Magnetic resonance imaging-based risk factors of hepatocellular carcinoma after direct-acting antiviral therapy: A multicenter observational study.

AIM: To determine risk factors associated with hepatocellular carcinoma (HCC) development following direct-acting antiviral (DAA) therapy. METHODS: We enrolled patients with chronic hepatitis C who underwent direct-acting antiviral therapy and achieved sustained virologic response at 12 weeks between 2012 and 2018. Subsequently, patients were followed up. The primary endpoint was the development of HCC or the date of the last follow up when the absence of HCC was confirmed. Uni- and multivariate Cox proportional hazards models were used to identify factors contributing to HCC development, including gadoxetic acid-enhanced magnetic resonance imaging findings. The cumulative incidence rates of HCC development were calculated using the Kaplan-Meier method, and differences between groups were assessed using the log-rank test. RESULTS: The final study cohort comprised 482 patients (median age 70.5 years; 242 men). The median follow-up period was 36.8 months. Among 482 patients, 96 developed HCC (19.9%). The 1-, 3-, and 5-year cumulative rates of HCC development were 4.9%, 18.6%, and 30.5%, respectively. Multivariate analysis revealed that age, male sex, history of HCC, and hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were independent risk factors significantly associated with HCC development (p < 0.001-0.04). The highest risk group included patients with both a history of HCC and the presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement (the 1- and 3-year cumulative HCC development rates were 14.2% and 62.2%, respectively). CONCLUSION: History of HCC and presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were strong risk factors for HCC development following direct-acting antiviral therapy.

Histopathological growth pattern and vessel co-option in intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA) exhibits different blood imaging features and prognosis depending on histology. To clarity histopathological growth patterns (HGPs) and vascularization processes of iCCA, we collected 145 surgical specimens and histologically classified them into large bile duct (LBD) (20 cases), small bile duct (SBD) (54), cholangiolocarcinoma (CLC) (35), combined SBD-CLC (cSBD-CLC) (26), and ductal plate malformation (DPM) (10) (sub)types. According to the invasive pattern at the interface between tumor and adjacent background liver, HGPs were classified into desmoplastic, pushing, and replacing HGPs. Desmoplastic HGP predominated in LBD type (55.5%), while replacing HGP was common in CLC (82.9%) and cSBD-CLC (84.6%) subtypes. Desmoplastic HGP reflected angiogenesis, while replacing HGP showed vessel co-option in addition to angiogenesis. By evaluating microvessel density (MVD) using vascular markers, ELTD1 identified vessel co-option and angiogenesis, and ELTD1-positive MVD at invasive margin in replacing HGP was significantly higher than those in desmoplastic and pushing HGPs. REDD1, an angiogenesis-related marker, demonstrated preferably higher MVD in the tumor center than in other areas. iCCA (sub)types and HGPs were closely related to vessel co-option and immune-related factors (lymphatic vessels, lymphocytes, and neutrophils). In conclusion, HGPs and vascular mechanisms characterize iCCA (sub)types and vessel co-option linked to the immune microenvironment.

Dynamic CT and Gadoxetic Acid-enhanced MRI Characteristics of P53-mutated Hepatocellular Carcinoma.

Background Imaging markers of hepatocellular carcinoma (HCC) on the basis of molecular classification are important for predicting malignancy grade and prognosis. P53-mutated HCC is a major aggressive subtype; however, its imaging characteristics have not been clarified. Purpose To clarify the imaging characteristics of P53-mutated HCC at dynamic CT and gadoxetic acid-enhanced MRI that are correlated with its clinical features, pathologic findings, and prognosis. Materials and Methods In this retrospective single-center study, patients with surgically resected HCC between January 2015 and May 2018 in a university hospital were evaluated. HCC was classified into P53-mutated HCC and non-P53-mutated HCC using immunostaining. Dynamic CT and gadoxetic acid-enhanced MRI findings, clinical features, pathologic findings, and prognosis were compared using Mann-Whitney test, χ2 test, multivariable regression analysis, receiver operating characteristic analysis, Kaplan-Meier method, and log-rank test. Immunohistochemical expression of P53, organic anion transporting polypeptide 1B3 (OATP1B3), and CD34 were evaluated, and the correlations were analyzed using the Pearson correlation test. Results In total, 149 patients (mean age, 67 years ± 9 [SD]; 103 men) with 173 HCCs were evaluated. P53-mutated HCC (n = 28) demonstrated higher serum α-fetoprotein (median, 127.5 ng/mL vs 5.5 ng/mL; P < .001), larger size (40.4 mm ± 29.7 vs 26.4 mm ± 20.5; P = .001), and higher rates of poorly differentiated HCC (22 of 28 [79%] vs 24 of 145 [17%]; P < .001). Dilated vasculature in the arterial phase of dynamic CT (odds ratio, 14; 95% CI: 3, 80; P = .002) and a lower relative enhancement ratio in the hepatobiliary phase (odds ratio, 0.05; 95% CI: 0.01, 0.34; cutoff value, 0.69; P = .002) independently predicted P53-mutated HCC. OATP1B3 expression and P53 expression were inversely correlated (P = .002; R = -0.24). Five-year overall survival was worse for P53-mutated HCC (50.0% vs 72.6%; P = .02). Conclusion Dilated vasculature at the arterial phase of dynamic CT and a lower relative enhancement ratio at the hepatobiliary phase of gadoxetic acid-enhanced MRI were useful markers for P53-mutated hepatocellular carcinoma with poor prognosis. © RSNA, 2022 Online supplemental material is available for this article.

