Radiological features of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: case series and systematic review.

PURPOSE: To comprehensively summarize the clinical data and CT/MRI characteristics of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA). METHODS: Twenty-seven lesions from 25 study articles identified through a systematic review and three lesions from our institution associated with TL-LGNPPA were evaluated. RESULTS: The mean age of the patients at diagnosis was 35.7 years, and the male-to-female ratio was nearly half. The chief complaint was nasal obstruction, followed by epistaxis. All patients underwent excision. None of the patients had neck nodes or distant metastases. All patients survived with no locoregional/distant recurrence during 3-93 months of follow-up. All lesions were located at the posterior edge of the nasal septum, attached to the nasopharyngeal parietal wall, and showed no laterality. The mean lesion diameter was 1.7 cm. The margins of lesions were well-defined and lobulated, followed by well-defined smooth margins. None of lesions were associated with parapharyngeal space or skull base destruction. All lesions were iso- and low-density on non-contrast CT. Adjacent skull base sclerosis was detected in 63.6% of lesions. High signal intensity on T2-weighted imaging and mostly iso-signal intensity on T1-weighted imaging compared to muscle tissue. Most lesions were heterogeneous and exhibited moderate contrast enhancement. Relatively large lesions (≥1.4 cm) tended to be more lobulated than smooth margins compared to relatively small lesions (<1.4 cm) (p = 0.016). CONCLUSION: We summarized the clinical and radiological features of TL-LGNPPA to facilitate accurate diagnosis and appropriate management.

Evaluation of the Usefulness of Contrast-Enhanced Computed Tomography for the Early Detection of Anastomotic Leakage After Esophagectomy.

OBJECTIVE: Anastomotic leakage is one of the most severe complications after esophagectomy. However, a diagnostic gold standard for anastomotic leakage has not been established yet. This retrospective cohort study aimed to evaluate the potential use of routine postoperative contrast-enhanced computed tomography findings as an early predictor of anastomotic leakage in patients who underwent esophagectomy for esophageal cancer. METHODS: This study included 75 patients who underwent Mckeown esophagectomy, of whom 22 developed anastomotic leakage after surgery. The computed tomography findings for this patient cohort were categorized into 3 grades based on mural enhancement patterns observed at the anastomotic site. Both semiquantitative and quantitative analyses were performed, and the interobserver agreement between the 2 experienced radiologists was assessed. RESULTS: It was found that poor enhancement in both the early and portal venous phases (grade 2) had a robust association with the occurrence of anastomotic leakage. The computed tomography enhancement ratio that is used to estimate wall degeneration and ischemia was significantly higher in patients with anastomotic leakage. CONCLUSIONS: Routine postoperative contrast-enhanced computed tomography could be beneficial for the early detection of anastomotic leakage, even in asymptomatic patients, after esophagectomy.

Changes in pulmonary vein size and narrowing depend on the cardiac cycle before and after pulmonary vein isolation.

Accurate measurement of the pulmonary vein dimension (PVD) is important for determining stenosis and efficacy following pulmonary vein isolation (PVI). Little is known about the quantitative evaluation of the impact of the cardiac cycle on pulmonary vein (PV) morphology before and after PVI. This study aims to investigate variations in the ostial size of the PV during the cardiac cycle before and after PVI and the effect of the cardiac cycle on PV stenosis and reduction rate using cardiac computed tomography (CT). Sixty-eight patients with atrial fibrillation who underwent cardiac CT before and after PVI at our institution between 23 January 2021 and 5 February 2022 were retrospectively analyzed. The maximum and minimum PVD were measured at each segment before and after the PV. Each PV was evaluated according to the PVD reduction rate (ΔPVD), calculated as follows: (1 - post-PVD/pre-PVD) × 100 (%). The average dimension of all PVs at the end-diastolic frame was significantly reduced compared to that at the end-systolic frame before PVI. The average dimensions of the right superior and right inferior PV at the end-diastolic frame were significantly reduced compared with those at the end-systolic frame following PVI. The average reduction rate of dimension-classified stenosis of PVs, except for the left inferior PV at the end-diastolic frame, was significantly reduced compared with that at the end-systolic frame. The cardiac cycle affects PVD assessment, including PV stenosis, after PVI. PVD measurement is recommended to be unified to the end-systolic frame of the cardiac cycle to avoid underestimating PV stenosis before and after PVI, ensuring appropriate management and follow-up.

