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Biomedical subjects

S D Wall

Publications and source records attributed to S D Wall.

At least 55 records · Page 3Linked to original sources
PubMed1985

Low incidence of IgA nephropathy in blacks.

The clinical and pathologic features were evaluated in 106 IgA nephropathy patients identified in 1,753 consecutive patients undergoing renal biopsy in the southeastern United States. Special attention was paid to the proportion of Blacks among the IgA nephropathy patients compared with non-IgA nephropathy patients, and any differences in clinical or pathologic findings between Whites and Blacks with IgA nephropathy. The incidence of IgA nephropathy was approximately six times lower in Blacks (6 out of 461) than in Whites (100 out of 1,292) undergoing renal biopsy (P less than 0.001). There were no morphologic or immunohistopathologic differences between Whites and Blacks with IgA nephropathy. The only clinical difference was a marked shift in the male to female sex ratio from 3.5:1 in Whites to 1:5 in Blacks (P less than 0.004). The low incidence and reversed sex ratio of IgA nephropathy in Blacks were also supported by a review of previously published data.

Adult↗
PubMed1985

Gallbladder bile: an experimental study in dogs using MR imaging and proton MR spectroscopy.

Magnetic resonance (MR) imaging, proton MR spectroscopy, and biochemical analysis were performed to investigate MR signal intensity (SI) differences between concentrated and dilute gallbladder bile of seven fasting and five sincalide-treated dogs. MR images revealed high SI from bile of fasting dogs and low to medium SI in sincalide-treated dogs when spin-echo (SE) pulse sequences with repetition rates of 0.5 and 2.0 sec were used. Proton MR spectra were similar for fasting and sincalide-treated dogs. In fasting dogs, water content in the bile was slightly lower, and cholesterol, phospholipid, and bile acid concentrations were higher. More than 90% of proton signals in all Fourier transform free induction decay spectra emanated from water molecules, and no lipid proton resonances were detected in Fourier transform SE spectra after tau delays of 7 msec. These results indicate that the differences in SI are caused by alterations in relaxation times of water protons, possibly resulting from the interactions of water protons and macromolecules.

Animals↗
PubMed1985

Hepatic vascular anatomy on magnetic resonance imaging.

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.

Hepatic Artery↗
PubMed1985

Magnetic resonance imaging in the evaluation of abscesses.

Ten patients with percutaneous biopsy or surgically proven abscesses were evaluated with magnetic resonance imaging (MRI) to describe the appearance of abscesses, define the capability of MRI to localize abscesses, and compare the capabilities of MRI and CT for the diagnosis and determination of the extent of an abscess. Comparative CT scans were available in six cases. The most common MRI finding was an abnormal area of low signal intensity, either homogeneous or heterogeneous, on the short repetition rate (500 msec TR) images with a relative increase in signal intensity on the longer repetition rate (1500 or 2000 msec TR) images. MRI demonstrated a more clear delineation of the extent of inflammatory changes than did CT, and MRI demonstrated the abscess as a collection distinct from surrounding structures on at least one repetition rate. Intravenous contrast medium was unnecessary with MRI to evaluate vasculature or to define the capsule around an abscess. With CT, unless an abscess contained air or was of low attenuation, it often blended with the surrounding structures and was difficult to differentiate from them. Surgical clips in the postoperative patient with an abscess did not degrade the MR images as often occurred with CT. This study describes the MRI appearance of abscess and indicates a potential value of the use of MRI to evaluate abscess outside the central nervous system and spine.

Abdomen↗
PubMed1985

Feasibility of the peroral pneumocolon in evaluating the ileocecal region.