Diagnostic Performance in Low- and High-Contrast Tasks of an Image-Based Denoising Algorithm Applied to Radiation Dose-Reduced Multiphase Abdominal CT Examinations.

BACKGROUND. Anatomic redundancy between phases can be used to achieve denoising of multiphase CT examinations. A limitation of iterative reconstruction (IR) techniques is that they generally require use of CT projection data. A frequency-split multi-band-filtration algorithm applies denoising to the multiphase CT images themselves. This method does not require knowledge of the acquisition process or integration into the reconstruction system of the scanner, and it can be implemented as a supplement to commercially available IR algorithms. OBJECTIVE. The purpose of the present study is to compare radiologists' performance for low-contrast and high-contrast diagnostic tasks (i.e., tasks for which differences in CT attenuation between the imaging target and its anatomic background are subtle or large, respectively) evaluated on multiphase abdominal CT between routine-dose images and radiation dose-reduced images processed by a frequency-split multiband-filtration denoising algorithm. METHODS. This retrospective single-center study included 47 patients who underwent multiphase contrast-enhanced CT for known or suspected liver metastases (a low-contrast task) and 45 patients who underwent multiphase contrast-enhanced CT for pancreatic cancer staging (a high-contrast task). Radiation dose-reduced images corresponding to dose reduction of 50% or more were created using a validated noise insertion technique and then underwent denoising using the frequency-split multi-band-filtration algorithm. Images were independently evaluated in multiple sessions by different groups of abdominal radiologists for each task (three readers in the low-contrast arm and four readers in the high-contrast arm). The noninferiority of denoised radiation dose-reduced images to routine-dose images was assessed using the jackknife alternative free-response ROC (JAFROC) figure-of-merit (FOM; limit of noninferiority, -0.10) for liver metastases detection and using the Cohen kappa statistic and reader confidence scores (100-point scale) for pancreatic cancer vascular invasion. RESULTS. For liver metastases detection, the JAFROC FOM for denoised radiation dose-reduced images was 0.644 (95% CI, 0.510-0.778), and that for routine-dose images was 0.668 (95% CI, 0.543-0.792; estimated difference, -0.024 [95% CI, -0.084 to 0.037]). Intraobserver agreement for pancreatic cancer vascular invasion was substantial to near perfect when the two image sets were compared (κ = 0.53-1.00); the 95% CIs of all differences in confidence scores between image sets contained zero. CONCLUSION. Multiphase contrast-enhanced abdominal CT images with a radiation dose reduction of 50% or greater that undergo denoising by a frequency-split multiband-filtration algorithm yield performance similar to that of routine-dose images for detection of liver metastases and vascular staging of pancreatic cancer. CLINICAL IMPACT. The image-based denoising algorithm facilitates radiation dose reduction of multiphase examinations for both low- and high-contrast diagnostic tasks without requiring manufacturer-specific hardware or software.

Computer-Aided Detection of Subsolid Nodules on Chest Computed Tomography: Assessment of Visualization on Vessel-Suppressed Images.

OBJECTIVES: This study aimed to clarify the performance of automatic detection of subsolid nodules by commercially available software on computed tomography (CT) images of various slice thicknesses and compare it with visualization on the accompanying vessel-suppression CT (VS-CT) images. METHODS: A total of 95 subsolid nodules from 84 CT examinations of 84 patients were included. The reconstructed CT image series of each case with 3-, 2-, and 1-mm slice thicknesses were loaded into a commercially available software application (ClearRead CT) for automatic detection of subsolid nodules and generation of VS-CT images. Automatic nodule detection sensitivity was assessed for 95 nodules on each series of images acquired at 3 slice thicknesses. Four radiologists subjectively evaluated visual assessment of the nodules on VS-CT. RESULTS: ClearRead CT automatically detected 69.5% (66/95 nodules), 68.4% (65/95 nodules), and 70.5% (67/95 nodules) of all subsolid nodules in 3-, 2-, and 1-mm slices, respectively. The detection rate was higher for part-solid nodules than for pure ground-glass nodules at all slice thicknesses. In the visualization assessment on VS-CT, 3 nodules at each slice thickness (3.2%) were judged as invisible, while 26 of 29 (89.7%), 27 of 30 (90.0%), and 25 of 28 (89.3%) nodules, which were missed by computer-aided detection, were judged as visible in 3-, 2-, and 1-mm slices, respectively. CONCLUSIONS: The automatic detection rate of subsolid nodules by ClearRead CT was approximately 70% at all slice thicknesses. More than 95% of subsolid nodules were visualized on VS-CT, including nodules undetected by the automated software. Computed tomography acquisition at slices thinner than 3 mm did not confer any benefits.

