparisons. Prostate Imaging Reporting and Data System (PI-RADS) score agreement between sequences was compared by using Cohen κ. Results This study included 109 male participants (mean age, 68 years ± 8 [SD]). Acquisition time of T2DL was 36% and 29% lower compared with that of T2C and T2NC (mean duration, 164 seconds ± 20 vs 257 seconds ± 32 and 230 seconds ± 28; P < .001 for both). T2DL showed improved image sharpness compared with standard sequences using both qualitative (median score, 5 [IQR, 4-5] vs 4 [IQR, 3-4] for T2C and 4 [IQR, 3-4] for T2NC; P < .001 for both) and quantitative (mean edge rise distance, 0.75 mm ± 0.39 vs 1.15 mm ± 0.68 for T2C and 0.98 mm ± 0.65 for T2NC; P < .001 and P = .01) methods. PI-RADS score agreement between T2NC and T2DL was excellent (κ range, 0.92-0.94 [95% CI: 0.87, 0.98]). Conclusion DL reconstruction of low-resolution T2-weighted TSE sequences enabled accelerated acquisition times and improved image quality compared with standard acquisitions while showing excellent agreement with conventional sequences for PI-RADS ratings. Clinical trial registration no. NCT05820113 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Turkbey in this issue.

Study Protocol of a Prospective, Monocentric, Single-Arm Study Investigating the Safety and Efficacy of Local Ablation of Symptomatic Uterine Fibroids with US-Guided High-Intensity Focused Ultrasound (HIFU).

Uterine fibroids are the most common benign tumors of the uterus. Approximately 20-50% of women with myomas experience a variety of symptoms such as vaginal bleeding, abdominal pain, pelvic pain and pressure, and urological problems, possibly interfering with fertility and pregnancy. Although surgery remains the standard treatment option for fibroids, non-invasive therapeutic options, such as high-intensity focused ultrasound (HIFU), have emerged over the last dec ade. During HIFU, ultrasound is focused on the target tissue causing coagulation necrosis. HIFU has, meanwhile, become an established method for treating uterine fibroids in many countries. Clinical data have shown that it effectively alleviates fibroid-related symptoms and reduces fibroid size with a very low rate of side effects. However, there is a lack of data on how this treatment affects laboratory parameters and structural features of uterine tissue. As our center is the only one in German-speaking countries where ultrasound-guided HIFU technology is currently established, the aim of this prospective, monocentric, single-arm trial is not only to evaluate the safety and efficacy of local US-guided HIFU in symptomatic uterine fibroid patients according to GCP standards but also to explore its effects on blood parameters and the structural integrity of uterine tissue using elastographic methods.

Back to the Future II-A Comprehensive Update on the Rapidly Evolving Field of Lymphatic Imaging and Interventions.

ABSTRACT: Lymphatic imaging and interventional therapies of disorders affecting the lymphatic vascular system have evolved rapidly in recent years. Although x-ray lymphangiography had been all but replaced by the advent of cross-sectional imaging and the scientific focus shifted to lymph node imaging (eg, for detection of metastatic disease), interest in lymph vessel imaging was rekindled by the introduction of lymphatic interventional treatments in the late 1990s. Although x-ray lymphangiography is still the mainstay imaging technique to guide interventional procedures, several other, often less invasive, techniques have been developed more recently to evaluate the lymphatic vascular system and associated pathologies. Especially the introduction of magnetic resonance, and even more recently computed tomography, lymphangiography with water-soluble iodinated contrast agent has furthered our understanding of complex pathophysiological backgrounds of lymphatic diseases. This has led to an improvement of treatment approaches, especially of nontraumatic disorders caused by lymphatic flow abnormalities including plastic bronchitis, protein-losing enteropathy, and nontraumatic chylolymphatic leakages. The therapeutic armamentarium has also constantly grown and diversified in recent years with the introduction of more complex catheter-based and interstitial embolization techniques, lymph vessel stenting, lymphovenous anastomoses, as well as (targeted) medical treatment options. The aim of this article is to review the relevant spectrum of lymphatic disorders with currently available radiological imaging and interventional techniques, as well as the application of these methods in specific, individual clinical situations.

