Resting host and tumor perfusion as determinants of tumor vascular responses to norepinephrine.

Blood flow determinations and arteriograms were obtained in rat (Walker carcinoma) and rabbit (V2 carcinoma) liver tumors at rest and after norepinephrine administration. Resting tumor blood flow exceeded resting hepatic flow in both models, and both tumors responded with vasoconstriction and reduced blood flow. In tumors and the surrounding normal host tissue, the greater the perfusion prior to drug administration, the greater is the response (decrease in perfusion) to the vasoconstrictor. Although tumor perfusion decreased after vasoconstrictor, post-norepinephrine angiograms revealed an improved diagnostic image because of the enlarged but unresponsive tumor feeder vessels, persistent tumor blush, and simultaneous vasoconstriction in the normal liver. In these models, improved tumor visualization resulted even though a decrease in tumor blood flow had occurred. The angiographic image is related therefore to the lack of vasoconstriction in the tumor feeder vessel, which has, however, a decreased blood flow and the correspondingly greater volume of normally constricting hepatic arteries which results in a marked decrease in the background of vessels upon which the tumor image is superimposed.

Prostate visualization studies in males homozygous and heterozygous for 5 alpha-reductase deficiency.

Male pseudohermaphrodites with 5 alpha-reductase deficiency have ambiguous genitalia and nonpalpable prostates on rectal examination, suggesting the dihydrotestosterone dependency of these structures. To clearly delineate the status of the prostate, male pseudohermaphrodites with 5 alpha-reductase deficiency had transrectal sonography of the prostate performed, and the results were compared to that of age-matched male controls. In six male pseudohermaphrodites, magnetic resonance imaging studies of the prostate were also performed. Heterozygote fathers also had transrectal sonography of the prostate performed and the results compared to age-matched controls. The prostates of the male pseudohermaphrodites appeared as platelike soft tissue structures posterior to the urethra on both prostatic ultrasound and magnetic resonance imaging. Prostatic volume, as determined on prostatic ultrasound by two different methods, was significantly smaller (approximately one-tenth) than the volume of age-matched controls. Transurethral ultrasound guided biopsy of the prostate in two affected subjects revealed stromal tissue. These results correlate with undetectable prostate-specific antigen in affected subjects, suggesting atrophic epithelium or lack of epithelial differentiation. This study demonstrates the dihydrotestosterone dependence of the prostate for normal differentiation and growth. The presence of some prostatic tissue in the male pseudohermaphrodites may be due to the fact that there is a decrease and not an absence of 5 alpha-reductase activity, and/or that the increased level of testosterone in subjects with this condition partially compensates for the decreased level of dihydrotestosterone. There was no difference, however, in prostate size between heterozygous fathers and age-matched control males. The heterozygote fathers had dihydrotestosterone production sufficient for normal prostate growth and development.

Computed tomography and ultrasound in diagnosis of pelvic lipomatosis.

Computed tomography (CT) and ultrasound are emerging as useful diagnostic adjuvants in the confirmation of pelvic lipomatosis. A case of pelvic lipomatosis studied by CT and sonography is presented. These two techniques offer greater precision in the demonstration of fatty tissue density within the true pelvis. The findings appear characteristic and unique. CT and ultrasound confirmation of pelvic lipomatosis provide added confidence in an accurate clinical diagnosis and may obviate the need for diagnostic surgical exploration.

Computed tomography in urologic patients: preliminary assessment.

Computed tomography (CT) body scanning has specific application to the precise diagnosis of urologic disease. The advantage of visualizing the density of normal and abnormal tissue provides new accuracy in evaluation of renal, retroperitoneal, and pelvic masses. The penetration of the pelvic cavity allows the urologist to assess local, nodal, and skeletal involvement from prostatic and bladder neoplasms in a single diagnostic examination. Cost/efficacy analysis and the role of computed tomography in patient managment must await further review and experience.

Sonographic diagnosis of cisternal subarachnoid hemorrhage in the premature infant.

