Hypovascular Areas Research Articles

Nodular regenerative hyperplasia of the liver: clinical and radiologic observations.

This report describes 21 cases of nodular regenerative hyperplasia (NRH) and its clinical and radiologic features. NRH of the liver is an established pathologic entity that should not be confused with focal nodular hyperplasia, hepatocellular adenoma, or the regenerative nodules associated with cirrhosis. Correct diagnosis will prevent an unnecessary hepatic lobectomy should NRH be mistaken for hepatocellular adenoma. Unlike focal nodular hyperplasia, NRH may bleed, may be associated with portal hypertension in one-half of cases, and is often associated with a systemic disease such as a myelo- or lymphoproliferative disorder. Correct diagnosis is important because the prognosis in patients with NRH and portal hypertension is better than that in patients with portal hypertension due to cirrhosis. Radiologically, multiple nodules, large masses, or an apparently normal liver (containing nodules less than 0.5 cm in diameter) were visible. The nodules may take up technetium sulfur colloid and have variable echogenicity on sonography. They are often hypodense on CT without significant enhancement. The nodules may fill from the periphery on angiography, are vascular, and sometimes contain small hypovascular areas due to hemorrhage. A large nodule may rupture and cause hemoperitoneum. These findings may resemble some features of focal nodular hyperplasia, hepatocellular adenoma, or metastases. NRH is probably underdiagnosed owing to a lack of recognition of the entity and limited sampling of liver tissue by needle biopsy. Scintigraphy, sonography, and CT of the liver should be performed in cases of idiopathic portal hypertension to detect NRH. In cases with compatible findings, multiple needle biopsies or a laparoscopically guided needle biopsy or wedge liver biopsy should be recommended for definitive diagnosis.

Atypical radiographic findings in hepatic cavernous hemangioma: correlation with histologic features

Three cases of cavernous hemangioma of the liver having atypical imaging features are described. In the first case, an 11 x 10 cm hypervascular mass with a central hypovascular area supplied by many large tortuous vessels was demonstrated on angiography, CT, and sonography. The mass had a central cavity that contained fluid. In the second case there was a 2-cm isoechoic mass with a peripheral halo, despite the presence of typical features of hemangioma on angiography. The halo was shown histologically to be fibrous tissue surrounding the tumor. In the third case, a 6.5 x 4.3 cm mass exhibited slight peripheral enhancement on CT but was not detectable by angiography. Histologically, the tumor was hyalinized with only scattered small foci of hemangioma within it.

Post-traumatic-shock lung: postmortem microangiographic and pathologic correlation.

In post-traumatic-shock lung, increased pulmonary vascular resistance and pulmonary hypertension are prominent features. The explanation for them was sought by postmortem microangiography of the lungs of 17 patients dying of respiratory failure after trauma. The 10 patients with thoracic injury died earlier (1-8 days). Extravasation of contrast material due to alveolar capillary rupture was present in all but one specimen and occupied 20% of the sampled area. Pulmonary artery thrombi lay proximal to these extravasations. Hypovascular areas due to infection and hemorrhagic alveolitis were found in all patients and involved 40% of the surface area. The small pulmonary arteries were poorly filled and contained many microthrombi. Some patients had hematomas, cavities, and areas of interstitial edema occupying about 5% of the lung area and associated with compressed or occluded vessels. Several mechanisms including pulmonary trauma may be responsible for the antemortem rupture and obstruction of small blood vessels. In the post-traumatic-shock lung, small artery occlusion and compression are associated with pulmonary hemorrhage, infarction, and infection and are important contributors to perfusion abnormalities and respiratory failure.

Effect of perfluorochemicals on BCNU chemotherapy in a 9L rat brain tumor model

Perfluorochemicals are characterized by their small size and high propensity for carrying oxygen and carbon dioxide. This study was undertaken to identify the combined effect of a perfluorochemical (Fluosol-43, 20 ml/kg) and a chemotherapeutic agent (BCNU, LD10 dose: 13.3 mg/kg) in a 9L rat brain tumor model. Brain tumor was induced by intracerebral implantation of 9L rat glioma cells (7×105 cells) into male CD Fisher 344 rats weighing about 100 g. The tumor growth curve of this model was exponential, and at 7 days after implantation, the control animals had a macrotumor weighing about 51 mg. The tumor-bearing rats on day 7 after implantation were randomly divided into 5 groups: control; BCNU alone; Fluosol-43 with oxygen; Fluosol-43 plus BCNU; and Fluosol-43 plus BCNU with oxygen. High oxygen was produced in an oxygen chamber with 95% oxygen and 5% carbon dioxide, and the PaO2 was maintained between 300 and 400 mmHg. Control animals had a mean survival time of 15.23 ± 2.84 (S.D.) days, and the Fluosol-43 with oxygen group showed no prolongation of the mean survival time (p>0.2). BCNU treatment alone prolonged the mean survival time to 20.90 ± 3.80 days (p<0.05), whereas the Fluosol-43 plus BCNU group had no further prolongation of the mean survival time: The Fluosol-43 plus BCNU with oxygen showed a mean survival time of 32.27 ± 4.80 days, which was significantly longer than that of the BCNU treatment alone (p < 0.005). Perfluorochemicals (Fluosol-43) with oxygen may have a synergistic effect on BCNU chemotherapy for malignant brain tumor. Fluosol-43 with oxygen might have oxygenated the hypoxic cells so that they became sensitized to BCNU. Also, the transport of BCNU into hypoxic and hypovascular areas might have been enhanced by Fluosol-43 and oxygen.

The anatomy of the arteries and veins of the breast.

Textbook accounts of this subject are inadequate. This review considers the work of Cooper and Salmon and reproduces some of their figures. Applications in the diagnosis and treatment of cancer are discussed. The largest mammary arteries are the lateral (from the axillary) and the anterior medial and posterior medial (from the internal thoracis). The branches of these arteries do not follow the duct system, but instead form a plexus in the anterior fat layer. Normally there are no hypervascular or hypovascular areas. The contribution of the mammary branches of the posterior (aortic) intercostal arteries is minor. There are superficial and deep sets of veins, the latter associated with arteries. Mammary vessels of living women are demonstrated by infrared photography, thermography, and mammography. In the diagnostic use of these methods there is a tendency to rely upon the concept of normal vascular symmetry, but this is a fallacy.