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P. :1

The Society of Gastrointestinal Meeting, February 1991 Elizabeth



The 20th annual meeting of The Society of Gastrointestinal Radiologists (SGR) was held February 1 8-21 1 991 at the La Costa Resort and Spa, Carlsbad, CA. Among the activities offered at the meeting were 36 presentations of scientific papers, 21 workshops, five panel discussions, a categorical course on gastrointestinal oncoradiology, poster sessions, clinical vignettes, and an unknown-film contest between East Coast and West Coast teams of society members. The Walter B. Cannon lecture is always a highlight of this annual meeting; this year, David Eddy (Duke University, Durham, NC) spoke on the role of the barium enema in screening for colorectal cancer. ,


20th Annual









and Becky Carpenter (University of Minnesota Hospital, Mmneapolis) won an award for their poster presentation, “Abdominal Complications in Pediatric Bone Marrow Patients.” The Roscoe Miller award for the best scientific paper was presented to James A. Nelson (University of Washington, Seattle) for his presentation of “Percutaneous Portacaval Shunt,” which is described in the section on gastrointestinal bleeding complications. Randall Radin was the winner of the Memorial Award, which recognizes the best presentation by a first presenter at an SGR meeting; Dr. Radin (University of Southem California, Los Angeles) presented a study of CT findings that may distinguish Mycobacterium tuberculosis from Mycobacterium avium-intracellulare in patients with AIDS, which is described in the section on gastrointestinal imaging in AIDS.

AJR page limitations do not allow complete coverage entire program. However, the next few pages contain manes






gastrointestinal radiology: liver imaging, gallbladder imaging, colorectal imaging, aging in AIDS, gastrointestinal bleeding,


of the sum-



pancreatic imaging, gastrointestinal imand contrast mate-


Liver Imaging In a study colonic

of 15 patients





F. Bennett






Ohio State University Hospitals, Columbus) found that threedimensional (3-D) MR imaging can be helpful to surgeons who resect the metastases. Studies have shown that total removal of the hepatic tumor improves 5-year survival rate, but despite the improvement of preoperative and intraoperative techniques, no imaging technique has yet been able to identify every small lesion. These researchers obtained preoperative T2-weighted MR images in these patients; they then generated a 3-D image of the liver parenchyma that showed portal veins, hepatic veins, the inferior vena cava, hemangiomas, and metastases. Also, they photographed certam projections with wedged sections and discussed these with

the surgeon







rated these preoperative 3-D MR images as not useful at all; somewhat useful (e.g., helped in overall perception of surgical

Contributing editor, American Journal of Roentgenology, Ste. 103, 2223 Avenida de Ia Playa, La Jolla, CA 92037. Editor’s note-Meeting News” articles report the highlights of important national radiology meetings. The intent is to provide Journal readers with succinct, substantive, and accurate reviews of topics of current interest, written in a readable fashion and published promptly after the meeting. The articles will not undergo the peer review usually required of AJR publications, nor will they offer a critique of the information provided. The sole purpose of the series is to apprise AJR readers of topics of current concern in an interesting and timely fashion. 1

AJR 157:187-193,

July 1991 0361-803X/91/1571-0187

© American


Ray Society

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needs); or very useful (e.g., altered course of surgery). In seven patients, resections were performed (three wedge resections, three trisegmentectomies, and one right lobectomy); in five, no resections were performed because of extrahepatic disease seen on preoperative imaging; in two, no resections were performed because of extensive hepatic metastases (3 units of packed RBCs); artery, superior mesenteric vein, and clinical diagnosis of gastric bleeding. 6-20 units of packed RBCs (mean,

arteriography of celiac left gastric artery; and These patients required 1 1 units); conservative






in five




lization was performed in seven. Of the five patients treated conservatively, one had exsanguination from an overlooked 6-cm midesophageal ulcer; two had massive recurrent hemorrhage, one case of which was fatal. One patient with embolization had exsanguination. In these types of cases, a major question is whether physicians can rely on the results of endoscopy performed during the acute phase of bleeding. In four of six acute-phase endoscopies in this study, visibility was markedly impaired and one fatal ulcer was missed; in one, the diagnosis of a Mallory-Weiss tear led to treatment of that problem, but the patient died from a undiagnosed bleeding pyloric ulcer 9 days later; and in one case, the acutephase endoscopy results were correct. Dr. Lang emphasized that, in accepting negative angiography as a sign of successful


in these





significant lesions in noninjected territories; these patients run a high risk of ongoing or recurrent hemorrhage. She strongly recommended continued and aggressive workup of such patients (regardless of angiographic results) and suggested that a multicenter trial might be able to evaluate the benefits of prophylactic embolization of the left gastric artery in patients with massive upper gastrointestinal bleeding.





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Maureen White (Evanston Hospital, Evanston, IL) presented a study of 40 patients with hepatic tumors (including metastatic disease, hemangioma, and hepatocellular carcinoma) who underwent MR imaging with and without the use of gadopentetate dimeglumine. The MR protocol included use of axial, 1 0-mm slices, 256 x 128 matrix, respiratory compensation, cardiac gating, and presaturation pulses. After the precontrast images were obtained, gadopentetate dimeglumine was injected at 0.1 mmol/kg body weight. Patterns seen with contrast enhancement included 70% heterogeneous enhancement (43% mixed, 23% peripheral, and 4% central), 23% uniform enhancement, and 7% isointense enhancement. Blinded reviewers evaluated the MR images for the number and size of lesions; the reviews were done in correlation with other studies, and a lesion was considered confirmed if it was seen on two or more studies. The highest detection rate for lesions was found with the precontrast T2-weighted spinecho imaging (87%); the second highest detection rate occurred when the reviewers evaluated postcontrast gradient-recalled echo images (80%). With gadopentetate dimeglumine-enhanced MR imaging, various patterns on lesion contrast were found, and some contrast reactions occurred. Dr. White and coworkers concluded that use of gadopentetate dimeglummne did not significantly improve conspicuity of liver lesions on MR images and suggested that dynamic imaging with gadopentetate dimeglumine may produce better results.