Retrograde insufflation of air into the terminal ileum via a rectal tube (peroral pneumocolon) is a simple adjunct to the conventional gastrointestinal small-bowel follow-through examination. The purpose of this study was to determine the feasibility and diagnostic value of peroral pneumocolon in 170 patients who were being evaluated by upper gastrointestinal series with conventional small-bowel follow-through. Retrograde passage of air into the terminal ileum was successful in 87% of 140 patients with normal anatomic relations and in all 30 patients with small bowel-colonic anastomoses. In most cases, retrograde air insufflation yielded additional diagnostic information, particularly in detection of ulcerations, edematous mucosa, and cobblestone patterns. The length of the small bowel segment affected by pathologic changes could be determined more accurately in over 60% of the peroral pneumocolon examinations. No procedure-related complications were observed.

Adolescent↗
PubMed1984

Gastrointestinal Kaposi's sarcoma in AIDS: radiographic manifestations.

About one-third of all patients with the acquired immunodeficiency syndrome (AIDS) have Kaposi's sarcoma. Gastrointestinal involvement has been noted in 50% of homosexual men with cutaneous Kaposi's sarcoma and AIDS. We report the abnormalities on barium studies of nine homosexual men from the San Francisco bay area who have AIDS and documented gastrointestinal Kaposi's sarcoma. Submucosal nodularity and infiltrative irregularity were the most frequently noted findings and were demonstrated in the stomach, duodenum, small bowel, and colon. The duodenum was the most frequent site of abnormality. Coalescent plaques, some with umbilications, were seen in the colon. Although nonspecific, these radiographic abnormalities are highly suspicious for Kaposi's sarcoma, particularly in patients with or at high risk for AIDS, especially homosexual men.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Aortoesophageal fistula after perigraft abscess with characteristic CT findings.

Aortoesophageal fistula is a rare cause of massive gastrointestinal hemorrhage, and may occur as a sequela to prosthetic replacement of the thoracic aorta. Esophageal compression necrosis with leakage of microorganisms into the proximal suture line is probably central to pathogenesis. Like the more common aortoduodenal fistula, diagnosis by traditional radiographic and endoscopic methods is difficult. We report here such a fistula, in which computed tomographic soft tissue abnormalities were characteristic of perigraft abscess; fistulization occurred subsequently. CT holds potential for being a sensitive study to show localized perivascular infection, an important precursor to aortoenteric fistula, and as such should be positive early in the development of a fistula.

Abscess↗
PubMed1984

Effect of glucagon on the diagnostic accuracy of double-contrast barium enema examinations.

The effect of glucagon-induced hypotonicity on the diagnostic accuracy of double-contrast barium enema examinations was determined in 133 consecutive patients in a double-blind crossover study. All patients underwent colonoscopy and served as their own controls by undergoing a double-contrast study after intravenous injection of 1 mg of glucagon and another after intravenous injection of 1 ml of saline placebo, in randomized order. The frequencies of good/excellent hypotonicity and quality of examinations after first doses of glucagon (55.3% and 80.8%) were not significantly different from the frequencies of good/excellent results after first doses of saline (51.3% and 86.5%). The sensitivity was 72.6% after glucagon and 64.5% after placebo; the specificity was 88.7% after glucagon and 77.9% after placebo; and the respective accuracies were 81.2% and 71.9%. These percentages should be used only to compare results with and without glucagon and, by study design, do not represent results of a complete double-contrast study. The variation among these percentages was not statistically significant, but diverticulitis was more accurately diagnosed after glucagon. It was concluded that glucagon does not significantly improve the sensitivity and specificity of the double-contrast barium enema examination and should be used only in selected instances.

Adult↗
PubMed1984

Cryptosporidiosis of the stomach and small intestine in patients with AIDS.

Cryptosporidiosis is a parasitic disease of the gastrointestinal tract that causes a choleralike diarrhea in patients with the acquired immunodeficiency syndrome (AIDS). Review of barium studies of the stomach and small intestine in 16 AIDS patients with cryptosporidiosis showed that the studies were abnormal in 13. Of these, five had moderate or marked prominence of the mucosal folds, and eight had slight prominence. The jejunum was predominantly involved in nine; the entire small intestine was uniformly affected in the other four. Three of the 16 patients had moderate or marked dilatation of the small intestine. One had marked dilution of the barium, and one had marked fragmentation and flocculation of the barium. There was narrowing and rigidity of the gastric antrum in two patients. These radiographic findings are nonspecific, but are indicative of cryptosporidiosis in a patient with AIDS and protracted diarrhea.