Free-breathing pseudo-golden-angle bSSFP cine cardiac MRI for biventricular functional assessment in congenital heart disease.

PURPOSE: To compare standard breath-hold (BH) cine imaging to a radial pseudo-golden-angle free-breathing (FB) technique in congenital heart disease (CHD). METHODS: In this prospective study, short-axis and 4-chamber BH and FB cardiac MRI sequences of 25 participants with CHD acquired at 1.5 Tesla, were quantitatively compared regarding ventricular volumes, function, interventricular septum thickness (IVSD), apparent signal to noise ratio (aSNR), and estimated contrast to noise ratio (eCNR). For qualitative comparison, three image quality criteria (contrast, endocardial edge definition, and artefacts) were rated on a 5-point Likert scale (5: excellent, 1: non-diagnostic). Paired t-Test was used for group comparisons, Bland-Altman analysis for agreement between techniques. Inter-reader agreement was compared using intraclass correlation coefficient. RESULTS: IVSD (BH 7.4 ± 2.1 mm vs FB 7.4 ± 1.9 mm, p =.71), biventricular ejection fraction (left ventricle [LV]: 56.4 ± 10.8% vs 56.1 ± 9.3%, p =.83; right ventricle [RV]: 49.5 ± 8.6% vs 49.7 ± 10.1%, p =.83), and biventricular end diastolic volume (LV: 176.3 ± 63.9 ml vs 173.9 ± 64.9 ml, p =.90; RV: 185.4 ± 63.8 ml vs 189.6 ± 66.6 ml, p =.34) were comparable. Mean measurement time for FB short-axis sequences was 8.1 ± 1.3 compared to 4.4 ± 1.3 min for BH (p <.001). Subjective image quality between sequences was deemed comparable, (4.6 ± 0.6 vs 4.5 ± 0.6, p =.26, for 4-chamber views) with a significant difference regarding short-axis views (4.9 ± 0.3 vs 4.5 ± 0.6, p =.008). aSNR was similar (BH 25.8 ± 11.2 vs FB 22.2 ± 9.5, p =.24), while eCNR was higher for BH (89.1 ± 36.1 vs 68.5 ± 32.1, p =.03). CONCLUSION: FB sequences yielded comparable results to BH regarding image quality, biventricular volumetry, and function, though measurement times were longer. The FB sequence described might be clinically valuable when BHs are insufficiently performed.

Cardiovascular Magnetic Resonance in Survivors of Critical Illness: Cardiac Abnormalities Are Associated With Acute Kidney Injury.

Background The objective of this study was to investigate cardiac abnormalities in intensive care unit (ICU) survivors of critical illness and to determine whether temporary acute kidney injury (AKI) is associated with more pronounced findings on cardiovascular magnetic resonance. Methods and Results There were 2175 patients treated in the ICU (from 2015 until 2021) due to critical illness who were screened for study eligibility. Post-ICU patients without known cardiac disease were prospectively recruited from March 2021 to May 2022. Participants underwent cardiovascular magnetic resonance including assessment of cardiac function, myocardial edema, late gadolinium enhancement, and mapping including extracellular volume fraction. Student t test, Mann-Whitney U test, and χ2 tests were used. There were 48 ICU survivors (46±15 years of age, 28 men, 29 with AKI and continuous kidney replacement therapy, and 19 without AKI) and 20 healthy controls who were included. ICU survivors had elevated markers of myocardial fibrosis (T1: 995±31 ms versus 957±21 ms, P<0.001; extracellular volume fraction: 24.9±2.5% versus 22.8±1.2%, P<0.001; late gadolinium enhancement: 1% [0%-3%] versus 0% [0%-0%], P<0.001), more frequent focal late gadolinium enhancement lesions (21% versus 0%, P=0.03), and an impaired left ventricular function (eg, ejection fraction: 57±6% versus 60±5%, P=0.03; systolic longitudinal strain: 20.3±3.7% versus 23.1±3.5%, P=0.004) compared with healthy controls. ICU survivors with AKI had higher myocardial T1 (1002±33 ms versus 983±21 ms; P=0.046) and extracellular volume fraction values (25.6±2.6% versus 23.9±1.9%; P=0.02) compared with participants without AKI. Conclusions ICU survivors of critical illness without previously diagnosed cardiac disease had distinct abnormalities on cardiovascular magnetic resonance including signs of myocardial fibrosis and systolic dysfunction. Findings were more abnormal in participants who experienced AKI with necessity of continuous kidney replacement therapy during their ICU stay. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT05034588.

