Biomedical subjects
Publications and source records attributed to S McCarthy.
Magnetic resonance imaging demonstrates gynecologic anatomy not visible with other techniques. Tissue layers within and outside the uterine corpus, cervix, and vagina are defined in any plane. Such soft tissue contrast resolution is promising for the noninvasive diagnosis of disease.
Magnetic resonance imaging of the female pelvis permits visualization of soft tissue structure previously unseen with other radiological techniques. The internal architecture of the corpus uterus, cervix and vagina are directly visualized in any plane. Furthermore, the hormonal environment of the female can be indirectly determined via assessment of the MR appearance of the uterus. Similarly, the complex changes which occur during pregnancy, such as cervical effacement and the relationship of internal os, fetal part and placenta, are easily documented. MR pelvimetry enables fast, safe depiction of the birth canal. Finally, the demonstrated fetal anatomy may prove particularly useful in the evaluation of intrauterine growth retardation and anomalies indeterminate by ultrasound.
The role of magnetic resonance (MR) imaging in the detection of gallbladder disease was evaluated in 39 individuals (16 healthy, five with asymptomatic gallstones, and 18 with clinical symptoms of gallbladder disease). MR imaging was performed after they fasted for 12 hours. Imaging sequences included a combination of repetition times (TR) of 0.5 and 1.5 sec and echo times (TE) of 28 and 56 msec. On the images obtained at TR = 0.5 sec and TE = 56 msec, gallbladder bile was hyperintense compared with the liver in all healthy and asymptomatic subjects and was hypointense (n = 9), isointense (n = 4), or hyperintense (n = 5) in symptomatic patients, eight of whom had surgical confirmation of cholecystitis. Comparison of normal versus pathologically proved cases for the presence of gallbladder disease yielded a specificity of 100%, sensitivity of 75%, and a significant difference of P less than .01. Thus, with a pulse sequence of TR = 0.5 sec and TE = 56 msec, MR was sensitive in detecting gallbladder disease. However, the role of MR in the radiologic workup of gallbladder disease will be determined by more experience with this modality.
Magnetic resonance (MR) imaging was performed on 21 women in different phases of the menstrual cycle, nine who used oral contraceptives and 12 who did not. Sagittal images in a dual spin-echo sequence were obtained to assess conspicuity and dimensions of the corpus uteri, cervix, vagina, and their component tissues. The endometrium, junctional zone, myometrium, cervical canal, fibrous stroma, and vaginal canal were seen in all cases and the vesicovaginal septum, rectovaginal septum, and levator ani in 90%, 86%, and 100%, respectively. The uterus was retrodisplaced in 19% of the women. In the nonpill group, endometrial width was significantly larger (P less than .025) in the secretory phase (mean, 5 mm) than in the follicular phase (3.1 mm). In the pill-using group, endometrial width was 1.1 mm in both phases, significantly smaller than in the nonpill group (P less than .025, follicular; P less than .0005, secretory). Junctional zone width was significantly smaller in the pill-using group (P less than .005). Qualitatively, the myometrium was relatively brighter on second echo images in the pill-using group, compatible with known edema that occurs with use of oral contraceptives. MR can reliably demonstrate gynecologic structure and anatomic changes that occur during the menstrual cycle and with use of oral contraceptives.
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Corn was grown under greenhouse and controlled light quality conditions incluing full spectrum, red (R), and far-red (FR) sources. Young leaf samples were analyzed for pigments, pigment-proteins, membrane polypeptides, and ultrastructure. Chloroplast development in full spectrum white light was similar to that found in R but different from that found in FR plus low R. Compared to greenhouse and R, FR plus low R (670-760) repressed the formation of photosystem I reaction center protein (CP1 + CP1a) and enhanced those of photosystem II (CPa) in both bundle sheath and mesophyll cells. Photosystem II polypeptides were present in both cell types, with the 46 and 34 kilodalton proteins predominant in mesophyll cells. Bundle sheath cells contained relatively more of the 51 kilodalton and less of the 46 kilodalton proteins. However, they also contained measurable amounts of ribulose bisphosphate carboxylase which may interfere with estimates of the 51 kilodalton protein.
