Akira Yogi

Percutaneous ipsilateral portal vein embolization using a modified four-lumen balloon catheter with fibrin glue: initial clinical experience

PurposeThe purpose of the present study was to show the feasibility and safety of ipsilateral portal vein embolization (PVE) using an improved four-lumen balloon catheter with fibrin glue.Materials and methodsTo improve the ipsilateral PVE with fibrin glue, we modified a commercially available four-lumen balloon catheter to create a catheter comprising one lumen with a catheter tip for a guidewire, one lumen for an occlusion balloon, and two lumens, each with a side-hole just proximal to the balloon. Eight patients had hepatobiliary disease (three with bile duct carcinoma, two with gallbladder carcinoma, one with hepatocellular carcinoma, one with Caroli disease, and one with metastatic carcinoma).ResultsAll embolization procedures were technically successful. After embolization, the volume of the future remnant liver increased a mean of 131%. There was no inadvertent embolization of portal vein branches and no major procedure-related complications.ConclusionOur method is potentially easier and safer than the traditional ipsilateral method with fibrin glue using a three-lumen balloon catheter because the fourth lumen makes possible the use of a guidewire to access the targeted portal vein and measurement of any portal vein pressure elevation following PVE via the fourth lumen.

Use of Diffusion Weighted Imaging in Differentiating Between Maligant and Benign Meningiomas. A Multicenter Analysis.

BACKGROUND Meningioma is the most frequent intracranial tumor and is often an incidental finding on imaging. Some imaging-based scores were suggested for differentiating low- and high-grade meningiomas. The purpose of this work was to compare diffusion-weighted imaging findings of different meningiomas in a large multicenter study by using apparent diffusion coefficient (ADC) values for predicting tumor grade and proliferation potential. METHODS Data from 7 radiologic departments were acquired retrospectively. Overall, 389 patients were collected. All meningiomas were investigated by magnetic resonance imaging (1.5-T scanner) by using diffusion-weighted imaging (b values of 0 and 1000 s/mm(2)). The comparison of ADC values was performed by Mann-Whitney U test. RESULTS World Health Organization grade I was diagnosed in 271 cases (69.7%), grade II in 103 (26.5%), and grade III in 15 patients (3.9%). Grade I meningiomas showed statistically significant higher ADC values (1.05 ± 0.39 × 10(-3) mm(2)s(-1)) in comparison with grade II (0.77 ± 0.15 × 10(-3) mm(2)s(-1); P = 0.001) and grade III tumors (0.79 ± 0.21 × 10(-3) mm(2)s(-1); P = 0.01). An ADC value of <0.85 × 10(-3) mm(2)s(-1) was determined as the threshold in differentiating between grade I and grade II/III meningiomas (sensitivity, 72.9%; specificity, 73.1%; accuracy, 73.0%). Ki67 was associated with ADC (r = -0.63, P < 0.001). The optimal threshold for the ADC was (less than) 0.85 × 10(-3) mm(2)s(-1) for detecting tumors with high proliferation potential (Ki67 ≥5%). CONCLUSIONS The estimated threshold ADC value of 0.85 can differentiate grade I meningioma from grade II and III tumors. The same ADC value is helpful for detecting tumors with high proliferation potential.

Distribution patterns of metastatic pelvic lymph nodes assessed by CT/MRI in patients with uterine cervical cancer

BackgroundTo investigate the three-dimensional (3D) distribution patterns of clinically metastatic (positive) lymph nodes on pretreatment computed tomography (CT)/magnetic resonance imaging (MRI) images of patients with locally advanced cervical cancer.MethodsWe enrolled 114 patients with uterine cervical cancer with positive nodes by CT/MRI (≥10 mm in the shortest diameter). Pretreatment CT/MRI data were collected at 6 institutions. The FIGO stage was IB1 in 2 patients (2%), IB2 in 6 (5%), IIA in 3 (3%), IIB in 49 (43%), IIIB in 50 (44%), and IVA in 4 (4%) patients. The median cervical tumor diameter assessed by T2-weighted MRI was 55 mm (range, 10–87 mm). The anatomical distribution of the positive nodes was evaluated on CT/MRI images by two radiation oncologists and one diagnostic radiologist.ResultsIn these patients, 273 enlarged nodes were assessed as positive. The incidence of positive nodes was 104/114 (91%) for the obturator region, 31/114 (27%) for the external iliac region, 16/114 (14%) for the internal iliac region, 22/114 (19%) for the common iliac region, and 6/114 (5%) for the presacral region. The external iliac region was subdivided into four sub-regions: lateral, intermediate, medial, and caudal. The obturator region was subdivided into two sub-regions: cranial and caudal. The majority of patients had positive nodes in the cranial obturator and/or the medial external iliac region (111/114). In contrast, few had positive nodes in the lateral external iliac, caudal external iliac, caudal obturator, internal iliac and presacral regions. All cases with positive nodes in those low-risk regions also had positive nodes in other pelvic nodal regions concomitantly. The incidence of positive nodes in the low-risk regions/sub-regions was significantly related to FIGO stage (p=0.017) and number of positive nodes (p<0.001).ConclusionsWe demonstrated the 3D distribution patterns of clinical metastatic pelvic lymph nodes on pretreatment CT/MRI images of patients with locally advanced cervical cancer. These findings might contribute to future individualization of the clinical target volume of the pelvic nodes in patients with cervical cancer.