Computed tomography derived cervical fat-free muscle fraction as an imaging-based outcome marker in patients with acute ischemic stroke: a pilot study.

BACKGROUND: Outcome assessment in stroke patients is essential for evidence-based stroke care planning. Computed tomography (CT) is the mainstay of diagnosis in acute stroke. This study aimed to investigate whether CT-derived cervical fat-free muscle fraction (FFMF) as a biomarker of muscle quality is associated with outcome parameters after acute ischemic stroke. METHODS: In this retrospective study, 66 patients (mean age: 76 ± 13 years, 30 female) with acute ischemic stroke in the anterior circulation who underwent CT, including CT-angiography, and endovascular mechanical thrombectomy of the middle cerebral artery between August 2016 and January 2020 were identified. Based on densitometric thresholds, cervical paraspinal muscles covered on CT-angiography were separated into areas of fatty and lean muscle and FFMF was calculated. The study cohort was binarized based on median FFMF (cutoff value: < 71.6%) to compare clinical variables and outcome data between two groups. Unpaired t test and Mann-Whitney U test were used for statistical analysis. RESULTS: National Institute of Health Stroke Scale (NIHSS) (12.2 ± 4.4 vs. 13.6 ± 4.5, P = 0.297) and modified Rankin scale (mRS) (4.3 ± 0.9 vs. 4.4 ± 0.9, P = 0.475) at admission, and pre-stroke mRS (1 ± 1.3 vs. 0.9 ± 1.4, P = 0.489) were similar between groups with high and low FFMF. NIHSS and mRS at discharge were significantly better in patients with high FFMF compared to patients with low FFMF (NIHSS: 4.5 ± 4.4 vs. 9.5 ± 6.7; P = 0.004 and mRS: 2.9 ± 2.1 vs.3.9 ± 1.8; P = 0.049). 90-day mRS was significantly better in patients with high FFMF compared to patients with low FFMF (3.3 ± 2.2 vs. 4.3 ± 1.9, P = 0.045). CONCLUSION: Cervical FFMF obtained from routine clinical CT might be a new imaging-based muscle quality biomarker for outcome prediction in stroke patients.

Fetal Cardiac Cine MRI with Doppler US Gating in Complex Congenital Heart Disease.

Purpose: To apply Doppler US (DUS)-gated fetal cardiac cine MRI in clinical routine and investigate diagnostic performance in complex congenital heart disease (CHD) compared with that of fetal echocardiography. Materials and Methods: In this prospective study (May 2021 to March 2022), women with fetuses with CHD underwent fetal echocardiography and DUS-gated fetal cardiac MRI on the same day. For MRI, balanced steady-state free precession cine images were acquired in the axial and optional sagittal and/or coronal orientations. Overall image quality was assessed on a four-point Likert scale (from 1 = nondiagnostic to 4 = good image quality). The presence of abnormalities in 20 fetal cardiovascular features was independently assessed by using both modalities. The reference standard was postnatal examination results. Differences in sensitivities and specificities were determined by using a random-effects model. Results: The study included 23 participants (mean age, 32 years ± 5 [SD]; mean gestational age, 36 weeks ± 1). Fetal cardiac MRI was completed in all participants. The median overall image quality of DUS-gated cine images was 3 (IQR, 2.5-4). In 21 of 23 participants (91%), underlying CHD was correctly assessed by using fetal cardiac MRI. In one case, the correct diagnosis was made by using MRI only (situs inversus and congenitally corrected transposition of the great arteries). Sensitivities (91.8% [95% CI: 85.7, 95.1] vs 93.6% [95% CI: 88.8, 96.2]; P = .53) and specificities (99.9% [95% CI: 99.2, 100] vs 99.9% [95% CI: 99.5, 100]; P > .99) for the detection of abnormal cardiovascular features were comparable between MRI and echocardiography, respectively. Conclusion: Using DUS-gated fetal cine cardiac MRI resulted in performance comparable with that of using fetal echocardiography for diagnosing complex fetal CHD.Keywords: Pediatrics, MR-Fetal (Fetal MRI), Cardiac, Heart, Congenital, Fetal Imaging, Cardiac MRI, Prenatal, Congenital Heart DiseaseClinical trial registration no. NCT05066399 Supplemental material is available for this article. © RSNA, 2023See also the commentary by Biko and Fogel in this issue.