This study evaluated the ability of magnetic resonance imaging (MRI) to depict the hepatic vasculature and surgical anatomy of the liver using the transaxial, coronal, and sagittal planes. Retrospective analysis of the abdominal MRI examinations of 94 patients was performed. The spin-echo imaging technique was used to obtain transaxial images in all patients and coronal and sagittal sections in 35 of these patients. Overall, the hepatic vasculature was better delineated on the longer repetition rates (2000 msec TR) and the first echo images (28 msec TE). The inferior vena cava, right and middle hepatic veins, and main and right portal veins were seen in 100% of the cases in the transaxial plane. The left hepatic vein was seen in 98%, the left portal vein in 93%, and the hepatic artery in 44% in the transaxial plane. In the sagittal and coronal planes, the inferior vena cava and main and right portal veins were seen in 100% of cases. The other hepatic vasculature was less frequently demonstrated. In the sagittal plane, the right hepatic vein was seen in 85% of the cases, the left hepatic vein in 62%, the middle hepatic vein in 90%, the left portal vein in 90%, and the hepatic artery in 14%. In the coronal plane, the right hepatic vein was seen in 85% of cases, the left hepatic vein in 14%, the middle hepatic vein in 79%, the left portal vein in 71%, and the hepatic artery in 7%. These results are from preliminary work. Further developments with MRI technology may render better visualization of hepatic vasculature.
We describe a newborn with multiple congenital anomalies due to the Amniotic Band Disruption Complex. Cerebral computerized tomography and plain films of the extremities corroborated the clinical diagnosis. The purpose of this case report is to alert the radiologist to the varied radiographic appearance of this little known entity and to provide a historical and embryologic background.
Twenty-two patients with gestational trophoblastic neoplasia (GTN) were examined by CT of the abdomen and pelvis to assess the usefulness of CT in the detection and staging of GTN. The most common manifestations of GTN by CT were an enlarged uterus in 16 of 20 patients (80%) with bilateral adnexal cysts in 12 of 22 patients (54%). Contrast enhancement of the uterus was inhomogeneous and the cysts were usually unilocular, ranging in size from 1.0 to 6.0 cm. Metastases were found in 13 of 22 cases (59%). Local extension into the broad ligament was present in 5 of 22 cases (23%). Pelvic or periaortic adenopathy or both was not present. Only one patient had liver metastases. We conclude that CT is a valuable tool in the evaluation of patients with GTN.
Magnetic resonance is potentially a second imaging modality that can be used to study the fetal cardiovascular system. Magnetic resonance imaging to date has not been associated with any harmful effects and, since it does not involve ionizing radiation, we are evaluating its role in fetal imaging. We report a case in which this modality showed the unique features of the cardiovascular system.
A prototype flow rate injector for intravenous administration of contrast agent was used successfully and without complications in 200 patients undergoing CT of pelvic, abdominal, and mediastinal structures. Improved contrast enhancement was routinely obtained.
A method for measuring discrepancies in leg length using digitized radiographs obtained with a CT scanner is described. This method is more rapid and delivers 50 to 100 times less radiation than the conventional radiographic method.
The complementary use of endoscopic retrograde cholangiopancreatography and computed tomography in the diagnosis and management of pleuropancreatic fistulas is described in relation to four cases in which computed tomography revealed the thoracic extension of a pancreatic fistula not demonstrable by endoscopic retrograde cholangiopancreatography, although the latter indicated an abnormal pancreatic duct. The complementary use of both techniques may be necessary to define the pathologic anatomy so that the appropriate therapy, particularly the surgical approach, can be decided.
The sonographic features of 15 histologically confirmed renal oncocytomas in 14 patients are presented. Lesions were evaluated for homogeneity, echogenicity, margination, venous invasion, and nodal enlargement. Nine were less than 5.5 cm in diameter, homogeneous, and well circumscribed. Three lesions were greater than 8 cm in diameter, contained areas of central necrosis or calcification, and were nonspecific for renal oncocytoma. One of these lesions (12 cm) contained a central scar. Two masses were slightly inhomogeneous and, at best, moderately circumscribed. In no case were metastatic nodes or venous invasion present. Since about 6% of renal cell carcinomas may have this appearance, the homogeneous, well marginated renal mass that is isoechoic with cortex and less than 5.5 cm in diameter is as likely to represent renal cell carcinoma as it is an oncocytoma. Although only present in one of the cases, the central fibrotic scar in a larger mass has been described in oncocytoma and may be the most specific feature. Preoperative investigation with fine-needle aspiration biopsy for cytology may be indicated in an attempt to avoid radical nephrectomy in selected patients.
Five cases of crossed renal ectopia, three fused and two unfused, which were identified sonographically are presented. Bowel occupying the contralateral renal fossa can mimic mass or kidney and lead to confusion. A crossed-fused kidney can mimic a single kidney with a duplicated system or a kidney with a renal mass. A characteristic anterior and/or posterior notch provides a major clue to the correct diagnosis. In addition, correlation with plain radiographs and/or barium studies demonstrating bowel in the contralateral renal fossa, as well as real-time examination demonstrating peristalsis, should aid in the correct diagnosis.