Evaluation of the association between osteoporotic vertebral compression fractures and psoas major/paraspinal muscle mass and ADC measured on MRI.

OBJECTIVE: Evaluate magnetic resonance imaging factors associated with osteoporotic vertebral compression fractures. MATERIALS AND METHODS: We retrospectively reviewed 457 patients' records. Age, sex, and body mass index were recorded. Two blinded readers measured psoas major and paraspinal muscle areas at the L3 vertebral body level on transverse T2-weighted magnetic resonance images and the mean apparent diffusion coefficient values of the non-fractured vertebrae from Th12 to L5. Inter-reader reliability for continuous variables was assessed by intraclass correlation coefficients. RESULTS: We evaluated 210 patients (103 [49.0%] men). The osteoporotic vertebral compression fractures group was older and had lower BMI and smaller psoas major and paraspinal muscle areas than the group without vertebral compression fractures (p < 0.001). The mean apparent diffusion coefficient was weakly correlated with paraspinal muscle area in the osteoporotic vertebral compression fractures group. The intraclass correlation coefficient value was 0.83, and the intraclass correlation coefficients of the psoas major and paraspinal muscles were 0.94 and 0.97, respectively. Multivariate analysis revealed that decreased psoas major and paraspinal muscle areas and increased mean apparent diffusion coefficient values were significantly associated with the presence of osteoporotic vertebral compression fractures (all p < 0.05). Psoas major and paraspinal muscle areas showed relatively high predictive accuracy (57%, 61%). CONCLUSION: Psoas major and paraspinal muscle areas at the L3 level and the mean apparent diffusion coefficient value of non-fractured vertebrae from the Th12 to L5 level were associated with osteoporotic vertebral compression fractures. This may contribute to detecting the potential risk of healthy individuals developing osteoporotic vertebral compression fractures.

Differentiating gallbladder cancer from polyps using non-enhanced magnetic resonance imaging.

Purpose: This retrospective cohort study assessed the efficiency of non-enhanced magnetic resonance imaging (MRI) for differentiating gallbladder cancer (GBC) from gallbladder polyps (GBPs) measuring ≥ 10 mm. Material and methods: Patients diagnosed with GBCs or GBPs ≥ 10 mm and GBC ≤ T2 stage were eligible for inclusion. Two independent blinded readers assessed the continuity of the mucosal and muscular layers (CMML; present or absent) and normalised signal intensity ratio (NIR) on the apparent diffusion coefficient map (NIR-ADC), T1-weighted image (NIR-T1WI), and T2-weighted half-Fourier acquisition single-shot turbo spin-echo image. Univariate and multivariate logistic regression analyses and interobserver agreement analyses were performed to detect predictive variables differentiating GBCs from GBPs. Receiver operating characteristic (ROC) analysis was performed to evaluate diagnostic performance. A reproducibility test was performed to verify the predictive variables. Results: Multivariate analysis showed significant differences in CMML, NIR-ADC, and NIR-T1WI (p < 0.001). The positive predictive value (PPV) and specificity of the absence of CMML were approximately 100%. The CMML showed the best specificity, accuracy, and PPV in the reproducibility study. The sensitivity of CMML alone was approximately 50%, whereas it increased to approximately 70% when combined with NIR-ADC. The diagnostic performance of the combination, including sensitivity, was almost like that of tumour size. The combined tumour size and CMML assessment showed higher diagnostic performance than tumour size alone. Conclusions: The absence of CMML and NIR-ADC ≤ 1.86 helped in differentiating GBCs from GBPs. Evaluation of the absence of CMML and measurement of tumour size could better aid in determining between the two than measurement of tumour size alone.

