Development and multicenter validation of deep convolutional neural network-based detection of colorectal cancer on abdominal CT.

OBJECTIVES: This study aims to develop computer-aided detection (CAD) for colorectal cancer (CRC) using abdominal CT based on a deep convolutional neural network. METHODS: This retrospective study included consecutive patients with colorectal adenocarcinoma who underwent abdominal CT before CRC resection surgery (training set = 379, test set = 103). We customized the 3D U-Net of nnU-Net (CUNET) for CRC detection, which was trained with fivefold cross-validation using annotated CT images. CUNET was validated using datasets covering various clinical situations and institutions: an internal test set (n = 103), internal patients with CRC first determined by CT (n = 54) and asymptomatic CRC (n = 51), and an external validation set from two institutions (n = 60). During each validation, data from the healthy population were added (internal = 60; external = 130). CUNET was compared with other deep CNNs: residual U-Net and EfficientDet. The CAD performances were evaluated using per-CRC sensitivity (true positive/all CRCs), free-response receiver operating characteristic (FROC), and jackknife alternative FROC (JAFROC) curves. RESULTS: CUNET showed a higher maximum per-CRC sensitivity than residual U-Net and EfficientDet (internal test set 91.3% vs. 61.2%, and 64.1%). The per-CRC sensitivity of CUNET at false-positive rates of 3.0 was as follows: internal CRC determined by CT, 89.3%; internal asymptomatic CRC, 87.3%; and external validation, 89.6%. CUNET detected 69.2% (9/13) of CRCs missed by radiologists and 89.7% (252/281) of CRCs from all validation sets. CONCLUSIONS: CUNET can detect CRC on abdominal CT in patients with various clinical situations and from external institutions. KEY POINTS: • Customized 3D U-Net of nnU-Net (CUNET) can be applied to the opportunistic detection of colorectal cancer (CRC) in abdominal CT, helping radiologists detect unexpected CRC. • CUNET showed the best performance at false-positive rates ≥ 3.0, and 30.1% of false-positives were in the colorectum. CUNET detected 69.2% (9/13) of CRCs missed by radiologists and 87.3% (48/55) of asymptomatic CRCs. • CUNET detected CRCs in multiple validation sets composed of varying clinical situations and from different institutions, and CUNET detected 89.7% (252/281) of CRCs from all validation sets.

Ultrahigh-b diffusion-weighted imaging for quantitative evaluation of myelination in shiverer mouse spinal cord.

PURPOSE: To perform a quantitative evaluation of myelination on WT and myelin-deficient (shiverer) mouse spinal cords using ultrahigh-b diffusion-weighted imaging (UHb-DWI). METHODS: UHb-DWI of ex vivo on spinal cord specimens of two shiverer (C3HeB/FeJ-shiverer, homozygous genotype for MbPshi ) and six WT (Black Six, C3HeB/FeJ) mice were acquired using 3D multishot diffusion-weighted stimulated-echo EPI, a homemade RF coil, and a small-bore 7T MRI system. Imaging was performed in transaxial plane with 75 × 75 µm2 in-plane resolution, 1-mm-slice thickness, and radial DWI using bmax = 42,890 s/mm2 . Histological evaluation was performed on upper thoracic sections using optical and transmission electron microscopy. Numerical Monte Carlo simulations (MCSs) of water diffusion were performed to facilitate interpretation of UHb-DWI signal-b curves. RESULTS: The white matter ultrahigh-b radial DWI (UHb-rDWI) signal-b curves of WT mouse cords behaved biexponentially with high-b diffusion coefficient DH < 0.020 × 10-3 mm2 /s. However, as expected with less myelination, the signal-b of shiverer mouse cords behaved monoexponentially with significantly greater DH = 0.162 × 10-3 , 0.142 × 10-3 , and 0.164 × 10-3 mm2 /s at anterodorsal, posterodorsal, and lateral columns, respectively. The axial DWI signals of all mouse cords behaved monoexponentially with D = (0.718-1.124) × 10-3 mm2 /s. MCS suggests that these elevated DH are mainly induced by increased water exchange at the myelin sheath. Microscopic results were consistent with the UHb-rDWI findings. CONCLUSION: UHb-DWI provides quantitative differences in myelination of spinal cords from myelin-deficit shiverer and WT mice. UHb-DWI may become a powerful tool to evaluate myelination in demyelinating disease models that may translate to human diseases, including multiple sclerosis.

