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Objective: To evaluate the effectiveness and safety of transcatheter arterial embolization (TAE) of the branches of the subclavian and axillary arteries for hemorrhage control. Methods: Between January 2015 and June 2022, 35 TAE procedures were performed for hemorrhage from the branches of the subclavian and axillary arteries in 34 patients (22 men, 12 women; 1 male underwent TAE twice; mean age = 76 years). Pre-TAE CT showed hematomas in the chest (n = 25) and abdominal walls (n = 3), shoulder (n = 2), and lower neck (n = 2). CT showed hemothorax in eight cases. Angiographic findings, embolization technique, and technical and clinical success of TAE were retrospectively assessed in all cases. Results: TAE was performed by transfemoral (n = 16), transradial (n = 12), and transbrachial (n = 7) approaches. Angiography revealed contrast media extravasation or pseudoaneurysms in 32 cases (91.4%). The most commonly embolized arteries were the internal thoracic (n = 12), lateral thoracic (n = 6), and thoracoacromial (n = 6) arteries. Technical and clinical success rates were 100 and 85.7%, respectively. A complication (skin necrosis after injection of the liquid embolic agent) developed in only one patient (2.9%) and was conservatively managed. Conclusion: TAE is an effective and safe treatment for hemorrhage from the branches of the subclavian and axillary arteries. Advances in knowledge: Transfemoral approach has been used for TAE of the branches of the subclavian and axillary artery. Transradial and transbrachial approaches can also be considered.

Reports on the future liver remnant (FLR) hypertrophy rate in patients undergoing portal vein embolization (PVE) before left trisectionectomy are sparse. This study aimed to assess the FLR hypertrophy rate in patients undergoing PVE before left trisectionectomy.Between January 2010 and June 2021, 30 patients (22 men and eight women; mean age, 65.7 years) underwent PVE, mainly using gelatin sponge, before left trisectionectomy. The preoperative diagnosis was cholangiocarcinoma in 28 patients and colorectal liver metastases in two patients. The FLR hypertrophy rate, increase in the FLR volume (FLRV) ratio (the ratio of the FLRV to the total liver volume), and complications were evaluated. The patients were further divided into two groups: one group of patients with left portal vein stenosis or occlusion before PVE (n = 12) and another without left portal vein stenosis or occlusion before PVE (n = 18). The FLR hypertrophy rate and increase in the FLRV ratio were compared between the two groups.The FLR hypertrophy rate and increase in the FLRV ratio were 31.3% and 6.9%, respectively. One major complication, cholangitis, developed; however, its association with PVE was unclear. The difference in the FLR hypertrophy rate and the increase in the FLRV ratio between the two groups of patients was statistically insignificant.PVE before left trisectionectomy is effective in achieving FLR hypertrophy. PVE before left trisectionectomy was equally effective in patients with left portal vein stenosis or occlusion as compared to those without. The complication rates were acceptable.

Background Visceral fat obesity can be defined quantitatively by abdominal computed tomography, however, the usefulness of measuring visceral fat area to assess the etiology of gastrointestinal reflux disease has not been fully elucidated. Methods A total of 433 healthy subjects aged 40–69 years (234 men, 199 women) were included in the study. The relationship between obesity-related factors (total fat area, visceral fat area, subcutaneous fat area, waist circumference, and body mass index) and the incidence of reflux erosive esophagitis was investigated. Lifestyle factors and stomach conditions relevant to the onset of erosive esophagitis were also analyzed. Results The prevalence of reflux erosive esophagitis was 27.2% (118/433; 106 men, 12 women). Visceral fat area was higher in subjects with erosive esophagitis than in those without (116.6 cm2 vs. 64.9 cm2, respectively). The incidence of erosive esophagitis was higher in subjects with visceral fat obesity (visceral fat area ≥ 100 cm2) than in those without (61.2% vs. 12.8%, respectively). Visceral fat obesity had the highest odds ratio (OR) among obesity-related factors. Multivariate analysis showed that visceral fat area was associated with the incidence of erosive esophagitis (OR = 2.18), indicating that it is an independent risk factor for erosive esophagitis. In addition, daily alcohol intake (OR = 1.54), gastric atrophy open type (OR = 0.29), and never-smoking history (OR = 0.49) were also independently associated with the development of erosive esophagitis. Conclusions Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in subjects aged 40–69 years.

Granulocyte colony-stimulating factor (G-CSF)-producing tumors have an aggressive clinical course. Here, we report five cases of G-CSF-producing tumors and review the literature, focusing on imaging findings related to tumor-produced G-CSF. In addition to our cases, we identified 30 previous reports of G-CSF-producing tumors on which 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT, bone scintigraphy, or evaluation of bone marrow MR findings was performed. White blood cell count, serum C-reactive protein, and serum interleukin-6 were elevated in all cases for which these parameters were measured. G-CSF-producing tumors presented large necrotic masses (mean diameter 83.2 mm, range 17–195 mm) with marked FDG uptake (mean maximum standardized uptake value: 20.09). Diffuse FDG uptake into the bone marrow was shown in 28 of the 31 cases in which FDG-PET/CT was performed. The signal intensity of bone marrow suggested marrow reconversion in all seven MRI-assessable cases. Bone scintigraphy demonstrated no significant uptake, except in two cases with bone metastases. Splenic FDG uptake was increased in 8 of 10 cases in which it was evaluated. These imaging findings may reflect the effects of tumor-produced G-CSF. The presence of G-CSF-producing tumors should be considered in patients with cancer who show these imaging findings and marked inflammatory features of unknown origin.