PURPOSE: To evaluate sonographic criteria for the diagnosis of subarachnoid, and particularly cisternal, hemorrhage in the preterm infant. METHODS: The subarachnoid cisterns were studied on cadaveric anatomic sections and on postmortem ultrasonograms, as well as on in vivo ultrasonograms of healthy neonates. Based on the normal ultrasound appearances of these cisterns, criteria were developed for the recognition of abnormal cisternal fluid collections, which strongly suggest the presence of subarachnoid hemorrhage in the premature infant. These criteria were evaluated prospectively in a group of 63 preterm infants who underwent subsequent autopsy. RESULTS: In the 63 infants with neuropathologic verification, increased echogenicity and/or increased echo-free content of the subarachnoid cisterns correctly predicted subarachnoid hemorrhage with an accuracy of 75%, sensitivity of 69%, and specificity of 93%. The positive and negative predictive values were 97% and 46%, respectively. In 47% of the cases, ultrasound correctly detected cisternal subarachnoid hemorrhage before intraventricular hemorrhage could be diagnosed. CONCLUSION: A highly specific, although somewhat insensitive, sonographic diagnosis of subarachnoid hemorrhage can be made from the appearance of the subarachnoid cisterns. The diagnosis of subarachnoid hemorrhage may predate the ultrasound diagnosis of intraventricular hemorrhage and may alert the neonatologist to the need for follow-up sonograms in the absence of ultrasound evidence of intraventricular hemorrhage.

Topography of cerebral white-matter disease of prematurity studied prospectively in 1607 very-low-birthweight infants.

The objective of this study was to evaluate to what extent (1) the characteristics of localization, distribution, and size of echodense and echolucent abnormalities enable individuals to be designated as having either periventricular hemorrhagic infarction or periventricular leukomalacia and (2) the characteristics of periventricular hemorrhagic infarction and periventricular leukomalacia are independent occurrences. The population for this study consisted of 1607 infants with birthweights of 500 to 1500 g, born between January 1991 and December 1993, who had at least one cranial ultrasound scan read independently by at least two ultrasonographers. The ultrasound data collection form diagrammed six standard coronal views. The cerebrum was divided into 17 zones in each hemisphere. All abnormalities were described as being echodense or echolucent and were classified on the basis of their size, laterality, location, and evolution. Eight percent (134/1607) of infants had at least one white-matter abnormality. The prevalence of white-matter disease decreased with increasing gestational age. Most abnormalities were small or medium sized and unilateral; only large echodensities tended to be bilateral and asymmetric. Large abnormalities, whether echodense or echolucent, were more likely than smaller abnormalities to be widespread, and the extent of cerebral involvement was independent of whether abnormalities were unilateral or bilateral. Large abnormalities were relatively more likely than small abnormalities to involve anterior planes. Small abnormalities, whether echodense or echolucent, or whether unilateral or bilateral, preferentially occurred near the trigone. Using the characteristics of location, size, and laterality/symmetry, we were able to allocate only 53% of infants with white-matter abnormalities to periventricular hemorrhagic infarction or periventricular leukomalacia. Assuming that periventricular leukomalacia and periventricular hemorrhagic infarction are independent and do not share risk factors, and that each occurs in approximately 5% of infants, we would have expected 0.25%, or about 4 individuals, to have abnormalities with characteristics of both periventricular leukomalacia and periventricular hemorrhagic infarction, whereas we found 63 such infants. Most infants with white-matter disease could not be clearly designated as having periventricular hemorrhagic infarction or periventricular leukomalacia only. Periventricular hemorrhagic infarction contributes to the risk of periventricular leukomalacia occurrence, or the two sorts of abnormalities share common risk antecedent factors. The descriptive term echodense or echolucent and the generic term white-matter disease of prematurity should be used instead of periventricular leukomalacia or periventricular hemorrhagic infarction when referring to sonographically defined white-matter abnormalities.

Neurosurgical intra-operative ultrasound: tumor localization and characterization.

Intra-operative real-time ultrasound provides useful information for the neurosurgeon faced with the task of localization and extirpation of small subcortical brain tumors.

Computed tomography of the abdomen.