Optimal threshold score of aortic valve calcification for identification of significant aortic stenosis on non-electrocardiographic-gated computed tomography.

OBJECTIVES: This study evaluated the association between aortic valve calcification (AVC) and aortic stenosis (AS) by scoring the AVC to determine the threshold scores for significant AS on non-electrocardiographic (ECG)-gated computed tomography (CT). METHODS: We retrospectively analyzed the AVC scores of 5385 patients on non-contrast non-ECG-gated CT, who underwent transthoracic echocardiography (TTE) from March 1, 2013, to December 26, 2019, at our institution. Multivariable logistic regression models were used to identify potential risk factors for significant AS. The thresholds for significant AS were computed using receiver operator characteristic (ROC) curves, based on the AVC scores after propensity score matching. RESULTS: A significant association was found between AS and age (p < 0.001; odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02-1.06), female sex (p < 0.001; OR, 4.5; 95% CI, 2.75-7.36), bicuspid aortic valve (p < 0.001; OR, 23.2; 95% CI, 7.35-72.9), and AVC score (AVC score/100) (p < 0.001; OR, 1.82; 95% CI, 1.71-1.95). All sex-specific AVC thresholds for significant AS (moderate and over AS severity, moderate and over AS severity without discordance, discordant severe AS, and concordant severe AS) showed high sensitivity and specificity (AUC, 0.939-0.968; sensitivity, 84.6-96%; specificity, 84.2-97.1%). CONCLUSIONS: We determined the optimal AVC threshold scores for significant AS, which may aid in diagnosing significant asymptomatic AS on incidental detection of AVC through non-ECG-gated CT for non-cardiac indications. KEY POINTS: • Increased frequency of non-electrocardiographic (ECG)-gated computed tomography (CT) for non-cardiac indications has led to the increased incidental identification of aortic valve calcification (AVC). • It is important to identify patients with significant aortic stenosis (AS) who require additional echocardiographic assessment on incidental detection of AVC via non-ECG-gated CT. • We determined the AVC thresholds with high sensitivity and specificity to identify significant AS on non-ECG-gated CT, which could lead to early diagnosis of asymptomatic significant AS and improved prognosis.

Polymerization Properties of n-Butyl Cyanoacrylate Mixed with Ethiodized Oil in the Lymphatic System: In Vivo Investigation in a Rabbit Model.

PURPOSE: To evaluate the polymerization properties of a mixture of n-butyl cyanoacrylate (nBCA) and ethiodized oil in the lymphatic system using an animal model. MATERIALS AND METHODS: Nineteen male Japanese White rabbits underwent 28 lymphatic embolization procedures under fluoroscopic guidance using manually injected mixtures of nBCA and ethiodized oil at ratios of 1:2 (nBCA density of 33%), 1:4 (20%), 1:6 (14%), and 1:8 (11%) via the popliteal lymph node. The time required for polymerization and the distance traveled by the mixture were evaluated and compared among the groups using the Kruskal-Wallis test. Histopathologic intergroup comparisons and time-course changes were also evaluated using embolized lymph nodes. RESULTS: Among 23 successful procedures, the mean polymerization times were 14 ± 3, 88 ± 93, 331 ± 292, and 932 seconds ± 540 and the mean distances traveled were 13 ± 10, 31 ± 44, 85 ± 89, and 108 mm ± 35 in the 33% (n = 5), 20% (n = 6), 14% (n = 6), and 11% (n = 6) groups, respectively. The 11% group demonstrated a significantly longer polymerization time than the 33%, 20%, and 14% groups and distance traveled than the 33% group. Pathologically, the embolized lymph nodes showed inflammatory changes and massive necrosis regardless of the nBCA density. CONCLUSIONS: Polymerization times and distances traveled were increased when nBCA was diluted with increasing quantitites of ethiodized oil in this rabbit model of lymphatic embolization. These relationships should be considered when dilution is prescribed for clinical use.