To determine whether temporal subtraction (TS) CT obtained with non-rigid image registration improves detection of various bone metastases during serial clinical follow-up examinations by numerous radiologists. Six board-certified radiologists retrospectively scrutinized CT images for patients with history of malignancy sequentially. These radiologists selected 50 positive and 50 negative subjects with and without bone metastases, respectively. Furthermore, for each subject, they selected a pair of previous and current CT images satisfying predefined criteria by consensus. Previous images were non-rigidly transformed to match current images and subtracted from current images to automatically generate TS images. Subsequently, 18 radiologists independently interpreted the 100 CT image pairs to identify bone metastases, both without and with TS images, with each interpretation separated from the other by an interval of at least 30 days. Jackknife free-response receiver operating characteristics (JAFROC) analysis was conducted to assess observer performance. Compared with interpretation without TS images, interpretation with TS images was associated with a significantly higher mean figure of merit (0.710 vs. 0.658; JAFROC analysis, P = 0.0027). Mean sensitivity at lesion-based was significantly higher for interpretation with TS compared with that without TS (46.1% vs. 33.9%; P = 0.003). Mean false positive count per subject was also significantly higher for interpretation with TS than for that without TS (0.28 vs. 0.15; P

Background Transcatheter arterial embolization (TAE) is widely accepted as a treatment for bleeding from the pancreaticodoudenal artery (PDA) in patients with celiac artery stenosis. However, the technical aspect of TAE has not received much attention. Purpose To report the technical details and success rate of TAE for bleeding from the PDA in patients with CA stenosis. Material and Methods Between 2015 and 2021, nine TAE procedures were performed in eight patients (five women, three men; one woman underwent TAE twice). The cause of CA stenosis was compression by the median arcuate ligament in eight cases and CA dissection in one case. The cause of bleeding was flow-related aneurysm rupture in six cases. Pre-TAE CT showed a pseudoaneurysm in all cases. The technical details of TAE were recorded, and the success rate was evaluated. Results The technical and clinical success rates were 100%. In six cases, both the CA and superior mesenteric artery (SMA) were cannulated using two parent catheters: a microcatheter advancing to the pseudoaneurysm from the CA (the CA approach) to achieve embolization and another catheter for angiography advancing from the SMA to map the vascular anatomy. In five cases, the CA approach was successfully performed after failed attempts of advancing a microcatheter from the SMA. Conclusion TAE is an effective treatment for bleeding from the PDA in patients with CA stenosis. Using two parent catheters, one for CA cannulation and microcatheter advancement and another for SMA cannulation and vascular mapping, may be a useful technique.

This study aimed to evaluate the technical and clinical success rates of transcatheter arterial embolization (TAE) for subcapsular hematoma of the liver.Between January 2010 and March 2022, 34 patients underwent TAE for subcapsular hematomas of the liver. The causes of subcapsular hematoma were liver tumor rupture (n = 12), trauma (n = 12), iatrogenic complications (n = 9), and spontaneous bleeding (n = 1). The technical and clinical success rates of TAE, blood test results after TAE and additional treatments were evaluated. The patients were divided into either with or without retrograde segmental or lobar portal venous flow on angiography. Technical and clinical success rates and blood test results after TAE were compared between the two groups.Technical and clinical success rates were 94.1% and 73.5%, respectively. Six patients died within one month of TAE. A repeat TAE was performed in three patients. Surgical removal and hemostasis for subcapsular hematoma were done in four patients. One patient had liver failure. The retrograde portal venous flow was observed in 18 patients. The difference in technical and clinical success rates and blood test results after TAE between the two groups was statistically insignificant.TAE is an effective and safe treatment for subcapsular hematomas of the liver. The success rates of TAE and liver damage due to TAE did not differ between patients with and without retrograde portal venous flow.

We investigated the associations of time-dependent DWI, non-Gaussian DWI, and CEST parameters with histological biomarkers in a breast cancer xenograft model. 22 xenograft mice (7 MCF-7 and 15 MDA-MB-231) were scanned at 4 diffusion times [Td = 2.5/5 ms with 11 b-values (0–600 s/mm2) and Td = 9/27.6 ms with 17 b-values (0–3000 s/mm2), respectively]. The apparent diffusion coefficient (ADC) was estimated using 2 b-values in different combinations (ADC0–600 using b = 0 and 600 s/mm2 and shifted ADC [sADC200–1500] using b = 200 and 1500 s/mm2) at each of those diffusion times. Then the change (Δ) in ADC/sADC between diffusion times was evaluated. Non-Gaussian diffusion and intravoxel incoherent motion (IVIM) parameters (ADC0, the virtual ADC at b = 0; K, Kurtosis from non-Gaussian diffusion; f, the IVIM perfusion fraction) were estimated. CEST images were acquired and the amide proton transfer signal intensity (APT SI) were measured. The ΔsADC9–27.6 (between $${\text{sADC}}_{{9\,{\text{ms}}}}^{200{-}1500}$$ sADC 9 ms 200 - 1500 and $${\text{sADC}}_{{27.6\,{\text{ms}}}}^{200{-}1500}$$ sADC 27.6 ms 200 - 1500 and ΔADC2.5_sADC27.6 (between $${\text{ADC}}_{{2.5\, {\text{ms}}}}^{0{-}600}$$ ADC 2.5 ms 0 - 600 and $${\text{sADC}}_{{27.6\,{\text{ms}}}}^{200{-}1500}$$ sADC 27.6 ms 200 - 1500 ) was significantly larger for MCF-7 groups, and ΔADC2.5_sADC27.6 was positively correlated with Ki67max and APT SI. ADC0 decreased significantly in MDA-MB-231 group and K increased significantly with Td in MCF-7 group. APT SI and cellular area had a moderately strong positive correlation in MDA-MB-231 and MCF-7 tumors combined, and there was a positive correlation in MDA-MB-231 tumors. There was a significant negative correlation between APT SI and the Ki-67-positive ratio in MDA-MB-231 tumors and when combined with MCF-7 tumors. The associations of ΔADC2.5_sADC27.6 and API SI with Ki-67 parameters indicate that the Td-dependent DW and CEST parameters are useful to predict the histological markers of breast cancers.