Barium Presenting the paper that received the 1 990 SGR Research Award, Pablo Ros (University of Florida, Gainesville) discussed the evaluation of barium as a gastrointestinal negative contrast agent for MR imaging in normal subjects. The advantages of barium are its safety, acceptance by patients, low cost, and availability; these researchers specifically assessed the usefulness of barium as an oral or rectal MR contrast agent, as well as patients’ tolerance of side effects of barium used with MR imaging. The 1 0 subjects underwent MR imaging before and after administration of 60% weight/ weight barium sulfate (600-900 cm3 orally or 400 cm3 rectally). For evaluation of the images, precontrast and postcontrast images were separated and randomized, and three independent readers assessed image quality on a rating scale of 1 to 5; the parameters evaluated included bowel marking for six segments and anatomic delineation for 1 2 anatomic structures. After the administration of barium, the mean score of bowel delineation on MR images improved (percent change) as follows: 79%, coronal Ti -weighted images; 67%, axial Ti weighted images; 52%, axial T2-weighted images; and 55%, proton-density-weighted images. In terms of anatomic structures, the rectum and distal bowel were the structures whose delineation was most improved on Ti -weighted axial images;




July 1991

the uterus and vagina were the structures whose delineation was most improved on T2-weighted images; the pelvic side walls and seminal vesicles were the structures whose delineation was most improved on proton-density-weighted images. Only one structure, the vagina, was seen less well after contrast administration than before (on coronal Ti -weighted images). In summary, with barium as a contrast agent, a significant improvement was seen in the quality of gastrointestinal MR images (p < .01 ); better bowel opacification was seen; and a trend of improvement was seen on all pulse sequences, with the most improvement seen on axial Ti weighted images. No image degradation or artifacts occurred in any case. The only side effects in patients were nausea (four cases), cramps (three), and constipation (two); these are similar to the side effects that occur when barium is used as a radiologic contrast medium, and they all resolved without medication. Ros noted that all the subjects in this study were normal volunteers, and he and his colleagues are now pursuing the important question of whether the use of barium as a negative contrast agent is clinically useful. On the basis of their observation of a variety of coating artifacts with barium (including one that mimicked a villous tumor), Abraham H. Dachman and colleagues (Uniformed Services University, Bethesda, MD) conducted a study to demonstrate coating-related double-contrast artifacts and to study the mechanism of this type offlow-related artifact. They reviewed clinical material and performed experiments on dog colon, pig colon, and balloons to mimic a human colon. In the experiments, after the colon model was flushed with saline, 1 00 cm3 of liquid barium was introduced; the colon models were rotated i 5 times in the course of imaging. The six balloon experiments showed interdigitating artifacts related to luminal flow and polypoid artifacts related to surface flow. In the three animal studies, luminal-flow artifacts were seen (including mnterdigitating and foreign-matter artifacts). The resuIts indicated that, even with good coating, coating artifacts can occur with the flow of viscous barium. The types of coating artifacts observed included those related to bare areas, luminal flow, surface flow, and nodular patterns. The anterior surface of the stomach is the most likely place to find a bare area on the wall, and contact time and changing the position of the patient may help avoid these artifacts. Luminalflow artifacts include pseudo-intraluminal diverticulum and irregular (“villous”) structures. To summarize the findings of this study, Dr. Dachman noted the variable appearance of coating artifacts, the importance of recognizing such artifacts and not confusing them with lesions, and the further study required for the nodular-pattern artifacts and complete factor analysis. The role of latex sensitivity in adverse reactions to barium enema (administered using a latex tip) was discussed by Peter J. Feczko (William Beaumont, Royal Oak, Ml). The study focused on 1 94 patients who had a nonfatal reaction to barium enema and i 3 whose reaction was fatal. In the group that had nonfatal reactions, the time between administration of the enema and the onset of the reaction was less than 2 mm in 38 patients, 3-5 mm in 47, 5-i 5 mm in 63, and more than i 5 mm in 35 (including three in which the time to -

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July 1991

reaction was more than i hr). The most common nonfatal reactions were urticaria/rash/itch (80 patients), facial edema (64), difficulty breathing (52), dizziness/faintness (35), and nausea/sick” feeling (34). Less common reactions included warmth/burning sensation (20 patients), anxiety (1 8), sneezing (i i), a “funny feeling” (1 1), and seizures (eight). In this group, 37 patients revealed either before or after the procedure that they were allergic to latex, and only one patient had had a previous reaction to barium. In the group of patients with fatal reactions to barium enema, all enemas appeared to have been administered with a latex-tipped device. Five patients had autopsies, and no cardiovascular disease was



found in this group. Data from 1 3 of these patients shows that the onset of fatal reactions was less than 2 mm in seven patients, 3-5 mm in four patients, and more than 5 mm in two patients. The allergic reaction to latex is probably due to a protein molecule and has been reported in all kinds of devices from different manufacturers. Although one cannot say conclusively that latex reaction was the cause of all these deaths, Dr. Feczko believes that it probably was the cause in the great majority of them and that changing materials used in barium enema tips should resolve some of the negative side effects and prevent many of the deaths occurring after that procedure.

Come to the American Roentgen RaySoiety

nd Scientific






Course Neuroradiology


The Caldwell Award


hours) on




Exhibits and Tennis Programs










Orlando World May 10-15, 1992


The Society of Gastrointestinal Radiologists: 20th annual meeting, February 1991.

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