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S D Wall

Publications and source records attributed to S D Wall.

At least 37 records · Page 2Linked to original sources
PubMed1993

Positive bowel contrast agent for MR imaging of the abdomen: phase II and III clinical trials.

PURPOSE: To evaluate the efficacy and safety of two dose levels of an orally administered ferric ammonium citrate-based contrast agent for bowel enhancement on T1-weighted spin-echo magnetic resonance (MR) images in 222 patients with known or suspected abnormality of the upper abdomen. MATERIALS AND METHODS: Adverse reactions were graded for intensity, frequency, duration, and relationship to the contrast agent. Twelve unblinded readers compared enhanced with unenhanced images; all MR images were evaluated by two independent offsite radiologists in a blinded review. RESULTS: No statistically significant changes in mean vital signs or laboratory values were seen. Forty-eight of 220 patients (22%) reported minor side effects. The readers found increased intraluminal signal intensity and improved contrast enhancement of the gastrointestinal tract and distention and improved signal homogeneity in 101-107 cases (89%-98%) after ingestion; the blinded reviewers' findings were similar. CONCLUSION: The contrast agent provided new or additional radiologic information in 142 patients (64%), specific additional information in a detected abnormality in 46 of 142 patients (32%), and information that changed diagnosis, management, or surgical approach in 22 of 142 patients (15%).

Abdomen↗
PubMed1992

Gastrointestinal tract in the immunocompromised host: opportunistic infections and other complications.

In the decade since the early 1980s, the increasing use of immunosuppressive therapy for cancer and autoimmune disease, as well as for organ transplantation, has combined with the acquired immunodeficiency syndrome epidemic to increase greatly the incidence of opportunistic infections and other complications of the gastrointestinal tract. Consequently, barium fluoroscopic and cross-sectional imaging studies tailored to address these problems are no longer uncommon. Although overlap exists, there are radiographic patterns that can direct the diagnosis to an opportunistic infection and sometimes to a specific pathogen. This article describes and illustrates the radiographic findings of gastrointestinal superinfection with Candida albicans, cytomegalovirus, Cryptosporidium spp, herpes simplex virus, Mycobacterium tuberculosis, M avium-intracellulare, and human immunodeficiency virus. Other gastrointestinal tract complications of immunosuppression are discussed, including graft-versus-host disease following bone marrow transplantation, typhlitis, and pseudomembranous colitis.

AIDS-Related Opportunistic Infections↗
PubMed1992

Gastrointestinal disease in the immunocompromised host.

Gastrointestinal disease in two groups of immunocompromised patients, namely the AIDS patient and the post-bone marrow transplant patient, are discussed. Disease entities include opportunistic infections, Kaposi's sarcoma, lymphoma and other B cell proliferative disorders, cancer following transplantation, typhlitis, and pseudomembranous colitis.

Acquired Immunodeficiency Syndrome↗
PubMed1991

AIDS risk and risk reduction in the radiology department.

As the AIDS epidemic progresses, concern about the risk of occupational transmission of the causative organism, human immunodeficiency virus (HIV), is increasing. In this article, we summarize the risk of occupational acquisition of HIV in the health care setting and specify protocol and equipment that can reduce this risk in the radiology department. Accidental needle-stick injury is the most common form of exposure to infected blood, which is the only body fluid implicated to date in the occupational transmission of HIV. Prospective cohort studies demonstrate a 0.3-0.4% risk of infection for each needle-stick event. The most important instruction to health care workers that can reduce this risk is the following: Do not recap needles. Other risk-reduction measures include the adoption of universal precautions against transmission of infectious disease; sharp-instrument precautions; the use of protective garb to prevent skin and mucous membrane contamination when blood or bloody body fluid may splash; the availability of stable, puncture-resistant disposal containers for sharp instruments; the exclusion of breakable glass syringes; and the accessibility of resuscitation equipment in all rooms in order to avoid direct mouth-to-mouth contact. These and other measures discussed here are designed to prevent exposure of skin or mucous membrane to blood. If exposure does occur, the contaminated area should be washed immediately. A multicenter research protocol to evaluate the effectiveness of zidovudine (AZT) therapy in preventing seroconversion after exposure to HIV-contaminated blood recommends AZT therapy after massive exposure (e.g., injection of measurable quantities of blood) and endorses it for serious parenteral exposure (e.g., deep needle sticks).