Acquired Immunodeficiency Syndrome↗
PubMed1984

The clinical role of magnetic resonance imaging.

The development of magnetic resonance imaging ( MRI ) is in an exponential phase and holds unbelievably exciting possibilities for the future of diagnostic medicine. It has many advantages and very few disadvantages compared to other imaging modalities. MRI is rapidly becoming the preferred method for the study of most organs. Spectroscopy will bei combined with imaging and will lead to the study of small volumes of normal and abnormal tissue selected from the MR proton density imager.

Brain Diseases↗
PubMed1983

The comatose patient. A systematic diagnostic approach for you to follow.

Coma is a frightening state requiring immediate medical attention. Because the patient's history may be unavailable and the possible causes of coma are numerous, the physician must concurrently support and protect the patient and evaluate the cause of coma. A systematic, orderly approach to diagnosis, using modern diagnostic tools to complement thorough physical examination, can help illuminate and alleviate this often perplexing problem.

Coma↗
PubMed1983

A fatal eosinophilic process in a Laotian refugee.

A 17-year-old Laotian refugee developed an ultimately fatal disease process characterized by formation of an abdominal eosinophilic mass, peripheral eosinophilia, and elevated serum IgE. No parasitic pathogens that could explain her disease were isolated during life or identified at autopsy. Furthermore, the disease was not consistent with previously described neoplastic, inflammatory, or idiopathic diseases. We believe this process represents a unique, aggressive variation of the hypereosinophilic syndrome, and that immunosuppressive therapy may be warranted.

Adolescent↗
PubMed1983

CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma.

Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination or plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows.

Abdominal Injuries↗
PubMed1982

High frequency CT findings within 24 hours after cerebral infarction.

Twenty-six patients with clinically documented acute cerebral infarction were evaluated by computed tomography within the first 24 hr. In 21 patients, subtle mass effects and/or focal areas of decreased attenuation corresponding to areas of clinical deficit were demonstrated. Enhancement occurred in only five of 15 infarctions rescanned after contrast administration. In three of these, the region of infarction became isodense after contrast administration. In a patient with multifocal infarcts, enhancement was the only clue to infarction in one focus. The improved spatial and contrast resolution of current generation scanners appears to have significantly increased the sensitivity of computed tomography in demonstrating acute cerebral infarction and has important clinical application.

Acute Disease↗
PubMedDate not supplied

Radiologic imaging of AIDS.

The acquired immunodeficiency syndrome (AIDS) is an increasingly important disease that has become a social phenomenon. Although our therapeutic options for treating AIDS patients are limited at present, radiologic investigation is often of crucial importance in determining the extent and stage of opportunistic infections and neoplasms. This manuscript deals in depth with the manifestations of AIDS in the chest, abdomen, and central nervous system. It emphasizes the importance of cross-sectional imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound as well as guided fine needle aspiration biopsy. The first chapter is a brief overview of the general management of AIDS patients in the radiology department. It seeks to emphasize a careful caring approach to patients with this disease. It also emphasizes the importance of educating all radiology personnel to an awareness of how precautions can be taken to avoid the spread of AIDS while dealing with patients in a professional, courteous manner.

AIDS-Related Complex↗
PubMedDate not supplied

CT attenuation numbers in the lumbar spine and their utility in diagnosing disc disease.

Normal CT attenuation values for various structures in the lumbar spine were obtained on several CT scanners. The wide range of normal makes using absolute CT numbers unreliable. The utility and pitfalls of using CT attenuation numbers in the lumbar spine are discussed and several examples are illustrated. CT numbers used as absolute values can be misleading, whereas, when used as relative values for comparison with other structures, they can be quite valuable.

Humans↗