Systematic Analysis of Common Factors Impacting Deep Learning Model Generalizability in Liver Segmentation.

Purpose: To investigate the effect of training data type on generalizability of deep learning liver segmentation models. Materials and Methods: This Health Insurance Portability and Accountability Act-compliant retrospective study included 860 MRI and CT abdominal scans obtained between February 2013 and March 2018 and 210 volumes from public datasets. Five single-source models were trained on 100 scans each of T1-weighted fat-suppressed portal venous (dynportal), T1-weighted fat-suppressed precontrast (dynpre), proton density opposed-phase (opposed), single-shot fast spin-echo (ssfse), and T1-weighted non-fat-suppressed (t1nfs) sequence types. A sixth multisource (DeepAll) model was trained on 100 scans consisting of 20 randomly selected scans from each of the five source domains. All models were tested against 18 target domains from unseen vendors, MRI types, and modality (CT). The Dice-Sørensen coefficient (DSC) was used to quantify similarity between manual and model segmentations. Results: Single-source model performance did not degrade significantly against unseen vendor data. Models trained on T1-weighted dynamic data generally performed well on other T1-weighted dynamic data (DSC = 0.848 ± 0.183 [SD]). The opposed model generalized moderately well to all unseen MRI types (DSC = 0.703 ± 0.229). The ssfse model failed to generalize well to any other MRI type (DSC = 0.089 ± 0.153). Dynamic and opposed models generalized moderately well to CT data (DSC = 0.744 ± 0.206), whereas other single-source models performed poorly (DSC = 0.181 ± 0.192). The DeepAll model generalized well across vendor, modality, and MRI type and against externally sourced data. Conclusion: Domain shift in liver segmentation appears to be tied to variations in soft-tissue contrast and can be effectively bridged with diversification of soft-tissue representation in training data.Keywords: Convolutional Neural Network (CNN), Deep Learning Algorithms, Machine Learning Algorithms, Supervised Learning, CT, MRI, Liver Segmentation Supplemental material is available for this article. © RSNA, 2023.

Use of Skeletal Muscle Index as a Predictor of Wait-List Mortality in Patients With End-Stage Liver Disease.

The aim of this study is to validate a proposed definition of sarcopenia in predicting wait-list mortality. We retrospectively evaluated 355 adults (age ≥18 years) with cirrhosis listed for first-time LT from January 1, 2010, to April 1, 2018 from our center. Demographic, laboratory, and outcome data were collected in conjunction with computed tomography scans performed within 3 months of listing. Using imaging analysis software, the skeletal muscle index (SMI), which is a marker for sarcopenia-related mortality, was calculated. A survival analysis was performed to evaluate the association of the proposed sarcopenia definition of SMI <50 cm2 /m2 for men or <39 cm2 /m2 for women with wait-list mortality or delisting. Median SMI was 54.1 cm2 /m2 (range, 47-60 cm2 /m2 ). A total of 61 (17.2%) patients exhibited sarcopenia according to the proposed threshold, and 24.6% (57/232) of men were sarcopenic compared with 3.3% (4/123) of women (P < 0.001). Mean (standard deviation [SD]) SMI was also higher for men (56.6 ± 9.6 cm2 /m2 ) than for women (50.7 ± 8.0 cm2 /m2 ; P < 0.001). Median follow-up time among patients was 2.1 months (0-12 months), and 30 events were observed (hazard ratio, 0.98; 95% confidence interval, 0.95-1.02; P = 0.41). There was no statistically significant difference in time on the waiting list between patients with and without sarcopenia (P = 0.89) as defined at the threshold. Using the prespecified definitions of sarcopenia based on SMI, there was no statistically significant difference in mortality and delisting from the transplant waiting list between patients with and without sarcopenia in this population. Practice and region-specific patterns for pretransplant selection and median Model for End-Stage Liver Disease at transplant may affect SMI as a predictor of wait-list mortality.

Relative Sarcopenia With Excess Adiposity Predicts Survival After Transjugular Intrahepatic Portosystemic Shunt Creation.

