Akihiro Nishie

Detection and characterization of focal liver lesions: a Japanese phase III, multicenter comparison between gadoxetic acid disodium-enhanced magnetic resonance imaging and contrast-enhanced computed tomography predominantly in patients with hepatocellular carcinoma and chronic liver disease.

Objectives:To prospectively evaluate the safety and efficacy of combined unenhanced and gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging compared with unenhanced MR imaging and triphasic contrast-enhanced spiral computed tomography (CT) for the detection and characterization of focal liver lesions. Materials and Methods:The study was reviewed and approved by the institutional review board at each of the 15 centers involved in the study, and informed written consent was given by all patients. In total, 178 patients with suspected focal hepatic lesions (based, in most patients, on CT, tumor marker and ultrasound examinations) underwent combined MR imaging with a single, rapid injection of Gd-EOB-DTPA 0.025 mmol/kg, including T1-weighted dynamic and delayed MR images 20 to 40 minutes postinjection. Triphasic contrast-enhanced CT, the comparator examination, was performed within 4 weeks of MR imaging. Standard of references (SOR) were resection histopathology and intraoperative ultrasonography, or combined CT during arterial portography and CT hepatic arteriography; in cases where, although the major lesions were treated, some lesion(s) were not treated, follow-up superparamagnetic iron oxide-enhanced MR imaging was additionally performed. All images were assessed for differences in lesion detection and characterization (specific lesion type) by on-site readers and 3, blinded (off-site) reviewers. All adverse events (AEs) occurring within 72 hours after Gd-EOB-DTPA administration were reported. Results:Overall, 9.6% of patients who received Gd-EOB-DTPA reported 21 drug-related AEs. A total of 151 patients were included in the efficacy analysis. Combined MR imaging showed statistically higher sensitivity in lesion detection (67.5%–79.5%) than unenhanced MR imaging (46.5%–59.1%; P < 0.05 for all). Combined MR imaging also showed higher sensitivity in lesion detection than CT (61.1%–73.0%), with the results being statistically significant (P < 0.05) for on-site readers and 2 of 3 blinded readers. Higher sensitivity in lesion detection with combined MR imaging compared with CT was also clearly demonstrated in the following subgroups: lesions with a diameter ≤20 mm (lesions ≤10 mm: 38.0%–55.4% vs. 26.1%–47.3%, respectively; lesions 10–20 mm: 71.1%–87.3% vs. 65.7%–78.4%, respectively); in cirrhotic patients (64.5%–75.4% vs. 54.5%–70.3%, respectively); and in patients with hepatocellular carcinoma (66.6%–78.6% vs. 59.1%–71.6%, respectively). Combined MR imaging demonstrated a higher proportion of correctly characterized lesions (50.5%–72.1%) than unenhanced MR imaging (30.2%–50.0%; P < 0.05 for all), whereas there were no significant differences compared with CT (49.0%–68.1%), except for one blinded reader (P < 0.05). Conclusion:In this study, hepatocyte-specific Gd-EOB-DTPA was shown to be safe and to improve the detection and characterization of focal hepatic lesions compared with unenhanced MR imaging. When compared with spiral CT, Gd-EOB-DTPA enhanced MRI seems to be beneficial especially for the detection for smaller lesions or hepatocellular carcinoma underlying cirrhotic liver.

Sarcopenia as a predictor of prognosis in patients following hepatectomy for hepatocellular carcinoma

Sarcopenia was identified recently as a poor prognostic factor in patients with cancer. The present study investigated the effect of sarcopenia on short‐ and long‐term outcomes following partial hepatectomy for hepatocellular carcinoma (HCC), and aimed to identify prognostic factors.

Diffusion-weighted echo-planar MR imaging and ADC mapping in the differential diagnosis of ovarian cystic masses: Usefulness of detecting keratinoid substances in mature cystic teratomas

To elucidate whether apparent diffusion coefficient (ADC) values calculated from echo‐planar diffusion‐weighted MR imaging (EPDWI) are useful in the differential diagnosis of ovarian cystic masses.

Natural history of pancreatic intraductal papillary mucinous tumor of branch duct type: follow-up study by magnetic resonance cholangiopancreatography.