Usefulness of the apparent diffusion coefficient (ADC) for predicting the consistency of intracranial meningiomas

Meningioma consistency is an important factor for surgical treatment. Tumor cellularity and fibrous tissue contribute to the consistency of tumors, and it is proposed that the minimum apparent diffusion coefficient (ADC) value is significantly correlated with meningioma consistency. Twenty-seven consecutive patients with 28 meningiomas were retrospectively enrolled. Minimum ADC values in meningiomas with a hard consistency were significantly lower than those with a soft consistency. The minimum ADC value might have clinical use as a predictor of meningioma consistency.

Cerebellar Size Estimation from Endocranial Measurements: An Evaluation Based on MRI Data

Cerebellar volume (CBV) estimation of fossil hominins can help in understanding the evolution of modern behavior, considering that recent neurological studies suggest significant contribution of the cerebellum to high cognitive abilities of modern humans. However, there has been no reliable methods to estimate the CBV from the endocranial cavity. In order to develop the method, the correlation between CBV and the volume and linear measurements of the posterior cranial fossa (PCF), which were taken from MRI data of thirty-two Japanese subjects, was examined. Estimation equations were then obtained from the bivariate relationships and the validity were evaluated based on prediction intervals. We found that, among the PCF metrics we examined, PCF volume was most highly correlated with CBV (r = 0.88), and the estimation equation provides CBV estimates with the error of about ±12 cc for specimens from the reference population sample. This result could offer a promising prospect for CBV estimation of fossil hominins including Neanderthal examples.

Pulmonary metastases from angiosarcoma: a spectrum of CT findings

Background Though a few reports have summarized the computed tomography (CT) findings of pulmonary metastases from angiosarcoma, the detailed CT findings of cysts are not well known, except for their characteristic thin walls. Purpose To retrospectively summarize the CT findings of pulmonary metastases from angiosarcoma, focusing mainly on the CT findings of cysts. Material and Methods Thirty-three patients with pulmonary metastases from angiosarcoma were selected retrospectively. Two radiologists reviewed and assessed patients’ chest CT images on a consensus basis for nodules, cysts, the CT halo sign, pneumothorax, pleural effusion, and enlarged lymph nodes. Cysts were also evaluated by wall thickness and smoothness, air-fluid levels, and vessels or bronchi penetrating the cysts. The relationship between cysts and pneumothorax was assessed using the Chi-square test. Results Nodules were found in 28 (85%) patients. Cysts were found in 19 (58%) patients; 17 had thin and smooth walls, 10 had thin and irregular walls, and four had thick and irregular walls. In addition, 12 patients showed vessels or bronchi penetrating the cysts, and six showed air-fluid levels. The CT halo sign, pneumothorax, pleural effusion, and mediastinal lymphadenopathy were seen in 19 (58%), 16 (48%), 26 (78.8%), and five (15.2%) patients, respectively. Pneumothorax occurred significantly more frequently in patients with cysts (P = 0.002). Conclusion Cysts showed variability in their walls, and air-fluid levels and vessels or bronchi penetrating the cysts appeared to be characteristic findings, which may be useful for detection and accurate diagnosis in patients with pulmonary metastases from angiosarcoma.

Endometrial carcinoma with peritoneal keratin granulomas mimicking peritoneal carcinomatosis: a case report and imaging diagnosis

We report the case of a 71-year-old woman diagnosed as having endometrioid adenocarcinoma with squamous differentiation (adenoacanthoma, grade 1) and peritoneal keratin granuloma. Preoperative diagnostic imaging showed a uterine cavity filled with a large mass, many peritoneal nodules, and free fluid in the Douglas pouch, indicating a peritoneal carcinomatosis. Endometrial biopsy revealed grade 1 endometrioid adenocarcinoma. Eventually, postoperative histopathological examination led to the diagnosis. Although peritoneal keratin granulomas mimicking peritoneal carcinomatosis are due to endometrial carcinomas containing squamous elements, gynecological oncologists should keep in mind such situations. The combination of contrast-enhanced T1-weighted and diffusion-weighted magnetic resonance imaging is helpful for preoperative differential diagnosis.