Epoprostenol is a prostacyclin (prostaglandin I2) analog that causes vasodilation and inhibits platelet aggregation and is used in the management of severe pulmonary arterial hypertension (PAH). We herein report a patient with PAH who developed pancreatic enlargement after the initiation of therapy including epoprostenol. Although it is well known that thyroid enlargement occurs in patients with PAH receiving epoprostenol therapy, the pancreatic findings associated with epoprostenol therapy have not been well described. Although the size of the pancreas was clearly increased, there was no blood data or symptoms suggestive of abnormal pancreatic function and pancreatitis, and the patient's abdominal complaints improved quickly, despite the continuation of epoprostenol therapy. Eleven months after the start of continuous intravenous epoprostenol infusion therapy, the pancreatic enlargement was still evident on imaging, but there were no abdominal symptoms or elevated pancreatic enzymes. This case highlights the fact that epoprostenol therapy may cause pancreatic changes that mimic acute or autoimmune pancreatitis.

Objectives: To measure phosphorus metabolites in human parotid glands by 31P-MRS using three-dimensional chemical-shift imaging (3D-CSI), and ascertain whether this method can capture changes in adenosine triphosphate (ATP) and phosphocreatine (PCr) levels due to saliva secretion. Study Design: The parotid glands of 20 volunteers were assessed by 31P-MRS using 3D-CSI on 3T MRI. After obtaining a first (baseline) measurement, the participants took vitamin-C tablets and measurements were obtained twice more, in a continuous manner. The peak area ratios of PCr and β-ATP were evaluated. Results: A high proportion of PCr (0.26 ± 0.08) and ATP (α: 0.16 ± 0.06; β: 0.27 ± 0.06; γ: 0.21 ± 0.03) was noted at baseline. A significant decrease in β-ATP was observed between baseline (“pre”; 0.27 ± 0.06) and the first scan after vitamin-C stimulation (“post-1”; 0.19 ± 0.07, p Conclusions: 31P-MRS with 3D-CSI can assess the major phosphorus metabolites in human parotid glands and capture changes in their levels due to saliva secretion. This technique is simple, non-invasive, and provides new information regarding saliva secretion.

To develop and evaluate a radiomics approach for classifying histological subtypes and epidermal growth factor receptor (EGFR) mutation status in lung cancer on PET/CT images. PET/CT images of lung cancer patients were obtained from public databases and used to establish two datasets, respectively to classify histological subtypes (156 adenocarcinomas and 32 squamous cell carcinomas) and EGFR mutation status (38 mutant and 100 wild-type samples). Seven types of imaging features were obtained from PET/CT images of lung cancer. Two types of machine learning algorithms were used to predict histological subtypes and EGFR mutation status: random forest (RF) and gradient tree boosting (XGB). The classifiers used either a single type or multiple types of imaging features. In the latter case, the optimal combination of the seven types of imaging features was selected by Bayesian optimization. Receiver operating characteristic analysis, area under the curve (AUC), and tenfold cross validation were used to assess the performance of the approach. In the classification of histological subtypes, the AUC values of the various classifiers were as follows: RF, single type: 0.759; XGB, single type: 0.760; RF, multiple types: 0.720; XGB, multiple types: 0.843. In the classification of EGFR mutation status, the AUC values were: RF, single type: 0.625; XGB, single type: 0.617; RF, multiple types: 0.577; XGB, multiple types: 0.659. The radiomics approach to PET/CT images, together with XGB and Bayesian optimization, is useful for classifying histological subtypes and EGFR mutation status in lung cancer.

To compare observer performance of detecting bone metastases between bone scintigraphy, including planar scan and single-photon emission computed tomography, and computed tomography (CT) temporal subtraction (TS). Data on 60 patients with cancer who had undergone CT (previous and current) and bone scintigraphy were collected. Previous CT images were registered to the current ones by large deformation diffeomorphic metric mapping; the registered previous images were subtracted from the current ones to produce TS. Definitive diagnosis of bone metastases was determined by consensus between two radiologists. Twelve readers independently interpreted the following pairs of examinations: NM-pair, previous and current CTs and bone scintigraphy, and TS-pair, previous and current CTs and TS. The readers assigned likelihood levels to suspected bone metastases for diagnosis. Sensitivity, number of false positives per patient (FPP), and reading time for each pair of examinations were analysed for evaluating observer performance by performing the Wilcoxon signed-rank test. Figure-of-merit (FOM) was calculated using jackknife alternative free-response receiver operating characteristic analysis. The sensitivity of TS was significantly higher than that of bone scintigraphy (54.3% vs. 41.3%, p = 0.006). FPP with TS was significantly higher than that with bone scintigraphy (0.189 vs. 0.0722, p = 0.003). FOM of TS tended to be better than that of bone scintigraphy (0.742 vs. 0.691, p = 0.070). Sensitivity of TS in detecting bone metastasis was significantly higher than that of bone scintigraphy, but still limited to 54%. TS might be superior to bone scintigraphy for early detection of bone metastasis. • Computed tomography temporal subtraction was helpful in early detection of bone metastases. • Sensitivity for bone metastasis was higher for computed tomography temporal subtraction than for bone scintigraphy. • Figure-of-merit of computed tomography temporal subtraction was better than that of bone scintigraphy.

BACKGROUND Diffusion-weighted imaging (DWI) is an important method for clinically significant prostate cancer (csPCa) diagnosis; however, the Prostate Imaging-Reporting and Data System (PI-RADS) requires the subjective assessment of "markedly hypointense or not" on apparent diffusion coefficient (ADC) map. We hypothesize that weighted diffusion subtraction (WDS) images, created by weighted subtraction of high and low b-value DWIs, might better show areas of ADC values below a set threshold, thus decreasing the subjectivity of the assessment. PURPOSE To evaluate the diagnostic ability of WDS for csPCa by comparing scores based on WDS images (DWI/WDS) with those based on PI-RADS DWI (DWI/ADC). STUDY TYPE Retrospective. SUBJECTS Eighty-six PCa patients. FIELD STRENGTH/SEQUENCES 3.0 T; DWI. ASSESSMENT Four readers assessed the probability of csPCa in lesions (overall, in the peripheral zone [PZ] and transitional zone [TZ]) using 5-point DWI/ADC and DWI/WDS scores. Prostatectomy specimens were the reference standard. ADC values and contrast between csPCa and normal prostate tissue on ADC maps and WDS images were calculated with reference to the pathological map. STATISTICAL TESTS Diagnostic ability was evaluated by Jackknife alternative free-response receiver-operating characteristic curve. Figure of merit (FOM), sensitivity, and positive predictive value (PPV) between the DWI/ADC and DWI/WDS scores were compared using paired t-test. Inter-reader agreement was analyzed using κ statistics, and the significance probability was calculated using the Z statistic. Wilcoxon signed-rank test was used to compare contrast between csPCa and normal prostate tissue on ADC maps and WDS images. A P value