Preoperative magnetic resonance imaging-based prognostic model for mass-forming intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: As most staging systems for intrahepatic cholangiocarcinoma (iCCA) are based on pathological results, preoperative prognostic prediction is limited. This study aimed to develop and validate a prognostic model for the overall survival of patients with mass-forming iCCA (MF-iCCA) using preoperative magnetic resonance imaging (MRI) and clinical findings. METHODS: We enrolled a total of 316 patients who underwent preoperative MRI and surgical resection for treatment-naive MF-iCCA from six institutions, between January 2009 and December 2015. The subjects were randomly assigned to a training set (n = 208) or validation set (n = 108). The MRIs were independently reviewed by three abdominal radiologists. Using MRI and clinical findings, an MRI prognostic score was established. We compared the discrimination performance of MRI prognostic scores with those of conventional pathological staging systems. RESULTS: We developed an MRI prognostic score consisting of serum CA19-9 and three MRI findings (tumour multiplicity, lymph node metastasis and bile duct invasion). The MRI prognostic score demonstrated good discrimination performance in both the training set (C-index, 0.738; 95% confidence interval [CI], 0.698-0.780) and validation set (C-index, 0.605; 95% CI, 0.526-0.680). In the validation set, MRI prognostic score showed no significant difference with AJCC 8th TNM stage, MEGNA score and Nathan's stage. CONCLUSIONS: Our MRI prognostic score for overall survival of MF-iCCA showed comparable discriminatory performance with pathological staging systems and might be used to determine an optimal treatment strategy.

Preoperative prediction of postsurgical outcomes in mass-forming intrahepatic cholangiocarcinoma based on clinical, radiologic, and radiomics features.

OBJECTIVES: Current prognostic systems for intrahepatic cholangiocarcinoma (IHCC) rely on surgical pathology data and are not applicable to a preoperative setting. We aimed to develop and validate preoperative models to predict postsurgical outcomes in mass-forming IHCC patients based on clinical, radiologic, and radiomics features. METHODS: This multicenter retrospective cohort study included patients who underwent curative-intent resection for mass-forming IHCC. In the development cohort (single institution data), three preoperative multivariable Cox models for predicting recurrence-free survival (RFS) were constructed, including the clinical-radiologic, radiomics, and clinical-radiologic-radiomics (CRR) models based on clinical and CT findings, CT-radiomics features, and a combination of both, respectively. Model performance was evaluated in the test cohort (data from five institutions) using Harrell's C-index and compared with postoperative prognostic systems. RESULTS: A total of 345 patients (233, development cohort; 112, test cohort) were evaluated. The clinical-radiologic model included five independent CT predictors (infiltrative contour, multiplicity, periductal infiltration, extrahepatic organ invasion, and suspicious metastatic lymph node) and showed similar performance in predicting RFS to the radiomics model (C-index, 0.65 vs. 0.68; p = 0.43 in the test cohort). The CRR model showed significantly improved performance (C-index, 0.71; p = 0.01) than the clinical-radiologic model and demonstrated similar performance to the postoperative prognostic systems in predicting RFS (C-index, 0.71-0.73 vs. 0.70-0.73; p ≥ 0.40) and overall survival (C-index, 0.68-0.71 vs. 0.64-0.74; p ≥ 0.27) in the test cohort. CONCLUSIONS: A model integrating clinical, CT, and radiomics information may be useful for the preoperative assessment of postsurgical outcomes in patients with mass-forming IHCC. KEY POINTS: • The radiomics analysis had incremental value in predicting recurrence-free survival of patients with intrahepatic mass-forming cholangiocarcinoma. • The clinical-radiologic-radiomics model demonstrated similar performance to the postoperatively available prognostic systems (including 8th AJCC system) in predicting recurrence-free survival and overall survival. • The clinical-radiologic-radiomics model may be useful for the preoperative assessment of postsurgical outcomes in patients with mass-forming intrahepatic cholangiocarcinoma.

Feasibility of Changing Intra-Arterial Flow Direction by Temporary Occlusion Using Retrievable Coils: Study with a Normal Pig Model.