Cardiac involvement in non-cirrhotic portal hypertension: MRI detects myocardial fibrosis and oedema similar to compensated cirrhosis.

AIMS: The exact role of portal hypertension in cirrhotic cardiomyopathy remains unclear, and it is uncertain whether cardiac abnormalities also occur in non-cirrhotic portal hypertension (NCPH). This magnetic resonance imaging (MRI) study aimed to evaluate the presence of subclinical myocardial dysfunction, oedema, and fibrosis in NCPH. METHODS AND RESULTS: In this prospective study (2018-2022), participants underwent multiparametric abdominal and cardiac MRI including assessment of cardiac function, myocardial oedema, late gadolinium enhancement (LGE), and abdominal and cardiac mapping [T1 and T2 relaxation times, extracellular volume fraction (ECV)]. A total of 111 participants were included [44 participants with NCPH (48 ± 15 years; 23 women), 47 cirrhotic controls, and 20 healthy controls]. The cirrhotic group was dichotomized (Child A vs. Child B/C). NCPH participants demonstrated a more hyperdynamic circulation compared with healthy controls (cardiac index: 3.7 ± 0.6 vs. 3.2 ± 0.8 L/min/m², P = 0.004; global longitudinal strain: -27.3 ± 4.6 vs. -24.6 ± 3.5%, P = 0.022). The extent of abnormalities indicating myocardial fibrosis and oedema in NCPH was comparable with Child A cirrhosis (e.g. LGE presence: 32 vs. 33 vs. 69%, P = 0.004; combined T1 and T2 elevations: 46 vs. 27 vs. 69%, P = 0.017; NCPH vs. Child A vs. Child B/C). Correlations between splenic T1 and myocardial T1 values were found (r = 0.41; P = 0.007). Splenic T1 values were associated with the presence of LGE (odds ratio, 1.010; 95% CI: 1.002, 1.019; P = 0.013). CONCLUSION: MRI parameters of myocardial fibrosis and oedema were altered in participants with NCPH to a similar extent as in compensated cirrhosis and were associated with splenic markers of portal hypertension, indicating specific portal hypertensive cardiomyopathy.

Linear multi-scale modeling of diffusion MRI data: A framework for characterization of oriented structures across length scales.

Diffusion-weighted magnetic resonance imaging (DW-MRI) has evolved to provide increasingly sophisticated investigations of the human brain's structural connectome in vivo. Restriction spectrum imaging (RSI) is a method that reconstructs the orientation distribution of diffusion within tissues over a range of length scales. In its original formulation, RSI represented the signal as consisting of a spectrum of Gaussian diffusion response functions. Recent technological advances have enabled the use of ultra-high b-values on human MRI scanners, providing higher sensitivity to intracellular water diffusion in the living human brain. To capture the complex diffusion time dependence of the signal within restricted water compartments, we expand upon the RSI approach to represent restricted water compartments with non-Gaussian response functions, in an extended analysis framework called linear multi-scale modeling (LMM). The LMM approach is designed to resolve length scale and orientation-specific information with greater specificity to tissue microstructure in the restricted and hindered compartments, while retaining the advantages of the RSI approach in its implementation as a linear inverse problem. Using multi-shell, multi-diffusion time DW-MRI data acquired with a state-of-the-art 3 T MRI scanner equipped with 300 mT/m gradients, we demonstrate the ability of the LMM approach to distinguish different anatomical structures in the human brain and the potential to advance mapping of the human connectome through joint estimation of the fiber orientation distributions and compartment size characteristics.