Dedicated breast positron emission tomography (dbPET) is a new diagnostic imaging modality recently used in clinical practice for the detection of breast cancer and the assessment of tumor biology. dbPET has higher spatial resolution than that of conventional whole body PET systems, allowing recognition of detailed morphological attributes of radiotracer accumulation within the breast. 18F-fluorodeoxyglucose (18F-FDG) accumulation in the breast may be due to benign or malignant entities, and recent studies suggest that morphology characterization of 18F-FDG uptake could aid in estimating the probability of malignancy. However, across the world, there are many descriptors of breast 18F-FDG uptake, limiting comparisons between studies. In this article, we propose a lexicon for breast radiotracer uptake to standardize description and reporting of image findings on dbPET, consisting of terms for image quality, radiotracer fibroglandular uptake, breast lesion uptake.

To develop convolutional neural network (CNN) models for differentiating intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC) and predicting histopathological grade of HCC. Preoperative computed tomography and tumor marker information of 617 primary liver cancer patients were retrospectively collected to develop CNN models categorizing tumors into three categories: moderately differentiated HCC (mHCC), poorly differentiated HCC (pHCC), and ICC, where the histopathological diagnoses were considered as ground truths. The models processed manually cropped tumor with and without tumor marker information (two-input and one-input models, respectively). Overall accuracy was assessed using a held-out dataset (10%). Area under the curve, sensitivity, and specificity for differentiating ICC from HCCs (mHCC + pHCC), and pHCC from mHCC were also evaluated. We assessed two radiologists’ performance without tumor marker information as references (overall accuracy, sensitivity, and specificity). The two-input model was compared with the one-input model and radiologists using permutation tests. The overall accuracy was 0.61, 0.60, 0.55, 0.53 for the two-input model, one-input model, radiologist 1, and radiologist 2, respectively. For differentiating pHCC from mHCC, the two-input model showed significantly higher specificity than radiologist 1 (0.68 [95% confidence interval: 0.50–0.83] vs 0.45 [95% confidence interval: 0.27–0.63]; p = 0.04). Our CNN model with tumor marker information showed feasibility and potential for three-class classification within primary liver cancer.

PURPOSE: We aimed to evaluate mid- to long-term results of endovascular treatment for portal vein thrombosis (PVT) after living-donor liver transplantation (LDLT). METHODS: Thirty cases (14 males, 16 females; age range, 0.67–65 years) who underwent endovascular treatment including thrombolysis, angioplasty, stent placement, and/or collateral embolization for PVT after LDLT from 2001 to 2017 were retrospectively reviewed. Clinical and procedural data were collected and analyzed regarding the patency of the PVT site at the last follow-up date (PVT-free persistency) using Log-rank test. Results were considered statistically significant at p < 0.05. RESULTS: Median follow-up was 120 months. The technical success rate was 80% (n=24). Patency rates at 1 week and 1, 3, 6, 12, 36, and 60 months were 73%, 59%, 55%, 51%, 51%, 51%, and 51% for primary patency and 80%, 70%, 66%, 66%, 66%, 61%, and 61% for assisted patency after secondary endovascular treatment. PVT-free persistency rates regarding the subgroups were as follows: children under 12 years vs. adults, 50% vs. 68% (p = 0.42); acute vs. nonacute, 76% vs. 46% (p = 0.10); localized vs. extensive, 90% vs. 50% (p = 0.035); transileocolic approach vs. percutaneous-transhepatic approach, 71% vs. 54% (p = 0.39); and thrombolysis-based treatment vs. non-thrombolysis-based treatment, 71% vs. 44% (p = 0.12), respectively. Among technically successful cases, PVT-free persistency rate was 94% for those with hepatopetal flow in the peripheral portal vein vs. 17% for those without hepatopetal flow (p < 0.001). The only major complication occurring was pleural hemorrhage (n=1). Minor complications (i.e., fever) occurred in 18 patients (60%). CONCLUSION: In conclusion, mid- to long-term portal patency following endovascular treatment was approximately 50%–60% in PVT patients after LDLT. PVT site patency over three months after the first endovascular treatment, localized PVT, and hepatopetal flow in the peripheral portal vein were identified as key prognostic factors for mid- to long-term portal patency.

Background It is important to understand how elderly patients with locally advanced pancreatic carcinoma (LAPC) should be treated, since the number of elderly cancer patients will increase. However, the optimal treatment for elderly patients with LAPC remains unclear. The purpose of this study was to evaluate the efficacy and safety of hypofractionated intensity-modulated radiotherapy (IMRT) with concurrent gemcitabine for elderly patients with LAPC. Methods We retrospectively analysed the data from LAPC patients aged ≥ 75 years treated with hypofractionated IMRT (48 Gy in 15 fractions) with concurrent weekly gemcitabine at our institution from February 2013 to December 2018. Overall survival (OS), progression-free survival (PFS), locoregional progression-free survival (LRPFS), distant metastasis-free survival (DMFS), and the pattern of recurrence and toxicity were analysed. Results Fifteen patients received treatment during the study period. The median age was 78 years (range 75–86 years), and the Eastern Cooperative Oncology Group (ECOG) performance status (PS) of all patients was 0–1. The median survival time (MST) and median PFS were 20.4 [95% confidence interval (CI) 10.3–36.8] and 13.5 (95% CI 6.4–20.3) months, respectively, and the 1-year OS and PFS rates were 80.0% (95% CI 50–93.1%) and 66.7% (95% CI 37.5–84.6%), respectively. The median LRPFS and median DMFS were 15.6 (95% CI 6.4–36.8) and 14.9 (95% CI 7.0–20.5) months, respectively, and the 1-year LRPFS and DMFS rates were 73.3% (95% CI 43.6–89.1%) and 66.7% (95% CI 37.5–84.6%), respectively. Non-haematologic grade 3 toxicity was observed in three cases, of which only one was induced by radiotherapy, whereas grade 4–5 non-haematologic acute or late toxicities were not observed. Conclusions The OS and PFS of elderly patients with LAPC treated using hypofractionated IMRT with concurrent gemcitabine were favourable and without the occurrence of severe toxicity. This treatment strategy is feasible and promising for elderly LAPC patients with good PS.