Objective: The purpose of this study was to elucidate the natural history of branch duct type pancreatic intraductal papillary mucinous tumor (IPMT) by evaluating serial changes in the magnetic resonance cholangiopancreatography (MRCP) findings of patients diagnosed with pancreatic IPMT of branch duct type. Methods: Thirty-five patients had branch duct type IPMT, including 9 patients with separate lesions, and underwent initial and follow-up MRCP over a period of more than 12 months. The maximum diameter of the cystic lesion, the presence of associated main pancreatic duct (MPD) dilatation, and the presence of a filling defect were evaluated. Serial changes in these findings were analyzed. Results: Tumor enlargement on follow-up MRCP was observed in 7 cases. Of the 29 branch duct IPMTs without associated MPD dilatation or a filling defect identified on initial MRCP, only 1 showed gradual tumor enlargement. In 4 cases, the cyst size decreased on follow-up MRCP. Conclusions: Branch duct type IPMTs grow slowly and can be monitored without operation provided that the tumor shows no associated MPD dilatation or filling defect.

Hepatocellular carcinoma with a pseudocapsule on gadolinium-enhanced MR images: correlation with histopathologic findings.

PURPOSE To evaluate the characteristics of hepatocellular carcinoma (HCC) with a pseudocapsule on dynamic magnetic resonance (MR) images. MATERIALS AND METHODS The institutional review board approval was obtained, and the requirements for informed consent were waived for this retrospective study. Dynamic MR studies of surgically resected 106 HCCs in 93 patients were retrospectively reviewed. A false-positive fibrous capsule (FC) on dynamic MR images was considered to be a pseudocapsule. Pathologic specimens of HCCs with a pseudocapsule were reviewed. The differences in size, tumor grade, the degree of liver fibrosis and background liver diseases, and the incidence of vascular invasion were compared between HCCs with a pseudocapsule on MR images and those with FC at histologic examination by using Student t, Kruskal-Wallis, and chi(2) tests. RESULTS The sensitivity, specificity, and accuracy of dynamic MR in the diagnosis of histologic FC were 94.0% (47 of 50), 73.2% (41 of 56), and 83.0% (88 of 106), respectively. There were 15 (14.2%) HCCs with a pseudocapsule. The pathologic specimens suggested possible causes of the pseudocapsule that included prominent sinusoids (n = 6), peritumoral fibrosis mimicking bridging fibrosis (n = 3), and both (n = 5). In one case, the capsulated HCC was surrounded by a well-differentiated HCC component. The mean size of a HCC with a pseudocapsule tended to be smaller than that with histologic FC, although it was not significant (mean +/- standard deviation: 2.8 cm +/- 1.0 vs 3.5 cm +/- 2.0, P = .09). Liver cirrhosis was less frequent in HCCs with a pseudocapsule than in those with a histologic FC (one of 14 [7.1%] vs 20 of 49 [40.8%], P < .05). The tumor grades were not significantly different, and the incidence of vascular invasion after standardizing the tumor size (<or=4 cm) was similar (five of 14 [35.7%] vs 12 of 37 [32.4%]). CONCLUSION Dynamic MR imaging is accurate in depicting FC in HCCs. HCC with a pseudocapsule at MR possibly consists of peritumoral sinusoids and/or fibrosis. The pseudocapsule may be similar to histologic FC in terms of tumor invasiveness.

Diagnostic performance of apparent diffusion coefficient for predicting histological grade of hepatocellular carcinoma

OBJECTIVE To investigate whether the histological grade of hepatocellular carcinoma (HCC) can be predicted using the apparent diffusion coefficient (ADC). MATERIALS AND METHODS This retrospective study group consisted of 80 patients with 85 surgically resected HCCs who underwent preoperative MRI exams including diffusion-weighted imaging. The tumors were histologically classified into five groups as follows: five well (w-), 17 well to moderately (wm-), 37 moderately (m-), 16 moderately to poorly (mp-), and 10 poorly (p-) differentiated HCCs. For ADC measurement of each HCC, the largest possible region of interest was placed on the solid region on the ADC map where ADC was considered to be the lowest. The average ADCs of the five histological grades were compared using Spearmans rank correlation test and Students t-test, and the diagnostic performance of ADC for mp- and p-HCCs was also evaluated using a receiver operating characteristic-based positive test. RESULTS The average ADC of p-HCC (0.76±0.10×10(-3) mm2/s) was significantly lower than those of the other four histological grades. The average ADC of mp-HCCs (0.99±0.20×10(-3) mm2/s) was significantly lower than those of w-, wm- and m-HCCs. The sensitivity, specificity, PPV, NPV, and accuracy, when an ADC of 0.972 or lower was considered an indicator of mp- and p-HCCs, were 73.1%, 72.9%, 54.3%, 86.0% and 72.9%, respectively. CONCLUSION ADCs of mp- and p-HCCs were lower than those of w-, wm- and m-HCCs. ADC can contribute to radiological diagnosis of poorly differentiated components in HCCs.