OBJECTIVE. The purpose of this study was to assess the impact of relative sarcopenia with excess adiposity on mortality after transjugular intrahepatic portosystemic shunt (TIPS) creation. MATERIALS AND METHODS. In this single-institution retrospective study, patients underwent abdominal CT scans within 100 days before or 30 days after TIPS creation. Subcutaneous and visceral adipose tissue and muscle were segmented at the L3 vertebral level. Relative sarcopenia with excess adiposity was defined as the lowest sex-specific quartile of muscle area divided by muscle plus adipose. Dates of death, liver transplantation, TIPS occlusion, and hepatic encephalopathy (HE) after TIPS creation were identified. Mortality was evaluated using competing risks survival analysis. Number of HE episodes and time to first episode were analyzed using negative binomial regression and competing risks survival analysis, respectively. RESULTS. A total of 141 patients (91 men; mean age, 56 years) were included in this study. In univariate analyses, Model for End-Stage Liver Disease (MELD) score (hazard ratio [HR], 1.09 per point; CI, 1.05-1.13; p < 0.001) and relative sarcopenia with excess adiposity (HR, 2.70; CI, 1.55-4.69; p < 0.001) were significant risk factors for shorter survival after TIPS. In multivariate analysis, both MELD score (HR, 1.09; CI, 1.03-1.15; p = 0.003) and relative sarcopenia with excess adiposity (HR, 2.65; CI, 1.56-4.51; p < 0.001) were significant predictors of worse survival. The C-index at 30 days was 0.71 for MELD score, 0.72 for relative sarcopenia with excess adiposity, and 0.80 for a model including both. There was no association between relative sarcopenia with excess adiposity and number of HE episodes (incidence rate ratio, 1.08; CI, 0.49-2.40; p = 0.84) or time to first HE episode (HR, 0.89; CI, 0.51-1.54; p = 0.67). CONCLUSION. Relative sarcopenia with excess adiposity is a risk factor for mortality after TIPS and contributes additional prognostic information beyond MELD score.

Cross-sectional CT Assessment of the Extent of Injectate Spread at CT Fluoroscopy-guided Cervical Epidural Interlaminar Steroid Injections.

Background Previous studies analyzed contrast agent spread during cervical interlaminar epidural steroid injections (CILESIs) by using planar fluoroscopy and reported wide variance of the rate of spread to the ventral epidural space (VES). Cross-sectional CT allows for direct viewing of contrast agent in the VES, providing improved spread assessment and thereby informing needle placement decisions when targeting pain generators. Purpose To determine the extent of injectate spread at CT fluoroscopy-guided CILESI, with particular attention to the VES and bilateral neuroforamina, by using cross-sectional CT. Materials and Methods This study reviewed 83 consecutive CT fluoroscopy-guided CILESIs at which a postprocedural cervical spine CT was performed (June 2016 to December 2017). All procedures used the same injectate (2 mL corticosteroid, 3 mL contrast agent). Postprocedural CT scans were reviewed for the presence of contrast within the VES, dorsal epidural space, ipsilateral neuroforamen, and contralateral neuroforamen in every cervical interlaminar level. Descriptive data are presented as frequencies or means. McNemar tests or hierarchical logistic models were used to assess associations between covariates and contrast agent spread to particular locations. Results The study cohort included 73 individual patients (59% women; 43 of 73) (mean patient age, 57.6 years ± 11.5 [standard deviation]). Mean number of levels of cranial spread were 0.6 level for VES, 1.9 levels for contralateral neuroforamen, 2.1 levels for ipsilateral neuroforamen, and 3 levels for dorsal epidural space. No VES spread in any level was found with 35% (29 of 83) of injections. VES spread was more likely to occur in the level of needle placement (43%; 36 of 83) than in other interlaminar levels (19.5%; 97 of 498; P < .001). Spread was more likely to occur in the neuroforamen ipsilateral to the needle approach compared with contralateral (P < .001). Conclusion Cervical interlaminar epidural steroid injections have injectate spreads with a mean of less than one level cranially in the ventral epidural space (VES) and approximately two levels in the neuroforamen. VES spread occurs more frequently at the level of needle placement and within the ipsilateral neuroforamen. © RSNA, 2019.

DIfferential Subsampling With Cartesian Ordering With Respiratory Triggering Versus Conventional Liver Acquisition With Volume Acquisition: A Multiple Reader Preference Study.