Prediction of spontaneous echocardiographic contrast within the left atrial appendage in cardiac computed tomography of patients with atrial fibrillation.

This study aimed to assess the predictors of spontaneous echocardiographic contrast (SEC) using left atrial appendage (LAA) findings in cardiac computed tomography (CT) of patients with atrial fibrillation (AF). We retrospectively analyzed cardiac CT findings of the LAA, including morphology, volume, and filling defects, of 641 patients who underwent transesophageal echocardiography (TEE) prior to pulmonary vein isolation (PVI) from January 6, 2013 through December 16, 2019 at our institution. We investigated potential associated factors that might be predictors of SEC using cardiac CT findings and computed a receiver operator characteristic, choosing a threshold value at which the likelihood of SEC could be predicted based on the LAA volume indexed for body size. SEC correlated significantly with indexed LAA volume (P < 0.001; odds ratio [OR], 1.31; 95% confidence interval [CI], 1.17-1.48) of 7.75 cm3/m2 or greater (sensitivity, 76.0%; specificity, 57.7%), LAA early filling defect (P = 0.005; OR, 2.72; 95% CI, 1.35-5.48), a history of persistent AF (P < 0.001; OR, 3.81; 95% CI, 1.86-7.80), and LAA flow velocity (P < 0.001; OR, 0.97; 95% CI, 0.96-0.99). Findings of LAA in cardiac CT can allow for the noninvasive estimation of SEC to determine the need for additional TEE investigation and the need to obtain additional information for risk stratification and management of thromboembolic events in patients with AF.

CT in osteoarthritis: its clinical role and recent advances.

Computed tomography (CT) is a widely available imaging method and considered as one of the most reliable techniques in bone assessment. Although CT has limited tissue contrast and needs radiation exposure, it has several advantages like fast scanning time and high spatial resolution. In this regard, CT has unique roles in osteoarthritis (OA) and its variable utilities have been reported. Hence, this review highlights the clinical role of CT in OA of representative joints. In addition, CT showed the several technical advancements recently, for example, acquiring the CT image with standing, obtaining the dual-energy data, and novel photon-counting detector development. Therefore, the recent studies and potential utility of these new CT systems in OA are also discussed.

Preoperative prediction for mastoid extension of middle ear cholesteatoma using temporal subtraction serial HRCT studies.

OBJECTIVES: This study investigated the utility of temporal subtraction computed tomography (TSCT) obtained with temporal bone high-resolution computed tomography (HRCT) for the preoperative prediction of mastoid extension of middle ear cholesteatomas. METHODS: Twenty-eight consecutive patients with surgically proven middle ear cholesteatomas were retrospectively evaluated. The presence of black color in the mastoid region on TSCT suggested progressive changes caused by bone erosion. Enlarged width of the anterior part of mastoid on HRCT was interpreted as suggestive of mastoid extension. Fisher's exact test was used to compare the widths and black color on TSCT for cases with and without mastoid extension. The diagnostic accuracy of TSCT and HRCT for detecting mastoid extension and interobserver agreement during the evaluation of black color on TSCT were calculated. RESULTS: There were 15 cases of surgically proven mastoid extension and 13 cases without mastoid extension. Patients with black color on TSCT were significantly more likely to have a mastoid extension (p < 0.001). The sensitivity and specificity of TSCT were 0.93 and 1.00, respectively. Patients in whom the width of the anterior part of the mastoid was enlarged were significantly more likely to have a mastoid extension (p = 0.007). The sensitivity and specificity of HRCT to detect the width of the anterior part of the mastoid were 0.80 and 0.77, respectively. Interobserver agreement during the evaluation of TSCT findings was good (k = 0.71). CONCLUSIONS: This novel TSCT technique and preoperative evaluations are useful for assessing mastoid extension of middle ear cholesteatomas and making treatment decisions. KEY POINTS: •TSCT shows a clear black color in the mastoid region when the middle ear cholesteatoma is accompanied by mastoid extension. •TSCT obtained with preoperative serial HRCT of the temporal bone is useful for assessing mastoid extension of middle ear cholesteatomas.

