Hypovascular Nodules Research Articles

Poorly Differentiated Large Cell Neuroendocrine Carcinoma of the Transverse Colon: Case Report

Introduction: Neuroendocrine carcinomas (NECs) of the colon and rectum are extremely rare malignant subtypes of neuroendocrine tumors, with a reported incidence of 0.1% to 3.9% of all colorectal malignancies. Large cell neuroendocrine carcinomas of the colon (LCNECs) are even rarer, aggressive in nature and have a poor prognosis due to their tendency to early metastasis. Case report: Large cell neuroendocrine carcinoma in the transverse colon with liver metastasis of a 66 years- old male patient, who reported cramping abdominal pain for two months, weight loss of 12 kilos and melena during this period. Abdominal tomography showing circumferential parietal thickening with an infiltrative and stenosing appearance in the transverse colon on the right and multiple hypovascular solid hepatic nodules. Pathology of the lesion compatible with poorly differentiated carcinoma and liver metastases was metastatic adenocarcinoma. Material from the colon biopsy and liver lesions were sent for immunohistochemical studies confirming the diagnosis of high-grade neuroendocrine carcinoma. Conclusion: Early detection can offer a better prognosis for other patients and correct diagnosis is of great importance, as they are often misdiagnosed as adenocarcinoma or another malignant tumor on first imaging or histological study.

Solitary hypovascular hepatic nodules: comparison and differentiation between peripheral nodular cholangiocarcinoma and atypical liver hemangioma with MRI.

Peripheral nodular cholangiocarcinoma (PCC) and hepatic hemangioma (HG) significantly differ in treatment strategies and prognosis. However, they can present similar imaging characteristics, making them difficult to distinguish. The distinction between PCC and atypical HG using pre-operative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) holds substantial significance. Fifty-four cases of solitary hypovascular hepatic nodules (nodules ≤3 cm in diameter and enhancement not exceeding the hepatic parenchyma) confirmed pathologically were collected, including 25 cases of PCC and 29 cases of HG. The clinical and DCE-MRI features were observed, and the apparent diffusion coefficient (ADC) values were compared. The t-test or Fisher's exact test was used to compare the differences between the two groups. Receiver operating characteristic (ROC) curve analysis was performed on the diagnostic results of the two readings before and after the study by three diagnostic physicians. The signal of PCC was more heterogeneous and could be shown as a ring hyperintensity signal on diffusion weighted imaging (DWI). The T2-weighted imaging (T2WI) signal of HG lesions showed a more homogeneous high-intense signal. The ADC value of PCC patients was lower than that of HG patients. Most of the patients in the two groups presented marginal enhancement in the arterial phase with infrequent abnormal perfusion around. The intratumoral vascular traversal signs in the PCC group showed a diagnostic significance. Among the lesions with marginal enhancement at arterial stage, the enhancement in PCC group was more likely to have annular enhancement with the main manifestation of delay reduction and nebulous or separated/astral center. On the other hand, HG tended to be more likely to have nodular enhancement in the arterial phase with delayed invariance at the margins and with no significant enhancement at the center. The area under the curves (AUC) of the three radiologists before and after the two readings were 0.645 and 0.888, respectively. In the differentiation of PCC and atypical liver hemangioma, the presence of a circular hyper-intense signal in DWI, the ADC values, and the pattern and extent of enhancement of marginal and central lesions were of diagnostic significance.

Predicting Progression to Hypervascular HCC in Hypovascular Hypointense Nodules in Gadoxetic Acid-enhanced MR Images in Patients with Chronic Liver Disease