Deep learning for standardized, MRI-based quantification of subcutaneous and subfascial tissue volume for patients with lipedema and lymphedema.

OBJECTIVES: To contribute to a more in-depth assessment of shape, volume, and asymmetry of the lower extremities in patients with lipedema or lymphedema utilizing volume information from MR imaging. METHODS: A deep learning (DL) pipeline was developed including (i) localization of anatomical landmarks (femoral heads, symphysis, knees, ankles) and (ii) quality-assured tissue segmentation to enable standardized quantification of subcutaneous (SCT) and subfascial tissue (SFT) volumes. The retrospectively derived dataset for method development consisted of 45 patients (42 female, 44.2 ± 14.8 years) who underwent clinical 3D DIXON MR-lymphangiography examinations of the lower extremities. Five-fold cross-validated training was performed on 16,573 axial slices from 40 patients and testing on 2187 axial slices from 5 patients. For landmark detection, two EfficientNet-B1 convolutional neural networks (CNNs) were applied in an ensemble. One determines the relative foot-head position of each axial slice with respect to the landmarks by regression, the other identifies all landmarks in coronal reconstructed slices using keypoint detection. After landmark detection, segmentation of SCT and SFT was performed on axial slices employing a U-Net architecture with EfficientNet-B1 as encoder. Finally, the determined landmarks were used for standardized analysis and visualization of tissue volume, distribution, and symmetry, independent of leg length, slice thickness, and patient position. RESULTS: Excellent test results were observed for landmark detection (z-deviation = 4.5 ± 3.1 mm) and segmentation (Dice score: SCT = 0.989 ± 0.004, SFT = 0.994 ± 0.002). CONCLUSIONS: The proposed DL pipeline allows for standardized analysis of tissue volume and distribution and may assist in diagnosis of lipedema and lymphedema or monitoring of conservative and surgical treatments. KEY POINTS: • Efficient use of volume information that MRI inherently provides can be extracted automatically by deep learning and enables in-depth assessment of tissue volumes in lipedema and lymphedema. • The deep learning pipeline consisting of body part regression, keypoint detection, and quality-assured tissue segmentation provides detailed information about the volume, distribution, and asymmetry of lower extremity tissues, independent of leg length, slice thickness, and patient position.

T2 Turbo Spin Echo With Compressed Sensing and Propeller Acquisition (Sampling k-Space by Utilizing Rotating Blades) for Fast and Motion Robust Prostate MRI: Comparison With Conventional Acquisition.