Acquired Immunodeficiency Syndrome↗
PubMed1990

Aortoenteric fistula and perigraft infection: evaluation with CT.

A blinded retrospective study was performed to determine the sensitivity and specificity of computed tomography (CT) in detecting perigraft infection (PGI) and aortoenteric fistula (AEF), rare but devastating complications of aortic reconstructive surgery. Two observers independently reviewed CT scans in 55 cases including AEF (n = 23); PGI (n = 12); and normal, noninfected grafts (n = 20). Each scan was assessed for ectopic gas, focal bowel wall thickening, perigraft fluid, perigraft soft tissue, pseudoaneurysm formation, disruption of the aneurysmal wrap, and increased soft tissue between the graft and surrounding wrap. Comparison of CT findings with operative results revealed that each observer correctly identified as abnormal 33 of 35 cases of PGI either with or without AEF (sensitivity, 94%) and that results were falsely positive in three cases (specificity, 85%). CT findings ranged from large amounts of perigraft soft tissue and ectopic gas to subtle findings of minimal or no abnormalities; thus, strict criteria must be applied to the interpretation of CT scans after aortic surgery. Although CT is not 100% sensitive or specific, the authors conclude that it will continue to be valuable for diagnosing PGI and AEF.

Aged↗
PubMed1988

Gastrointestinal imaging in AIDS--luminal gastrointestinal tract.

Barium radiography of the gastrointestinal tract in patients with AIDS can assist in the evaluation of numerous problems including dysphagia, odynophagia, diarrhea, abdominal pain, symptoms of intermittent obstruction, and/or gastrointestinal bleeding. It can localize disease, evaluate complications, guide endoscopic biopsy, and monitor the progress of therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Improved survival with early CT diagnosis of pancreatic abscess.

Until recently pancreatic abscess was often a lethal complication of acute pancreatitis. A major factor contributing to this high mortality has been delay in diagnosis. When combined with diagnostic needle aspiration, computed tomography (CT) has greatly enhanced the early detection of pancreatic abscesses. In the past 5 years at our institutions 23 patients with proven pancreatic abscesses were evaluated early in their clinical course by CT. In follow-up ranging from 4 months to 4 1/2 years there were only 4 deaths: a mortality rate of 17%. Many of the surviving patients had a long and protracted clinical course (mean length of hospitalization, 58 days) and reoperation for recurrent abscess or gastrointestinal complications was required in 9 patients (39%). Computed tomography proved helpful both in localizing the site of de novo or recurrent pancreatic abscess and in detecting postoperative complications. An aggressive approach to early CT scanning with diagnostic needle aspiration appears to be a factor in the improved survival of these patients.

Abscess↗
PubMed1987

Pancreatic abscess: predictive value of early abdominal CT.

The value of a recently reported grading system of early abdominal computed tomography (CT) for predicting development of pancreatic abscess in patients with acute pancreatitis was reassessed. When the previously described CT grading system was used in another patient population, it did not demonstrate the same degree of prognostic value of baseline CT. In this series pancreatic abscess occurred in only eight of 29 patients (28%) with grade E CT scans (with grade E representing the most severe involvement), compared with 60% in the previous series. Of 44 patients with either grade D or E baseline CT scans, abscesses developed in only 30%, with a minimum clinical follow-up of 3 months. A second grading system, which used a semiquantitative analysis of the degree of peripancreatic inflammation (a "CT severity score"), also did not strongly correlate with the future risk of abscess, The authors conclude that early abdominal CT should be performed selectively in patients with acute pancreatitis and reserved for patients who are either diagnostic dilemmas or who fail to respond to supportive treatment and have clinically suspected surgical complications such as pancreatic abscess.

Abscess↗
PubMed1986

Utility of ceruletide in promoting intestinal opacification for abdominal and pelvic computed tomography.