Background Ultrasonography (US) is useful when implanting fiducial markers in the liver. However, the implant position is sometimes lost. Recently, real-time image fusion technology (Volume Navigation [V-navi]; GE Healthcare, Milwaukee, WI, USA) has been introduced as a technique for using images from different modalities, and its utility for fiducial marker implantation has been hypothesized. Purpose To evaluate the utility of US-guided fiducial marker implantation in the liver using V-navi compared to conventional US. Material and Methods We retrospectively reviewed 35 patients who underwent fiducial marker implantation for stereotactic body radiation therapy of liver tumors in 2013–2018. To avoid artifacts obscuring the tumor, the target point of implantation was set 10 mm cranial or caudal to the tumor. Marker implantation was then performed using US alone (US group, n = 24) or V-navi with computed tomography (CT) or magnetic resonance imaging (V-navi group, n = 11). Postprocedural CT was evaluated to determine technical success, distances between marker and either tumor surface or target point, and whether marker-induced artifacts obscured the tumor. Complications were also evaluated. Results were compared between groups. Results Technical success was obtained in 33 patients. Distance between the tumor and marker showed no significant difference between groups. Distance between target point and marker was shorter in the V-navi group ( P = 0.0093). Tumor-obscuring artifacts were seen in 12 patients (V-navi group, n = 1; US group, n = 11; P = 0.055). The only complication was minor bleeding in the US group (n = 1). Conclusion V-navi appears useful for US-guided fiducial marker implantation in the liver compared with conventional US.

This study aimed to evaluate the clinical and radiological findings of hemorrhagic hepatic cysts with enhancing mural nodules. The radiology databases of five facilities were retrospectively searched for reports indicating hemorrhagic hepatic cysts or hepatic cystic tumors. Cases of hemorrhagic hepatic cysts with enhancing mural nodules based on pathological or radiological findings were identified and reviewed. We included 14 cases (11 female and 3 male) with a mean patient age of 72.6 years. Up until the enhancing mural nodules were detected, the cysts had decreased in size in all ten cases for which radiological imaging was available for a period of > 3 years previous to detection. Dynamic contrast-enhanced CT or MRI showed focal enhancement in the early phase and progressive centrifugal enhancement in the delayed phase in all 16 mural nodules ≥ 10 mm in diameter. Thirteen of 14 MRI assessable enhancing mural nodules ≥ 10 mm in diameter showed a hypointense rim with central hyperintensity on T2-weighted imaging. All cases showed calcification of the cyst wall. In the three referred cases, 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT demonstrated no intense FDG uptake in the enhancing mural nodules. In the four resected cases, histopathology of the enhancing mural nodules revealed neovascularization within an organized hematoma, including extensive dilated vessels and hemangioma-like lesions. Features including a decrease in cyst size, a progressive centrifugal enhancing pattern on dynamic contrast-enhanced CT or MRI, a hypointense rim with central hyperintensity on T2-weighted MRI, and cyst wall calcification may indicate a hemorrhagic hepatic cyst.

Background: Fusion image improves lesion detectability and can be an effective tool for percutaneous ultrasound (US)-guide procedure. We describe the clinical benefit of US-guided lung biopsy using fusion image. Purpose: To retrospectively compare the diagnostic accuracy and complication rates of US-guided lung biopsy with B-mode alone and those of a fusion image created using real-time US and computed tomography (CT). Materials and Methods: Between September, 2013 and September, 2016, 50 peripheral lung lesions in 50 patients (40 males, 10 females; median, 74 years old) were performed by US-guided percutaneous cutting needle biopsy using the B-mode alone or fusion image. Final diagnoses were based on surgical outcomes or clinical follow-up results for at least 12 months after biopsy. To assess prebiopsy characteristics, all lesions were divided into two groups: group 1 (identification on B-mode) and group 2 (identification on fusion image). Results: Of 50 peripheral lesions, 40 lesions (80%) were detected by means of B-mode alone (group 1), and 10 lesions (20%) were identified by fusion image (group 2). The diagnostic accuracy of group 1 was 90% (36/40 lesions), and the diagnostic accuracy of group 2 was 100% (10/10 lesions). Nodule type and the size of the lesions showed significant group wise differences (p < 0.001 and p = 0.02, respectively). Pneumothorax occurred immediately after the first puncture in five of 50 (10%) lesions, with no symptom development in all patients. Conclusion: Fusion images created using real-time US and CT may be useful for identification of the minimal size of potential target lung lesions and may be more suitable for improved yields with US-guided lung biopsy.

