Biomedical subjects
Publications and source records attributed to R F Mattrey.
Cystosarcoma phyllodes of the prostate is a rare, relatively benign sarcoma of the prostate. We describe the magnetic resonance imaging findings in an unusual case of cystosarcoma phyllodes which resulted in extensive local recurrence and sarcomatous degeneration. Although uncommon, radiologists should be aware of the existence of cystosarcoma phyllodes of the prostate.
Cross-sectional imaging techniques have the potential for measuring left ventricular (LV) wall thickness (WTh) dynamics. This proposition was assessed in a canine experimental model, using prospectively gated computed tomography (CT) scans before and after occlusion of a coronary artery. Gated CT scans detected loss of wall thickening in the LV anterior segment immediately after occlusion of the left anterior descending coronary artery in two dogs. After demonstrating the feasibility of using gated CT scans to demonstrate ischemic functional abnormalities by monitoring wall thickness changes, we assessed the relationship between regional wall thickening dynamics and coronary blood flow in eight anesthetized dogs. Graded circumflex (Cx) coronary artery stenosis (CAS) was produced while sonomicrometer crystals continuously recorded LV WTh and extent of wall thickening (EWTh) in the anterior descending and the Cx distributions. The first significant change in EWTh in the ischemic segment occurred at 33% decrease in CBF (P less than .05) which corresponded to an 80% CAS. At 33% decrease in CBF, there was a concomitant increase in EWTh in the normal segment. In conclusion, we have demonstrated the feasibility of using gated CT to detect myocardial ischemia by monitoring WTh dynamics. Physiologic studies document a close relationship between regional wall thickening dynamics and coronary blood flow and should provide a basis for interpretation of dynamic cross-sectional images of the left ventricle in ischemic heart disease.
Perfluoroctylbromide (PFOB) is a relatively new noniodinated contrast media that, after intravenous administration, produces prolonged opacification of the blood pool and subsequently selectively enhances the liver and spleen on computed tomography. There has been concern regarding the hemodynamic effect of this agent but little actual knowledge exists in this regard. Accordingly, the acute transient hemodynamic effects of PFOB emulsion were evaluated in five pigs and compared with the standard ionic contrast agent meglumine sodium diatrizoate (Renografin-76). Left ventricular (LV) pressure, internal diameter, and wall thickness were monitored during the alternate intravenous administration of 930 mg/ml PFOB and 370 mg/ml R-76 at a rate of 20 mls/second for a total volume of 1 ml/kg body weight. Renografin-76 caused a significant decrease in LV pressure and dp/dt (rate of change of LV pressure), and an increase in LV end-systolic diameter and a decrease in LV end-diastolic wall thickness. PFOB caused no change in LV pressure and dimensions. Thus, rapid intravenous administration of PFOB does not induce significant acute alterations in left ventricular pressure, dp/dt, dimension, or wall thickness.
Perfluoroctylbromide (PFOB), a radiopaque reticuloendothelial system contrast media for computed tomography, has been shown to accumulate in macrophages. In the current study PFOB was tested in rabbits as an abscess imaging agent. Two abscesses were induced in each of 24 rabbits, one in the liver and the other in the peritoneal cavity. CT of the rabbit abdomen was performed four days later, two days after the administration of 5 gm/Kg of PFOB to 12 of these rabbits. The average enhancement of the wall of liver abscesses was by 140 Hounsfield units (HU) relative to the enhanced liver and peritoneal abscesses by 135 HU relative to the control group. This enhancement was secondary to the intense accumulation of PFOB filled macrophages in the abscess wall. In those rabbits where the liver abscess ruptured, the edges of the peritoneal collections enhanced by 147 HU. Regions of inflammation prior to liquifaction enhanced considerably. These areas could not be detected in the animals not receiving PFOB. Though the liquified center of liver abscesses could be seen in the absence of PFOB, none of the peritoneal abscesses could be detected in the animals not receiving PFOB. In contradistinction, all peritoneal abscesses enhanced considerably following PFOB allowing their prospective localization. In conclusion, PFOB accumulates in abscess walls and areas of inflammation producing marked CT enhancement of liver and peritoneal abscess collections. This enhancement allowed the differentiation of peritoneal abscess collections from adjacent bowel.
Venous fluid-fluid levels were seen on CT or MR of three patients being evaluated for possible thrombosis. In all three cases, further investigation (by ultrasonography, venography, or surgery) revealed the cause of the fluid-fluid level to be slowly flowing blood without thrombosis. On CT done after intravenous contrast medium administration, the nondependent half of the vessel was denser than the dependent half. In an attempt to confirm this MR and CT picture and, particularly, to explain the dense upper half on CT, we conducted an in vitro study. Our study confirmed that when blood with diatrizoate sodium is not clotted and allowed to settle, a similar fluid-fluid level is observed by CT imaging. Our results indicate that an intravascular fluid-fluid level seen on cross-sectional images represents slowly flowing blood, not thrombosis.
Vasculitis of the testis, although common pathologically, has been difficult to diagnose clinically and to detect noninvasively. This report describes the added benefit of MR imaging in directing clinical management in a patient where the first manifestation of vasculitis was scrotal pain and swelling. This subject was diagnosed and treated for epididymitis. Although he had a normal appearing testis on sonography, magnetic resonance showed testicular changes more characteristic for focal infarcts which led to testicular biopsy and to altered diagnosis and treatment.