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Biomedical subjects

W M Thompson

Publications and source records attributed to W M Thompson.

At least 55 records · Page 3Linked to original sources
PubMed1988

Gastric adenocarcinoma: CT versus surgical staging.

Seventy-five patients with gastric carcinoma underwent preoperative staging with computed tomography (CT). In 14 patients, CT failed to demonstrate lymphadenopathy despite the presence of malignant lymph nodes at surgery. In 13 patients, CT demonstrated enlarged nodes, but no malignant involvement was found at surgery. Although spread to the pancreas was correctly predicted in three patients with lack of fat plane between tumor and pancreas, five patients lacking a fat plane had no invasion, whereas eight patients with an intact fat plane had invasion. Thirty-five patients (47%) were incorrectly staged with CT:23 (31%) were understaged and 12 (16%) were overstaged. CT does not accurately display the true extent of disease in patients with gastric carcinoma and therefore should not be used routinely for staging.

Adenocarcinoma↗
PubMed1988

Percutaneous aspiration and drainage of abdominal fluid collections after pancreatic transplantation.

Pancreatic transplantation, performed to avert or delay the long-term complications of insulin-dependent diabetes mellitus, is sometimes complicated by the development of intraabdominal fluid collections. We performed 33 sonographically guided and CT-guided percutaneous abdominal aspiration and drainage procedures in 22 transplant patients; 25 procedures were done with the pancreatic graft-in-situ, and eight were done after removal of the transplant. All 11 percutaneous aspirations performed in 10 patients were successful in obtaining microbiologic culture material, and there were no complications. Sixteen percutaneous catheter drainages were performed in 13 patients with the graft-in-situ. Subsequent surgical intervention was avoided after only five (31%) of these drainage procedures. However, further intervention was unnecessary after five (83%) of six percutaneous catheter drainages in five patients who had previously undergone transplant pancreatectomy. No significant short-term or long-term complications were identified. Guided percutaneous aspiration of abdominal fluid collections after pancreatic transplantation is a safe and effective means of obtaining diagnostic material, and guided catheter drainage is definitive treatment in approximately one-third of procedures with the graft-in-situ and in most procedures done after removal of the graft.

Adult↗
PubMed1988

Imaging of vascular complications after hepatic transplantation.

Vascular complications after hepatic transplantation can compromise graft and patient survival. Angiography defines the need for revascularization or retransplantation, but the value of noninvasive imaging in this setting is not clear. To assess the relative merit of noninvasive imaging techniques (sonography, scintigraphy, CT, and MR), we retrospectively reviewed 19 major vascular complications that occurred in 15 of 98 hepatic recipients over a 3 1/2-year period. Portal venous thrombosis was seen in seven patients, donor aortic or hepatic arterial thrombosis in seven, and inferior vena caval thrombosis in five. Sonography provided the initial diagnosis of portal venous thrombosis in three, arterial compromise in five, and caval obstruction in four. CT was the first diagnostic examination to identify portal occlusion in two, donor aortic thrombosis in one, and inferior vena caval thrombosis in one. Scintigraphy and MR imaging provided complementary data. Both sonography and CT are useful in the evaluation of vascular complications that occur after hepatic transplantation; however, neither is sufficiently sensitive to obviate angiographic assessment.

Adolescent↗
PubMed1987

Computed tomographic staging of gastrointestinal tract malignancies. Part I. Esophagus and stomach.

The utility and limitations of CT staging of carcinomas of the esophagus, stomach, small bowel, and colon are reviewed. Routine preoperative staging of esophageal carcinoma is recommended because of CT's sensitivity of more than 90% in detecting mediastinal invasion and a specificity of more than 85% in collected series. We recommend the use of CT as a problem-solving technique rather than as a routine preoperative test in patients with gastroesophageal junction, and gastric and small bowel malignancies. Routine use of CT to stage colorectal carcinomas also does not seem justifiable, due to the inability of CT to determine the depth of bowel wall involvement and to detect tumor in normal size lymph nodes. CT can help differentiate tumors that invade the pelvic side walls from more limited cancers and, therefore, in certain cases can aid in therapy planning. CT is the best method for detecting local recurrence in patients with rectosigmoid carcinomas.

Aortography↗
PubMed1987

Contrast enhancement of the liver. Evaluation by automated contiguous pixel search.

Eight dogs were infused with one of three different contrast agents: meglumine diatrizoate, iosulamide meglumine, or an ethiodized oil emulsion (EOE 13). Image intensity in the liver was evaluated globally and regionally by means of an automated pixel sampling method to determine differences in the rate of enhancement produced by the three agents. The results of the automated method were compared with those of the standard manual cursor method. The automated method showed that liver parenchyma was enhanced uniformly by all three contrast agents. The maximum degree of enhancement (Mean +/- SEM) for the three agents was diatrizoate, 12.0 +/- 3.5 Hounsfield units (HU); iosluamide, 21.3 +/- 3.5 HU; and EOE 13, 37.2 +/- 4.25 HU. With the manual cursor method, contrast enhancement was about 20% more than estimated by the automated method. The automated method is better for evaluating the magnitude and pattern of contrast agent enhancement of the entire liver, since the currently employed cursor technique requires multiple evaluations to evaluate the entire liver.