Usefulness of the calculated apparent diffusion coefficient value in the differential diagnosis of retroperitoneal masses

To elucidate whether or not the apparent diffusion coefficient (ADC) values calculated from echo‐planar diffusion‐weighted (EPDW) MR images are useful in the differential diagnosis of retroperitoneal masses.

Evaluation of locally recurrent pelvic malignancy: Performance of T2- and diffusion-weighted MRI with image fusion

To evaluate the performance of T2‐ and diffusion‐weighted magnetic resonance imaging (MRI) with image fusion for detection of locally recurrent pelvic malignancy.

Radiologic Detectability of Minute Portal Venous Invasion in Hepatocellular Carcinoma

OBJECTIVE The objective of this study was to evaluate whether minute portal venous invasion in hepatocellular carcinoma (HCC) can be diagnosed radiologically. MATERIALS AND METHODS CT hepatic arteriography and CT with arterioportography (CTAP) of 15 patients with minute portal venous invasion (group 1) and 30 patients without it (group 0) were evaluated. An area showing low attenuation on CTAP and high attenuation on CT hepatic arteriography around the tumor was defined as an area of peritumoral hemodynamic change. The shape and size of the area were compared between the two groups. The ratio of the area of peritumoral hemodynamic change volume to tumor volume (area volume-tumor volume ratio) was used as an indicator of the size of the area of peritumoral hemodynamic change and was categorized as one of three grades: grade I, 10% or less; grade II, between 10% and 30%; and grade III, 30% or more. The detectability of minute portal invasion was assessed when grade III was considered as an indicator. Each comparison was also made independently when the tumor diameter either was limited to less than 3 cm or was 3 cm or more. RESULTS Three types of area of peritumoral hemodynamic change were identified: wedge-shaped, belt-shaped or irregular, and linear. No significant difference in the frequency of each type of area of peritumoral hemodynamic change was observed between the two groups. The area volume-tumor volume ratio in group 1 was larger than that in group 0, with statistical significance when the tumor diameter was less than 3 cm (p = 0.046). Positive and negative predictive values were 71.4% and 75.0%, respectively, when the tumor diameter was less than 3 cm. CONCLUSION The area of peritumoral hemodynamic change in HCC patients with minute portal invasion (group 1) may be larger than in those without it (group 0), especially when tumors are small.

Fitz-Hugh-Curtis syndrome. Radiologic manifestation.

Objectives To clarify radiologic findings of Fitz-Hugh-Curtis syndrome (FHCS). Methods Thirteen women with right upper abdominal pain who were clinically diagnosed with FHCS were included. Biphasic helical computed tomography (CT) of the abdomen was performed in all patients. Posttherapeutic follow-up CT was available in 7 patients. Ultrasonography (US) was also performed in 12 patients. These imaging findings were reviewed retrospectively. Results On enhanced CT, hepatic and splenic capsular enhancement was identified in 13 and 4 patients, respectively. Hepatic capsular enhancement on the early phase, which was detected in all patients, disappeared after treatment. No adhesive band or fluid collection around the liver was evident. No enhancement of the “bare area” of the liver and spleen was seen. No definite abnormality of the liver or perihepatic region was detected by US. Conclusions Hepatic and splenic capsular enhancement on abdominal enhanced CT may be characteristic of FHCS. Enhanced CT may be a useful and noninvasive modality to help a diagnosis of FHCS, especially in young women with right upper abdominal pain without significant findings on US and gastrointestinal endoscopy.