Bladder cancer usually forms a papillary structure. Progression along the cavity or membranous structures surrounding the bladder, rectum, or retroperitoneum without formation of a discrete mass is rare. We here present two patients with duodenal obstruction caused by retroperitoneal progression of bladder cancer, in both of whom computed tomography revealed bladder and rectal wall thickening with a malignant target sign, thickened mesorectal fascia with abnormal tissue stranding, and increased perirectal fat density. Both cancers progressed despite treatment, as indicated by faint abnormal tissue stranding and increased retroperitoneal fat density along the retromesenteric plane from the pelvis to the duodenum. Subsequently, both patients developed obstruction in the horizontal portion of the duodenum, still without formation of a mass lesion. These two patients highlight the challenges associated with retroperitoneal invasion by bladder cancer in the absence of a mass lesion and underscore the importance of considering cancer progression in patients with bowel obstruction, even when there is no obvious mass lesion and/or only minor retroperitoneal findings. Progression along the retromesenteric plane may be the key pathway via which progressive bladder cancer results in duodenal obstruction without or with a minor mass lesion.

To determine imaging hallmarks for distinguishing intrahepatic mass-forming biliary carcinomas (IMBCs) from hepatocellular carcinoma (HCC) and to validate their diagnostic ability using Bayesian statistics. Study 1 retrospectively identified clinical and imaging hallmarks that distinguish IMBCs (n = 41) from HCC (n = 247) using computed tomography (CT) and magnetic resonance imaging (MRI). Study 2 retrospectively assessed the diagnostic ability of these hallmarks to distinguish IMBCs (n = 37) from HCC (n = 111) using Bayesian statistics with images obtained from a different institution. We also assessed the diagnostic ability of the hallmarks in the patient subgroup with high diagnostic confidence (≥ 80% of post-test probability). Two radiologists independently evaluated the imaging findings in studies 1 and 2. In study 1, arterial phase peritumoral parenchymal enhancement on CT/MRI, delayed enhancement on CT/MRI, diffusion-weighted imaging peripheral hyperintensity, and bile duct dilatation were hallmarks indicating IMBCs, whereas chronic liver disease, non-rim arterial phase hyperenhancement on CT/MRI, enhancing capsule on CT/MRI, and opposed-phase signal drop were hallmarks indicating HCC (p = 0.001–0.04). In study 2, Bayesian statistics-based post-test probability combining all hallmark features had a diagnostic accuracy of 89.2% (132/148) in distinguishing IMBCs from HCC for both readers. In the high diagnostic confidence subgroup (n = 120 and n = 124 for readers 1 and 2, respectively), the accuracy improved (95.0% (114/120) and 93.5% (116/124) for readers 1 and 2, respectively). Combined interpretation of CT and MRI to identify hallmark features is useful in discriminating IMBCs from HCCs. High post-test probability by Bayesian statistics allows for a more reliable non-invasive diagnosis. • Combined interpretation of CT and MRI to identify hallmark features was useful in discriminating intrahepatic mass-forming biliary carcinomas from hepatocellular carcinoma. • Bayesian method-based post-test probability combining all hallmark features determined in study 1 showed high (> 90%) sensitivity and specificity for distinguishing intrahepatic mass-forming biliary carcinomas from hepatocellular carcinoma. • If the post-test probability or the confidence was ≥ 80% when combining the imaging features of CT and MRI, the high specificity of > 95% was achieved without any loss of sensitivity to distinguish hepatocellular carcinoma from intrahepatic mass-forming biliary carcinomas.

Objectives/purpose To determine the diagnostic value of morphological features on computed tomography (CT) in the differentiation of pulmonary arteriovenous malformation (pAVM) and its mimics. Materials and methods We retrospectively examined 59 consecutive patients (109 lesions) with initially suspected or occult pAVM who underwent contrast-enhanced chest CT from January 2006 to June 2016. All lesions were divided into two groups based on their diagnosis: AVM (n = 93) and non-AVM (n = 16). The non-AVM group comprised patients with an anomalous unilateral single pulmonary vein and congenital pulmonary venous atresia. Two board-certified radiologists reviewed the CT images and achieved consensus. Paired abnormal vessels were assessed with respect to their configuration, direction and continuity with the hilum, location, angle between them, and dilation ratio. Results All pAVM lesions had parallel, straight-running, paired abnormal vessels; most of the vessels ran through the identical segment. Conversely, in the non-AVM group, paired abnormal vessels did not run in parallel but detoured to the hilum through different segments from each other (i.e., the configuration, direction and continuity with the hilum and the location of the vessels were all significantly different between the two groups). The angle between the paired abnormal vessels was significantly narrower in the AVM group. The dilation ratio was not significantly different between the two groups. Conclusion Morphological features can be useful in the differentiation of pAVM and its mimics without contrast-enhanced CT to directly visualize the connection between the abnormal and normal pulmonary vessels. Pulmonary AVMs characteristically had a narrow angle between the two vessels, appearing like a pair of pine-needle leaves.

Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join outside the duodenal wall, usually forming a long common channel. A major issue in patients with PBM is the risk of biliary cancer. Because the sphincter of Oddi does not regulate the pancreaticobiliary junction in PBM, pancreatic juice frequently refluxes into the biliary tract and can cause various complications, including biliary cancer. Most cancers arise in the gallbladder or dilated common bile duct, suggesting that bile stasis is related to carcinogenesis. Early diagnosis and prophylactic surgery to reduce the risk of cancer are beneficial. The diagnosis of PBM is made mainly on the basis of imaging findings. The development of diagnostic imaging modalities such as multidetector CT and MR cholangiopancreatography has provided radiologists with an important role in diagnosis of PBM and its complications. Radiologists should be aware of PBM despite the fact that it is rare in non-Asian populations. In this review, the authors present an overview of PBM with emphasis on diagnosis and management of PBM and its complications. For early diagnosis, the presence of extrahepatic bile duct dilatation or gallbladder wall thickening may provide a clue to PBM with or without biliary dilatation, respectively. The pancreaticobiliary anatomy should be closely examined if imaging reveals these findings. Radiologists should also carefully evaluate follow-up images in PBM patients even years after prophylactic surgery because residual bile ducts remain at risk for cancer.©RSNA, 2020.