Animals↗
PubMed1987

Scientific presentations. What to do and what not to do.

An effective scientific presentation requires skill, experience, and effort. In planning the presentation, a skilled speaker first forms clear conclusions through analysis of the data, then tailors the details of the proof of these conclusions to the interests and background of the audience. The facts and conclusions are presented in a practiced, specific, clear, and logical manner. It is not the topic or the data alone, but the sympathetic and strategic communication of the material to a particular audience that makes a meaningful presentation.

Audiovisual Aids↗
PubMed1987

Adult esophageal candidiasis: a radiographic spectrum.

With the increasing use of cancer chemotherapy and organ transplantation requiring immunosuppressive therapy, and with the incidence of immunodeficiency states such as AIDS increasing, it is to be expected that candida esophagitis will occur with increasing frequency. Though fiberoptic endoscopy is a more specific and more sensitive approach to the diagnosis of candida esophagitis than barium esophagography, it is also more invasive, and many patients will continue to be examined radiologically, at least initially. The radiologist continues, therefore, to play a significant role in suggesting the diagnosis and it is incumbent on him to familiarize himself with the spectrum of common and unusual radiographic manifestations of this disease.

Adult↗
PubMed1987

Computed tomography of the rectum.

CT is an important diagnostic procedure in patients with suspected or known disease of the rectum. Knowledge of proper technique for CT of the rectum, as well as an understanding of normal pelvic anatomy, is essential to its effective use. CT can demonstrate the extent of perirectal and pararectal abnormalities detected on barium enema. While routine preoperative staging of rectal cancer is not justified, CT can be used to solve specific problems. Perhaps the most important role of rectal CT is in evaluating postoperative rectosigmoid cancer patients in an attempt to detect early asymptomatic recurrences and, thereby, prolong patient survival.

Abscess↗
PubMed1987

Diagnosis of acute colonic diverticulitis: comparison of barium enema and CT.

The contrast enema and CT studies in 102 patients with a clinical diagnosis (41%) or surgically confirmed (59%) diagnosis of colonic diverticulitis were reviewed retrospectively to determine the sensitivity of the two techniques. Combined results from all patients showed that the contrast enema was correct in 77% of patients. The contrast enema was falsely negative in 15% and was indeterminate in 7%. The CT examination was diagnostic in 41%, consistent with the diagnosis of diverticulitis in 38%, and falsely negative in 21% of patients. Both CT and contrast enemas were more accurate in patients with severe disease requiring surgery. No complications occurred from 109 enemas performed. Patient management was altered in only one patient as a result of the additional information provided by CT. The contrast enema should remain the initial and routine examination for the evaluation of patients with suspected diverticulitis. CT should be reserved for patients who are unable to have an adequate contrast enema, those with suspected distant or diffuse abdominal abscess, those who are unresponsive to medical therapy, and those who are candidates for percutaneous drainage.

Acute Disease↗
PubMed1987

Hepatic regenerating nodules in hereditary tyrosinemia.

Hereditary tyrosinemia is an autosomal recessive, enzymatic disorder that results in micro- and macronodular cirrhosis in early childhood. Hepatocellular carcinoma occurs in approximately one-third of affected children. We evaluated the imaging studies performed in five children with this disorder. Pathologic examination of all five of the livers revealed cirrhosis and multiple regenerating nodules; hepatocellular carcinoma was present in two of the five livers. All five patients had high-attenuation or high- and low-attenuation foci within the liver. These high-attenuation foci were not apparent as focal lesions in three of four hepatic sonograms or in one of two hepatic nuclear scans. Angiography showed tumor vascularity in one patient with a focal hepatocellular carcinoma, but was indeterminate in a second patient with severe cirrhosis and multifocal hepatocellular carcinoma. Children with cirrhosis due to tyrosinemia may develop regenerating nodules that appear as high-attenuation hepatic foci on CT scans. It is difficult to differentiate regenerating nodules from multifocal hepatocellular carcinoma in these patients.

Amino Acid Metabolism, Inborn Errors↗
PubMed1986

Transection of the thoracic aorta: assessment of a trauma system.