OBJECTIVES: The aim of this study was to compare a new compressed sensing (CS) method for T2-weighted propeller acquisitions (T2 CS ) with conventional T2-weighted propeller sequences (T2 conv ) in terms of achieving a higher image quality, while reducing the acquisition time. MATERIALS AND METHODS: Male participants with a clinical suspicion of prostate cancer were prospectively enrolled and underwent prostate magnetic resonance imaging at 3 T. Axial and sagittal images of the T2 conv sequence and the T2 CS sequence were acquired. Sequences were qualitatively assessed by 2 blinded radiologists concerning artifacts, image-sharpness, lesion conspicuity, capsule delineation, and overall image quality using 5-point Likert items ranging from 1 (nondiagnostic) to 5 (excellent). The apparent signal-to-noise ratio and apparent contrast-to-noise ratio were evaluated. PI-RADS scores were assessed for both sequences. Statistical analysis was performed by using Wilcoxon signed rank test and paired samples t test. Intrarater and interrater reliability of qualitative image evaluation was assessed using intraclass correlation coefficient (ICC) estimates. RESULTS: A total of 29 male participants were included (mean age, 66 ± 8 years). The acquisition time of the T2 CS sequence was respectively 26% (axial plane) and 24% (sagittal plane) shorter compared with the T2 conv sequence (eg, axial: 171 vs 232 seconds; P < 0.001). In the axial plane, the T2 CS sequence had fewer artifacts (4 [4-4.5] vs 4 [3-4]; P < 0.001), better image-sharpness (4 [4-4.5] vs 3 [3-3.5]; P < 0.001), better capsule delineation (4 [3-4] vs 3 [3-3.5]; P < 0.001), and better overall image quality (4 [4-4] vs 4 [3-4]; P < 0.001) compared with the T2 conv sequence. The ratings of lesion conspicuity were similar (4 [4-4] vs 4 [3-4]; P = 0.166). In the sagittal plane, the T2 CS sequence outperformed the T2 conv sequence in the categories artifacts (4 [4-4] vs 3 [3-4]; P < 0.001), image sharpness (4 [4-5] vs 4 [3-4]; P < 0.001), lesion conspicuity (4 [4-4] vs 4 [3-4]; P = 0.002), and overall image quality (4 [4-4] vs 4 [3-4]; P = 0.002). Capsule delineation was similar between both sequences (3 [3-4] vs 3 [3-3]; P = 0.07). Intraobserver and interobserver reliability for qualitative scoring were good (ICC intra: 0.92; ICC inter: 0.86). Quantitative analysis revealed a higher apparent signal-to-noise ratio (eg, axial: 52.2 ± 9.7 vs 22.8 ± 3.6; P < 0.001) and a higher apparent contrast-to-noise ratio (eg, axial: 44.0 ± 9.6 vs 18.6 ± 3.7; P ≤ 0.001) of the T2 CS sequence. PI-RADS scores were the same for both sequences in all participants. CONCLUSIONS: CS-accelerated T2-weighted propeller acquisition had a superior image quality compared with conventional T2-weighted propeller sequences while significantly reducing the acquisition time.

Percutaneous transhepatic biliary drainage: a retrospective single-center study of 372 patients.

BACKGROUND: Complication rates in percutaneous transhepatic biliary drainage (PTBD) are non-uniform and vary considerably. In addition, the impact of peri-procedural risk factors is under-investigated. PURPOSE: To compare success and complication rates of PTBD in patients with and without accompanying technical risk factors. MATERIAL AND METHODS: A single-center retrospective study was conducted from January 2004 to December 2016. Patients receiving PTBD due to biliary obstruction or biliary leakage were included. Technical risk factors (non-distended bile ducts, ascites, obesity, anasarca, non-compliance) were assessed. Complications were classified according to the Society of Interventional Radiology. RESULTS: In total, 372 patients were included (57.3% men, 42.7% women; mean age = 66 years). Overall, 466 PTBDs were performed. Of the patients, 70.1% presented with malignancy and biliary obstruction; 26.8% had benign biliary obstruction; 3.1% had biliary leakage. Technical risk factors were reported in 57 (15.3%) patients. Overall technical success of initial PTBD was 98.7%, primary technical success was 97.9%. In patients with non-dilatated bile ducts, primary technical success was 68.2%. Overall complication rate was 15.0% (8.1% major complications, 6.9% minor complications). Neither major nor minor complications were more frequent in patients with technical risk factors (P > 0.05). In left-sided PTBD, hemorrhage was more frequent (P = 0.015). Patients with malignancy were significantly more affected by drainage-related complications (P = 0.004; odds ratio = 2.03). The mortality rate was 0.5% (n = 2). CONCLUSION: PTBD is a safe and effective method for the treatment of biliary obstruction and biliary leaks. Complication rates are low, even in procedures with risk factors.

Improvement of fibroid-associated symptoms and quality of life after US-guided high-intensity focused ultrasound (HIFU) of uterine fibroids.