OBJECTIVE. The purpose of this article is to evaluate the radiologic findings predicting the future liver remnant hypertrophy ratio after portal vein embolization of the right branch. MATERIALS AND METHODS. The associations between the radiologic findings and the future liver remnant hypertrophy ratio for 79 patients who underwent portal vein embolization of the right branch between July 2007 and April 2017 were retrospectively analyzed. Multiple linear regression was performed to adjust for potential confounders, and the volume ratio of the right lobe anterior segment, number of proximal small branches from the right anterior and posterior portal veins, transient hepatic parenchymal enhancement, portal vein invasion, and variants of main portal vein anatomy were evaluated. The potential confounders were age, ratio of future liver remnant hypertrophy to total liver volume, indocyanine green clearance rate, maximum serum total bilirubin before portal vein embolization, and history of chemotherapy. RESULTS. Statistically significant associations were found between the future liver remnant hypertrophy ratio and the number of proximal small branches from the right anterior and posterior portal veins (p < 0.001), transient hepatic parenchymal enhancement (p < 0.001), portal vein invasion (p = 0.017), and variants of main portal vein anatomy (p = 0.048). The mean future liver remnant hypertrophy rate was 51.0% (n = 16) in patients without the radiologic findings showing statistically significant differences, and 25.8% (n = 63) in patients with at least one significant finding. CONCLUSION. When added to previously reported factors, the radiologic findings identified can help determine the indications for portal vein embolization and novel strategies for major hepatectomy.

To develop and evaluate a radiomics approach for classifying histological subtypes and epidermal growth factor receptor (EGFR) mutation status in lung cancer on PET/CT images.PET/CT images of lung cancer patients were obtained from public databases and used to establish two datasets, respectively to classify histological subtypes (156 adenocarcinomas and 32 squamous cell carcinomas) and EGFR mutation status (38 mutant and 100 wild-type samples). Seven types of imaging features were obtained from PET/CT images of lung cancer. Two types of machine learning algorithms were used to predict histological subtypes and EGFR mutation status: random forest (RF) and gradient tree boosting (XGB). The classifiers used either a single type or multiple types of imaging features. In the latter case, the optimal combination of the seven types of imaging features was selected by Bayesian optimization. Receiver operating characteristic analysis, area under the curve (AUC), and tenfold cross validation were used to assess the performance of the approach.In the classification of histological subtypes, the AUC values of the various classifiers were as follows: RF, single type: 0.759; XGB, single type: 0.760; RF, multiple types: 0.720; XGB, multiple types: 0.843. In the classification of EGFR mutation status, the AUC values were: RF, single type: 0.625; XGB, single type: 0.617; RF, multiple types: 0.577; XGB, multiple types: 0.659.The radiomics approach to PET/CT images, together with XGB and Bayesian optimization, is useful for classifying histological subtypes and EGFR mutation status in lung cancer.

Purpose To determine the optimal b-value for accurate depiction of pancreatic cancer (PC) in patients with active tumor-associated pancreatitis (TAP), using computed diffusion-weighted imaging (cDWI) with a range of b-values up to 3000 s/mm2. Methods The study protocol was approved by the institutional review board. We retrospectively analyzed 34 consecutive PC cases with active TAP who underwent pancreatectomy without preoperative therapy. Four cDWI datasets with b-values of 1500–3000 s/mm2 (cDWI1500–cDWI3000) were generated from the original DWI datasets with b-values of 0 and 1000 s/mm2 obtained using a 3-T scanner. Two board-certified radiologists evaluated images qualitatively (tumor conspicuity and total image quality), and another two board-certified radiologists placed regions of interest for quantitative evaluations (apparent diffusion coefficient [ADC] values of both lesions, contrast ratio [CR] of PC to active TAP, and volume ratio [VR] of PC to surgical specimen). Results As the b-value increased, tumor conspicuity improved significantly in cDWI2000 and cDWI2500 (P = 0.0121 and 0.0015, respectively), although total image quality decreased in all cDWIs compared with DWI1000 (P Conclusion Accurate depiction of PC was optimal with cDWI2000 in the presence of active TAP.

Background This study was performed to evaluate the clinical feasibility of a U-net for fully automatic uterine segmentation on MRI by using images of major uterine disorders. Methods This study included 122 female patients (14 with uterine endometrial cancer, 15 with uterine cervical cancer, and 55 with uterine leiomyoma). U-net architecture optimized for our research was used for automatic segmentation. Three-fold cross-validation was performed for validation. The results of manual segmentation of the uterus by a radiologist on T2-weighted sagittal images were used as the gold standard. Dice similarity coefficient (DSC) and mean absolute distance (MAD) were used for quantitative evaluation of the automatic segmentation. Visual evaluation using a 4-point scale was performed by two radiologists. DSC, MAD, and the score of the visual evaluation were compared between uteruses with and without uterine disorders. Results The mean DSC of our model for all patients was 0.82. The mean DSCs for patients with and without uterine disorders were 0.84 and 0.78, respectively (p = 0.19). The mean MADs for patients with and without uterine disorders were 18.5 and 21.4 [pixels], respectively (p = 0.39). The scores of the visual evaluation were not significantly different between uteruses with and without uterine disorders. Conclusions Fully automatic uterine segmentation with our modified U-net was clinically feasible. The performance of the segmentation of our model was not influenced by the presence of uterine disorders.

