Percutaneous placement of a retrievable fully covered metal stent with anchoring flaps for the treatment of biliary anastomotic stricture following LDLT.

To investigate the outcomes following percutaneous placement of a retrievable fully covered self-expanding metal stent (fcSEMS) with anchoring flaps at proximal and distal ends for the treatment of biliary anastomotic strictures following living-donor liver transplantation (LDLT). We retrospectively reviewed the medical records of nine patients who underwent this procedure at our centre between April 2020 and March 2021. Percutaneous stent placement was technically successful in 100% patients, and all stents were successfully retrieved. No proximal or distal stent migration or occlusion was observed during the mean (±SD) stent indwelling period of 191(± 77) days. Clinical success was 89%. There was one major bleeding complication related to the biliary approach and one minor stent-related complication of calculus/sludge. During the mean (±SD) follow-up period of 595 ± 207 days after stent retrieval, only one patient developed recurrent clinical biliary stricture and symptoms. Percutaneous placement of a retrievable fcSEMS with anchoring flaps is safe and feasible for the treatment of biliary anastomotic strictures following LDLT.

Diagnostic performance of dual-energy computed tomography for HCC after transarterial chemoembolization: Utility of virtual unenhanced and low keV virtual monochromatic images.

The purpose of this study is to evaluate the usefulness of virtual unenhanced (VUE) and low keV virtual monochromatic images (VMI) for diagnosing viable hepatocellular carcinomas (HCC) after transarterial chemoembolization (TACE). This retrospective study included 53 patients with suspected viable HCC after TACE who underwent multiphasic liver computed tomography including true unenhanced (TUE) phase and conventional (CV) enhanced phases on a dual-energy scanner. VUE images, 40 keV and 55 keV VMIs of enhanced phases were reconstructed using dual-energy computed tomography data. For every patient, six combination image sets (TUE-CV; TUE-55; TUE-40; VUE-CV; VUE-55; VUE-40) were evaluated by two readers and compared with the reference standard.There was no statistically significant difference (P > .05) in sensitivity or specificity among all image combinations. In most combinations, interobserver agreements were almost perfect. The diagnostic odds ratio showed a higher trend in combinations with conventional images. Currently, with regards to diagnostic performance, liver computed tomography including TUE and CV enhanced phases is recommended for tumor surveillance after TACE because VUE and VMIs do not have a distinct advantage compared to conventional images.

Comparison of spin-echo echo-planar imaging magnetic resonance elastography with gradient-recalled echo magnetic resonance elastography and their correlation with transient elastography.

PURPOSE This study aimed to assess the agreement between liver stiffness (LS) values obtained by the gradient-recalled echo (GRE) magnetic resonance elastography (MRE) and spin-echo echo-planar imaging (SE-EPI) MRE with those of transient elastography (TE), respectively. METHODS We retrospectively included 48 participants who underwent liver MRE with both GRE and SE-EPI sequences in the same session and also TE within 1 year. We obtained LS values for MRE by drawing free-hand region of interest, and TE was performed using a FibroScan device. We assessed the relationship between the mean LS values obtained by each MRE sequence and TE using the correlation coefficients and Bland-Altman plots, respectively. We also compared LS values and technical failure rates of measured values from MRE between SE-EPI and GRE sequences using the paired t-test and McNemar's test. The MRE failure was defined as the absence of pixel value with a confidence index above 95%. RESULTS The LS values from SE-EPI and GRE sequences strongly correlated with those from TE (GRE; r = 0.73, P < .001 vs. SE-EPI; r = 0.79, P < .001). In addition, the LS values from the 2 MRE sequences showed excellent relationship (intraclass correlation coefficient, 0.94 [0.89-0.97], P < .001). The LS values from SE-EPI and GRE MRE were not significantly different (4.14 kPa vs. 3.88 kPa, P = .19). Furthermore, the technical success rate of SE-EPI MRE was superior to that of GRE (100% vs. 83.8%, P = .031). CONCLUSION The measured LS values obtained using TE correlated strongly with those obtained using GRE and SE-EPI MRE techniques, even though SE-EPI-MRE resulted a higher technical success rate than GRE-MRE. Therefore, we believe that TE, GRE, and SE-EPI MR elastography techniques may complement each other according to the appropriate individual situation.

Treatment failure after rotational atherectomy and balloon angioplasty in recurrent cystic adventitial disease of the popliteal artery: a case report.