Objective: To identify patient characteristics and MR imaging features of hypovascular hypointense nodules in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MR imaging in patients with chronic liver disease associated with progression to hypervascular hepatocellular carcinoma (HCC). Materials and Methods: The institutional review board approved this retrospective review of 40 patients with 60 hypovascular hypointense nodules in the HBP of gadoxetic acid-enhanced MR imaging. Univariate and multivariate Cox regression analyses for hypervascular HCC development were used to define variables, including initial nodule size, cause of cirrhosis, history of locoregional therapy of HCC, fat-containing, signal intensity on T1W, T2W, portal and equilibrium phases of dynamic phase, and DW images. The cumulative percentage incidence of hypervascularity and growth rate were calculated using the receiver operating characteristic (ROC) curve. Results: The prevalence of progression to hypervascular HCC was 45% (27 out of 60). The Multivariable Cox analysis of developing hypervascularization was an initial nodule diameter more than 1 cm. (P=0.027; HR 2.52; 95% CI: 1.11,5.74) The mean growth rate was significantly higher in subsequent hypervascular nodules than in those without hypervascularization (P < 0.001). The cumulative risk incidence of hypervascularization at 3, 6, 12, 24 months was 5%, 20%, 35%, 44 %, respectively. Conclusion: An initial nodule diameter of more than 1 cm and nodules with higher growth rates are significant predictive factors for hypervascular transformation of hypovascular hypointense nodules in the HBP of gadoxetic acid-enhanced MR imaging.

Effect of ultrasound parameters of benign thyroid nodules on radiofrequency ablation efficacy

Background and aimUltrasound-guided radiofrequency ablation (RFA) is a minimally invasive therapy for thyroid nodules (TNs). Understanding the determinants of RFA efficacy can improve treatment and prognosis. This study aims to investigate the relationship between ultrasound parameters of benign TNs and the efficacy of RFA.MethodsA pretest–posttest interventional study was conducted in 2021 on 250 randomly sampled patients with benign TNs, receiving RFA. For this purpose, the volume reduction (VR) and the VR ratio (VRR) of the nodules were measured at the 1-, 3-, 6-, and 12-month follow-up periods after the RFA completion. The technical success rate (TSR) of this procedure was then categorized into four states, including low (VRR < 25%), moderate (VRR = 25–49%), high (VRR = 50–74%), and very high (VRR ≥ 75). Ordered logistic regression (OLR) was further utilized to investigate the effect of the ultrasound parameters of TNs on the TSR. The analyses were notably performed using Stata 14.2.ResultsThe VRR at the 1-, 3-, 6-, and 12-month follow-up periods were 38.7%, 53.6%, 59.3%, and 59.9%, respectively. The mean VR was also statistically significant at all follow-ups (p < 0.001). At the 1-, 3-, and 6-month follow-up periods, the VR of over 50% was observed in 28.2%, 52.1%, and 65.2% of the nodules, respectively. The odds ratios (ORs) of the RFA success were found to be 4.3 times higher for the nodules in the left lobe compared to the right lobe (OR: 4.31, p = 0.002), 6.3 times greater for isoechoic nodules compared to hyperechoic nodules (OR: 6.39, p < 0.001), 6.2 times higher for hyper-vascular nodules compared to hypo-vascular nodules (OR: 6.25, p = 0.005), and 2.3 times greater for mixed nodules compared to solid ones (OR: 2.37, p = 0.049).ConclusionThe ultrasound parameters of TNs had a statistically significant effect on the efficacy of RFA. Small-sized, isoechoic, and hyper-vascular nodules, as well as those with mixed tissue, were observed to respond better to RFA, leading to a better prognosis in terms of VR after treatment.

Preoperatively misdiagnosed pancreatic malignant tumor: a case of pancreatic perivascular epithelioid cell tumor (PEComa) and a review of the literature

Background: Pancreatic perivascular epithelioid cell tumors (PEComas) are exceedingly uncommon mesenchymal tumors. Herein we have mainly focused on the radiologic features of pancreatic PEComas to achieve a better knowledge of the disease. Case report: We present the case of a 41-year-old woman who had a benign pancreatic PEComa that was misinterpreted as a malignant tumor based on a preoperative CT scan before undergoing surgery for a hysteromyoma. Laboratory tests revealed no significant abnormal findings except an elevated CA-125 (428 U/L). CT and MRI images showed a solid, well-defined, hypovascular nodule approximately 10 mm in diameter in the pancreatic uncinate process that was hyperintense on diffusion-weighted imaging (DWI) and hypointense on apparent diffusion coefficient (ADC) maps. Because of a suspected malignant pancreatic neoplasm, she underwent a pancreaticoduodenectomy. The pathologic examination confirmed the diagnosis of a pancreatic PEComa. Conclusions: Because of the rarity of pancreatic PEComas, we highlighted the radiologic characteristics to facilitate the diagnosis and therapy.