Temporal subtraction of CT (TS) images improves detection of newly developed bone metastases (BM). We sought to determine whether TS improves detection of BM by radiology residents as well. We performed an observer study using a previously reported dataset, consisting of 60 oncology patients, each with previous and current CT images. TS images were calculated using in-house software. Four residents independently interpreted twice the 60 sets of CT images, without and with TS. They identified BM by marking suspicious lesions likely to be BM. Lesion-based sensitivity and number of false positives per patient were calculated. Figure-of-merit (FOM) was calculated. Detectability of BM, with and without TS, was compared between radiology residents and board-certified radiologists, as published previously. FOM of residents significantly improved by implementing TS (p value

We have developed a novel medical device software program that is intended to improve radiologists’ performance with regard to the detection of bone metastases on CT images. To establish the protocol of the clinical performance evaluation for regulatory approval, the feasibility of nonclinical study (NCS) and clinical study (CS) conforming to the principles of GCP was compared. There were two main issues with establishing the protocol in Japan. Firstly, retrospective case collection was not accepted for CS due to concerns regarding selection bias. However, it is difficult to prospectively collect cases for use in an observer study due to the wide variety of bone metastases cases required. Secondly, when setting the reference standard (RS) for bone metastases, the utilization of any patient information was not accepted for NCS due to concerns regarding an inappropriate RS setting. However, it was predicted that it would be difficult to set accurate RSs only using CT images. Consequently, following discussion with a Japanese regulatory body, the protocol was established as an NCS using retrospectively collected CT images. Furthermore, we agreed to use anonymized clinical images to set the RS and to rescue the test results by reviewing the RS after the observer study, hence ensuring reliability. An NCS was a feasible method of evaluating the novel medical device software while also complying with quality management systems. By using real-world clinical image databases, this clinical performance evaluation method may be both effective and efficient as a path to regulatory approval of certain medical device software.

The purpose of this study was to evaluate the imaging characteristics of liver metastases overlooked at contrast-enhanced CT.The records of 746 patients with a diagnosis of liver metastases from colorectal, breast, gastric, or lung cancer between November 2010 and September 2017 were reviewed. Images were reviewed when liver metastases were first diagnosed, and images from prior contrast-enhanced CT examinations were checked if available. These lesions were classified into two groups: missed lesions (those missed on the prior images) and detected lesions (those correctly identified and invisible on the prior images or there were no prior images). Tumor size, contrast-to-noise ratio, location, presence of coexisting liver cysts and hepatic steatosis, and indications for examination were compared between the groups. The t test and Fisher exact test were used to analyze the imaging characteristics of previously overlooked lesions.The final analysis included 137 lesions, of which 68 were classified as missed. In univariate analysis, contrast-to-noise ratio was significantly lower in missed lesions (95% CI, 2.65 ± 0.24 vs 3.90 ± 0.23; p0.001). The proportion of subcapsular lesions (odds ratio, 3.44; p0.001), hepatic steatosis (odds ratio, 6.35; p = 0.007), and examination indication other than survey of malignant tumors (odds ratio, 9.07; p = 0.02) were significantly higher for missed lesions.Liver metastases without sufficient contrast enhancement, those in patients with hepatic steatosis, those in subcapsular locations, and those found at examinations for indications other than to assess for tumors were significantly more likely to be overlooked.

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Purpose To identify biochemical factors associated with liver enhancement over time on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) images and predict the optimal time point of the hepatobiliary phase in various clinical settings. Materials and Methods This study was approved by the institutional review boards, and written informed consent was obtained from the 1903 patients enrolled. Simple and multiple logistic regression analyses were performed to investigate the biochemical factors associated with liver-to-spleen contrast (LSC) of at least 1.5 in the hepatobiliary phase. Changes in LSC and lesion-to-liver contrast (LLC) of lesions over time (at 5, 10, 15, and 20 minutes) were investigated with a linear mixed-effects model in patients and lesions. For LSC, the optimal cutoff value was determined with receiver operating characteristic analysis of the most significant variable. Differences in LSC and LLC were analyzed in various clinical settings. Results Ultimately, 1870 patients were evaluated, as 33 were excluded according to study criteria. Prothrombin (PT) activity, total bilirubin level (P = .020), and total cholesterol level (P = .005) were significantly associated with LSC of at least 1.5 at 20 minutes, and PT activity was identified as the most significant factor (odds ratio, 1.271; 95% confidence interval: 1.109, 1.455; P = .001). LSC of at least 1.5 at 20 minutes with PT activity of at least 86.9% and less than 86.9% occurred in 555 of 626 patients (88.6%) and 388 of 575 patients (67.5%), respectively. Satisfactory liver enhancement at 20 minutes was significantly more likely to be achieved by patients with hepatitis B virus than by those with hepatitis C virus (P < .001) and by patients with metastasis than by those with hepatocellular carcinoma (P < .001). No significant difference in LLC was observed in patients examined at 1.5 and 3.0 T (P = .133). Conclusion Hepatic enhancement is significantly associated with PT activity, total bilirubin level, and total cholesterol level. PT activity of at least 86.9% could be used to shorten examination times at Gd-EOB-DTPA-enhanced MR imaging. © RSNA, 2016 Online supplemental material is available for this article.

Background In non-contrast-enhanced magnetic resonance (MR) arteriography, the flow-out method using a selective tagging pulse with a long inversion time (TI) and a non-selective inversion recovery pulse with a short TI (the modified flow-out method) might further contribute to the suppression of background signal and facilitate improved visualization of the hepatic artery. However, no report has focused on the image quality of non-contrast-enhanced MR arteriography using the modified flow-out method. Purpose To compare the flow-in method with the modified flow-out method and to determine which method better visualizes the hepatic artery. Material and Methods Twenty-seven healthy volunteers were examined using respiratory-triggered three-dimensional true steady-state free-precession MR with two selective inversion recovery pulses (the flow-in method) or with one tagging pulse and one non-selective inversion recovery pulse (the modified flow-out method). Results Artery-to-liver contrast was significantly increased in the modified flow-out method relative to the flow-in method ( P Conclusion The modified flow-out method for non-contrast-enhanced MR angiography is a promising technique for visualizing the hepatic artery.

The aim is to investigate the added value of computed diffusion-weighted magnetic resonance imaging (DWI) at 1.5T in detecting hepatic metastases. Fifty-six patients with a total of 100 hepatic metastases were included. Computed DWI was synthesized from lower b values. Diagnostic performance was evaluated by receiver operating characteristic (ROC) curve analysis. The sensitivity was calculated and analyzed. The area under the ROC curve of the computed DWI was larger than that of acquired DWI. Both readers detected significantly more hepatic metastases with combined acquired DWI/computed DWI. Combined use of computed DWI with acquired DWI helped to provide higher sensitivity at 1.5T.