Computed tomography and magnetic resonance imaging of a plexiform angiomyxoid myofibroblastic tumor: a case report.

BACKGROUND: Plexiform angiomyxoid myofibroblastic tumor (PAMT) is a very rare mesenchymal tumor of the stomach. Here we report a case of pathologically confirmed PAMT with an unique cyst formation. CASE PRESENTATION: A 55-year-old male with a 10-year history of a gastric subepithelial tumor underwent computed tomography (CT) and magnetic resonance imaging (MRI). Two cysts were observed in the tumor, and the cyst wall showed moderately high intensity on T2-weighted images compared with the gastric wall. On dynamic study, the cyst wall showed a gradual enhancement pattern, and prominent enhancement was observed in the delayed phase. Laparoscopic partial gastric resection was performed, and a pathological diagnosis of PAMT was rendered. CONCLUSION: We present a rare case of gastric PAMT, which was uniquely presented as cysts. One of the cysts in the tumor had an epithelial wall lining, which had never been reported before in gastric mesenchymal tumor, in addition to partial glandular structure. We reviewed our case, focusing on radiologic-pathologic correlation, and suggested hypothesis of cyst formation. According to our findings, PAMT with cyst formation would be included of differential diagnosis of gastric subepithelial tumors.

Automatic detection of vertebral number abnormalities in body CT images.

PURPOSE: The anatomical anomaly of the number of vertebral bones is one of the major anomalies in the human body, which can cause confusion of the spinal level in, for example, surgery. The aim of this study is to develop an automatic detection system for this type of anomaly. METHODS: We utilized our previously reported anatomical landmark detection system for this anomaly detection problem. This system uses a landmark point distribution model (L-PDM) to find multiple landmark positions. The L-PDM is a statistical probabilistic model of all landmark positions in the human body, including five landmarks for each vertebra. Given a new volume, the proposed algorithm applies five hypotheses (normal, 11 or 13 thoracic vertebrae, 4 or 6 lumbar vertebrae) to the given spine and attempts to detect all the landmarks. Then, the most plausible hypothesis with the largest posterior likelihood is selected as the anatomy detection result. RESULTS: The proposed method was evaluated using 300 neck-to-pelvis CT datasets. For normal subjects, the vertebrae of 211/217 (97.2%) of the subjects were successfully determined as normal. For subjects with 23 or 25 vertebrae without a transitional vertebra (TV), the vertebrae of 9/10 (90%) of the subjects were successfully determined. For subjects with TV, the vertebrae of 71/73 (97.3%) of subjects were judged as partially successfully determined. CONCLUSION: Our algorithm successfully determined the number of vertebrae, and the feasibility of our proposed system was validated.

The natural history of streptozotocin-stimulated non-alcoholic steatohepatitis mice followed by Gd-EOB-DTPA-enhanced MRI: Comparison with simple steatosis mice.

PURPOSE: To clarify the development of HCC, temporal change of steatosis and Gd-EOB-DTPA enhancement of non-alcoholic steatohepatitis (NASH) model mice by magnetic resonance imaging (MRI). MATERIALS AND METHODS: All animal experiments were approved by the institution's Animal Research Committee. MRI was performed on six NASH and six simple steatosis (SS) model mice every 2weeks from the ages of 8weeks to 16weeks. The sequential changes in the number and size of the focal liver lesions detected on Gd-EOB-DTPA-enhanced MRI were evaluated. Additionally, the hepatic fat fraction (HFF), contrast-to-noise ratio (CNR) and relative enhancement (RE) were calculated at each time point. The temporal changes and correlations in these parameters were evaluated. RESULTS: All alive NASH model mice demonstrated focal liver lesions from week 10, at the latest. Number of the lesions increased with time, and all the lesion enlarged with time. All the lesions larger than 1mm were confirmed as hepatocellular carcinoma (HCC) pathologically. While the HFF remained constant in NASH model mice, HFF in SS model mice dramatically increased with time. CNR of the NASH model mice remained constant through the study period, while CNR in SS model mice decreased with time. Although no correlation was seen in NASH model mice, the HFF showed a negative correlation against CNR and RE in SS model mice. CONCLUSION: Development of HCC was observed using Gd-EOB-DTPA-enhanced MRI only in NASH model mice. Degree of steatosis and hepatic enhancement by Gd-EOB-DTPA was both constant in NASH model mice, while steatosis increased and hepatic enhancement decreased with time in SS model mice.

Hepatic Involvement of Histiocytic Sarcoma: CT and MRI Findings.

Histiocytic sarcoma in the liver is an extremely rare hematological malignancy. Herein, we reported the case of a 68-year-old woman who presented with characteristic wedge-shaped abnormality bounded by hepatic veins on computed tomography and magnetic resonance imaging of the liver. In the wedge-shaped area, decreased portal flow and the deposition of iron were observed. These imaging findings are consistent with intrasinusoidal tumor cell infiltration. A liver biopsy was performed, and histiocytic sarcoma was confirmed histopathologically.

Radiation exposure to patients' skin during cardiac resynchronization therapy.

AIMS: The purpose of the current study is to evaluate the patients' entrance skin dose (ESD) during cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Entrance skin doses were assessed during 16 CRT procedures. Seven of the 16 patients were upgrade of conventional pacemaker to CRT. The patients wore jackets which had 100 radiosensitive indicators placed on the back during the procedures. After the procedure, the patients' ESDs were calculated from the colour difference of the indicators. Eleven of the 16 patients were implanted devices with a defibrillator, and three patients those without a defibrillator. In the other two, the procedures failed. The average total fluoroscopic time (TFT), total numbers of cine frames, and the maximum ESDs were 56.7 +/- 28.0 min, 674 +/- 342 frames, and 1.0 +/- 0.6 Gy, respectively. Of the 16 patients, six received ESDs exceeding 1 Gy, TFT, total number of cine frames, and the maximum ESD tended to decrease as the operator experience increased. CONCLUSION: The patients' ESDs during CRT procedures can exceed the thresholds for radiation skin injuries due to prolonged fluoroscopic times. Therefore, interventionalists should estimate the doses.

Rice alpha-mannosidase digesting the high mannose glycopeptide of glutelin.

alpha-Mannosidase (EC 3.2.1.24) from rice dry seeds was purified to homogeneity. Optimum pH and Km for pNP-alpha-Man hydrolysis were pH 4.3-4.5 and 1.04 mM, respectively. The enzyme digested mannobioses such as Manalpha-1,2Man, Manalpha-1,6Man, Manalpha-1,3Man but Manalpha-1,4Man. Zn2+ ion was required for the activity, whereas EDTA and swainsonine inhibited the activity by 80 and 96%, respectively. The rice storage protein, glutelin was prepared and its basic subunits were shown to have high mannose-type sugar chains by two-dimensional mapping using NH2-P and C18 silica columns. They were Man9GlcNAc2, Man8GlcNAc2, Man7GlcNAc2, Man6GlcNAc2 and Man5GlcNAc2. All these oligosaccharides were digested by the purified alpha-mannosidase, and Man-GlcNAc2 and mannose were formed. Glycopeptides, having these high mannose-type sugar chains, could also be digested by the alpha-mannosidase. Subunits were prepared from glutelin basic subunit and the richest subunit among them, subunit 2 (isoform 2), was digested by the alpha-mannosidase. Isoform 2 was digested by V8 protease only partially and slowly. However, isoform 2, pre-treated with the alpha-mannosidase, was rapidly and completely digested by V8 protease.