NTRK-rearranged spindle cell neoplasm of the lower extremity: radiologic-pathologic correlation.

Neurotrophic tyrosine receptor kinase (NTRK)-rearranged spindle cell neoplasm is a recently characterized soft tissue tumor and has been classified as provisional by the World Health Organization. Detection of the genetic rearrangement is important because these tumors are amenable to targeted tyrosine kinase inhibitor therapy, which can play a key role in patients with unresectable or advanced disease. Although the spectrum of histopathology associated with this entity is broad, one notable feature is the infiltrative growth pattern, which is most reminiscent of lipofibromatosis-like neural tumor. Description of their diverse histologic attributes has aided recognition, but so far little attention has been paid to correlating the gross appearance and imaging features of these lesions. In this report, we describe the clinical, imaging, histopathological, and genetic features of a soft tissue NTRK-rearranged spindle cell neoplasm. Inclusion of this more recently identified entity into the imaging differential of tumors with intratumoral relatively hypovascular nodules and infiltrative margins is important because testing for NTRK rearrangement is not routinely performed.

Uptake of gadoxetic acid in hepatobiliary phase magnetic resonance imaging and transporter expression in hypovascular hepatocellular nodules

AimsTo evaluate the association between contrast patterns on gadoxetic acid-enhanced hepatobiliary phase (HBP) MR images and transporter expression in surgically resected hypovascular hepatocellular nodules including early hepatocellular carcinomas (HCCs). MethodsForty-two hypovascular hepatic nodules and 43 hypervascular HCCs as a control were included in this retrospective study. Contrast of the nodules on HBP images was graded as hypo-, iso-, or hyperintense. Histopathological assessment was performed in the context of multistep hepatocarcinogenesis. Immunohistochemical staining of organic anion transporter 1B3 (OATP1B3) and multidrug resistance protein 2 (MRP2) was performed. Cramer’s coefficient was used to determine the linear relationship between contrast grades and transporter expression, and the Cochran-Armitage trend test was used to determine the relationship between transporter expression and progression of multistep hepatocarcinogenesis. ResultsModerate linear relationships between contrast grades and OATP1B3 expression were observed for both hypo- and hypervascular nodules. OATP1B3 expression was negatively correlated with the progression of multistep hepatocarcinogenesis. MRP2 expression was not associated with the contrast grades or histopathological results. ConclusionOATP1B3 expression was associated with contrast grades of hepatocellular nodules observed in HBP image of gadoxetic acid-enhanced MRI in the hypovascular hepatocellular nodules and was negatively correlated with hepatocarcinogenesis.

Multiregional whole-genome sequencing of hepatocellular carcinoma with nodule-in-nodule appearance reveals stepwise cancer evolution.

Recent genetic analyses revealed genetic heterogeneity in hepatocellular carcinoma (HCC), although it remains unclear how genetic alterations contribute to the multistage progression of HCC, especially the early step from hypovascular liver nodules to hypervascular HCC. We conducted multiregional whole-genome sequencing on HCCs with a nodule-in-nodule appearance, consisting of inner hypervascular HCC surrounded by hypovascular HCC arising from a common origin, and identified point mutations, structural variations, and copy-number variations in each specimen. According to the genetic landscape of the inner and outer regions, together with the pathological and radiological findings, we examined the stepwise evolution of cancer cells from slow-growing HCC to rapid-growing HCC. We first demonstrated that most tumor cells consisting of hypovascular well-differentiated HCCs already harbored thousands of point mutations and even several structural variations, including chromosomal translocations and chromothripsis, as the trunk events. Telomerase reverse transcriptase (TERT)-associated aberrations, including promoter mutations, chromosomal translocation, and hepatitis B virus DNA integration, as well as abnormal methylation status, were commonly detected as the trunk aberrations, while various liver cancer-related genes, which differed in each case, had additionally accumulated in the inner dedifferentiated nodules. Further, differences in the trunk and branch mutational signatures suggested a multistep contribution to the mutagenesis in each case. In conclusion, genomic alterations associated with the TERT gene could be the key driver events to form the hypovascular HCC, and additional case-specific driver mutations accumulate during the progression phase, forming intra- and inter-tumoral heterogeneity, confirming the importance of genetic testing before targeting therapy. These data shed light on the process of multistep hepatocarcinogenesis and will be helpful toward investigating new therapeutic strategies for HCC. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Contribution of scanner in the breast cancer extension assessment in the radiology department of CNHU-HKM in Benin