PURPOSE: To evaluate feasibility of changing intra-arterial flow direction by temporary occlusion using retrievable coils. MATERIALS AND METHODS: In 2 healthy pig livers, injection of a lipiodol mixture (lipiodol:saline = 2:1) was performed at the segmental arteries after occluding 1 of the subsegmental arteries. This was accomplished using a retrievable coil in 5 different segmental arteries (3 in pig A and 2 in pig B). Injection of the lipiodol mixture was performed through a 3-way system using a hemostatic valve, whereas the retrievable coil delivery system was in the lumen of a microcatheter. Successful coil deployment, occlusion of the vessel, and coil retrieval were evaluated. Redistribution of flow after placement of the coil and vessel patency after coil removal were angiographically evaluated. The distribution of lipiodol mixture was evaluated using cone beam computed tomography. RESULTS: All 5 of the retrievable coils were successfully deployed and removed. Angiography revealed successful occlusion of subsegmental artery after coil placement with flow redistribution followed by restoration of flow after coil retrieval in all cases. On cone beam computed tomography, lipiodol tagging was abundant in hepatic parenchyma supplied by the hepatic artery without coils compared with that supplied by the branch with coils. CONCLUSIONS: Temporary arterial flow redistribution using a retrievable coil was feasible in the healthy pig model and could be applicable for endovascular procedures in which superselection is difficult or unavailable.

Correlation Between Bile Reflux Gastritis and Biliary Excreted Contrast Media in the Stomach.

OBJECTIVE: This study aimed to evaluate the relationship between biliary excreted contrast media in the stomach and the presence of bile reflux gastritis. METHODS: Consecutive 111 patients who underwent both gadoxetic acid-enhanced magnetic resonance cholangiography (gadoxetic MRC) and gastric endoscopy were included in this study. We performed a review of the gadoxetic-MRC image sets acquired 60 minutes after intravenous injection of contrast media and endoscopic images. We recorded amount of contrast media in the stomach. The sensitivity, specificity, and accuracy of duodenogastric bile reflux diagnosis were evaluated for the gadoxetic MRC. Statistical analysis was performed using the Fisher exact test and the linear-by-linear association test. RESULTS: Among the 111 patients, 39 had 60-minute delayed images showing the presence of contrast media in the stomach. Of these 39 patients, 13 had bile reflux gastritis and 5 showed bile in the stomach without evidence of erythematous gastritis. Of the 72 patients who did not show contrast media in the stomach, none had bile reflux gastritis and 2 patients showed bile staining in the stomach without evidence of erythematous gastritis. Bile reflux gastritis was significantly more frequent in patients with contrast media in the stomach on gadoxetic MRC than in those without. Patients with high-grade extension of contrast media in the stomach had significantly frequent bile reflux gastritis than did those with low-grade extension. CONCLUSION: Biliary excreted contrast media in the stomach on 60-minute delayed gadoxetic MRC has a correlation with the presence of bile reflux gastritis on endoscopic examination.

Safety and efficacy of a non-contact radiofrequency device for body contouring in Asians.

BACKGROUND: The non-invasive reduction of subcutaneous abdominal fat became popular. Radiofrequency, non-contact, selective-field device Vanquish® has been developed to selectively induce deep fat tissue heating to reduce waist circumference. OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of clinical, radiological results of the radiofrequency, non-contact, selective-field device treatment. METHODS: Twelve healthy individuals with no underlying medical problem were treated with five sessions of radiofrequency treatment to reduce abdominal subcutaneous fat. 45-minute sessions were performed with an 1-week interval. For efficacy evaluation, patient's abdominal circumferences and body weight were measured, and photographs were taken at baseline and each follow-up visit for 12 weeks. One subject was examined with computed tomography (CT) before the first session and six weeks after the first CT scan, and we measured the volume of subcutaneous fat layer. Any adverse effect was assessed during the entire study period. RESULTS: Reduction in abdominal circumferences was noted in most participants (10 of 12 patients). No serious adverse effect was reported. Volume reduction of abdominal subcutaneous fat layer was confirmed in a subject who took CT scan. CONCLUSIONS: Our study shows that the selective-field radiofrequency treatment seems to be safe and efficient for reduction of abdominal subcutaneous fat.

Deep learning image reconstruction of diffusion-weighted imaging in evaluation of prostate cancer focusing on its clinical implications.