An analysis of the utility of parenteral ceruletide, a cholecystokinin-like synthetic decapeptide, in promoting bowel opacification for computed tomography (CT) scanning was performed. Abdominal and pelvic CT scans of 85 patients who had received intramuscular ceruletide following oral contrast administration and of 85 control patients were reviewed and the degree of bowel opacification evaluated. No significant advantage was conferred by ceruletide in opacifying the stomach or major part of the small intestine. However, a statistically significant difference was found between the 2 groups in the presence or absence of contrast in the terminal ileum and right colon. Contrast was detected in the terminal ileum in 52 experimental compared with 35 control patients (p less than 0.009) and in the right colon in 56 experimental and 39 control subjects (p less than 0.01). Intramuscular administration of ceruletide will be helpful when terminal ileal opacification is essential or in patients in whom colonic opacification is desired but rectal contrast contraindicated.

Ceruletide↗
PubMed1986

Cholangiocarcinoma: imaging by MR.

Magnetic resonance (MR) images and computed tomographic (CT) scans of nine patients with histologically proved cholangiocarcinoma were compared retrospectively to assess the potential of MR imaging in the detection and staging of the disease. Cholangiocarcinomas were demonstrated as soft-tissue masses by both techniques in seven of the nine patients. In three patients, the masses were more apparent with MR because of a greater degree of contrast between the tumor and the surrounding tissues. In all four patients with the scirrhous subtype of cholangiocarcinoma, the soft-tissue masses showed decreased signal intensity on the second spin-echo image (echo time = 56 msec). Displacement or encasement of the adjacent vessels was well demonstrated by MR. Distal extension of the tumor (hepatic metastases, regional lymphadenopathy) appeared on both MR images and CT scans but was more apparent with MR. Both MR and CT demonstrated intrahepatic bile duct dilatation, but CT demonstrated it more readily. MR appears to be an effective modality for the detection and staging of cholangiocarcinoma.

Adenoma, Bile Duct↗
PubMed1986

Multifocal abnormalities of the gastrointestinal tract in AIDS.

On review of 63 barium sulfate examinations in 44 patients with acquired immunodeficiency syndrome (AIDS), 61% of the 23 single-contrast examinations and 98% of the 40 double-contrast examinations were abnormal. Abnormalities involved all areas of the gastrointestinal (GI) tract and covered a wide spectrum of findings including thickened folds, nodularity, increased secretions, superficial erosions, ulcerations, plaque formation, and tumor mass. Abnormalities, when present, were most commonly multifocal (three or more sites) on upper GI study (64%) and barium enema (69%). Thirty-eight patients (86%) had at least one abnormal study; 27 of these patients had multifocal disease in either the upper or lower tract separately or combined. The most common site of abnormality was the duodenum on upper GI study and the sigmoid colon on barium enema. In 27 cases the radiographic abnormalities could be specifically correlated with a malignancy or an opportunistic infection by endoscopy, colonoscopy, culture, biopsy, or autopsy. Multifocal disease of the upper and/or lower GI tract, especially when the duodenum is involved, should suggest AIDS even in patients not thought to be at high risk for the disease.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Abdominal CT in acquired immunodeficiency syndrome.

Acquired immunodeficiency syndrome (AIDS) is a lethal infectious disease that has reached epidemic proportions in urban centers of the United States. Intraabdominal opportunistic infections and malignancies are common features of this syndrome. A prodromal phase or possibly milder form of infection is known as the AIDS-related complex. Abdominal computed tomography (CT) in patients with AIDS-related complex often demonstrates a triad of mild retroperitoneal and mesenteric adenopathy, splenomegaly, and perirectal inflammation. Lymph node enlargement greater than 1.5 cm is unusual in the AIDS-related complex and should prompt CT-guided biopsy. Abdominal adenopathy (greater than 1.5 cm) in AIDS, in our experience, is most commonly related to non-Hodgkin lymphoma, Kaposi sarcoma, or infection with Mycobacterium avium-intracellulare. In most instances, CT-guided biopsy with appropriate staining technique can readily distinguish these entities. However, the subtyping of non-Hodgkin lymphoma by fine-needle aspiration biopsy alone remains controversial. Unusual features of abdominal malignancies are common in AIDS. These include a purely lymphadenopathic form of AIDS-related Kaposi sarcoma and a predilection for extranodal sites of lymphoma in AIDS. In general, patients with AIDS-related lymphoma present with advanced stages of disease with highly malignant histologic subtypes. Abdominal CT may be useful clinically for diagnosing intraabdominal complications of AIDS.

