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.

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.

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.

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.

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.

Effect of adjuvant tamoxifen therapy on thyroid function in postmenopausal women with breast cancer.

Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4) and total tri-iodothyronine (TT3) concentrations were measured in 45 postmenopausal breast cancer patients before adjuvant treatment with tamoxifen and at 3- and 6-month intervals. A significant increase in TSH (p = 0.002) at the end of 3 months and a subsequent decrease at the end of 6 months was noted. There were no significant changes in TT3 and FT4. We concluded that tamoxifen therapy in postmenopausal women may result in a reversible increase in TSH after 3 months.

Seminoma: improved imaging and tumor characterization with computed tomography.

We report 2 cases of metastatic seminoma to emphasize the use of computed tomography in defining accurately the extent and volume of tumor before treatment. Computed tomography permits more direct visualization of the retroperitoneum, mesenteric and abdominal lymph nodes, and extra nodal extension of the tumor to other organ systems. Additionally, characteristic tissue densities are displayed (that is cyst and hemorrhage), which may serve as an index to the dynamics of tumor growth and change. Lymphography and venacavography are invasive studies and both share inherent limitations in imaging for seminoma. Cross-sectional imaging is more precise in describing treatment fields for radiation therapy. Results of treatment are monitored more confidently with computed tomography.

Computed tomography, sonography, and MR imaging of abdominal tuberculosis.

The CT, sonographic, and magnetic resonance findings of a case of abdominal tuberculosis are presented. A diffusely thickened, enhanced peritoneum was imaged best on CT. Sonography was the only imaging modality to demonstrate septations within the tuberculous ascites. Magnetic resonance contributed no additional information.

Posterior hepatodiaphragmatic interposition of the colon: ultrasonographic and computed tomographic appearance.

High posterior hepatodiaphragmatic interposition of the colon is an unusual normal variant that may mimic posterior hepatic lesions, posterior retroperitoneal masses, or a disrupted right diaphragm on sonography. The correct diagnosis of this entity may be suggested on plain abdominal films, and is made easily with computed tomography.

MR, CT, and ultrasonographic demonstration of splenic vein thrombosis.

The first case report of magnetic resonance imaging of splenic vein thrombosis is presented together with CT and ultrasound correlation.

CT of the pericardial recesses.

Within the pericardial cavity there are several recesses where fluid can collect in close contiguity to the major bronchi and lymph nodes. These include the transverse sinus, behind the ascending aorta and pulmonary trunk; the oblique sinus, behind the left atrium; and the left pulmonic recess, between the left pulmonary artery and the left superior pulmonary vein. There are also smaller pericardial recesses between the superior and inferior pulmonary veins, posterolateral to the superior vena cava, and between the inferior vena cava and coronary sinus. An understanding of sectional anatomy is valuable for differentiation of fluid within these recesses from mediastinal masses or enlarged lymph nodes on computed tomographic scans.

Large posterior abdominal masses: computed tomographic localization.

Large posterior abdominal masses, particularly those in the right upper abdomen, may be difficult to localize correctly into the peritoneal or retroperitoneal compartments. The following signs were found to be reliable CT indicators of retroperitoneal location: obliteration of the perinephric fat outlining the psoas muscle; lateral displacement of the fat outlining the posterior right lobe of the liver; rotation of the intrahepatic portal veins to the left; anterior displacement of the inferior vena cava and renal veins; and anterior displacement of the ascending colon, descending duodenum, or pancreatic head.

The perihepatic spaces: computed tomographic and ultrasound imaging.

The appearance of perihepatic fluid collections on sectional imaging is discussed. The coronary ligamentous attachments of the right lobe of the liver to the diaphragm delineate a bare area that separates the right subphrenic and posterior subhepatic spaces. These attachments explain the configuration of right perihepatic fluid collections on sectional images and allow differentiation of subphrenic, posterior subhepatic, and pleural fluid with ultrasound and computed tomography. More medially, the caudate lobe of the liver invaginates the superior recess of the lesser sac, so that fluid collections within this recess may mimic intrahepatic masses on sectional images. This is illustrated with anatomic sections, computed tomographic scans, and ultrasound images.

Computed tomography and magnetic resonance imaging of a superior gluteal artery pseudoaneurysm.

The magnetic resonance and computed tomography appearances of a superior gluteal artery pseudoaneurysm are described, with emphasis on the relative advantages and disadvantages of these two imaging procedures.

The portacaval space: CT with MR correlation.

Between the portal vein and the inferior vena cava lies a small space that may be occupied by multiple anatomic structures including the caudate and papillary processes of the caudate lobe of the liver, portacaval lymph nodes, replaced or accessory right hepatic arteries, posterosuperior pancreaticoduodenal vessels, the cystic duct, and the epiploic foramen to the lesser sac. The sectional anatomy of these structures is illustrated in this paper with particular emphasis on the portacaval nodes. Unlike the adjacent celiac lymph nodes, portacaval nodes appear rectangular or elliptical on transverse sections and may measure up to 1.3 cm in anteroposterior dimension. They may mimic portions of the pancreas, liver, or biliary tract on sectional images.

Posterior peritoneal recesses: assessment using CT.

Intraperitoneal compartments may extend posteriorly to the level of known retroperitoneal structures at several locations within the abdomen. These locations include the posterior subhepatic or hepatorenal space, the splenorenal space, the retropancreatic recess, the paracolic gutters, and the pararectal fossae. Because of their posterior location, fluid collections within these compartments may be mistaken radiologically for retroperitoneal masses. The sectional anatomy of these spaces, and particularly their appearance on computed tomographic scans, are illustrated in this paper.

Computed tomography, sonography, vesiculography, and MR imaging of a seminal vesicle cyst.

A case of crossed ectopia of seminal vesicle cyst is reported. Magnetic resonance (MR) appearance of the seminal vesicle cyst is described first. Brief review of the literature for the seminal vesicle cyst is made and role of new imaging modalities including ultrasound, CT, and MR is discussed.

Extraperitoneal paravesical spaces: CT delineation with US correlation.

The extraperitoneal space around the urinary bladder is lamellate, just like the retroperitoneal space around the kidneys. The bladder, urachus, and obliterated umbilical arteries lie within the perivesical space, surrounded by umbilicovesical fascia, analogous to the perinephric space within the renal fascia. A much larger prevesical space, analogous to the anterior pararenal space, lies anterior and lateral to the umbilicovesical fascia. Posterior to the urinary bladder, the lower uterine segment or seminal vesicles lie within the perivesical space, rather than in a separate compartment, corresponding to the posterior pararenal space. The cul-de-sac, and the inferolateral extension of its peritoneal layers as the rectovaginal or rectovesical septum, separate the posterior perivesical space from the rectum. The sectional anatomy of these spaces, and particularly their computed tomographic and ultrasound appearances, were noted in normal anatomic sections, patients with extraperitoneal fluid collections, and a cadaver into which fluid was injected.