Plasma Antithrombin III Levels Can Be a Prognostic Factor in Liver Cirrhosis Patients with Portal Vein Thrombosis.

Liver function influences the plasma antithrombin (AT)-III levels. AT-III is beneficial for patients with portal vein thrombosis (PVT) and low plasma AT-III levels. However, whether these levels affect prognosis in patients with cirrhosis-associated PVT remains unknown. This retrospective study involved 75 patients with cirrhosis and PVT treated with danaparoid sodium with or without AT-III. The plasma AT-III level was significantly lower in patients with liver failure-related death than in those with hepatocellular carcinoma (HCC)-related death (p = 0.005), although the Child-Pugh and albumin-bilirubin (ALBI) scores were not significantly different between these two groups. Receiver operating characteristic curve analysis of the plasma AT-III levels showed cutoff values of 54.0% at 5-year survival. Low plasma AT-III levels (<54.0%) were associated with significantly worse prognosis than high levels in both overall survival (p = 0.0013) and survival excluding HCC-related death (p < 0.0001). Low plasma AT-III (<54.0%) was also associated with a significantly worse prognosis among patients with Child-Pugh A/B or ALBI grade 1/2 (p < 0.0001). Multivariate analyses indicated that low plasma AT-III levels (<54.0%) were an independent prognostic factor for poor survival outcome. Low plasma AT-III levels may be associated with mortality, particularly liver failure-related death, independent of liver function.

Single-Center Analysis of Pegfilgrastim-induced Aortitis Using a Drug Prescription Database and CT Findings.

Background Pegfilgrastim-induced aortitis is a rare but serious adverse event in patients undergoing anticancer therapy with granulocyte colony-stimulating factor analogs. Despite previous case series and systemic reviews, the exact incidence, clinical presentation, and CT manifestations of pegfilgrastim-induced aortitis remain unclear. Purpose To clarify the incidence and clinicoradiologic characteristics of pegfilgrastim-induced aortitis. Materials and Methods Pegfilgrastim administration records from January 2015 to March 2021 were retrospectively collected from the drug prescription database of a single center and were matched with the relevant findings in the CT database. Corresponding CT images within 6 months were available for a total of 1462 doses of pegfilgrastim in 674 patients. Four radiologists reviewed the CT images for the presence of aortitis in two steps. Clinical information and the distribution of aortitis on CT images were examined for patients with a diagnosis of pegfilgrastim-induced aortitis. Results Pegfilgrastim-induced aortitis was observed in 18 of 674 patients (mean age, 62 years ± 13 [SD]; 424 men), resulting in incidence rates of 2.7% per patient (95% CI: 1.6, 4.2) and 1.2% per dose (95% CI: 0.7, 1.9). The most common original primary malignancies were esophageal cancer (n = 10, 9%), breast cancer (n = 3, 4%), and pancreatic cancer (n = 2, 2%). The most common anticancer drugs used at onset were 5-fluorouracil, cisplatin, and docetaxel. Seven cases were symptomatic, while the remaining 11 (61%) were asymptomatic. CT findings indicated that aortitis involved branches of the aortic arch in 13 cases (72%), aortic arch in 10 cases (56%), and abdominal aorta in two cases (11%). Conclusion Pegfilgrastim-induced aortitis may be more prevalent than previously reported and may be more common in patients with esophageal cancer and those who received 5-fluorouracil, cisplatin, and docetaxel as anticancer drugs. The findings also suggest that pegfilgrastim-induced aortitis is often characterized by aortic arch and proximal branch involvement at CT. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Krinsky in this issue.

Transcatheter arterial embolization of iatrogenic massive arterioportal fistula in the liver.