Comprehensive radiological features of laryngeal sarcoidosis: cases series and systematic review.

PURPOSE: To comprehensively summarize the characteristic radiological findings of laryngeal sarcoidosis. METHODS: We reviewed patients with laryngeal sarcoidosis who underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) and included 8 cases from 8 publications that were found through a systematic review and 6 cases from our institutions. Two board-certified radiologists reviewed and evaluated the radiological images. RESULTS: Almost all cases exhibited supraglottic lesions 13/14 (92.9%) and most of them involved aryepiglottic folds (12/13, 92.3%), epiglottis (11/14, 78.6%), and arytenoid region (10/14, 71.4%). Most lesions were bilateral (12/14, 85.7%). All cases showed well-defined margins and a diffuse swelling appearance (14/14, 100%). Non-contrast CT revealed a low density (4/5, 80%). The contrast-enhanced CT showed a slight patchy enhancement predominantly at the margin of the lesion in most cases (12/13, 92.3%). In one case, T2-weighted images showed high signal intensity peripherally and low signal intensity centrally (1/1, 100%). Gadolinium-enhanced MRI showed moderate heterogeneous enhancement predominantly at the margin of the lesion (2/2, 100%). In one case, diffusion-weighted imaging showed intermediate signal intensity; the apparent diffusion coefficient value was 2.4 × 10-3 mm2/s. The larynx was the only region affected by sarcoidosis in 57.1% (8/14) of the cases. Involvement of the neck lymph nodes and distant organs was observed in 4/14 (28.6%) patients, respectively. CONCLUSION: We summarized the CT and MRI findings of patients with laryngeal sarcoidosis. Knowledge of these characteristics is expected to facilitate prompt diagnosis and appropriate management.

Radiological features of human papillomavirus-related multiphenotypic sinonasal carcinoma: systematic review and case series.

PURPOSE: To comprehensively summarize the radiological characteristics of human papillomavirus (HPV)-related multiphenotypic sinonasal carcinomas (HMSCs). METHODS: We reviewed the findings for patients with HMSCs who underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) and included nine cases from nine publications that were identified through a systematic review and three cases from our institution. Two board-certified radiologists reviewed and evaluated the radiological images. RESULTS: The locations in almost all cases included the nasal cavity (11/12, 91.7%). The involved paranasal sinuses included the ethmoid sinus (6/12, 50.0%) and maxillary sinus (3/12, 25.0%). The mean long diameter of the tumors was 46.3 mm. The margins in 91.7% (11/12) of the cases were well-defined and smooth. Heterogeneous enhancement on contrast-enhanced CT, heterogeneous high signal intensities on T2-weighted images and heterogeneous enhancement on gadolinium-enhanced T1-weighted images were noted in 2/2, 5/5, and 8/8 cases, respectively. Mean apparent diffusion coefficient values in two cases of our institution were 1.17 and 1.09 × 10-3 mm2/s. Compressive changes in the surrounding structures were common (75%, 9/12). Few cases showed intraorbital or intracranial extension. None of the cases showed a perineural spread, neck lymph node metastasis, or remote lesions. CONCLUSIONS: We summarized the CT and MRI findings of HMSCs. Knowledge of such characteristics is expected to facilitate prompt diagnosis and appropriate management.

The Utility of Submucosal Linear Enhancement on Dynamic Computed Tomography for Patients With Internal Hemorrhoids.

