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Biomedical subjects

D M Balfe

Publications and source records attributed to D M Balfe.

At least 37 records · Page 2Linked to original sources
PubMed1999

Transverse colon diverticulitis: successful nonoperative management in four patients. Report of four cases.

PURPOSE: Diverticulitis of the transverse colon is a rare disorder and is often confused with other conditions. Previously reported cases of transverse colon diverticulitis were diagnosed and treated by surgical exploration. Four cases are presented that were successfully managed with a nonsurgical approach. METHODS AND RESULTS: Review of the literature in English disclosed 31 cases of transverse colon diverticulitis. The clinical characteristics and management of these patients are reviewed and compared with the current series of patients. The utility of computerized tomography in the diagnosis of diverticulitis is discussed. CONCLUSIONS: Medical therapy with bowel rest and antibiotics is appropriate for transverse colon diverticulitis when free perforation and peritoneal signs are absent and the inflammation is contained, as shown by computerized tomography. Operative exploration should be reserved for patients with diffuse peritonitis or those where perforated colon cancer cannot be excluded.

Adult↗
PubMed1999

Desmoplastic small round cell tumor of the abdomen: radiologic-histopathologic correlation.

PURPOSE: To characterize the imaging features of desmoplastic small round cell tumor of the abdomen and correlate them with the histopathologic findings. MATERIALS AND METHODS: Eleven of 14 patients with desmoplastic small round cell tumor had primary abdominal involvement. In nine of these patients (mean age, 20 years), results of imaging studies (computed tomography in nine patients, ultrasonography [US] in three) and histopathologic specimens were retrospectively analyzed. RESULTS: The hallmark imaging feature was lobulated peritoneal masses (mean number, 4.4; range, 1-17) with a mean diameter of 5.0 cm (range, 2-12 cm). Omental and paravesical tumors were each present in six patients. Retroperitoneal masses were present in three patients. The tumors were well defined and hypoechoic at US. Heterogeneity due to tumor hemorrhage or necrosis was seen in seven patients. Ascites was present in five patients. Parenchymal and/or serosal hepatic metastases, punctate calcifications, nodular peritoneal thickening, lymphadenopathy, hydronephrosis, and bowel obstruction were less common associated findings. CONCLUSION: Bulky peritoneal soft-tissue masses without an apparent organ-based primary site are characteristic of intraabdominal desmoplastic small round cell tumor. Although the findings are nonspecific, this diagnosis can be considered in adolescents and young adults with characteristic imaging findings.

Abdominal Neoplasms↗
PubMed1999

Comparison of two barium suspensions for dedicated small-bowel series.

OBJECTIVE: The in vivo radiographic features of two commercially available formulations of barium used as contrast media in dedicated small-bowel series were compared. SUBJECTS AND METHODS: Fifty-six consecutive outpatients referred for a dedicated small-bowel series were randomly administered either E-Z-Paque or Entrobar. Representative survey radiographs from each examination were randomized and reviewed by six gastrointestinal radiologists from three institutions. Each observer assigned a numeric score (1 = poor, 2 = fair, 3 = good, and 4 = excellent) that rated the quality of the radiograph with respect to these characteristics: definition of fold pattern, translucency, distention, and integrity of the barium column. Statistical analysis was performed for each characteristic using Wilcoxon's two-sample rank sum test. RESULTS: All six observers found a statistically significant difference between the two barium formulations for mean scores for definition of fold pattern and translucency. Mean scores for fold pattern were 3.3, 3.0, 3.2, 3.6, 3.3, and 3.4 for Entrobar and 2.1, 2.3, 2.4, 3.2, 2.6, and 2.7 for E-Z-Paque. Mean scores for translucency were 2.5, 2.7, 2.8, 3.1, 2.7, and 3.3 for Entrobar and 1.6, 1.7, 2.1, 2.3, 1.9, and 2.7 for E-Z-Paque. No statistically significant difference was found for mean score for distention or integrity of the barium column. CONCLUSION: On radiographs, Entrobar was found to have superior characteristics for visualization of fold pattern and translucency but offered no advantages for distention or integrity of the barium column. Improved translucency and definition of fold pattern may translate into improved sensitivity and confidence in diagnosing small-bowel abnormality.