Introduction: Breast cancer is the most common female cancer in the world. The prognosis depends on whether metastasis is present or not. The objective of this study was to provide an overview of the CT scan aspects identified during the evaluation of breast cancer extension in the Radiology department of the Teaching University Hospital of Hubert Koutoukou Maga (CNHU-HKM) in Cotonou in Benin.Materials and Methods: It was a descriptive study with retrospective collection, conducted from January 1, 2018 to January 31, 2019 (13 months), in the Radiology department of CNHU-HKM. It focused on patients referred for a chest-abdominal-pelvic computed tomography (PET) scan, as part of an extension assessment for breast cancer. Results: During the period of the study, 40 chest-abdominal-pelvic CT scans were compiled, of which 38 (95%) were women and 02 men (5%), and among which 23 were metastatic, accountings for a prevalence of 57.5%. The average age was 51.22 ± 16.33 with extremes of 30 and 83 years old. Among our patients, 32 (80%) had undergone a CT scan for an initial diagnostic of extension assessment, and 08 (20%) for the therapeutic response assessment. According to the TNM classification, T4 tumors accounted for 27.5% (11 cases). Lymph node involvement was found in 18 cases (43.90%), accounting for 12 (30%) of N1 and 6 (15%) of N3. The most commonly found metastatic sites were the lung in 25% followed by the pleura and the liver with equal percentages (10%). The metastases CT scan aspect was typically a carcinomatous lymphangitis appearance; fluid pleural effusions; hypodenses hypovascular nodules hepatics; osteolytic or mixed bone damage and peritoneum, especially fluid effusion associated with peritoneal nodules.Conclusion: The frequency of breast cancer metastases is high in Benin. The most commonly found metastatic sites on scanner in descending order are the lungs, liver and bones.

Rectosigmoid Endometriosis Vascular Patterns at Intraoperative Indocyanine Green Angiography and their Correlation with Clinicopathological Data.

Introduction. The objective of the study was to evaluate the presence of different rectosigmoid endometriosis (RSE) vascular patterns using intraoperative indocyanine green (ICG) angiography and their correlation with clinicopathological data. Material and Methods. A prospective pilot study on 30 consecutive symptomatic women affected by RSE and scheduled for minimally invasive surgery between May 2018 and January 2019. ICG was used for the intraoperative evaluation of RSE vascularization. Perfusion grade was classified as follows: 0-1 = no or low fluorescence (hypovascular pattern); 2 = regular fluorescence, similar to healthy surrounding rectosigmoid tract (isovascular pattern); and 3-4 = diffuse or abundant fluorescence (hypervascular pattern). Results. Thirty women were intravenously injected with ICG after nodule exposure. No adverse effects related to ICG use were noted. After a 5- to 50-s latency from ICG injection, the real-time direct visualization of RSE perfusion showed diffuse or abundant fluorescence in 12/30 (40%) women, while in the remaining 18/30 (60%), fluorescence was poor or absent. No statistical differences were observed between the 2 groups regarding preoperative, intraoperative, and histological variables analyzed, except for a maximum diameter of bowel lesions and microvessel density (MVD). Hypovascular nodules had a larger maximum diameter (39.5 ± 15.6mm vs 30.3 ± 11.4mm, P < .05) and lower MVD (154.6+/43.6 vs 281.1+/-77.4, P < .05) than hypervascular ones. Conclusions. ICG angiography is a feasible and safe technique to intraoperatively assess RSE vascularization. The majority (60%) of endometriotic nodule presented a hypovascular pattern. The hypovascular pattern seems to be associated with a larger nodule size and lower MVD.

