Biomedical subjects
Publications and source records attributed to J R Haaga.
Following intravenous administration of contrast material, intravenous gas was trapped by a mediastinal mass obstructing the superior vena cava (SVC). The computed tomographic demonstration of gas in the region of a mediastinal mass producing SVC obstruction is presented.
Reviewing our experience with 32 surgically and 13 percutaneously drained abdominal abscesses, we propose the following criteria for computed tomography (CT)-assisted percutaneous drainage: (1) the absence of more than two abscess cavities or loculations; (2) drainage route not traversing bowel, uncontaminated organs, or uncontaminated peritoneal or pleural spaces; (3) the absence of a source of continuous contamination; and (4) the absence of fungi as causative organisms. Of nine abscesses that met these criteria, seven were successfully drained percutaneously. In all abscesses that did not meet the criteria, percutaneous drainage resulted in complications. Of the 32 surgical patients, six would have been candidates for percutaneous drainage according to these criteria. Two of those patients experienced technical complications that might have been prevented by the use of percutaneous drainage. Surgical intervention is the preferred treatment in the majority of patients; however, in properly selected patients, CT-assisted percutaneous drainage is highly successful and can prevent unnecessary morbidity and mortality.
Two patients with breast abnormalities, one malignant and one benign, were studied with nuclear magnetic resonance (NMR) imaging utilizing a cryogenic superconducting magnet. Three-dimensional NMR images were obtained in one case and single slice planar images were obtained in the other. The NMR images correlated well with the corresponding mammograms. Although both conditions exhibited a different signal intensity for the area of abnormality compared to adjacent ductal and fatty tissue, the configuration of the abnormal areas allowed distinction between benign and malignant process.
Computed tomography (CT) is capable of imaging diverticulitis of the colon. Localized wall thickening, soft tissue density in the pericolic fat, and large soft tissue masses that may or may not contain gas have been observed in diverticulitis. Because of its noninvasive nature, CT may have an advantage in the acute phase of diverticulitis when there may be reluctance to do a barium enema. More experience will be needed to see if CT will be predictive of a need for surgery.
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Computed tomographic (CT) findings in six cases of primary sclerosing cholangitis (PSC) are described. Computed tomographic findings correlate with cholangiographic findings and show ductal dilatations and distortions in the porta hepatis and in the liver parenchyma. The CT features are round, oval, or irregular, sometimes branching, focal dilatations of the biliary tree. When subtle, irregular dilatations of the intrahepatic biliary tree are observed, the presumptive diagnosis of sclerosing cholangitis can be made from CT. Confirmation of this diagnosis with cholangiography is essential in all patients. Recognition of this entity by a noninvasive method will avoid long delays in diagnosis and will expedite the use of the more definitive procedures such as endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, or liver biopsy.
A 22 gauge "skinny core" (Madayag) biopsy needle, an 18 gauge Menghini needle, and a 14 gauge Tru-cut needle were compared in 51 patients. The Madayag needle was found to have a high recovery rate and provided adequate histological information in a large percentage of cases. However, the larger needles more consistently demonstrated a higher recovery rate and diagnostic specimen than the Madayag needle. The authors recommend that the radiologist become familiar with all three types of needles to facilitate selection of the proper instrument in each case.
Radiologists are frequently called upon to perform percutaneous biopsy. Selection of the proper needle is becoming more complex as the number of types increases and reports of better results with certain needles proliferate. The authors evaluated a wide variety of needles of different caliber, cutting tip, and bevel. Using a standard biopsy technique for in vitro specimens, the samples were analyzed quantitatively by precise weight measurement and qualitatively by cytopathological means. It was concluded that large-bore needles were superior to "skinny" needles, and small-bore needles having an acute bevel angle were superior to flat-bevel needles of similar gauge in terms of specimen size and preservation.