OBJECTIVE: The purpose of this study was to evaluate the utility of submucosal linear enhancement on dynamic computed tomography (CT) for patients with internal hemorrhoids. METHODS: We retrospectively reviewed patients who were admitted to our institution due to acute lower gastrointestinal bleeding and underwent both dynamic CT and colonoscopy. The presence of submucosal linear enhancement of the intestinal wall from the lower rectum to the anal canal was evaluated using arterial-phase CT images. Based on these images, patients were then classified into 2 groups by 2 blinded radiologists, as follows: group A (absence of submucosal linear enhancement) and group B (presence of submucosal linear enhancement). The relationship between the groups and the risk of bleeding in internal hemorrhoids was evaluated using the size and range of internal hemorrhoids measured during colonoscopy as reference standards. RESULTS: A total of 94 patients were reviewed; of these, 62 patients without submucosal linear enhancement were classified into group A, and 32 patients with submucosal linear enhancement were classified into group B. Group B showed a significantly greater range ( P = 0.017) and size ( P = 0.002) of internal hemorrhoids. The Cohen κ coefficient value for the group classifications between the 2 radiologists was 0.66. CONCLUSIONS: Submucosal linear enhancement on arterial-phase CT images could be a predictive finding suggesting the presence of internal hemorrhoids with a high risk of bleeding.

Cauda Equina Atrophy in Amyotrophic Lateral Sclerosis on Routine Lumbar Magnetic Resonance Imaging.

OBJECTIVE: The aim of the study was to evaluate the cross-sectional area of the cauda equina in amyotrophic lateral sclerosis (ALS) on routine lumbar magnetic resonance imaging and investigate the diagnostic accuracy in comparison with age- and sex-matched non-ALS controls. METHODS: This retrospective study included 15 ALS patients and 15 age- and sex-matched non-ALS controls. Two independent neuroradiologists measured and compared the total cross-sectional area of the cauda equina of ALS patients and the non-ALS controls at the level of the L3 and L4 using axial T2-weighted images. The cutoff value, sensitivity, specificity, and area under the curve were measured. The interobserver reproducibility of the 2 independently obtained measurements was evaluated. RESULTS: The total cross-sectional area of the cauda equina in the ALS group was significantly smaller than that in the non-ALS group (L3: median, 66.73 vs 90.19 mm 2 , P < 0.001; L4: median, 52.9 vs 67.63 mm 2 , P < 0.001). The cutoff values at L3 and L4 were 76.95 and 61.04 mm 2 with a sensitivity and specificity of 1 and 0.87 and 0.8 and 0.87, respectively. The area under the curve at L3 and L4 were high at 0.96 and 0.94, respectively. The interobserver reproducibility was 0.88 at L3 and 0.89 at L4. CONCLUSIONS: The ALS patients showed significant atrophy of the cauda equina compared with non-ALS patients.

Computed tomography findings associated with the reduction in left atrial appendage flow velocity in patients with atrial fibrillation.

The reduction in flow velocity within the left atrial appendage (LAAFV) is associated with a high risk of thromboembolic events. There has been few reports using sufficient sample size about the relationship between LAAFV reduction and LAA features on cardiac computed tomography (CT), including LAA volume and filling defects, in patients with atrial fibrillation (AF). We evaluated the predictors of reduced flow velocity within the LAA using the findings of cardiac CT in patients with AF. We retrospectively analysed the cardiac CT findings of the LAA of 440 patients who underwent transoesophageal echocardiography prior to pulmonary vein isolation between 12 February, 2013 and 16 December, 2019 at our institution. We investigated the potential predictors of reduced LAAFV and the difference in LAAFV between the different morphological types of the LAA. The reduced flow velocity within the LAA was significantly correlated with higher CHADS2 scores [P = 0.001; odds ratio (OR), 1.52; 95% confidence interval (CI), 1.18-1.95], early filling defect in the LAA (P = 0.001; OR, 3.36; 95% CI 1.63-6.93), and increased indexed LAA volume (P = 0.036; OR, 1.09; 95% CI 1.01-1.19). The LAA morphological type and AF type were not significant predictors of the LAAFV reduction. Increased LAA volume, early filling defects in the LAA, and higher CHADS2 scores were independent predictors of LAAFV reduction in patients with AF. Our findings suggest that cardiac CT findings might allow non-invasive estimation of reduced LAAFV. These CT-derived parameters may provide additional information for the risk stratification and management of thromboembolic events in patients with AF.