Background: Image-based assessment of prostate cancer (PCa) is increasingly emphasized in the diagnostic workflow for selecting biopsy targets and possibly predicting clinically significant prostate cancer (csPCa). Assessment is based on Prostate Imaging-Reporting and Data System (PI-RADS) which is largely dependent on T2-weighted image (T2WI) and diffusion weighted image (DWI). This study aims to determine whether deep learning reconstruction (DLR) can improve the image quality of DWI and affect the assessment of PI-RADS ≥4 in patients with PCa. Methods: In this retrospective study, 3.0T post-biopsy prostate magnetic resonance imaging (MRI) of 70 patients with PCa in Korea University Ansan Hospital from November 2021 to July 2022 was reconstructed with and without using DLR. Four DWI image sets were made: (I) conventional DWI (CDWI): DWI with acceleration factor 2 and conventional parallel imaging reconstruction, (II) DL1: DWI with acceleration factor 2 using DLR, (III) DL2: DWI with acceleration factor 3 using DLR, and (IV) DL3: DWI with acceleration factor 3 and half average b-value using DLR. Apparent diffusion coefficient (ADC) value, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured by one reviewer, while two reviewers independently assessed overall image quality, noise, and lesion conspicuity using a four-point visual scoring system from each DWI image set. Two reviewers also performed PI-RADSv2.1 scoring on lesions suspected of malignancy. Results: A total of 70 patients (mean age, 70.8±9.7 years) were analyzed. The image acquisition time was 4:46 min for CDWI and DL1, 3:40 min for DL2, and 2:00 min for DL3. DL1 and DL2 images resulted in better lesion conspicuity compared to CDWI images assessed by both readers (P<0.05). DLR resulted in a significant increase in SNR, from 38.4±14.7 in CDWI to 56.9±21.0 in DL1. CNR increased from 25.1±11.5 in CDWI to 43.1±17.8 in DL1 (P<0.001). PI-RADS v2.1 scoring for PCa lesions was more agreeable with the DL1 reconstruction method than with CDWI (κ value CDWI, DL1; 0.40, 0.61, respectively). A statistically significant number of lesions were upgraded from PI-RADS <4 in CDWI image to PI-RADS ≥4 in DL1 images for both readers (P<0.05). Most of the PI-RADS upgraded lesions were from higher than unfavorable intermediate-risk groups according to the 2023 National Comprehensive Cancer Network guidelines with statistically significant difference of marginal probability in DL1 and DL2 for both readers (P<0.05). Conclusions: DLR in DWI for PCa can provide options for improving image quality with a significant impact on PI-RADS evaluation or about a 23% reduction in acquisition time without compromising image quality.

A preoperative scoring system to predict lymph node metastasis in intrahepatic cholangiocarcinoma.

BACKGROUND: The abnormality of imaging finding of lymph node (LN) has demonstrated unsatisfactory diagnostic accuracy for pathologic lymph node metastasis (LNM). We aimed to develop and validate a simple scoring system predicting LNM in patients with intrahepatic cholangiocarcinoma (iCCA) prior to surgery based on MRI and clinical findings. METHODS: We retrospectively enrolled consecutive patients who underwent surgical resection for treatment-naïve iCCA from six institutions between January 2009 and December 2015. Patients who underwent lymph node dissection (LND) were randomly assigned to the training and validation cohorts at a 2:1 ratio, an¹ìd pathologic LN status was evaluated. Patients who did not undergo LND were assigned to the test cohort, and clinical LN status was evaluated. Using MRI and clinical findings, a preoperative LNM score was developed in the training cohort and validated in the validation and test cohorts. RESULTS: The training, validation, and test cohorts included 102, 53, and 118 patients, respectively. The preoperative LNM score consisted of serum carcinoembryonic antigen and two MRI findings (suspicious LN and bile duct invasion). The preoperative LNM score was associated with pathologic LNM in training (p < 0.001) and validation (p = 0.010) cohorts and clinical LNM in test cohort (p < 0.001). The preoperative LNM score outperformed MRI-suspicious LN alone in predicting pathologic LNM (area under the curve, 0.703 vs. 0.604, p = 0.004). The preoperative LNM score was also associated with overall survival in all cohorts (p < 0.001). CONCLUSIONS: Our preoperative LNM score was significantly associated with pathologic or clinical LNM and outperformed MRI-suspicious LN alone.

Typical and atypical imaging findings of intrahepatic cholangiocarcinoma using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging.

