Communications of the pelvic extraperitoneal spaces and their relation to the abdominal extraperitoneal spaces: helical CT cadaver study with pelvic extraperitoneal injections.

PURPOSE: To evaluate flow patterns and anatomic appearances in the pelvic extraperitoneal spaces and to determine their relation to the abdominal extraperitoneal spaces. MATERIALS AND METHODS: Helical computed tomographic (CT) guidance was used for injection of up to 1,000 mL of iodinated contrast material into one pelvic extraperitoneal space in each of five cadavers. Staged-volume injections into two prevesical spaces, one paravesical space, and one perivesical space were followed by helical CT. RESULTS: The injected pelvic extraperitoneal spaces freely communicated with each other and with the perirenal and anterior and posterior pararenal spaces of the abdomen. This abdominal communication was via the large infrarenal space posteriorly and the circumferential extraperitoneal spaces about the peritoneal cavity bounded deeply and superficially by the parietal peritoneum and transversalis fascia, respectively. The contrast material reached the diaphragm superiorly and the femoral vascular sheath space and inguinal canals inferiorly. After crossing the midline both anterior and posterior to the peritoneal cavity, the contrast material reached the mesenteric root in four cadavers and the propericardial space of the thorax in two cadavers. CONCLUSION: Intercommunication of the various extraperitoneal compartments occurs predominantly via the fascial-defined spaces, which contain mainly adipose tissue, but potential conduits exist through the communicating neurovascular structures where the fascia is anatomically perforated.

Anatomic communications between the three retroperitoneal spaces: determination by CT-guided injections of contrast material in cadavers.

OBJECTIVE: A variety of retroperitoneal diseases such as pancreatitis, infection, and trauma may cause fluid collections in the three major retroperitoneal spaces. The purpose of our study was to elucidate flow patterns of fluid between the various compartments to assist the clinical-radiologic assessment and treatment of various retroperitoneal diseases. MATERIALS AND METHODS: In eight cadavers, CT guidance was used to selectively inject 35-1000 ml of contrast medium by hand or power injector into five perirenal, two posterior pararenal, and two anterior pararenal spaces. After the injections, CT of the entire abdomen and pelvis was done with 10-mm-thick sections at intervals of 10-40 mm. All images were reviewed in detail by a group of experienced body imagers to assess the pathways of flow of contrast material between the three major retroperitoneal spaces. RESULTS: The caudal cone of perirenal fascia was uniformly patent. A narrow channel connected the two perirenal spaces in the midline; the posterior border of this channel abutted the anterior margins of the abdominal aorta and the inferior vena cava. The perirenal, anterior pararenal, and posterior pararenal spaces all communicated with the infrarenal space, which in turn connected with the extraperitoneal spaces in the pelvis. When large quantities of contrast medium are injected in the perirenal or pararenal spaces and the infrarenal space is filled, the infrarenal space may then serve as a conduit across the midline of the abdomen. The anterior pararenal space crossed the midline and had a distinct retrorenal extension but no intraperitoneal connection. The slender posterior pararenal space had an anterolateral extension en route to the prevesical space. CONCLUSION: Our findings show pathways and extensions of the perirenal, anterior pararenal, and posterior pararenal spaces that should be considered when assessing a variety of retroperitoneal diseases. Perinephric collections, such as hematomas and urinomas, have at least a potential conduit across the midline or into the pelvis. Our study explains how blood from a ruptured abdominal aortic aneurysm may enter either perinephric space. Anterior pararenal processes, such as pancreatitis or appendicitis, can extend into the pelvis or cross the midline, and posterior pararenal blood from trauma can also flow into the pelvis.

Embryonal heart rate as a predictor of pregnancy outcome: a prospective analysis.

To evaluate the association between embryonal heart rate and pregnancy outcome, we prospectively followed 50 very early pregnancies (4.5 to 7.3 weeks of gestation) through the first trimester. Of the 11 embryos that miscarried, 6 had initial heart rates below 85 beats per minute (bpm); in contrast, none of the viable embryos had initial heart rates of or below 85 bpm (P less than 0.0001). A rise in mean heart rate was seen among the viable embryos with increasing gestational age, in concordance with previously reported rates.

Epicardial lipoma: a CT diagnosis.

Primary cardiac tumors are rare and epicardial lipomas are rare within this group. We are reporting a case diagnosed by CT in an 89-yr-old female.