Inferior vena cava diameter on CT angiography predicts mesenteric angiography positive for extravasation in colonic diverticular bleeding.

PURPOSE: Transcatheter arterial embolization (TAE) for colonic diverticular bleeding (CDB), an established procedure for hemostasis, is sometimes complicated by spontaneous hemostasis and unclear bleeding site on angiography despite active arterial bleeding on preoperative computed tomography angiography (CTA). Therefore, to investigate and increase the feasibility of TAE, this retrospective study evaluates the clinical and radiological features related to positive extravasation on angiography. MATERIAL AND METHODS: Sixty CDB patients with extravasation on CTA underwent TAE between January 2011 and February 2021 and were divided into extravasation-positive (P-group; n = 25) and -negative groups (N-group; n = 35) based on the superior or inferior mesenteric angiography. Patient characteristics, laboratory findings, the diameter of the inferior vena cava (IVCD), the diameter of superior and inferior mesenteric veins, and technical outcomes were evaluated. RESULTS: TAE was successful in 24 patients in the P-group (96%) and 14 in the N-group (40%) (p < 0.001). Univariate analysis revealed "usage of anticoagulant" (p < 0.05) and "larger IVCD (p < 0.05) on preoperative CTA" to be significant predictors of positive extravasation. In the multivariate analysis, IVCD remained significant with an adjusted odds ratio of 1.17. The IVCD cutoff value was 13.6 mm (area under the curve = 0.72, sensitivity = 84.0%, specificity = 54.3%). There were no significant differences in other parameters. CONCLUSION: Measurement of IVCD in CDB with the cutoff value of 13.6 mm can be a simple and useful indicator to predict the detectability of extravasation following TAE procedures.

Quantitative Histogram Analysis of T2-Weighted and Diffusion-Weighted Magnetic Resonance Images for Prediction of Malignant Thymic Epithelial Tumors.

PURPOSE: To assess the value of histogram analysis for differentiating a high-risk thymic epithelial tumor (TET) from a low-risk TET using T2-weighted images and the apparent diffusion coefficient (ADC). METHODS: Forty-nine patients with histopathologically proven TET after thymectomy were enrolled in this study and retrospectively classified as having low-risk TET (low-risk thymoma) or high-risk TET (high-risk thymoma or thymic carcinoma). Twelve parameters were obtained from the quantitative histogram analysis. The histogram parameters were compared using the Mann-Whitney U test. Diagnostic efficacy was estimated by receiver-operating characteristic curve analysis. RESULTS: Twenty-five patients were classified as having low-risk TET and 24 as having high-risk TET. The mean ADC value showed diagnostic efficacy for differentiating high-risk TET from low-risk TET, with an area under the curve of 0.7, and was better than when using conventional methods alone. CONCLUSION: The ADC-based histogram analysis could help to differentiate between high-risk and low-risk TETs.

Endovascular micro-arterial stenting for arterial pseudoaneurysm after pancreatic surgery.

Although arterial pseudoaneurysm is one of the most serious complications after pancreatic surgery, the best practice with maximum efficacy and minimum adverse effects to overcome such a serious situation has not yet been elucidated. We performed endovascular micro-arterial stenting (EMAS) to manage this serious situation while preserving a sufficient hepatic arterial flow, and herein report the technical details and challenges of the procedure. Dilation of the stent using a balloon catheter to adhere to the parent artery, and embolization of the surrounding artery to prevent type I and type II endo-leaks are the most important points for ensuring a successful procedure. We applied this technique to 6 cases of hepatic arterial pseudoaneurysm, with a mean size of 6.5 ± 1.3 mm. The mean time of the procedure was 81 ± 22 min, without adverse events, including hepatic necrosis or arterial bleeding. EMAS may be the ideal procedure for treating pseudoaneurysm after pancreatic surgery while preserving the hepatic arterial inflow.