Uterine fibroids are the most common benign uterine tumors and can cause various severe symptoms as abnormal menstrual bleeding or pelvic pain. Therefore, the primary objective in the treatment of uterine fibroids is a sufficient symptom relief. Ultrasound (US)-guided High-intensity focused ultrasound (HIFU) is an effective non-invasive treatment strategy for ablation of uterine fibroids that can achieve a significant tumor volume reduction. The aim of the study is to evaluate if US-guided HIFU treatment can reduce fibroid-associated symptoms leading to an improvement of health-related quality of life. Fifty-five women with symptomatic uterine fibroids underwent US-guided HIFU ablation. Clinical evaluation was performed on the basis of the Uterine Fibroid Symptom and Health-Related Quality of Life Questionnaire (UFS-QOL) at baseline, 6 weeks, 3, 6, 9 and 12 months after HIFU. Imaging follow-up included contrast-enhanced ultrasound (CEUS) and contrast-enhanced MRI. A significant reduction of the Symptom Severity Scale (SSS) was observed between 6 weeks and 12 months after HIFU (49.9 ± 19.4 at baseline vs. 42.2 ± 20.1 at 6 weeks and 23.6 ± 12.7 at 12 months after treatment, p < 0.001) correlating with a significant improvement (p < 0.001) of Health-related Quality of Life (HRQL) (52.5 ± 22.7 at baseline vs. 59.8 ± 22 at 6 weeks and 77.9 ± 17.3 at 12 months after treatment). Significant postinterventional improvement was observed in every subscale of HRQL. In the majority of patients, only minor, short-lasting and self-limiting side effects were observed, e.g. soft tissue edema of the anterior lower abdominal wall in the acoustic pathway or transient moderate lower abdominal pain as during menstruation. One patient with a very large fibroid experienced strong short-lasting pain after the procedure; two patients experienced post-procedurally a transient sciatic nerve irritation. US-guided HIFU of uterine fibroids reduces disease-related symptoms and improves health-related quality of life.

Cardiac magnetic resonance follow-up of COVID-19 vaccine associated acute myocarditis.

Background: Mass COVID-19 vaccination campaigns have helped impede the COVID-19 pandemic. In rare cases, some vaccines have led to vaccine associated myocarditis in a specific subset of the population, usually young males. Cardiac magnetic resonance (CMR) can reliably diagnose vaccine associated myocarditis, but follow-up data of CMR proven acute myocarditis is scarce. Materials and methods: Nine patients with acute vaccine associated myocarditis underwent baseline and follow-up CMR examinations and were compared to baseline parameters at initial presentation and to a group of 20 healthy controls. CMR protocol included functional assessment, T1 and T2 mapping, T2 signal intensity ratio, strain feature tracking, and late gadolinium enhancement (LGE). Results: Myocarditis patients (n = 9, aged 24 ± 6 years, 8 males) underwent CMR follow-up after an average of 5.8 ± 4.3 months. All patients showed a complete resolution of visual myocardial edema while also demonstrating a reduction in overall LGE extent from baseline to follow-up (4.2 ± 2.1 vs. 0.9 ± 0.8%, p < 0.001), although visual LGE was still noted in all patients. Left ventricular ejection fraction was normal at baseline and at follow-up (58 ± 6 vs. 62 ± 4%, p = 0.10) as well as compared to a healthy control group (60 ± 4%, p = 0.24). T1 (1024 ± 77 vs. 971 ± 34 ms, p = 0.05) and T2 relaxations times (57 ± 6 vs. 51 ± 3 ms, p = 0.03) normalized at follow-up. Most patients reported a resolution of clinical symptoms, while two (22%) reported new onset of exertional dyspnea. Conclusion: Patients with COVID-19 vaccine associated acute myocarditis showed a complete, uncomplicated resolution of myocardial inflammation on follow-up CMR, which was associated with a near complete resolution of symptoms. Minor, residual myocardial scarring was present on follow-up LGE imaging. The long-term implications of the remaining myocardial scar-tissue after vaccine associated myocarditis remain unknown warranting further studies.