BACKGROUND: Massive arterioportal fistula (APF) is naturally irreversible and can induce portal hypertension and portal vein thrombosis (PVT), worsening survival outcomes. PURPOSE: To evaluate the clinical course and details of transarterial embolization (TAE) procedures for massive APF. MATERIAL AND METHODS: This retrospective single-center observational study evaluated the time until embolization after puncture, imaging, embolization methods, and laboratory data of 10 consecutive patients who were diagnosed with massive APF after puncture and underwent TAE at our hospital from 1 April 2012 to 30 September 2019. RESULTS: Out of 10 cases, eight demonstrated a simple type and the other two cases a complex network type on the digital subtraction angiography pattern of massive APF. In two simple-type cases for which re-embolization was required, other subsegmental branches were embolized. The two cases showing a complex network type had been embolized via not only the subsegmental branch, but also the extrahepatic and multiple subsegmental branches. Child-Pugh scores were improved in eight of the ten cases. PVT was seen in six cases before embolization, but disappeared after embolization in all cases, despite the fact that three cases had not received anticoagulant therapy. Six cases had digestive varices before embolization, suggesting portal hypertension, and two of the six cases with esophageal varices and one with gastric varices decreased after embolization. CONCLUSION: TAE for massive APF contributed to the improvement of hepatic reserve, the disappearance of PVT, and the improvement of portal hypertension; however, embolization of multiple branches may still be required in some cases.

Ultrasonography of IgG4-related dacryoadenitis and sialadenitis: Imaging features and clinical usefulness.

OBJECTIVES: To clarify the ultrasonographic features of immunoglobulin G4 (IgG4)-related dacryoadenitis and sialadenitis (IgG4-DS) and their usefulness in clinical diagnostic sessions. METHODS: By re-evaluating 96 consecutive patients with IgG4-related disease, we identified 54 patients (male:female = 37:17; median age, 69.5 years) who underwent lacrimal or submandibular gland (LG or SG, respectively) ultrasonography and computed tomography (CT). Their clinical and ultrasonographic features were retrospectively analysed. Radio-pathological correlations were also examined in LG (23 cases) and SG lesions (20 cases). Additionally, the diagnostic accuracy of CT for LG/SG lesions was evaluated. RESULTS: Abnormal ultrasonographic findings were detected in 33 (LGs) and 38 (SGs) patients, and most of them were observed bilaterally. All lesions were well demarcated and demonstrated diffuse low-echoic areas (rocky pattern) or multiple low-echoic nodules surrounded by high-echoic linear shadows (cobblestone pattern) corresponding to intra-lobular inflammation and inter-lobular fibrosis. Moreover, 42% (LGs; 14/33) and 42% (SGs; 16/38) patients had glandular lesions without clinical symptoms associated with the affected glands. The diagnostic accuracy of CT was ∼80% for LG and 55% for SG. CONCLUSIONS: Ultrasonographic findings in IgG4-DS included diffuse or nodular low-echoic areas with linear high-echoic structures corresponding to inflamed lobules and inter-lobular fibrosis. These findings can help detect IgG4-DS.

Diversity in cell differentiation, histology, phenotype and vasculature of mass-forming intrahepatic cholangiocarcinomas.

AIMS: Mass-forming intrahepatic cholangiocarcinomas (MF-iCCAs), involving small bile ducts, bile ductules or canals of Hering, remain treated as a single entity. We aimed to examine the diversity in histology, phenotype and tumour vasculature of MF-iCCAs. METHODS AND RESULTS: Based on morphology and immunophenotype, we classified MF-iCCAs into small bile duct (SBD), cholangiolocarcinoma (CLC), ductal plate malformation (DPM) and hepatocellular carcinoma (HCC)-like subtypes. Genetic correlations among the histological subtypes were examined by multi-region tumour sequencing. Vasculatures and other clinicopathological features were compared among tumour groups with various proportions of the histological subtypes in 62 MF-iCCAs. Cases of pure SBD, CLC, DPM and HCC-like subtypes numbered 18 (29%), seven (11.3%), none (0%) and two (3%), respectively; the remaining 35 (56.4%) cases comprised several components. Genetic alterations, isocitrate dehydrogenase (IDH)1/2, KRAS, TP53, polybromo-1 (PBRM1) and BRCA1-associated protein 1 (BAP1), were shared among SBD, CLC, DPM and hepatoid components within a tumour. We uncovered distinct vascularisation mechanisms among SBD, CLC and DPM subtypes with a prominent vessel co-option in CLC tumours. iCCA with a DPM pattern had the highest vascular densities (mean microvascular density,140/mm2 ; arterial vessel density, 18.3/mm2 ). Increased CLC component was correlated with longer overall survival time (r = 0.44, P = 0.006). Pure SBD tumours had a lower 5-year overall survival rate compared with MF-iCCA with CLC pattern (30.5 versus 72.4%, P = 0.011). CONCLUSIONS: MF-iCCAs comprise four histological subtypes. Given their sharing some driver gene alterations, indicating they can have a common cell origin, SBD, CLC and DPM subtypes, however, differ in cell differentiation, histology, phenotype or tumour vasculature.