Eighteen patients with hilar or mediastinal masses demonstrated at CT were selected for examination by nuclear magnetic resonance (NMR). Only regions identified as abnormal on CT scans were scanned by NMR. All patients had histologically proved disease or characteristic findings on the CT scan. The NMR images of two patients were uninterpretable, but all other images clearly distinguished masses from either blood vessels or normal mediastinal tissues without the use of contrast medium. In four cases NMR showed a greater extent of disease than did CT. NMR is a promising modality for visualizing hilar and mediastinal masses.
Pelvic NMR scans were obtained on 29 patients using a 0.3 T superconducting magnet system. Pathologies studied included four bladder carcinomas, four prostatic carcinomas, four ovarian dermoid cysts, three ovarian cysts, three endometrial carcinomas, two endometriomas, and one each of serous cystadenoma of the ovary, benign prostatic hypertrophy, pelvic hematoma, and undifferentiated sarcoma. NMR is a very promising method for characterizing pelvic masses and in staging pelvic malignancies. It can show primary tumors of the prostate, bladder, and uterus and reveals tumor extension into pelvic fat. The pelvis is particularly well suited to NMR scanning because of the abundant natural contrast provided by pelvic fat and by urine in the bladder and gas in the bowel. There is also less motion blurring than in the upper abdomen and chest because there is relatively little respiratory motion of pelvic organs. Various pulse sequences were used in scanning the pelvis; their relative merits are discussed.
The usefulness of nuclear magnetic resonance (NMR) images in the evaluation of spinal disorders below the craniocervical junction was studied. Six normal subjects and 41 patients with various spinal abnormalities were examined. NMR proved capable of demonstrating important normal and pathologic anatomic structures; it was useful in the evaluation of syringohydromyelia and cystic spinal cord tumors, and the bright signal intensity of lipoma was quite impressive. In the evaluation of herniated disk, NMR images offered a new perspective by visualizing abnormal degradation of the signal intensity of the nucleus pulposus itself. NMR images were least valuable in the evaluation of spondylosis and spinal stenosis. Although NMR imaging of the spine is still in a very early developmental stage, the absence of both ionizing radiation and risks associated with contrast material makes it especially attractive as a new diagnostic method. This limited experience with currently available equipment suggests that, with technical refinement, the efficacy of NMR of the spine will increase.
Nuclear magnetic resonance (NMR) scans of the mediastinum and/or hili were obtained in 22 of 25 patients selected on the basis of an abnormal CT scan. All patients had proven disease; 19 malignant and four benign processes were studied successfully. The high contrast resolution of NMR in the mediastinum allowed clear definition of disease in all cases. In six, NMR showed a greater extent of disease than CT. The ability of NMR to perform sagittal and coronal images also aided in disease analysis. In this preliminary study, NMR proved to be as useful as CT, or more so, in the evaluation of malignant disease of the hili and mediastinum.
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Focal fatty metamorphosis of the liver is an entity that has recently been well described. This abnormality should be included in the differential computed tomographic (CT) diagnosis of lesions of decreased attenuation. In this paper, we report three cases in which blunt liver trauma (of varying degrees) resulted in focal fatty metamorphosis that was documented by CT.
Computed tomographic (CT) evaluation of a rare thymic tumor in a child is described. The CT characteristics, pre- and postcontrast enhancement, are described and correlated with ultrasound and plain radiographic findings. Correlation is made between the CT results and the thymic lymphangioma with a subsequently identified abdominal lymphangioma.
In order to determine the clinical usefulness of nuclear magnetic resonance (NMR) imaging, the investigators examined a variety of normal volunteers, patients with neoplastic lesions, and experimental animals. Preliminary results were obtained with the use of potential contrast agents. It was found that imaging applications of NMR in the vascular system, spine, brain, lung, and mediastinum offer certain advantages over other modalities. The absence of biological hazard as well as the ability to obtain unenhanced, noninvasive, gated images of the vascular system, as demonstrated in this study, make NMR particularly attractive. In addition to single-section capability, NMR makes it possible to obtain volume images of the spine and other organs which can be displayed in any desired plane or section thickness.