Contribution of Scanner in the Breast Cancer Extension Assessment in the Radiology Department of CNHU-HKM in Benin

Objective: Breast cancer is the most common female cancer in the world. The prognosis depends on whether metastasis is present or not. The objective of this study was to provide an overview of the CT scan aspects identified during the evaluation of breast cancer extension in the Radiology department of the Teaching University Hospital of Hubert Koutoukou Maga (CNHU-HKM) in Cotonou in Benin. Materials and methods: It was a descriptive study with retrospective collection, conducted from January 1, 2018 to January 31, 2019 (13 months), in the Radiology department of CNHU-HKM. It focused on patients referred for a chest-abdominal-pelvic computed tomography (PET) scan, as part of an extension assessment for breast cancer. Results: During the period of the study, 40 chest-abdominal-pelvic CT scans were compiled, of which 38 (95%) were women and 02 men (5%), and among which 23 were metastatic, accountings for a prevalence of 57.5%. The average age was 51.22±16.33 with extremes of 30 and 83 years old. Among our patients, 32 (80%) had undergone a CT scan for an initial diagnostic of extension assessment, and 08 (20%) for the therapeutic response assessment. According to the TNM classification, T4 tumors accounted for 27.5% (11 cases). Lymph node involvement was found in 18 cases (43.90%), accounting for 12 (30%) of N1 and 6 (15%) of N3. The most commonly found metastatic sites were the lung in 25% followed by the pleura and the liver with equal percentages (10%). The metastases CT scan aspect was typically a carcinomatous lymphangitis appearance; fluid pleural effusions; hypodenses, hypovascular nodules hepatics; osteolytic or mixed bone damage and peritoneum, especially fluid effusion associated with peritoneal nodules. Conclusion: The frequency of breast cancer metastases is high in Benin. The most commonly found metastatic sites on scanner in descending order are the lungs, liver and bones.

Hypovascular hepatic nodules as a predictive factor for transcatheter arterial chemoembolization refractoriness in hepatocellular carcinoma.

Intermediate-stage hepatocellular carcinoma (HCC) targeted for transcatheter arterial chemoembolization (TACE) corresponds to a highly heterogeneous population for whom the factors predicting TACE efficacy have not been established. This study aimed to evaluate the impact of hypovascular hepatic nodules coexisting with intermediate-stage HCC as a significant predictive factor for TACE refractoriness. A total of 66 patients with intermediate-stage HCC who received initial TACE were retrospectively analyzed. Hypovascular hepatic nodules were detected by dynamic computed tomography or magnetic resonance imaging, as well as angiography, before all initial TACE. The time to TACE refractoriness (TTTR) was defined as the period from initial TACE until the diagnosis of TACE refractoriness. Hypovascular hepatic nodules were detected in 36 patients (54.5%), 15 (41.7%) of whom had a single nodule, whereas 21 (58.3%) had multiple nodules, and the median size of the maximum nodule was 10mm (range 5-80mm). The median TTTR was 17.4months for all patients, and 7.3 and 33.1months for patients with and without hypovascular hepatic nodules, respectively. The TTTR was significantly shorter for patients with hypovascular hepatic nodules than that for the other patients. In the multivariate analysis, the presence of hypovascular hepatic nodules (HR 7.016, 95% CI 3.534-13.930; P < 0.001) and being out of the up-to-seven criteria (HR 2.861, 95% CI 1.493-5.486; P = 0.002) were independent risk factors for a short TTTR. The presence of hypovascular hepatic nodules with intermediate-stage HCC represents a significant predictive risk factor for TACE refractoriness.