Hemosiderin deposition in papillary renal cell carcinoma and its potential to mask enhancement on MRI: analysis of 110 cases.

OBJECTIVES: To evaluate the relationship between imperceptible T1 enhancement of papillary renal cell carcinoma (pRCC) on MR and intratumoral hemosiderin deposition. METHODS: One hundred ten pRCCs (≤ 7 cm) were evaluated by MR with in- and opposed-phase spoiled gradient echo (GRE) and T1-weighted spoiled GRE with fat suppression before and after contrast. Hemosiderin deposition was assessed by SIindex and Dindex on in- and opposed-phase images. SIindex and Dindex are calculated as (SIin - SIopp)/(SIin) × 100, where SIin and SIopp are tumor signal intensities on in- and opposed-phase images and (Din)/(Dopp), where Din and Dopp are tumor diameters on in- and opposed-phase images, respectively. The degree of tumor enhancement was classified as grade 1 (no), grade 2 (subtle), or grade 3 (definite). Tumor enhancement on CT was assessed when available. RESULTS: Five (5%), 10 (9%), and 95 (86%) tumors were categorized as grades 1, 2, and 3 enhancement, respectively. The mean SIindex was - 33.9, - 25.3, and 1.00, whereas the mean Dindex was 1.26, 1.05, and 1.00 in tumors with grades 1, 2, and 3 enhancement, respectively. Tumors with grade 1 enhancement had significantly lower SIindex (p = 0.001) and higher Dindex (p = 0.005) than those with grade 3 enhancement. Among six tumors with grade 1 or 2 enhancement and available CT, four tumors showed > 20 HU enhancement. CONCLUSIONS: pRCC with no subjective enhancement on contrast-enhanced MR showed hemosiderin deposition evident by lower SIindex and higher Dindex. Hemosiderin deposition might mask the tumor enhancement on MR. KEY POINTS: • 5% of papillary renal cell carcinoma showed imperceptible enhancement on contrast-enhanced MR. • Hemosiderin deposition in papillary renal cell carcinoma might mask the tumor enhancement on contrast-enhanced MR due to T2/T2*-shortening effects. • A renal lesion with extensive hemosiderin deposition but no perceptible enhancement on MR should be considered suspicious for papillary renal cell carcinoma.

Mucus plugs and bronchial wall thickening on three-dimensional computed tomography in patients with unexplained chronic cough whose sputum yielded filamentous Basidiomycetes.

OBJECTIVES: This study was conducted in order to identify imaging features on three-dimensional computed tomography (CT) of unexplained chronic cough (UCC) patients with positive sputum cultures for filamentous Basidiomycetes (f-BM). METHODS: UCC outpatients who had been given various questionnaires for cough, pulmonary function tests, and fungal cultures of sputum were evaluated. Multidetector row CT (MDCT) was performed for three-dimensional CT analysis of the lungs. Retrospective analysis was carried out with three groups: f-BM culture-positive group, other fungal culture-positive group, and culture-negative group. The Kruskal-Wallis test, analysis of variance, Fischer exact test, χ2 test, Student's t test, Mann-Whitney U test, Spearman's correlation coefficient, and Dunn-Bonferroni post hoc method were used for statistical analysis. RESULTS: Of the 50 patients, 3 were excluded and the remaining 47 were included in the analysis. There were no significant differences in respiratory function or clinical characteristics among the three groups. The common features on high-resolution CT (HRCT) included tree-in-bud (TIB) pattern, multiple centrilobular nodules, and bronchial wall thickening. Bronchiolar mucus plugs were detected in 7 (15%) of 47 cases. Bronchiole wall thickness and %FEV1 appeared to be slightly correlated (p = 0.033, r = 0.357). The bronchiole walls were significantly thicker when mucus plugs were found (p = 0.010). Bronchiolar walls were the thickest and the score of mucus plugs was the highest in patients with f-BM culture-positive sputum (p = 0.008). CONCLUSIONS: Imaging findings for identifying f-BM culture-positive fungus-associated chronic cough (FACC) patients include high mucus plug scores and bronchiolar wall thickening on three-dimensional CT. KEY POINTS: • Three-dimensional computed tomography helps clinicians assess patients with unexplained chronic cough and identify those with fungus-associated chronic cough. • A retrospective single-center study showed that computed tomography images in patients with filamentous Basidiomycetes cultured from sputum had mucus plugs and bronchiolar wall thickening. • UCC patients with sputum cultures positive for filamentous Basidiomycetes may have fine airway lesions that could not be detected without three-dimensional computed tomography.