Barium Sulfate↗
PubMed1998

Cystic fibrosis: CT findings of colonic disease.

PURPOSE: To determine the computed tomographic (CT) findings that are indicative of bowel disease in patients with cystic fibrosis. MATERIALS AND METHODS: CT scans in patients with cystic fibrosis were retrospectively reviewed for evidence of colonic abnormalities, including wall thickening, mural striation, fatty proliferation of the mesentery, and soft-tissue infiltration of pericolonic fat. RESULTS: Ten patients with colonic abnormalities on CT scans (case patients) and 16 patients with normal CT results (cohort patients) were identified. Colonic abnormalities in case patients included wall thickening (mean thickness, 6.4 mm) and mesenteric infiltration in all, increased pericolonic fat in six, and mural striation in five. The right colon was involved in all case patients; contiguous extension involved the transverse colon in five, the descending colon in two, and all segments in one. Wall thickness in cohort patients was less than 2 mm. Eight case patients had abdominal pain; one had bloody diarrhea. Histopathologic examination results included nonspecific mucosal inflammation in four case patients, wall edema in one, and no abnormality in one. No patient had identifiable infectious colitis, colonic stricture, bowel obstruction, fibrosis, or Crohn disease. Mean dose of pancreatic enzyme replacement was similar in both groups. CONCLUSION: Proximal colonic wall thickening without stricture, pericolonic fat proliferation, and mesenteric infiltration are CT findings of colonic disease associated with cystic fibrosis.

Adolescent↗
PubMed1997

Spiral computed tomographic colonography: determination of the central axis and digital unraveling of the colon.

RATIONALE AND OBJECTIVES: The authors developed and tested automated and semiautomated bowel-lumen tracking and colon-unraveling techniques for determining the central axis of the bowel. METHODS: A computer-simulated gastrointestinal tract phantom was used to test the accuracy of an automated algorithm for central axis determination and bowel unraveling. Variations in cross-sectional features between straight and unraveled formats were compared in a canine bowel segment in vitro and a human colon in vivo by using spiral computed tomography. Three readers each performed three semiautomated evaluations. RESULTS: Accuracy of the automated algorithm was confirmed by the high degree of correlation in the cross-sectional feature measurements (length error, < 1%). For the canine colon segment, accuracy of the semiautomated algorithm was confirmed by comparison with the automated tracing. For the human colon, readings were reproducible with 3.3% (+/- 1.9 standard deviation) mean variation in length. CONCLUSION: An automated algorithm for central axis deterioration and unraveling the colon has been validated in a gastrointestinal tract phantom. A semiautomated algorithm has been shown to be reproducible and time-efficient.

Algorithms↗
PubMed1997

Visualization of colorectal polyps with spiral CT colography: evaluation of processing parameters with perspective volume rendering.

PURPOSE: To evaluate two key processing steps for detection of colon polyps with spiral computed tomographic (CT) colography with perspective volume rendering (PVR): image reconstruction and opacity assignment of the attenuation data. MATERIALS AND METHODS: Spiral CT was performed in 10 patients with known polyps confirmed at colonoscopy, and detailed quantitative analyses were performed of data obtained in four. First, anatomic fidelity of three-dimensional (3D) images generated from two-dimensional (2D) source images with equal voxel dimensions (87%-90% overlap) was compared with 3D images generated from 2D source images with unequal voxel dimensions (0%-80% overlap). Next, the relative dimensions of colorectal polyps to adjacent structures were evaluated for various opacity threshold settings. Then, step and sigmoidal opacity functions were compared with respect to image smoothness and edge sharpness. RESULTS: PVR images generated after interpolation of image data reconstructed with at least 60% overlap were equivalent in image quality to PVR images generated from source images with equal voxel dimensions. Relative polyp-to-haustral fold dimensions demonstrated substantial distortions with opacity thresholds below -700 HU. The 3D PVR images generated with the sigmoidal opacity function were significantly smoother than those generated with the step opacity function (paired t test, P < .02), with small differences noted in edge sharpness. CONCLUSION: Use of highly overlapping source images (87%-90%) was not necessary to generate 3D PVR images of colorectal polyps. Image artifacts were suppressed with use of an appropriate opacity threshold and a sigmoidal opacity function without substantial loss in edge sharpness.