Contribution of Scanner in the Breast Cancer Extension Assessment in the Radiology Department of CNHU-HKM in Benin

Objective: Breast cancer is the most common female cancer in the world. The prognosis depends on whether metastasis is present or not. The objective of this study was to provide an overview of the CT scan aspects identified during the evaluation of breast cancer extension in the Radiology department of the Teaching University Hospital of Hubert Koutoukou Maga (CNHU-HKM) in Cotonou in Benin. Materials and methods: It was a descriptive study with retrospective collection, conducted from January 1, 2018 to January 31, 2019 (13 months), in the Radiology department of CNHU-HKM. It focused on patients referred for a chest-abdominal-pelvic computed tomography (PET) scan, as part of an extension assessment for breast cancer. Results: During the period of the study, 40 chest-abdominal-pelvic CT scans were compiled, of which 38 (95%) were women and 02 men (5%), and among which 23 were metastatic, accountings for a prevalence of 57.5%. The average age was 51.22±16.33 with extremes of 30 and 83 years old. Among our patients, 32 (80%) had undergone a CT scan for an initial diagnostic of extension assessment, and 08 (20%) for the therapeutic response assessment. According to the TNM classification, T4 tumors accounted for 27.5% (11 cases). Lymph node involvement was found in 18 cases (43.90%), accounting for 12 (30%) of N1 and 6 (15%) of N3. The most commonly found metastatic sites were the lung in 25% followed by the pleura and the liver with equal percentages (10%). The metastases CT scan aspect was typically a carcinomatous lymphangitis appearance; fluid pleural effusions; hypodenses, hypovascular nodules hepatics; osteolytic or mixed bone damage and peritoneum, especially fluid effusion associated with peritoneal nodules. Conclusion: The frequency of breast cancer metastases is high in Benin. The most commonly found metastatic sites on scanner in descending order are the lungs, liver and bones.

Hyperintense nodule-in-nodule on hepatobiliary phase arising within hypovascular hypointense nodule: Outcome and rate of hypervascular transformation

PurposeTo investigate the clinical implications and natural history of observations showing a “nodule-in-nodule” architecture on hepatobiliary phase (HBP) in a cirrhotic population. MethodThis is an IRB-approved retrospective study conducted in a single institution. We identified 20 patients (11 men and 9 women, mean age 71 years, range 51–83 years) who had a hyperintense nodule on HBP arising within a larger HBP-hypointense nodule without arterial phase hyperenhancement (APHE) at gadoxetate disodium-enhanced MRI. Size and signal intensity of the nodules were evaluated in all sequences, along with the evolution of the nodules at serial MRI studies. ResultsTwenty-four nodules were analyzed in 20 patients. Mean diameter of the inner hyperintense nodule on HBP was 1.1 cm (range 0.6–1.8 cm) and that of the outer hypovascular hypointense nodule was 2.1 cm (range 1.2–4.1 cm). All intranodular foci were hyperintense on HBP and showed a typical pattern for hepatocellular carcinoma (HCC) with APHE and washout on portal venous phase (PVP) (n = 11, 46%), washout only (n = 7, 29%) or APHE with no washout (n = 6, 25%). The hyperintensity on 3-, 5- and 10-minute phases was seen in 21%, 58% and 83% of the nodules, respectively. In twelve out of sixteen (75%) nodules with subsequent imaging available the hyperintensity on HBP occurred before either the appearance of APHE or washout on PVP. ConclusionsHBP-hypointense nodules without APHE may contain a hyperintense smaller nodule-in-nodule on HBP that can precede the appearance of either APHE or washout on PVP.

Hepatic methotrexate-associated lymphoproliferative disorders identified by multiple liver tumors: a case report and review of the literature