OBJECTIVE: The aim of this study was to compare respiratory-triggered DIfferential Subsampling with Cartesian Ordering (rtDISCO) and breath-held Liver Acquisition with Volume Acquisition (LAVA) image quality. METHODS: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant prospective study, 25 subjects underwent T1 imaging with rtDISCO and LAVA before and after intravenous contrast. Three readers scored individual series and side-by-side comparisons for motion and noise. Eight clinical tasks were qualitatively assessed. RESULTS: As individual series, readers rated rtDISCO images as more degraded by motion on both precontrast (mean rtDISCO score, 2.7; LAVA, 1.6; P < 0.001) and postcontrast images (rtDISCO, 2.4; LAVA, 1.8; P < 0.001). Readers preferred LAVA images based on motion on both precontrast (mean preference, -1.2; P < 0.001) and postcontrast images (mean preference, -0.7; P < 0.001) on side-by-side assessment. There was no preference between sequences for 6 of 8 clinical tasks on postcontrast images. CONCLUSIONS: Readers preferred LAVA with respect to motion but not noise; there was no preference in most of the tested clinical tasks.

LI-RADS Treatment Response Algorithm: Performance and Diagnostic Accuracy.

Background In 2017, the Liver Imaging Reporting and Data System (LI-RADS) included an algorithm for the assessment of hepatocellular carcinoma (HCC) treated with local-regional therapy. The aim of the algorithm was to enable standardized evaluation of treatment response to guide subsequent therapy. However, the performance of the algorithm has not yet been validated in the literature. Purpose To evaluate the performance of the LI-RADS 2017 Treatment Response algorithm for assessing the histopathologic viability of HCC treated with bland arterial embolization. Materials and Methods This retrospective study included patients who underwent bland arterial embolization for HCC between 2006 and 2016 and subsequent liver transplantation. Three radiologists independently assessed all treated lesions by using the CT/MRI LI-RADS 2017 Treatment Response algorithm. Radiology and posttransplant histopathology reports were then compared. Lesions were categorized on the basis of explant pathologic findings as either completely (100%) or incompletely (<100%) necrotic, and performance characteristics and predictive values for the LI-RADS Treatment Response (LR-TR) Viable and Nonviable categories were calculated for each reader. Interreader association was calculated by using the Fleiss κ. Results A total of 45 adults (mean age, 57.1 years ± 8.2; 13 women) with 63 total lesions were included. For predicting incomplete histopathologic tumor necrosis, the accuracy of the LR-TR Viable category for the three readers was 60%-65%, and the positive predictive value was 86%-96%. For predicting complete histopathologic tumor necrosis, the accuracy of the LR-TR Nonviable category was 67%-71%, and the negative predictive value was 81%-87%. By consensus, 17 (27%) of 63 lesions were categorized as LR-TR Equivocal, and 12 of these lesions were incompletely necrotic. Interreader association for the LR-TR category was moderate (κ = 0.55; 95% confidence interval: 0.47, 0.67). Conclusion The Liver Imaging Reporting and Data System 2017 Treatment Response algorithm had high predictive value and moderate interreader association for the histopathologic viability of hepatocellular carcinoma treated with bland arterial embolization when lesions were assessed as Viable or Nonviable. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Gervais in this issue.

Imaging-guided percutaneous thrombin injection for the treatment of iatrogenic femoral artery pseudoaneurysms.

PURPOSE: To evaluate factors that may affect successful ultrasound-guided percutaneous thrombin injection of iatrogenic femoral artery pseudoaneurysms (PSA). MATERIALS AND METHODS: This was an IRB-approved, HIPAA-compliant retrospective study of 326 consecutive subjects (138 males, 188 females; mean age 68 years, range 18-95) who underwent thrombin injection for treatment of femoral PSA; follow-up ultrasound was available in 145 subjects. The number of PSA lobes and dimensions, pre-procedure laboratory values (international normalized ratio [INR], activated partial thromboplastin time [aPTT], platelet count), and concomitant anticoagulation therapy were recorded. RESULTS: Technical success was achieved in 98.2% (320/326) of subjects. Primary effectiveness (complete thrombosis at 24 h) was achieved in 74.5% (108/145). Twenty-five subjects underwent repeat thrombin injection, successful in 21 subjects, for a total effectiveness rate of 97.0% (129/133). No imaging factor was associated with technique failure, including number of lobes (p = 0.898), largest dimension (p = 0.344), or volume (p = 0.697). No statistically significant difference in pre-procedure INR, aPTT, or platelet count was found between subjects with CT and those with IT (p > 0.138). Anticoagulation therapy was associated with incomplete thrombosis (35.5% [38/107] for CT vs. 63.9% [23/26] for IT; p = 0.002). CONCLUSION: Imaging-guided percutaneous thrombin injection has high technical success and effectiveness rates for the treatment of iatrogenic femoral artery PSA. Anticoagulation therapy was the only factor associated with incomplete thrombosis.