Radiological differences in computed tomography findings and texture analysis between cystic lymph node metastases of human papillomavirus-positive oropharyngeal cancer and second branchial cysts.

PURPOSE: The study aimed to analyse radiological differences in computed tomography (CT) findings and texture analysis between cystic lymph node metastases (CNM) in human papillomavirus (HPV)-positive oropharyngeal cancer (OPC) and second branchial cleft cysts (2nd BC). MATERIAL AND METHODS: Patients with pathological evidence of CNM-HPV-OPC and 2nd BC, who underwent contrast-enhanced CT, were retrospectively evaluated. The evaluated characteristics include age, sex, and CT findings. CT findings included the maximum and minimum transverse diameters, maximum caudal diameter, thickness of the peripheral wall, presence of internal septation, presence of surrounding fat stranding, location, and 40 texture parameters. RESULTS: A total of 13 patients had CNM-HPV-OPC (19 lesions), while 20 patients had 2nd BC (20 lesions). Patients with 2nd BC were significantly younger than those with CNM-HPV-OPC (p < 0.001). In terms of diameter, 2nd BC lesions were significantly larger than the CNM-HPV-OPC lesions (p < 0.001). CNM-HPV OPC lesions had significantly thicker walls than 2nd BC lesions (p < 0.001). CNM-HPV-OPC lesions had significantly higher association with internal septations than 2nd BC lesions (p < 0.001). Second BC lesions were significantly less common at level III than CNM-HPV-OPC lesions (p = 0.047). Among the 40 texture parameters measured, 8 had significant differences (p ≤ 0.001). CONCLUSIONS: There were significant differences in CT findings and textural parameters between CNM-HPV-OPC and 2nd BC lesions. These results may help in differentiating one from the other.

3D quantitative analysis of diffusion-weighted imaging for predicting the malignant potential of intraductal papillary mucinous neoplasms of the pancreas.

PURPOSE: To investigate the predictors of intraductal papillary mucinous neoplasms of the pancreas (IPMNs) with high-grade dysplasia, using 2-dimensional (2D) analysis and 3-dimensional (3D) volume-of-interest-based apparent diffusion coefficient (ADC) histogram analysis. MATERIAL AND METHODS: The data of 45 patients with histopathologically confirmed IPMNs with high-grade or low-grade dysplasia were retrospectively assessed. The 2D analysis included lesion-to-spinal cord signal intensity ratio (LSR), minimum ADC value (ADCmin), and mean ADC value (ADCmean). The 3D analysis included the overall mean (ADCoverall mean), mean of the bottom 10th percentile (ADCmean0-10), mean of the bottom 10-25th percentile (ADCmean10-25), mean of the bottom 25-50th percentile (ADCmean25-50), skewness (ADCskewness), kurtosis (ADCkurtosis), and entropy (ADCentropy). Diagnostic performance was compared by analysing the area under the receiver operating characteristic curve (AUC). Inter-rater reliability was assessed by blinded evaluation using the intraclass correlation coefficient. RESULTS: There were 16 and 29 IPMNs with high- and low-grade dysplasia, respectively. The LSR, ADCoverall mean, ADCmean0-10, ADCmean10-25, ADCmean25-50, and ADCentropy showed significant between-group differences (AUC = 72-93%; p < 0.05). Inter-rater reliability assessment showed almost perfect agreement for LSR and substantial agreement for ADCoverall mean and ADCentropy. Multivariate logistic regression showed that ADCoverall mean and ADCentropy were significant independent predictors of malignancy (p < 0.05), with diagnostic accuracies of 80% and 73%, respectively. CONCLUSION: ADCoverall mean and ADCentropy from 3D analysis may assist in predicting IPMNs with high-grade dysplasia.