BackgroundMethotrexate, an immunosuppressant, is widely used as the standard therapeutic drug for rheumatoid arthritis. With the increasing frequency of use of methotrexate, adverse effects of methotrexate have been reported, one of which is known as methotrexate-associated lymphoproliferative disorders. The etiology of hepatic methotrexate-associated lymphoproliferative disorders remains largely unknown. To date, there have only been ten cases of hepatic methotrexate-associated lymphoproliferative disorders reported in the English literature and a case report is very rare.Case presentationAn 82-year-old Japanese man with rheumatoid arthritis treated with methotrexate presented with fever. Contrast-enhanced computed tomography showed multiple hypovascular nodules in his liver, spleen, and lung, and para-aortic lesions. Endoscopic ultrasound-guided fine-needle aspiration biopsy for liver tumors was performed, and pathological results identified cluster of differentiation 20-positive lymphocytes. Discontinuance of methotrexate led to regression of the nodules and a final definitive diagnosis of methotrexate-associated lymphoproliferative disorders was made.ConclusionsWe review 11 reported cases of hepatic methotrexate-associated lymphoproliferative disorders including the present case. Physicians should discontinue methotrexate in patients with rheumatoid arthritis treated with methotrexate when elevated soluble interleukin-2 receptor and hypovascular lesions in contrast-enhanced computed tomography are confirmed considering the possibility of methotrexate-associated lymphoproliferative disorders.

Differentiation between inflammatory myofibroblastic tumor and cholangiocarcinoma manifesting as target appearance on gadoxetic acid-enhanced MRI.

To determine the differential features of inflammatory myofibroblastic tumor (IMT) and intrahepatic cholangiocarcinoma (ICC) manifesting as target appearance on gadoxetic acid-enhanced MRI. Twenty-seven patients with 36 IMTs (1.2-6.0cm) and 34 patients with 34 ICCs (1.5-6.0cm) who underwent gadoxetic acid-enhanced MRI were enrolled in this study. Two reviewers evaluated morphology, signal intensity, and enhancement features of tumors on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and gadoxetic acid-enhanced imaging. As for 32 IMTs with target appearance, IMTs most commonly demonstrated early target appearance characterized by a peripheral hypointense rim on unenhanced T1WI (n = 27, 84.4%), central enhanced area with a hypointense rim on arterial phase (AP) and portal venous phase (PVP) (n = 29, 90.6%), and transitional phase (TP) (n = 28, 87.5%). Meanwhile, most of the ICCs showed homogeneous hypointensity on T1WI (100%), a hyperenhancing rim on AP, late target appearance on TP (n = 32, 94.1%) and HBP (n = 32, 94.1%). Target appearance on DWI appearing as hyperintensity with central hypointense area was seen in 2 IMTs and 32 ICCs. On T2WI, 24 IMTs (n = 24, 75.0%) displayed central iso- and peripheral hyperintensity and 27 ICCs (84.4%) showed layered hyperintensity with either brighter or darker area in center. The remaining six IMTs with no target were observed as cystic appearing nodules (n = 3) or ill-defined hypovascular nodules (n = 2) and fibrotic mass (n = 1). IMTs often show early target appearance on unenhanced T1WI, and early dynamic phases of gadoxetic acid-enhanced MRI. Target appearance on later phases, such as TP and HBP, and DWI target appearance were commonly in ICCs, but rare in IMTs.

Hypovascular hypointense nodules in hepatobiliary phase without T2 hyperintensity: long-term outcomes and added value of DWI in predicting hypervascular transformation

PurposeTo evaluate outcomes and risk factors associated with hypervascularization in hypovascular, hepatobiliary phase (HBP) hypointense nodules (HHNs) without T2 hyperintensity on gadoxetic acid-enhanced magnetic resonance (MR) images in chronic liver disease patients. Materials and methods222 HHNs were analyzed. Multivariate analysis with a Cox proportional hazard regression model was used. Results41 nodules became hypervascular hepatocellular carcinoma (HCC). History of HCC, hyperintensity on T1WI or DWI, and higher growth rate were risk factors for hypervascularization (P < .05). ConclusionHistory of HCC, hyperintensity on T1WI or DWI, and higher growth rate were associated with nodular progression to hypervascular HCC.

Progression of Hepatic Hypovascular Nodules with Hypointensity in the Hepatobiliary Phase of Gd-EOB-DTPA-enhanced MRI in Hepatocellular Carcinoma Cases.