PURPOSE: The objective of this study was to examine the imaging features of classic mass-forming intrahepatic cholangiocarcinoma (MICC) and nonclassic hypervascular MICC on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging. METHODS: Twenty pathologically confirmed MICCs were included. Two radiologists retrospectively reviewed the imaging characteristics on T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced images, and hepatobiliary phase (HBP) of each MICC. For the morphologic feature of defect, HBP signal intensity (SI) ratio was calculated by dividing the SI of the MICC by nearby normal liver parenchyma SI. RESULTS: Classic MICCs (n = 14) showed classic rim or peripheral enhancement at arterial dominant phase with centripetal enhance in the delayed phases. Hypervascular MICCs (n = 6) showed complete (n = 4) or near-complete (n = 2) arterial enhancement and washout (n = 6) on delayed phases. On HBP, 13 classic MICCs (93%) and 2 hypervascular MICCs (33%) showed cloud-like SI in the center ("EOB cloud") with peripheral defect. Mean SI ratio was 0.77 in classic MICCs and 0.59 in hypervascular MICC (P = 0.057). CONCLUSIONS: Classic MICCs (70%) frequently showed progressive centripetal enhancement on dynamic phase, and central EOB-cloud appearance with distinct peripheral defect on HBP. Nonclassic hypervascular MICCs comprised 30% of the MICCs in this study. Compared with classic MICCs, hypervascular MICCs showed wash-in on arterial dominant phase and washout on delayed phase.

Endovascular repair of growing chronic type B aortic dissection with a vascular plug.

We report the successful endovascular repair of a growing chronic type B aortic dissection using an Amplatzer Vascular Plug II. A 44-year-old man, with previous medical history of aortic surgery and stenting complained of vague back pain. An approximately 5-mm entry remained in the stented segment of the aorta on computed tomography (CT). Endovascular closure of the entry with a Vascular Plug was uneventful. A 3-month follow-up CT showed no leak, complete false lumen thrombosis in the thoracic segment, shrinkage of the false lumen, and a reduced diameter of thoracic aorta.

Evaluation of Abdominal CT Obtained Using a Deep Learning-Based Image Reconstruction Engine Compared with CT Using Adaptive Statistical Iterative Reconstruction.

Purpose: To compare the image quality of CT obtained using a deep learning-based image reconstruction (DLIR) engine with images with adaptive statistical iterative reconstruction-V (AV). Materials and Methods: Using a phantom, the noise power spectrum (NPS) and task-based transfer function (TTF) were measured in images with different reconstructions (filtered back projection [FBP], AV30, 50, 100, DLIR-L, M, H) at multiple doses. One hundred and twenty abdominal CTs with 30% dose reduction were processed using AV30, AV50, DLIR-L, M, H. Objective and subjective analyses were performed. Results: The NPS peak of DLIR was lower than that of AV30 or AV50. Compared with AV30, the NPS average spatial frequencies were higher with DLIR-L or DLIR-M. For lower contrast objects, TTF in images with DLIR were higher than those with AV. The standard deviation in DLIR-H and DLIR-M was significantly lower than AV30 and AV50. The overall image quality was the best for DLIR-M (p < 0.001). Conclusions: DLIR showed improved image quality and decreased noise under a decreased radiation dose.

Clinical Staging of Mass-Forming Intrahepatic Cholangiocarcinoma: Computed Tomography Versus Magnetic Resonance Imaging.

We compared the performance of computed tomography (CT) and magnetic resonance imaging (MRI) for preoperative clinical staging of mass-forming intrahepatic cholangiocarcinoma (iCCA), using the eighth American Joint Committee on Cancer (AJCC) system. This retrospective, multicenter, cohort study consecutively identified patients who underwent partial hepatectomy for mass-forming iCCA and had preoperative CT and MRI performed from January 2009 to December 2015. CT and MRI characteristics were used to determine clinical stage based on the eighth AJCC system. Performances of CT and MRI for clinical T and N staging were compared using generalized estimating equations. In 334 patients (median age, 63 years; 221 men), MRI sensitivities were significantly higher than CT sensitivities for detecting T1b or higher stages (91.0% vs. 80.5%, respectively, P < 0.001), T2 or higher stages (89.1% vs. 73.8%, respectively, P < 0.001), and T3 or T4 stage (77.8% vs. 58.0%, respectively, P < 0.001). MRI was also more sensitive at identifying multiple tumors than CT (66.7% vs. 50.0%, respectively, P = 0.026), without a significant difference in specificity (78.1% vs. 80.1%, respectively, P = 0.342). Sensitivities were comparable between CT and MRI for determination of size >5 cm (i.e., T1b for single tumor) and extrahepatic organ invasion (i.e., T4). Sensitivities of CT and MRI were not different for N stage (65.0% vs. 64.0%, respectively, P = 0.808), but the specificity of CT was significantly higher than that of MRI (80.7% vs. 72.9%, respectively, P = 0.001) when using a composite reference standard. Conclusion: MRI showed superior sensitivity to CT for diagnosing T2 and T3 stages, particularly multiple tumors. CT and MRI had comparable sensitivity for N staging, but CT provided higher specificity than MRI.