Brain metabolite alterations in Eisenmenger syndrome: Evaluation with MR proton spectroscopy.

OBJECTIVE: Eisenmenger syndrome (ES) is a life-threatening disease characterized by pulmonary hypertension and cyanosis in patients with congenital heart diseases. The aim of this study was to determine the brain metabolite changes in Eisenmenger syndrome compared with a control group using MR proton spectroscopy. METHODS AND MATERIALS: The study included 10 children (3 male, 7 female) with congenital heart diseases and a diagnosis of Eisenmenger syndrome. The control group consisted of 10 healthy volunteer children. All were examined with a 1.5T MRI scanner and single voxel spectroscopy was performed to obtain spectra from three different regions; left frontal subcortical white matter, left lentiform nucleus and left thalamus. Peak integral values obtained from the spectra were used as quantitative data. RESULTS: The ages of the children with ES were between 5 and 16 years, and between 5 and 15 years in the control group. Periventricular white matter hyperintensities were observed in 3 patients. On MR spectroscopy study, significantly lower levels of Choline metabolite (Cho) were detected in the frontal subcortical region and thalamus regions of the patients compared with the control group. There was no statistically significant difference between the levels of other metabolites (NAA, Cr, mI and Glx). In the lentiform nucleus, although the average value of Cho in ES patients was lower than that of the control group, it was not statistically significant. CONCLUSION: Cho metabolite was determined to have an important role in brain metabolism in Eisenmenger syndrome patients. Oral Cho treatment may help to extend survival.

Brain diffusion changes in Eisenmenger syndrome.

OBJECTIVE: This preliminary study aimed to evaluate whether there are changes in the apparent diffusion coefficient (ADC) values of the brain in patients presenting with Eisenmenger syndrome (ES). METHODS: This cross-sectional study included 10 consecutively recruited patients with ES and 10 healthy control subjects. In the patients and controls, eight distinct neuroanatomical locations were selected for analysis. Quantitative measurements of ADC values of the frontal white matter (FWM), occipital white matter, lentiform nucleus (LN), thalamus, frontal cortex, anterior and posterior limbs of the internal capsule and caudate nucleus were measured. Statistical analysis was performed using SPSS® (IBM Corp., New York, NY; formerly SPSS Inc., Chicago, IL) for Windows v. 20. Data were presented as mean ± standard deviation values. The Kruskal-Wallis test was used to assess differences in the ADC values of each brain location between the ES group and the control group. Statistical significance was accepted at the level of p < 0.05. RESULTS: The ADC values of the FWM and LN were significantly higher in the ES group than that in the control group. The mean ADC levels of other brain regions were not significantly different between the groups. CONCLUSION: Chronic hypoxia in patients with ES may lead to diffusion changes in the brain tissue. There is a need for further studies to assess the clinical significance of cerebral ADC values in patients with ES. Advances in knowledge: The ratio of extracellular volume to intracellular volume in the FWM and LN can be considered to be increased in patients with ES.

Comparison of the Efficacy of Dry Needling and High-Power Pain Threshold Ultrasound Therapy with Clinical Status and Sonoelastography in Myofascial Pain Syndrome.