Objective We investigated the possible factors for predicting the future progression to hepatocellular carcinoma (HCC) from hypovascular nodules detected in the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI). Methods A total of 91 hypovascular nodules detected by Gd-EOB-DTPA-MRI in 28 patients without any past history of treatment for HCC were retrospectively examined. The nodules were categorized into those with and without HCC progression, then comparisons were made to identify any factors possibly related to a progression to HCC in each case. In addition, we performed a receiver operating characteristics (ROC) analysis to determine the cut-off value for the initial nodule size for predicting HCC progression within 12 months. Results The observation period of the 28 patients was 1,172.6±95.6 (mean±standard error) days. The number of hypovascular nodules that changed to hypervascular ones was 15 (16.5%), and the cumulative incidence of hypervascular transformation was 7.1% at 12 months and 12.7% at 24 months. Of all 91 hypovascular nodules, 33 in 18 patients were diagnosed as HCC based on hypervascular transformation and/or size enlargement, while the remaining 58 did not progress to HCC. There was no significant difference regarding the background characteristics between the HCC progressed and non-progressed groups according to a multivariate analysis, or between the patients who had nodules that progressed to HCC and those with nodules that did not progress to HCC. Regarding HCC progression at 12 months, the area under the ROC (AUROC) had a level of 0.745 and showed that an initial nodule cut-off size of 9.5 mm (sensitivity, 57.9%; specificity, 87.3%) was predictive. Conclusion In patients without a past HCC treatment history, it is difficult to determine whether hypovascular nodules have a high risk of progression to HCC based on background factors alone.

Imaging characteristics of subcutaneous amyloid deposits in diabetic patients: the "insulin ball".

The purpose of this study was to describe the imaging characteristics of subcutaneous amyloid deposits occurring at sites of insulin injection, commonly known as "insulin balls," in diabetic patients on ultrasound, CT, and MRI with pathologic correlation. We retrospectively reviewed the radiographic findings of 14 lesions in 9 patients diagnosed with subcutaneous amyloid deposits at our institution between 2005-2015. Three board-certified radiologists analyzed the following: (1) the shape, size, margin, morphologic characteristics, and blood flow on US using the color Doppler signal, (2) shape, size, margin, attenuation, and presence or absence of contrast enhancement on CT, and (3) shape, size, margin, signal intensity, and presence or absence of contrast enhancement on MRI. All lesions showed ill-defined hypovascular subcutaneous nodules with irregular margins. The median diameter of lesions was 50.4mm on US, 46.8mm on CT, and 51.4mm on MRI. The internal echogenicity of subcutaneous amyloid deposits was hypoechoic and heterogeneous on US. All lesions showed isodensity compared to muscle with irregular margins and minimal contrast enhancement on CT. Both T1- and T2-weighted MR images showed low signal intensity compared with subcutaneous fat. Normal diffusion and minimal contrast enhancement were seen. Subcutaneous amyloid deposits which cause insulin resistance are typically ill-defined and heterogeneous hypovascular subcutaneous nodules with irregular margins on imaging that correspond to insulin injection sites. It is also characteristic that T2WI shows low intensity compared with fat on MRI, reflective of the amyloid content.

Differentiating peripheral cholangiocarcinoma in stages T1N0M0 and T2N0M0 from hepatic hypovascular nodules using dynamic contrast-enhanced MRI

Because cholangiocarcinoma shows no specific clinical signs or symptoms and presents with non-specific biological and tumor markers in the early stages, MRI findings often lack typical features before this lesion becomes symptomatic and might be mistaken for other liver lesions. An evaluation of relevant radiological findings in nodular cholangiocarcinoma (≤3 cm) in stages T1N0M0 and T2N0M0 is urgently needed. In our study, we compared two groups of liver hypovascular nodules and found that a distinct margin and enhanced area/nodule size >2/3 in the delayed phase were more frequently observed in cholangiocarcinoma cases than in metastatic nodule cases in which markedly high signal intensity on T2WI was common (p < 0.05). The results also revealed that in the both the portal and delayed phases, an enhanced area/nodule size >2/3 favored cholangiocarcinoma, whereas the presence of regional markedly higher SI on T2WI favored benign nodules. Furthermore, signs of peripheral washout in the delayed phase only appeared in cholangiocarcinoma cases.