Communication between spaces formed by fasciae of male external genitalia and perineum: computed tomographic cadaveric study and clinical significance.

OBJECTIVE: The purposes were to evaluate the communication and the extent of the spaces formed by fasciae of the male external genitalia and the perineum and to correlate the spaces with clinical observations regarding anatomic progression of diseases. MATERIALS AND METHODS: Multi-detector row computed tomography (CT) was performed through the perineum and the pelvis of 5 fresh cadavers injected with contrast material in the space between dartos and Buck fasciae of the penis. Two of the 5 cadavers, injected with the contrast material mixed with blue ink, were dissected to confirm the observations made on multi-detector row computed tomography. Computed tomographic images of 11 patients with diseases involving the potential spaces formed by the fasciae of the male genitalia and the perineum were correlated with observations made on CT of the cadavers. RESULTS: The contrast material filling the scrotal cavity extended posteriorly in the perineum, remained far below the urogenital diaphragm, and reached superiorly to the potential space along Scarpa fascia in all cadavers. At cadaveric dissection, the ink-stained spaces were confined by the fascial planes involving Colles, Buck, dartos, and Scarpa fasciae. Spread of disease in the 11 patients (6 patients with localized genital edema, 4 with Fournier gangrene, and 1 with bulbous urethral rupture) was confined in the spaces demonstrated on CT images of the cadavers. CONCLUSIONS: Free communication and disease spread occur within the confines of the superficial perineal, scrotal, penile, and abdominal wall spaces formed by Colles, Buck, dartos, and Scarpa fasciae.

Feasibility of computed tomography texture analysis of hepatic fibrosis using dual-energy spectral detector computed tomography.

PURPOSE: To evaluate feasibility of computer tomography texture analysis (CTTA) at different energy level using dual-energy spectral detector CT for liver fibrosis. MATERIALS AND METHODS: Eighty-seven patients who underwent a spectral CT examination and had a reference standard of liver fibrosis (histopathologic findings, n = 61, or clinical findings for normal, n = 26) were included. Mean gray-level intensity, mean number of positive pixels (MPP), entropy, skewness, and kurtosis using commercially available software (TexRAD) were compared at different energy levels. Optimal CTTA parameter cutoffs to diagnose liver fibrosis were evaluated. CTTA parameters at different energy levels correlated with liver fibrosis. The association of CTTA parameters with energy level was evaluated. RESULTS: Mean gray-level intensity, skewness, kurtosis, and entropy showed significant differences between patients with and without clinically significant hepatic fibrosis (P < 0.05). Mean gray-level intensity at 50 keV was significantly positively correlated with liver fibrosis (ρ = 0.502, P < 0.001). To diagnose stages F2-F4, entropy and mean gray-level intensity at low keV level showed the largest area under the curve (AUC; 0.79 and 0.79). Estimated marginal means (EMMs) of mean gray-level intensity showed prominent differences at low energy levels. CONCLUSION: CTTA parameters from different keV levels demonstrated meaningful accuracy for diagnosis of liver fibrosis or clinically significant hepatic fibrosis.

Giant Fibroepithelial Stromal Polyp of the Vulva: Diffusion-Weighted and Conventional Magnetic Resonance Imaging Features and Pathologic Correlation.