A large, heavily populated area regionalized the care of critical trauma in 1980. To evaluate the system, we reviewed patient outcome for thoracic aortic transection due to blunt injury for the first 18 months of trauma system operation. Of the total of 86 patients, 43 were transferred to trauma centers, 8 to nontrauma centers, and 35 were either directly transported to the coroner or dead on arrival at the hospital. Of the eight patients transported to non-trauma centers, seven were in cardiopulmonary arrest during transport and the eighth was pronounced dead shortly after admission to the emergency department. Twenty-seven of the 43 patients transferred to trauma centers were dead within 24 minutes of admission. The cause of death was rupture of a transected aorta in 22 patients and other multiple injuries in the remaining 5. Sixteen were alive long enough in the emergency department for evaluation. Nine of these patients underwent correction of aortic transection as well as other injuries and all survived. Two of the nine survivors sustained partial or complete spinal cord damage. The remaining seven patients died, but in only one patient did the undiagnosed aortic injury contribute to the cause of death. This patient had a normal cineangiogram and the diagnosis was made at autopsy. He was considered potentially salvageable, so 9 of 10 potentially salvageable patients survived (90 percent). Of the total of 86 patients with aortic transection, 77 died (90 percent). This study shows that regionalization of trauma care offers an excellent chance for survival of patients with thoracic aortic transection.

Accidents, Traffic↗
PubMed1986

Contrast media tonicity. Part I. Effects upon IV-DSA time-concentration curve peak and width: experimental studies.

Prior to the formation of an intravenous digital subtraction angiography (IV-DSA) image, contrast medium passes through the lesser circulation and is diluted by the blood volume of the heart and lungs. If the contrast medium alone influences central blood volume or cardiac output, the shape of the resultant time-concentration curve may be degraded. To the extent that contrast medium tonicity reduces curve peak or increases width, image quality for mask mode IV-DSA will suffer. To quantify the effect of contrast medium tonicity upon curve shape, contrast medium (1) at increasing iodine concentration and increasing osmolality and (2) at constant iodine concentration and increasing osmolality was injected into the right atria of mongrel dogs. In both experiments, increasing osmolality was associated with an increase in central blood volume (CBV) and cardiac output. With an increase in CBV, curve peak fell. With an increase in both CBV and cardiac output, curve width was not influenced by increasing osmolality. The effect of osmolality upon CBV was highly variable; in these experiments CBV was influenced more by subject-to-subject variability. However, on the average, higher tonicity contrast media produced curves with lower peaks. These studies suggest that isotonic contrast medium does not increase CBV and that isotonic contrast medium is preferable to hypertonic contrast medium for IV-DSA image formation.

Angiography↗
PubMed1986

CT differentiation of pleural effusion from ascites. An evaluation of four signs using blinded analysis of 52 cases.

Four criteria have been described to differentiate ascites from pleural effusion by computed tomography (CT). These four signs (the diaphragm sign, the displaced crus sign, the interface sign, and the bare area sign) were compared in a retrospective blinded analysis in 52 patients with ascites, right pleural effusion, or both ascites and right pleural effusion. There were limitations with each of the four criteria. Each of the individual criteria was reliable when only one abnormal fluid collection, either pleural effusion or ascites, was present. When both a right pleural effusion and ascites were present, none of the four criteria reliably identified both fluid collections. The combined use of the four criteria, however, led to a correct identification of all the abnormal fluid collections.

Ascites↗
PubMed1986

Esophageal cancer staging by CT: long-term follow-up study.

To evaluate the utility of computed tomographic (CT) staging in patients with esophageal cancer, the length of patient survival was compared with pretherapy CT findings in 89 patients. Regardless of therapy, patients with evidence of mediastinal invasion, liver metastases, or abdominal adenopathy had a statistically shortened survival (P less than .05). Specific CT criteria that predicted a shortened survival included evidence of tracheal, aortic, or pericardial invasion. Patients with evidence of both mediastinal invasion and abdominal metastases had a mean survival of 180.4 days; those with no evidence, 479.6 days. The presence of enlarged upper abdominal lymph nodes indicated the worst prognosis (mean survival, 90 days). The patients with squamous cell tumors were classified by the CT staging system, and survival data were compared according to surgical procedure. Patients who underwent attempted curative surgery did not have a statistically significant difference in survival by analysis of survival curves but demonstrated a longer mean survival than those who underwent palliative or no surgery.

Adult↗
PubMed1986

Optimal cholangiographic technique for detecting bile duct stones.

Twenty-eight patients with proven bile duct stones were evaluated during either operative or T-tube cholangiography. Two radiographs were obtained for each patient without changing patient position between films. The first was performed with low peak kilovoltage (75-80 kVp) and 15% iodinated contrast medium and the second with high kVp (110) and 38% iodinated contrast. Seven radiologists evaluated the radiographs individually and in matched pairs for ductal filling, ductal penetration, motion unsharpness, overall quality, and stone detectability. The high-kVp radiographs were rated significantly better overall than the low-kVp studies (p less than 0.001) for all five criteria. In the second evaluation, which compared the pairs from the same patients, the 28 high-kVp radiographs were considered superior to the 28 low-kVp studies by the radiologists in almost two-thirds of the comparisons (ductal filling, 68%; penetration, 59%; less motion unsharpness, 65%; overall quality, 77%; stone detection, 62%). On the basis of the results of this study, high-kVp technique with full-strength contrast medium for operative and T-tube cholangiography is recommended.

Cholangiography↗