Gadoxetic acid-enhanced MR imaging for hepatocellular carcinoma: molecular and genetic background.

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) plays important roles in diagnosis of hepatic lesions because of its superiority in the detectability of small lesions, its differentiation ability, and its utility for the early diagnosis of hepatocellular carcinoma (HCC). In HCC, expression of organic anion transporting polypeptide (OATP) 1B3 correlates with the enhancement ratio in the hepatobiliary phase. Gadoxetic acid-enhanced MRI, an indirect molecular imaging method, reflects OATP1B3 expression in HCC. OATP1B3 expression gradually decreases from the dysplastic nodule stage to advanced HCC. Decreased expression is a sensitive marker of multistep hepatocarcinogenesis, especially in the early stages. Hypervascular HCCs commonly show hypointensity in the hepatobiliary phase corresponding to a decrease in OATP1B3; however, approximately 10% of HCCs show hyperintensity due to OATP1B3 overexpression. This hyperintense HCC shows less aggressive biological features and has a better prognosis than hypointense HCC. Hyperintense HCC can be classified into a genetic subtype of HCC with a mature hepatocyte-like molecular expression. OATP1B3 expression and the less aggressive nature of hyperintense HCC are regulated by the molecular interaction of ß-catenin signaling and hepatocyte nuclear factor 4α, a tumor suppressor factor. Gadoxetic acid-enhanced MR imaging has the potential to be an imaging biomarker for HCC. KEY POINTS: • The hepatobiliary phase is a sensitive indirect indicator of organic anion transporting polypeptide1B3 (OATP1B3) expression in hepatocellular carcinoma (HCC). • The OATP1B3 expression, namely, enhancement in the hepatobiliary phase, decreases from the very early stage of hepatocarcinogenesis, contributing to early diagnosis of HCC. • HCC showing hyperintensity on the hepatobiliary phase is a peculiar genetic subtype of HCC with OATP1B3 overexpression, a less aggressive nature, and mature hepatocyte-like molecular/genetic features.

Gadoxetate disodium-related event during image acquisition: a prospective multi-institutional study for better MR practice.

PURPOSE: To acknowledge the facts of gadoxetate disodium-related events in Japan and to achieve better MR practice by analyzing large cohort data with various MR parameters. MATERIALS AND METHODS: This prospective multi-institutional study included 1993 patients (1201 men, mean age 66.4 ± 12.8 years), who received dynamic MRI with gadoxetate disodium (gadoxetate group, n = 1646) or extracellular gadolinium-based contrast agents (other-GBCAs group, n = 347) between January and November 2016. Recorded data covered adverse reactions including dyspnea, breath-hold failure during acquisition, respiratory artifacts rated with a four-point scale, and MR parameters. We compared data between the two groups in whole cohort and age-, gender-, and institution-matched subcohort using χ2 test (n = 640). Logistic regression model was used to reveal independent associates of substantial artifacts in arterial phase imaging. RESULTS: Transient dyspnea rarely occurred in gadoxetate or other-GBCAs group (both < 1%). Gadoxetate group (vs other-GBCAs group) showed higher rates of breath-hold failure (whole cohort, 18.2% vs 7.7%, p < 0.001; subcohort, 17.6% vs 6.3%, p < 0.001) and substantial artifacts in arterial phase (7.2% vs 2.2%, p = 0.001; 7.4% vs 1.7%, p = 0.001). With single arterial phase protocol, substantial artifacts under gadoxetate were independently associated with age (odds ratio [OR] = 1.04, p < 0.001), hearing difficulty (OR = 2.92, p = 0.008), breath-hold practice required (OR = 1.61, p = 0.039), and short acquisition time (OR = 0.43, p = 0.005). Multiple arterial phase acquisition did not reduce the incident rate of substantial artifacts. CONCLUSION: Gadoxetate disodium was associated with breath-hold failure and substantial artifacts in arterial phase imaging, but not with dyspnea in Japan. Shorter acquisition time should be used to sustain image quality in gadoxetate disodium-enhanced arterial phase imaging. KEY POINTS: • Gadoxetate disodium administration leads to breath-hold failure and substantial imaging artifacts in arterial phase MRI in Japan. • Contrast agent-induced dyspnea in arterial phase and adverse reactions are rare in Japan, without showing differences between gadoxetate disodium or other extracellular gadolinium-based contrast agents. • Shorter acquisition time significantly reduces gadoxetate-induced imaging artifacts in the arterial phase.

Doughnut-like hyperintense nodules on hepatobiliary phase without arterial-phase hyperenhancement in cirrhotic liver: imaging and clinicopathological features.