Abdominal Neoplasms↗
PubMed1986

Pharyngeal Kaposi's sarcoma in patients with AIDS.

The radiographic appearance of gastrointestinal Kaposi's sarcoma in patients with AIDS has been described previously, but little attention has been paid to pharyngeal involvement. This study compared the radiographic findings of pharyngeal Kaposi's sarcoma in eight patients with AIDS and dysphagia to those of visual inspection by laryngoscopy or bronchoscopy. Barium pharyngography (six patients) demonstrated nodular lesions without ulceration, ranging in extent from a single nodule to extensive confluent disease. CT (two patients) showed nodular or polypoid intraluminal protrusions, distortion of valleculae and pyriform sinuses, infiltration of deep-tissue planes, and adenopathy. A 4-mm nodular lesion was not seen on pharyngography. Radiographic evaluation provided supplemental information in six patients, especially regarding inferior extent of disease in four whose bulky lesions precluded adequate visual assessment. CT aided in defining deep-tissue-plane involvement and extent of nodal disease. It is concluded that barium pharyngography and CT are useful in the diagnostic evaluation of possible Kaposi's sarcoma in patients with AIDS and dysphagia.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Computerized tomographic assessment of graft incorporation after aortic reconstruction.

Computerized tomographic scanning is being used with increasing frequency for the detection of abdominal aortic prosthetic complications. Although computerized tomography remains a very precise method for direct imaging of the retroperitoneal space, the interpretation of a postoperative computerized tomographic scan is limited by the absence of any information on the normal appearance of the routine uncomplicated aortic graft. To study the normal tissue incorporation of aortic grafts, 29 patients were evaluated with periodic postoperative computerized tomographic scans. Seventeen patients had aortoiliac occlusive disease and 12 had aneurysmal disease. No patients who had reoperation were included and all patients had a normal postoperative course. Computerized tomographic scans were obtained in the early (mean 7 days), intermediate (mean 48 days), and late (mean 102 days) postoperative periods. A variable amount of perigraft hematoma was always present on the initial computerized tomographic scan. Perigraft air was seen in only four patients in the early study. Graft incorporation appeared complete in these patients by 48 days, although minimal hematoma persisted in one patient. This study provides baseline data on the appearance and timing of aortic graft incorporation which should facilitate subsequent computerized tomographic detection of aortic graft complications.

Aged↗
PubMed1985

Effects of hypoxic hypoxia on cerebral phosphate metabolites and pH in the anesthetized infant rabbit.

The effects of hypoxic hypoxia on high-energy phosphate metabolites and intracellular pH (pHi) in the brain of the anesthetized infant rabbit were studied in vivo using 31P nuclear magnetic resonance spectroscopy. Five 10- to 16-day-old rabbits were anesthetized with 1.5% halothane. Ventilation was controlled to maintain normocarbia. Inspired O2 fraction was adjusted to produce three states of arterial oxygenation: hyperoxia (PaO2 greater than 250 mm Hg), normoxia (PaO2 approximately 100 mm Hg), and hypoxia (PaO2 25-30 mm Hg). During hypoxia, blood pressure was kept within 20% of control values with a venous infusion of epinephrine. During hyperoxia, the phosphocreatine-to-ATP ratio was 0.86, a value that is 2-2.5 times less than that reported for adults. During normoxia, ATP decreased by 20% and Pi increased by 90% from hyperoxia values. During 60 min of hypoxia, the concentrations of high-energy phosphate metabolites did not change, but intracellular and arterial blood pH (pHa) decreased significantly. When hyperoxia was reestablished, pHi returned to normal and pHa remained low. These results suggest that during periods of hypoxemia, the normotensive infant rabbit maintains intracellular concentrations of cerebral high-energy phosphates better than has been reported for adult animals.

Adenosine Triphosphate↗