Significance of the anatomical properties of a myocardial bridge in coronary heart disease.

A myocardial bridge (MB), partially covering the coronary artery, is a congenital anatomical variant usually present in the left anterior descending coronary artery (LAD). MB causes coronary heart disease (CHD) by 2 distinct mechanisms influenced by the anatomical properties of the MB, such as its length, thickness, and location. One is direct MB compression of the LAD at cardiac systole, resulting in delayed arterial relaxation at diastole, reduced blood flow reserve, and decreased blood perfusion. The other is enhancement of coronary atherosclerosis causing stenosis of the LAD proximal to the MB, occurring because of endothelial injury arising from the abnormal hemodynamics provoked by retrograde blood flow up toward the left coronary ostium at cardiac systole. The magnitude of the effect of the 2 distinct mechanisms of the MB on LAD blood flow is prescribed by a common root of the MB-muscle mass volume generated by those properties. Furthermore, the anatomical properties of the MB are closely associated with the choice of treatment and therapeutic outcome in CHD patients having an MB. Thus, the anatomical properties of an MB should be considered in the diagnosis and management of CHD patients with this anomaly.

Low-grade fibromyxoid sarcoma of the small bowel mesentery: computed tomography and magnetic resonance imaging findings.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare tumor that commonly arises in the lower extremities but rarely in the mesentery. We report computed tomography (CT) and magnetic resonance imaging (MRI) findings of LGFMS of the small bowel mesentery. On CT, the mass was composed of two components. One component, on its right side, appeared to have isointense attenuation relative to muscle, whereas the other component, on its left side, appeared to have low attenuation. On MRI the mass on the right side showed hypointensity similar to muscle on both T1-and T2-weighted images as well as mostly slight enhancement on contrast-enhanced T1-weighted images. On the other hand, the mass on the left side showed relative hypointensity on T1-weighted images and hyperintensity on T2-weighted images as well as intense enhancement on contrast-enhanced T1-weighted images, suggesting that the tumor contained myxoid tissue. The myxoid area of LGFMS may have a tendency to reveal intense enhancement on contrast-enhanced images.

Notes on the application of the Matsui-Kitamura stent-graft for endovascular repair of abdominal aortic aneurysm.

Abdominal aortic and left common iliac aneurysms in a 79-year-old man who had undergone Miles' operation for rectal carcinoma were treated with endovascular repair of an abdominal aortic aneurysm (EVAR), taking into consideration the age, surgical history, and wishes of the patient and his family. The Matsui-Kitamura stent-graft (MK-SG) was designed based on preoperative angiographic mapping. At EVAR, the right leg of the MK-SG was caught at the aortic bifurcation because of unexpected contraction of the MK-SG. To resolve the problem, the body of the MK-SG was dilated with a balloon, slightly lifted while being gradually shortened, and eventually successfully connected to the leg of the MK-SG. Made of nitinol mesh, the MK-SG is stable and flexible enough to make it one of the best stent-grafts for EVAR. A serious drawback, however, is the high contraction rate of the MK-SG itself. It is difficult to estimate the appropriate length of the stent-graft owing to unpredictable contraction. It is important to understand its characteristics and to carefully design and acquire sufficient skills in manipulating MK-SG.

Paget's disease of the breast in a woman with neurofibromatosis.

Paget's disease of the breast is a rare and specific type of breast carcinoma in the nipple or areola. On the other hand, neurofibromatosis (NF) is also a rare neurocutaneous disease, which is inherited and affects mainly the skin and the nervous system. In addition, NF is rarely associated with malignant tumors. We present a case of Paget's disease concomitant with NF type 1 in a 66-year-old woman.

Detection of myocardial bridge and evaluation of its anatomical properties by coronary multislice spiral computed tomography.

BACKGROUND: Myocardial bridge (MB) is a common anatomical condition, under which a part of the coronary artery running in the epicardial adipose tissue, is covered with myocardial tissue. It regulates atherosclerosis development and sometimes evokes coronary heart disease through haemodynamic alterations. We attempted to efficiently detect MB and evaluate the anatomical properties of MB by coronary multislice spiral computed tomography (MSCT). METHODS: Sixteen-row MSCT was conducted on 148 patients with coronary heart disease. MSCT images were reconstructed and reformed with transverse scans, curved planar reformat and three-dimensional volume-rendered images. The MB, over 1.0 mm in thickness, was identified by the presence of the "step-down and step-up" appearance. After "trial and error" essays, we could consistently examine the frequency of MB and evaluate the anatomical properties of MB, especially its thickness, together with coronary wall lesions. RESULTS: Twenty-three patients (15.8%) had MB over 1.0 mm in thickness: 21 MBs (87.5%) were located in the left anterior descending artery with a mean thickness and length of 1.8+/-0.7 and 20.0+/-8.6 mm. Moreover, although the tunneled segment beneath MB was always free of coronary wall lesions, 79.2% (19/24) of the segments proximal to MB demonstrated coronary wall lesions. Of special significance were three symptomatic MB patients without any atherosclerotic lesion throughout all the coronary arteries. CONCLUSION: Coronary MSCT is a new imaging technique that provides a non-invasive diagnostic tool for MB and yields much better results of MB detection than previous imaging methods.

Measurement of visceral fat/subcutaneous fat ratio by 0.3 tesla MRI.

PURPOSE: Visceral fat-type obesity is known to be closely related to hyperlipidemia and diabetes. The visceral fat area/subcutaneous fat area ratio is used for the diagnosis of visceral fat-type obesity. In this study, we measured the visceral and subcutaneous fat areas in the fat images obtained using 0.3 Tesla open-type MRI, and investigated their usefulness. MATERIALS AND METHODS: A short TR was set to shorten the acquisition time, and in-phase and out-of-phase images were acquired during holding of breath. The visceral and subcutaneous fat areas were automatically measured from the fat image using a workstation. The measurements were compared with the visceral and subcutaneous fat areas measured by CT as the gold standard. RESULTS: No major differences were observed in the fat areas measured by MRI and CT. This method was capable of imaging during holding of breath, and clearly imaged visceral and subcutaneous fat. CONCLUSION: CT is not free from the concern of radiation exposure, whereas MRI is free from radiation. For measurement of the visceral and subcutaneous fat areas, 0.3 Tesla MRI was useful.