OBJECTIVES: To determine the imaging and clinicopathological features of MRI doughnut-like nodules (HBP-doughnut nodules), hyperintense at the hepatobiliary phase (HBP) after injection of gadoxetic acid (EOB) and without arterial-phase hyperenhancement (APHE) in cirrhotic liver. METHODS: The Institutional Review Board approved this retrospective study and informed consent was waived. We enrolled 309 consecutive patients with liver cirrhosis who were examined by EOB-MRI, dynamic CT, and angiography-assisted CT between 2008 and 2012 and searched for HBP-doughnut nodules. We evaluated imaging characteristics including haemodynamics and signal intensity of MRI, pathological findings, and frequency of malignant transformation. RESULTS: One hundred and one HBP-doughnut nodules without APHE were identified in 18 patients (6%), including seven of 59 (12%) patients with hepatitis-B-virus-related, nine of 230 (3.9%) with hepatitis-C-virus-related, and two of 33 (6.1%) with alcoholic cirrhosis. All nodules showed enhancement peaks in the portal phase, the same or increased intranodular portal supply on CT during arterial portography, and the same or decreased intranodular arterial supply on CT during hepatic arteriography. On T2-weighted and diffusion-weighted images, 37 (36%) and 24 (24%) nodules, respectively, showed hyperintensity predominantly in the central area. Three nodules were diagnosed by fine needle biopsy as non-neoplastic hepatic nodules. Ninety-three of 101 (92%) nodules in 16 patients were followed up during an observation period of 1163 ± 902 days (range 57-2920 days), and none showed malignant transformation. CONCLUSION: HBP-doughnut nodules without APHE in cirrhotic liver were not infrequent. None became malignant. We propose calling them 'multiacinar cirrhotic nodules' based on the classification by an International Working Party. KEY POINTS: • HBP-doughnut nodules without APHE were seen in 6% of patients with liver cirrhosis. • The enhancement peak of HBP-doughnut nodules without APHE was in the portal phase, which reflected the fact that they were supplied predominantly by the portal vein, based on angiography-assisted CT findings. • None of the HBP-doughnut nodules without APHE in cirrhotic liver became malignant, and in conjunction with limited pathological features, they may be corresponding to multiacinar cirrhotic nodules in the International Working Party classification.

CT imaging comparison between intraductal papillary neoplasms of the bile duct and papillary cholangiocarcinomas.

OBJECTIVES: To identify imaging features that assist in discriminating intraductal papillary neoplasms of the bile duct (IPNBs) from papillary cholangiocarcinomas (PCCs). METHODS: This study was approved by the institutional review board. Using the recently proposed histological diagnostic criteria for biliary papillary neoplasms, IPNBs and PCCs were selected from 537 biliary neoplasms consecutively resected in a 12.5-year period. Clinical and imaging features were compared between the two groups. RESULTS: The histology review identified 19 IPNBs and 48 PCCs, representing an estimated prevalence of IPNBs among biliary neoplasms of 4%. Approximately one half of IPNBs were incidentally found on imaging conducted for other purposes. In terms of tumor location, 15/19 IPNBs (79%) developed in intrahepatic bile ducts, and 41/48 PCCs (85%) in the distal bile duct. Cystic appearance was highly suggestive for IPNBs (p < 0.001). Using these two parameters, 78% of papillary bile duct neoplasms could be classified into IPNBs or PCCs. Other imaging findings favoring IPNBs included frond-like mural nodule, downstream bile duct dilatation, and the lack of abnormal enhancement in the adjacent bile duct. Interestingly, two patients with non-invasive or microinvasive IPNB had undergone abdominal imaging studies > 3 years before, and a retrospective review of the previous images identified small nodular or cystic lesions, suggesting a less progressive nature of IPNBs than currently thought. CONCLUSIONS: Imaging findings useful for discriminating IPNBs from PCCs appear to be tumor location, shape of tumor, appearance of mural nodules, duct dilatation at unaffected duct, and abnormal enhancement of the adjacent bile duct. KEY POINTS: • Intrahepatic location and cystic dilatation of the affected bile duct are the strong discriminators between IPNBs and PCCs. • The shape of the mural nodule and appearance of the neighboring bile duct are helpful for distinguishing IPNBs and PCCs. • The less aggressive behavior of IPNBs compared with PCCs may facilitate less invasive management in patients with IPNB.

CT Findings of Thoracic Paravertebral Lesions in IgG4-Related Disease.