Cystic adventitial disease (CAD), which usually affects the popliteal artery, is a rare vascular condition in which fluid accumulates in the sub-adventitial layer, compressing the lumen. Historically, surgical treatment is preferred over endovascular or minimally invasive techniques, due to its lower recurrence rates. Here, the case of a 67-year-old male patient, in whom rotational atherectomy was performed for recurrent CAD following surgical cyst excision and patch angioplasty is reported. The patient's symptoms recurred one day after the rotational atherectomy procedure and repeat computed tomography angiography showed recurrence of the disease. Due to gradual worsening of the condition during 8 months of follow-up, left distal femoral artery to popliteal artery (below-the-knee) bypass surgery was performed using an ipsilateral reversed great saphenous vein graft. Follow-up has continued for 2 years without complications or requirement of additional treatment. This novel case is the first report of atherectomy attempted for recurrent CAD that led to an early recurrence. Our experience emphasises that additional surgical approaches should be selected over endovascular procedures for treating recurrent CAD.

Diagnosing ulnar neuropathy at the elbow on MRI: importance of the longitudinal extent of the hyperintense ulnar nerve.

OBJECTIVE: To evaluate the usefulness of the longitudinal extent (LE) of high ulnar nerve signal intensity (SI) for the diagnosis of ulnar neuropathy at the elbow (UNE). MATERIALS AND METHODS: This retrospective study included 68 patients who underwent elbow MRI. Twenty-seven and 41 patients were enrolled in the UNE and control groups, respectively. Qualitative and quantitative analyses of the SI and size of the ulnar nerve at the cubital tunnel, proximal, and distal to the cubital tunnel were performed. Cross-sectional area (CSA) and nerve-to-muscle contrast ratio (NMCR) were measured at each level. The LE of the hyperintense ulnar nerve was evaluated using axial and coronal images. The presence of space-occupying lesions (SOLs), subluxation, and muscle denervation were recorded. Univariate and multivariate analyses were performed to identify independent predictive factors. RESULTS: Ulnar nerve hyperintensity at and distal to the cubital tunnel, presence of compression, SOL, muscle denervation, LE of hyperintense ulnar nerve, NMCR, and CSA at and distal to the cubital tunnel significantly differed between the two groups. Multivariate logistic regression analysis showed that the LE of the hyperintense ulnar nerve and CSA at the cubital tunnel were independent predictive factors for UNE (p < 0.05). CONCLUSION: LE of the hyperintense ulnar nerve could be a useful predictive factor for UNE.

Percutaneous cholecystostomy for acute cholecystitis after stent insertion in patients with malignant biliary obstruction: clinical outcomes of 107 patients.

BACKGROUND: The outcome of percutaneous cholecystostomy (PC) in malignant patients with acute cholecystitis (AC) after biliary stent insertion has not been investigated in a large group. PURPOSE: To evaluate the clinical outcomes of PC for AC after stent insertion in patients with malignant biliary obstruction. MATERIAL AND METHODS: From April 2007 to February 2019, 107 patients (57 men, 52 women; mean age = 67.5 years; age range = 27-93 years) who had undergone PC for AC after biliary stent insertion were retrospectively evaluated. Of the 107 patients, 86 underwent biliary stent insertion by the endoscopic approach and the remaining 21 patients by the percutaneous approach. All patients were classified into three groups: those with stent-induced AC; those with cancer-induced AC; and those with AC without mechanical cause (biliary stent, GB stone, or cancer invasion). The mean survival time, recurrence rate, symptom improvement, and cystic duct patency in each patient group were analyzed. RESULTS: Stent-induced AC (n = 40, 37.4%) developed with a mean onset time of six days (range = 0-14 days), AC without mechanical cause (n = 27, 25.2%), 87 days (range = 15-273 days), and cancer-induced AC (n = 40, 37.4%), 137 days (range = 15-447 days) after stent insertion. Symptom resolution and significant improvement in laboratory test values were achieved in 95 patients (88.8%) within four days after PC. CONCLUSION: PC is a technically safe and effective method for the treatment of AC after biliary stent insertion in patients with malignant biliary obstruction.

Transrenal Hemodialysis Catheter Insertion and Replacement in Patients with Upper Extremity Central Venous Access Exhaustion.

PURPOSE: Patients undergoing long-term hemodialysis may suffer upper extremity central venous access failure and require an alternative route. This study aimed to evaluate the safety and efficacy of transrenal hemodialysis catheter insertion/replacement in patients with upper extremity central venous access failure. MATERIALS AND METHODS: A multicenter retrospective cohort study was made of transrenal hemodialysis catheter insertion/replacement performed between 2014 and 2020. The history of renal replacement therapy and central venous catheters and the technical details of transrenal hemodialysis catheter insertion/replacement, patency, removal and complications were obtained for all patients. RESULTS: Six insertion and four replacement procedures involving transrenal hemodialysis catheters were evaluated in six patients (M:F = 3:3; median age, 49.5 years). Percutaneous transrenal (right:left = 1:5) hemodialysis catheter insertion was technically successful without complication in all six patients. In two patients, the tract was not lost because the safety guidewire was still in place, so no second puncture was required. The mean procedure time was 33.0 ± 9.2 min. The mean primary patency duration was 107.3 ± 70.9 days. During the mean follow-up duration of 141.2 ± 137.1 days, four hemodialysis catheter replacement procedures were successfully performed for catheter malfunction (n = 2) and dislodgement (n = 2). Catheter removal was successfully performed in four patients after confirming normal coagulation, followed by subsequent renal replacement therapy. CONCLUSION: Percutaneous insertion/replacement of transrenal hemodialysis catheters is feasible, safe, and effective when upper extremity central venous access is exhausted, and the catheters can be maintained for a reasonable period of time. LEVEL OF EVIDENCE: Level 4, Case Series.