BACKGROUND: Fibroepithelial stromal polyp (FESP) is a rare benign mass, usually presenting at the vagina. Herein we report, to our knowledge, the first case of contrast-enhanced magnetic resonance imaging (MRI) with diffusion-weighted images of a giant vulvar FESP, and compare the MRI features with the histopathologic results. CASE: A 14-year-old girl presented with a huge mass as large as 20 cm that originated from the labium majora. Preoperative MRI showed a polypoid mass consisting of a central stalk and surrounding stroma. Different signal intensities on MRI were correlated with various histopathologic features. The mass was cured by complete excision without remnant lesion. SUMMARY AND CONCLUSION: Contrast-enhanced MRI with diffusion-weighted images can help us differentiate FESP from other vulvovaginal stromal tumors with a complete evaluation of the external and internal structures and the depth of invasion.

Feasibility of using computed tomography texture analysis parameters as imaging biomarkers for predicting risk grade of gastrointestinal stromal tumors: comparison with visual inspection.

PURPOSE: To evaluate the feasibility of using computed tomography texture analysis (CTTA) parameters for predicting malignant risk grade and mitosis index of gastrointestinal stromal tumors (GISTs), compared with visual inspection. METHOD AND MATERIALS: CTTA was performed on portal phase CT images of 145 surgically confirmed GISTs (mean size: 42.9 ± 37.5 mm), using TexRAD software. Mean, standard deviation, entropy, mean of positive pixels (MPP), skewness, and kurtosis of CTTA parameters, on spatial scaling factor (SSF), 2-6 were compared by risk grade, mitosis rate, and the presence or absence of necrosis on visual inspection. CTTA parameters were correlated with risk grade. Diagnostic performance was evaluated with receiver operating characteristic curve analysis. Enhancement pattern, necrosis, heterogeneity, calcification, growth pattern, and mucosal ulceration were subjectively evaluated by two observers. RESULTS: Three to four parameters at different scales were significantly different according to the risk grade, mitosis rate, and the presence or absence of necrosis (p < 0.041). MPP at fine or medium scale (r = - 0.547 to - 393) and kurtosis at coarse scale (r = 0.424-0.454) correlated significantly with risk grade (p < 0.001). HG-GIST was best differentiated from LG-GIST by MPP at SSF 2 (AUC, 0.782), and kurtosis at SSF 4 (AUC, 0.779) (all p < 0.001). CT features predictive of HG-GIST were density lower than or equal to that of the erector spinae muscles on enhanced images (OR 2.1; p = 0.037; AUC, 0.59), necrosis (OR, 6.1; p < 0.001; AUC, 0.70), heterogeneity (OR, 4.3; p < 0.001; AUC, 0.67), and mucosal ulceration (OR, 3.3; p = 0.002; AUC, 0.62). CONCLUSION: Using TexRAD, MPP and kurtosis are feasible in predicting risk grade and mitosis index of GISTs. CTTA demonstrated meaningful accuracy in preoperative risk stratification of GISTs.

A case report of intrahepatic bile duct confluence anomalies in VACTERL syndrome.

RATIONALE: The clinical manifestations of VACTERL association include vertebral anomalies, anal atresia, congenital heart diseases, tracheoesophageal fistula, renal dysplasia, and limb abnormalities. The association of intrahepatic anomalies and VACTERL syndrome is a rare coincidence. VACTER syndrome and intrahepatic bile drainage anomalies might be genetically related. PATIENT CONCERNS: A 12-year-old girl presented with episodic colicky abdominal pain, nausea, and vomiting for several years. The individual episodes resolved spontaneously within a few days. She had a history of VACTERL syndrome, including a butterfly shape of the L3 vertebra, anal atresia, and an atrial septal defect. DIAGNOSES: On laboratory findings, abnormal liver function tests included elevated total bilirubin, alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase. There was no significant abnormal finding in hepatobiliary system sonography except mild gallbladder wall thickening. We performed magnetic resonance cholangiopancreatography and demonstrated an abnormal intrahepatic bile duct confluence, which showed 3 bile ducts draining directly into the neck of the gallbladder. INTERVENTION: Her symptoms related to bile reflux during gallbladder contraction. Cholecystectomy with choledochojejunostomy was undertaken because segments of the bile drainage were intertwined. OUTCOMES: After surgery, her symptoms decreased, but abdominal discomfort remained due to uncorrected left intrahepatic anomalies. LESSONS: Although hepatobiliary anomalies are not included in VACTERL association diagnostic criteria, detailed hepatobiliary work up is needed when gastrointestinal symptoms are present in VACTERL association patients.