OBJECTIVE. The objective of our study was to characterize the CT findings of IgG4-related paravertebral lesions. MATERIALS AND METHODS. We selected cases of IgG4-related paravertebral lesions that satisfied two inclusion criteria: first, lesions in patients with IgG4-related disease diagnosed by a multidisciplinary approach between April 2007 and June 2018; and, second, patients who had soft-tissue lesions in paravertebral regions on CT images. We added one case of an IgG4-related paravertebral lesion diagnosed pathologically in 2003. Finally, the study consisted of 30 patients (25 men and five women; median age, 69.5 years). We retrospectively evaluated the CT findings of the paravertebral lesions. RESULTS. A total of 31 paravertebral lesions were identified in 30 patients. All lesions were located around thoracic vertebrae, particularly the lower thoracic regions (n = 30). Twenty-six lesions (84%) involved two or more vertebrae in a row. The right side of vertebrae was predominantly affected in all cases except one (30/31 lesions). Radiologically, the paravertebral lesions were characterized as a bandlike, demarcated soft-tissue mass (mean maximum thickness, 8.7 mm) with homogeneous enhancement on late phase images of contrast-enhanced CT. All patients had IgG4-related lesions at other sites. Histologically, paravertebral lesions showed sclerosing inflammation consisting of diffuse lymphoplasmacytic infiltrations with many IgG4-positive plasma cells and irregular fibrosis. CONCLUSION. IgG4-related paravertebral lesions occur mainly in the right side of the lower thoracic vertebrae and present as a homogeneously enhanced bandlike mass corresponding to plasma cell-rich sclerosing inflammation.

Danaparoid sodium-based anticoagulation therapy for portal vein thrombosis in cirrhosis patients.

BACKGROUND: Portal vein thrombosis (PVT) is a common complication of cirrhosis. However, in patients with PVT and cirrhosis, there is no clear evidence supporting effective treatment modalities. In this study, we examined the effectiveness and safety of anticoagulation therapy using danaparoid sodium for PVT in patients with cirrhosis. METHODS: This retrospective study assessed 52 cirrhotic patients with PVT treated with danaparoid sodium for 2 weeks between November 2008 and September 2018. The primary outcome measure was the post-treatment status of PVT assessed by reduction in thrombus volume and safety of the therapeutic intervention. PVT status was evaluated with contrast-enhanced computed tomography (CECT). All patients received 1250 units of danaparoid sodium twice daily by intravenous injection for 14 days. Patients on antithrombin III (AT-III) combination therapy were additionally administered 1500 units of AT-III on days 1-5 and days 8-12. Effectiveness was evaluated by CECT from between days 13 and 18. The secondary outcome measure was the prognosis of PVT. RESULTS: All patients showed reduction in PVT volume without complications. Return of plasma AT-III level to > 70% during the treatment period contributes to ≥75% reduction of PVT volume. The prognosis in PVT patients depends on hepatic reserve capacity. When limited to Child-Pugh B and C liver cirrhosis patients, a ≥ 75% reduction of PVT volume improved the prognosis. CONCLUSIONS: Danaparoid sodium-based anticoagulation therapy was effective and safe for PVT in patients with cirrhosis. Return of plasma AT-III level to the normal range during the treatment period contributes to reduction of PVT volume. A reduction of ≥75% in PVT volume may improve the prognosis of Child-Pugh B and C decompensated cirrhosis patients with PVT.

Radiological and endocrinological evaluations with grading of hypothalamic perifocal edema caused by craniopharyngiomas.

INTRODUCTION: Hypophysial and hypothalamic dysfunction caused by craniopharyngioma is a serious problem despite the progress of surgical approaches and techniques. Perifocal edema induced by craniopharyngioma could be speculated as a potential factor resulting in pre- and post-operative hypophysial and hypothalamic dysfunction, as well as, their anatomical involvement. METHODS: Medical records of 54 patients with craniopharyngioma were retrospectively reviewed. The edema was characterized by a hyperintense area in magnetic resonance imaging, being classified into no edema (group A), only adjacent to the tumor (group B), and extending to the internal capsule or the optic tract (group C). Age, sex, tumor diameter, presence of cyst, hydrocephalus, intracranial pressure (ICP) elevation, visual function impairment, hypopituitarism, diabetes insipidus, memory disturbance, and obesity were investigated. RESULTS: The occurrence rate of edema was found more frequently in adults (73.7%) than in children (25.0%). The peritumoral edema grading system had an excellent correlation with the degree of hypothalamic involvement graded by the Puget's system. Pre-operative ICP elevation was significantly detected in group C when compared with the other groups. In adults patients, group C was significantly associated with the occurrence of hydrocephalus both in pre- and post-operatively. Pre- and post-operative hypothalamic dysfunction, including diabetes insipidus, memory disturbance, and obesity, were highest in group C. CONCLUSION: Hypothalamic dysfunctions greatly influence the quality of daily living following craniopharyngioma surgery. The grading of perifocal edema's extension could be a new index suggesting pre- and post-operative hypothalamic dysfunction caused by craniopharyngioma in addition to their anatomical involvement.