OBJECTIVE: The aim of this study was to compare the therapeutic efficacy of high-power pain threshold (HPPT) ultrasound therapy applied to the trigger points and dry needling (DN) in myofascial pain syndrome. DESIGN: Sixty-one patients were randomly assigned to an HPPT (n = 30) and dry needling (n = 31) groups. The primary outcome measures were the Visual Analog Scale (VAS) and Neck Pain and Disability Scale (NPDS), both at 1 week and 4 weeks after treatment. The secondary outcome measures were the number of painful trigger points, range of the tragus-acromioclavicular joint, the Short Form-36, the Beck Depression Inventory, the Beck Anxiety Inventory, and sonoelastographic tests after a 1-week treatment. RESULTS: More improvement was seen in anxiety in the HPPT group (P < 0.05). However, no significant differences were found between the groups with regard to other parameters (P > 0.05). A decrease in tissue stiffness was only seen in the HPPT group (P < 0.05). Significant posttreatment improvements were seen on all clinical scales in both groups (P < 0.05). After a treatment period of 4 weeks, a significant improvement was also observed on the visual analog scale and NPDS (P < 0.05). CONCLUSIONS: Our study favors the efficacy of both treatment methods in myofascial pain syndrome. Although a significant decrease was shown in tissue stiffness with HPPT, neither of these treatments had an apparent superiority.

Hyperdense Middle Cerebral Artery Sign Together with Pulmonary Thromboembolism.

BACKGROUND: Hyperdense middle cerebral artery sign is an appearance of the middle cerebral artery on non-contrast-enhanced computed tomography. Embolic occlusion of the pulmonary arterial system is referred to as pulmonary embolism. When pulmonary embolism coexists with a patent foramen ovale, increased pressure in the right atrium may result in widening of the foramen and consequently, cause serious conditions due to paradoxical embolus. Coexistence of hyperdense middle cerebral artery sign and pulmonary thromboembolism is very rare in the literature. CASE REPORT: We presented a 60-year-old female patient who had both hyperdense middle cerebral artery sign and pulmonary thromboembolism. CONCLUSIONS: To our knowledge, togetherness of hyperdense MCA sign and pulmonary thromboembolism is extremely rare in the literature. In our case, we found both pulmonary embolism due to DVT and paradoxical embolism due to existing patent foramen ovale.

Reverse U-shaped horseshoe kidney accompanied by gibbus deformity and spina bifida.

Horseshoe kidney (HSK) is the most common fusion anomaly of kidneys. Diagnosis of horseshoe kidneys is made by the demonstration of an isthmus or band of renal tissue between the lower poles of the kidneys. Connection between the upper poles of the kidneys is extremely rare. Several types of skeletal anomalies can be seen concomitantly with HSK. In our present case, where the patient was a 3-year-old male, the connection of renal tissue was located between the upper poles of the kidneys. Furthermore, there was an accompanying spina bifida and Gibbus deformity secondary to anterior hypoplasia of the T10 vertebral body.

[Diffusion magnetic resonance imaging of thorax]. / Toraks difüzyon manyetik rezonans görüntüleme.

Although magnetic resonance imaging (MRI) of Thorax is only useful for morphological evaluation, currently we can use it for functional evaluation such as diffusion weighted imaging. Currently, we can obtain higher quality images because of new technologies such as software that decrease motion artefact, use of multi-channel, parallel imaging and fast sequences. Many promising results of thorax MRI have been published. It may also be an alternative to thorax computed tomography in some indications without radiation exposure risk. In this review, we evaluated current literature on use of DWI MRI examination on the pathologies of lungs and mediastinum and aimed to present what kind of information is provided on recognition and characterization of thoracic pathologies.

A rare tuberculosis form: congenital tuberculosis.

Congenital tuberculosis is defined as infection developing as a result of the encounter between the infant and Mycobacterium tuberculosis bacilli during the intrauterine period or during normal birth. Although tuberculosis infection is very common all over the world congenital tuberculosis cases are rare and mortalities of 50% have been reported. Non-specific symptoms in congenital tuberculosis and difficulties encountered in the diagnosis of tuberculosis in general, make it difficult to reach a final diagnosis. Cases of congenital tuberculosis are generally known clinically during the first postnatal month. This case is important as the three-month infant was presented with pneumonia symptoms and diagnosed as congenital tuberculosis after an attentive anamnesis which is unusual during three postnatal months. To our knowledge, this case is one of a few cases in the literature diagnosed as congenital tuberculosis in three months. Our case emphasizes that it is necessary to consider congenital tuberculosis in the differential diagnosis of pulmonary infections in infants, particularly in countries where the incidence of tuberculosis is high. For this reason, we believe that a successfully obtained anamnesis is the parameter which provides a valid diagnosis. Furthermore, early and speedy initiation of treatment in cases with a potential diagnosis of tuberculosis is a very important factor that affects prognosis.