Ultrasonographic features of uterine cervical lesions.

Currently, ultrasound (US) is a valuable imaging tool for the initial assessment and evaluation of the female genital organs, uterus, and adnexa. However, it is easy to overlook the uterine cervix while conducting a pelvic US. Uterine cervical lesions may range from benign to malignant in nature. Therefore, meticulous examination with US may play a key role in assessing uterine cervical lesions. Although there is substantial overlap in the US findings across various uterine cervical lesions, some US features, in tandem with clinical characteristics, may suggest a specific diagnosis. Familiarity with the clinical settings and US characteristics of different uterine cervical lesions can support prompt and accurate diagnosis of suspicious lesions. This review article aims to describe the features of US and possible values for distinction of these lesions in the uterine cervix.

Reversed Approach through Lymphocele/Lymphatic Fluid Collection for Glue Embolization of Injured Lymphatic Vessels.

A total of 9 glue embolization procedures of injured lymphatic vessels with a reversed approach from the lymphocele/lymphatic fluid collection in 8 patients were retrospectively reviewed. The approach routes were via the indwelling chest tube for pleural effusion (n = 2), the drainage catheter tract for abdominopelvic lymphocele/lymphatic fluid collection/thigh lymphocele (n = 4), and the direct puncture of the lymphatic fluid collection at the operation bed (n = 2). All the procedures were technically successful without complications. The mean daily leakage rate decreased from 465 mL/d before the procedure to 42 mL/d after the procedure, and the drainage catheters could be removed after 8 procedures, achieving a clinical success rate of 88.9% (8 of 9 procedures).

Imaging Predictors of Survival in Patients with Single Small Hepatocellular Carcinoma Treated with Transarterial Chemoembolization.

OBJECTIVE: Clinical outcomes of patients who undergo transarterial chemoembolization (TACE) for single small hepatocellular carcinoma (HCC) are not consistent, and may differ based on certain imaging findings. This retrospective study was aimed at determining the efficacy of pre-TACE CT or MR imaging findings in predicting survival outcomes in patients with small HCC upon being treated with TACE. Besides, the study proposed to build a risk prediction model for these patients. MATERIALS AND METHODS: Altogether, 750 patients with functionally good hepatic reserve who received TACE as the first-line treatment for single small HCC between 2004 and 2014 were included in the study. These patients were randomly assigned into training (n = 525) and validation (n = 225) sets. RESULTS: According to the results of a multivariable Cox analysis, three pre-TACE imaging findings (tumor margin, tumor location, enhancement pattern) and two clinical factors (age, serum albumin level) were selected and scored to create predictive models for overall, local tumor progression (LTP)-free, and progression-free survival in the training set. The median overall survival time in the validation set were 137.5 months, 76.1 months, and 44.0 months for low-, intermediate-, and high-risk groups, respectively (p < 0.001). Time-dependent receiver operating characteristic curves of the predictive models for overall, LTP-free, and progression-free survival applied to the validation cohort showed acceptable areas under the curve values (0.734, 0.802, and 0.775 for overall survival; 0.738, 0.789, and 0.791 for LTP-free survival; and 0.671, 0.733, and 0.694 for progression-free survival at 3, 5, and 10 years, respectively). CONCLUSION: Pre-TACE CT or MR imaging findings could predict survival outcomes in patients with small HCC upon treatment with TACE. Our predictive models including three imaging predictors could be helpful in prognostication, identification, and selection of suitable candidates for TACE in patients with single small HCC.

CT for evaluation of urolithiasis: image quality of ultralow-dose (Sub mSv) CT with knowledge-based iterative reconstruction and diagnostic performance of low-dose CT with statistical iterative reconstruction.

