Biomedical subjects

Dennis M Balfe

Publications and source records attributed to Dennis M Balfe.

4 recordsLinked to original sources

PubMed2003

Detection of primary hepatic malignancy in liver transplant candidates: prospective comparison of CT, MR imaging, US, and PET.

PURPOSE: To determine and compare the diagnostic performance of computed tomography (CT), magnetic resonance (MR) imaging, ultrasonography (US), and positron emission tomography (PET) in the detection of hepatocellular carcinoma (HCC) or cholangiocarcinoma in liver transplant candidates and to determine interobserver variability between the readers. MATERIALS AND METHODS: Twenty-five patients were examined prospectively with CT, MR imaging, US, and PET. Each test result was interpreted independently by two radiologists. Explanted liver specimens were examined histologically to determine presence and type of lesion. Results were analyzed on a patient-by-patient basis with marginal homogeneity and effect likelihood ratio tests. RESULTS: HCC was diagnosed in nine patients. US diagnostic performance was superior to that of CT and MR imaging on a patient-by-patient basis. Sensitivities were higher for US (0.89 for both US readers) than they were for CT (0.67 and 0.56 for readers 1 and 2, respectively), MR imaging (0.56 and 0.50 for readers 1 and 2, respectively), and PET (0 for both readers). None of the differences (within test) between readers were significant (P >or=.32). Ratings by US and MR observers and one CT observer were significantly associated with truth (P <or=.04). One or more imaging tests depicted 68 lesions. Histologic analysis revealed 18 HCC nodules; of these, 13 were correctly identified at CT, 14 at MR imaging, 13 at US, and none at PET. There were nine false-positive diagnoses of HCC with CT, five with MR imaging, and nine with US. CONCLUSION: Although US had the best diagnostic performance in depicting HCC on a patient-by-patient basis and was substantially better than were MR imaging and CT (which had nearly equivalent diagnostic performances), CT, US, and MR imaging performed similarly on a lesion-by-lesion basis. Small tumor nodules were the most common cause of missed HCCs with all tests. PET did not depict any HCCs.

Adult↗

PubMed2002

Gastrointestinal manifestations of multiple endocrine neoplasia type 2.

OBJECTIVE: To determine the clinical features, natural history, and role of surgery for gastrointestinal manifestations of the multiple endocrine neoplasia type 2 (MEN 2) syndromes. SUMMARY BACKGROUND DATA: The MEN 2 syndromes are characterized by medullary thyroid carcinoma and other endocrinopathies. In addition, some patients with MEN 2A develop Hirschsprung's disease (HD), and all patients with MEN 2B have intestinal neuromas and megacolon that can cause significant gastrointestinal problems. METHODS: From 83 families with MEN 2A, eight patients with HD were identified (MEN 2A-HD). These and all patients with MEN 2B followed at the authors' institution (n = 53) were sent questionnaires to describe the onset and type of gastrointestinal symptoms and treatment they had before the diagnosis of MEN 2. Records of all patients responding were reviewed, including radiographic imaging, histology, surgical records, and genetic testing. RESULTS: Thirty-six of the 61 patients (59%) responded (MEN 2A = 8, MEN 2B = 28) to the questionnaires. All patients with MEN 2A-HD were operated on for HD 2 to 63 years before being diagnosed with MEN 2. All patients responding were underweight as infants and had symptoms of abdominal pain, distention, and constipation. Eighty-eight percent had hematochezia, 63% had emesis, and 33% had intermittent diarrhea before surgery. All patients with MEN 2A-HD had rectal biopsies with a diverting colostomy as the initial surgical procedure. This was followed by a colostomy takedown and pull-through procedure at a later interval. Ninety-three percent of patients with MEN 2B had gastrointestinal symptoms 1 to 24 years before the diagnosis of MEN 2. Symptoms included flatulence (86%), abdominal distention or being underweight as a child (64%), abdominal pain (54%), constipation or diarrhea (43%), difficulty swallowing (39%), and vomiting (14%). Seventy-one percent of patients with MEN-2B with gastrointestinal symptoms had radiographic imaging, 32% were admitted to the hospital, and 29% underwent surgery. CONCLUSIONS: Patients with MEN 2A-HD had a typical HD presentation and always required surgery. Patients with MEN 2B have significant gastrointestinal symptoms, but less than a third had surgical intervention. Understanding the clinical course and differences in these patients will improve clinical management.

Adolescent↗

PubMed2002

Acquired gastrointestinal fistulas: classification, etiologies, and imaging evaluation.

Fistulas are abnormal communications between two epithelial-lined surfaces. Gastrointestinal fistulas encompass all such connections that involve the alimentary tract, and they can be congenital or acquired in nature. This review focuses on acquired gastrointestinal fistulas. Development of an acquired gastrointestinal fistula can greatly affect patient outcome, yet the clinical manifestations are often protean in nature and the etiology, elusive. Imaging plays an important role in the detection and management of acquired gastrointestinal fistulas. The more routine use of cross-sectional imaging (especially computed tomography and magnetic resonance imaging) has altered the standard sequence of radiologic evaluation for possible fistulas, but fluoroscopic studies remain a valuable complement, especially for confirming and defining the anomalous communications. In this review, a classification scheme for gastrointestinal fistulas is provided, major causes are discussed, and individual fistula types are elaborated with an emphasis on contemporary imaging approaches.

Cutaneous Fistula↗

PubMed2002

CT colonography: multiobserver diagnostic performance.

PURPOSE: To prospectively evaluate multiobserver diagnostic performance and reader agreement for colorectal polyp detection in a well-characterized cohort of patients with increased number of polyps, compared with an average-risk patient, with colonoscopy as the reference standard. MATERIALS AND METHODS: A cohort of 70 patients suspected of having polyps was examined with spiral computed tomographic (CT) colonography, with colonoscopy performed the same day. After air insufflation per rectum, supine and prone images were obtained with single-detector row CT (5-mm collimation, 8-mm table increment, 2-mm reconstruction interval). Images were analyzed independently by four experienced abdominal radiologists using two-dimensional multiplanar reformation followed by selective use of three-dimensional endoscopic volume-rendered images. Data were analyzed both per polyp and per patient. RESULTS: Analysis per polyp demonstrated a pooled sensitivity of 0.68 for lesions 10 mm or larger (n = 40), with 75% agreement among the four readers. Analysis per patient demonstrated improved detection and agreement, with a pooled sensitivity of 0.88 for patients with polyps or cancers 10 mm or larger (n = 28), with 94% agreement. When sensitivity and receiver operating characteristic analyses were analyzed per polyp size threshold, results among readers converged and peaked at polyp diameters of approximately 10 mm. CONCLUSION: In this patient cohort, diagnostic performance and interobserver agreement with single-detector row CT colonography was sufficient for detection of patients with lesions 10 mm or larger, with more variable results for smaller polyps.

Adult↗