The CT applications described above are based on our experience with an integrated ultrasound-CT approach, tailored to the patient and aimed at reducing radiation and invasive diagnostic procedures. This approach is not presented as the ideal example to be followed by all. Rather, it is only a sample of the many possible uses of CT. Though there may be many disagreements with our approach, there can be no doubt that CT has revolutionized diagnostic abdominal imaging, to the benefit of all concerned.

Detection of the fetus in the cul-de-sac by transabdominal and transvaginal ultrasound. A case report.

The most common reason for a fetus in the cul-de-sac is ectopic pregnancy, such as rupture of tubal pregnancy, ovarian pregnancy, and intraabdominal pregnancy (1-3). A case of the fetus in the cul-de-sac complicated by uterine perforation was imaged transabdominally and transvaginally on September 13, 1990.

The use of deep inspiration preceding the Valsalva maneuver and rapid expiration in color Doppler imaging of the lower extremity veins.

Deep inspiration preceding Valsalva maneuver and rapid expiration immediately following it (DIVE) enhance venous blood flow on color Doppler flow imaging (CDI). The effect of DIVE was assessed in 115 consecutive lower extremity examinations. Of these, 95 or 115 (83%) had negative CDI sonograms, and 20 of 115 (17%) had partially (six of 115) or completely (14 of 115) occluding deep vein thrombosis. DIVE enhanced venous blood flow in 68% of the negative cases, resulting in transient venous distention, and/or more complete color filling, and/or greater spectral flow velocities. The 14 cases with completely occluding thrombi showed no response to DIVE. Six cases with partially occluding thrombi showed moderate to mild response to DIVE, with improved color delineation of the residual patent lumen around the thrombus. The authors conclude that DIVE facilitates deep venous CDI, especially when compression cannot be used to augment venous flow.

Sonographically detected subarachnoid hemorrhage: an independent predictor of neonatal posthemorrhagic hydrocephalus?

Blood from an intraventricular hemorrhage (IVH) can collect in the basilar cisterns and cause ventriculomegaly and eventual need for ventriculoperitoneal (VP) shunt. We looked for sonographic evidence of subarachnoid hemorrhage (SAH) in three basal cisterns and in the Sylvian fissure of 82 infants with IVH, 30 of whom had ventriculomegaly. We found that ultrasonographically diagnosed SAH and measurement of ventricular blood volume predict ventriculomegaly and need for VP shunt.

CT and US of the pancreas.

The diagnostic capabilities of pancreatic imaging continue to improve with technological advancements in computed tomography (CT), ultrasound (US), and magnetic resonance imaging (MRI). To update the practicing radiologist, this article summarizes the current literature on pancreatic imaging, with particular emphasis on CT and US. Pertinent clinical considerations of the disease entities are included, along with illustrative material from the authors' experience.

Recurrent renal cell carcinoma after 45 years.

Late recurrence of renal cell carcinoma (RCC), arbitrarily defined as > 10 years post nephrectomy, is rare. The longest known clinical disease-free interval of 36 years was reported by Walter and Gellespie in 1960. We report a case of recurrent RCC presenting 45 years after nephrectomy.

Posttraumatic renal infarction versus tumor: a helpful angiographic finding.

We report a case of segmental renal infarction due to a traumatic dissecting hematoma of a renal artery branch. Some features of the cross-sectional imaging studies were atypical of infarct and suggestive of tumor. Renal arteriography demonstrated aneurysmal dilatation of an approximately 3-cm portion of a segmental renal artery, an uncommon but highly suggestive finding of traumatic arteriopathy.

Appendiceal CT in 140 cases. Diagnostic criteria for acute and necrotizing appendicitis.

Computed tomography (CT) was performed in 140 patients with suspected acute appendicitis. Thin collimation (5 mm), intravenous contrast enhancement, 1-second scan times, and supplementary cecal air insufflation were emphasized. CT accuracy was 98% overall (137/140), and 99% in the 124 cases with early surgery. Necrotizing appendicitis was diagnosed by CT with 86% accuracy and 90% positive predictive value.