PURPOSE: To compare radiation dose and image quality in regular, low, and ultralow-dose CT protocols, and to evaluate diagnostic performance of low-dose CT for urolithiasis. MATERIALS AND METHODS: Sixty-five patients with suspected urolithiasis underwent three different scans under the regular, low, and ultralow-dose protocols. The regular dose scans were reconstructed using filtered back projection and the low-dose scans were reconstructed using a statistical iterative reconstruction. The ultralow-dose scans were reconstructed using both techniques in addition to a knowledge-based IR. Effective radiation doses were compared. Objective image noise was assessed by measuring standard deviation of HU and subjective image assessment was performed with a 3- or 5-point scale. Diagnostic performance of the low-dose image was evaluated, using the regular dose image as a standard reference and the interobserver agreement between two reviewers with different levels of experience was calculated. RESULTS: The effective radiation dose was significantly different in each protocol (p < 0.001) and estimated dose reduction of the low-dose and ultralow-dose protocols was 76.4% and 89.8%, respectively. The knowledge-based iterative reconstruction algorithm showed poorer subjective image quality than the regular and low-dose protocols, but it also had the least objective image noise. Overall, the low-dose image set showed a greater than 84% concordance rate and 100% in ureter stones larger than 3 mm. Interobserver agreement was substantial (kappa value = 0.61). CONCLUSIONS: The knowledge-based IR can provide a better quality image while reducing radiation exposure under the same protocol. Furthermore, the diagnostic performance of the low-dose CT protocol is comparable to the regular dose scan.

Imaging characteristics of sinonasal organized hematoma.

BACKGROUND: Sinonasal organized hematoma is a rare benign disease that may be mistaken for malignancy. PURPOSE: To define the imaging characteristics of sinonasal organized hematoma. MATERIAL AND METHODS: We retrospectively reviewed computed tomography (CT) images of eight patients (4 male patients, 4 female patients; mean age, 40 years; range, 9-83 years) with pathologically proven sinonasal organized hematomas; magnetic resonance imaging (MRI) was performed in one patient among them. The following lesions characteristics were analyzed: size, shape, location, expansile nature, density, signal intensity, internal structure, enhancement pattern, and surrounding bony wall change. RESULTS: The lesion sizes were in the range of 2-5.2 cm (mean, 3.55 cm), and the shapes were lobular, lumpy, or nodular. They were located in the nasal cavity (n = 1), maxillary sinuses (n = 2), or both nasal cavities and maxillary sinuses (n = 5). Expansile lesions with locally aggressive margins were observed in two cases. All lesions were hyperdense on precontrast CT scans; the smaller lesions showed even hyperdensity, whereas the larger lesions showed uneven density. The signal intensity was mixed on MRI, consisting of hemorrhage, fibrosis, and neovascularization. Papillary or frond-like enhancement was noted after contrast injection. All cases showed smooth erosion of the medial walls of the maxillary sinuses, and the epicenters were the secondary maxillary ostia. Two lesions showed erosion of the lateral walls of the maxillary sinuses and were expansile in nature. Non-hemorrhagic polyps accompanied the organized hematomas in three cases. CONCLUSION: Although sinonasal organized hematoma can be mistaken for a malignant tumor, the following characteristic imaging findings facilitate the diagnosis of an organized hematoma: erosion of the bony sinus walls, markedly heterogeneous signal intensity, and papillary or frond-like enhancement.

Semiautomated thyroid volumetry using 3D CT: prospective comparison with measurements obtained using 2D ultrasound, 2D CT, and water displacement method of specimen.

OBJECTIVE: The objective of our study was to measure thyroid volumes using semiautomated 3D CT and to compare the 3D CT volumes with volumes measured using 2D ultrasound, 2D CT, and the water displacement method. SUBJECTS AND METHODS: In 47 patients, 2D ultrasound volumes and 2D CT volumes of the thyroid gland were estimated using the ellipsoid volume formula, and 3D CT volumes were calculated using semiautomated reconstructive techniques. All volume data were compared with thyroid specimen volumes obtained using the water displacement method and were statistically analyzed using the one-way ANOVA, the Pearson correlation coefficient (R), linear regression, and the concordance correlation coefficient (CCC). The processing time of semiautomated 3D CT thyroid volumetry was measured. RESULTS: The paired mean differences ± SD between the three imaging-determined volumes and the specimen volumes were 0.8 ± 3.1 mL for 2D ultrasound, 4.0 ± 4.7 mL for 2D CT, and 0.2 ± 2.5 mL for 3D CT. A significant difference in the mean thyroid volume was found between 2D CT and specimen volumes (p = 0.016) compared with the other pairs (p = 0.937 for 2D ultrasound mean volume vs specimen mean volume, and p = 0.999 for 3D CT mean volume vs specimen mean volume). Between specimen volume and 2D ultrasound volume, specimen volume and 2D CT volume, and specimen volume and 3D CT volume, R values were 0.885, 0.724, and 0.929, respectively, and CCC values were 0.876, 0.598, and 0.925, respectively. The mean processing time of semiautomated 3D CT thyroid volumetry was 7.0 minutes. CONCLUSION: Thyroid volumes measured using 2D ultrasound or semiautomated 3D CT are substantially close to thyroid specimen volumes measured using the water displacement method. Semiautomated 3D CT thyroid volumetry can provide a more reliable measure of thyroid volume than 2D ultrasound.