Artifacts↗
PubMed1996

Bowel wall thickening: differentiation of inflammation from ischemia with color Doppler and duplex US.

PURPOSE: To determine whether ultrasonography (US) can be used to differentiate inflammatory from ischemic bowel wall thickening. MATERIALS AND METHODS: Thirty-five patients (aged 23-96 years) with inflammatory or ischemic bowel wall thickening underwent US. Thickness was recorded, echotexture categorized, color Doppler flow graded, presence of intramural arterial signal recorded, and resistive index calculated. RESULTS: The difference between inflammatory and ischemic bowel wall thicknesses was not significant (P = .49). Differences in color Doppler flow (P < .0001), arterial signal (P = .0005), and bowel wall echotexture (P < or = .0200) between patients with inflammatory and ischemic bowel wall thickening were significant. Absence of or barely visible color Doppler flow and absence of arterial signal suggested ischemia; readily visible color Doppler flow and a stratified echotexture suggested inflammation. A resistive index less than 0.60 indicated inflammation. The difference in resistive index between the two groups was not significant (P = .12). CONCLUSION: Duplex and color Doppler flow US are helpful in differentiation between ischemic and inflammatory bowel wall thickening.

Case-Control Studies↗
PubMed1996

Anatomy of the retroperitoneum: observations of the distribution of pathologic fluid collections.

PURPOSE: To correlate anatomic dissections with clinical observations regarding anatomic distribution of retroperitoneal fluid, and to document the existence of planes that lie between classically described retroperitoneal spaces. MATERIALS AND METHODS: Latex was injected in varying amounts into the pancreatic tail in three fresh cadavers to simulate peripancreatic fluid collections. Spiral computed tomography (CT) was performed of the abdomen and pelvis after each latex injection. Two cadavers were subsequently frozen and sectioned in axial planes; limited dissections were performed on these specimens. One was embalmed and underwent extensive anatomic dissection. Five embalmed, unprepared cadavers were also dissected to confirm observations made in the three prepared cadavers. RESULTS: Latex injected into the tail of the pancreas entered a retromesenteric plane that was posterior to the anterior pararenal space and anterior to the anterior renal fascia. The plane continued superiorly, extending to the diaphragm near the esophageal hiatus; inferiorly, extending to the pelvis along the anterolateral surface of the psoas muscle; and laterally, posterior to the descending colon and its mesentery. The plane also communicated with a retrorenal plane lying between the posterior renal fascia and the posterior pararenal space. CONCLUSION: Embryologic development of the dorsal mesenteries suggests the existence of retromesenteric planes, and clinical observations further support their existence. These findings may explain the observed distribution of retroperitoneal fluid collections from diaphragm to pelvis.

Cadaver↗
PubMed1996

CT and MR imaging in the staging of colorectal carcinoma: report of the Radiology Diagnostic Oncology Group II.

PURPOSE: To prospectively evaluate the relative accuracy of computed tomography (CT) and magnetic resonance (MR) imaging in the staging of colorectal carcinoma. MATERIALS AND METHODS: CT and MR studies were independently interpreted in a group of 478 patients with colorectal carcinoma in a study conducted from 1989 to 1993. The accuracy of each modality was assessed in a subset of 365 patients with primary tumors with respect to staging of local extent of tumor, status of local-regional lymph nodes, and the presence of liver metastases. RESULTS: In the staging of local extent of tumor, CT is more accurate than MR imaging, particularly in the definition of penetration of the muscularis propria by rectal cancer (74% vs 58%). Accuracies of CT and MR imaging were equivalent in depiction of transmural extent in colon cancers. CT and MR imaging exhibited accuracies of 62% and 64% in assessment of lymph node involvement with sensitivities of 48% and 22%, respectively. The accuracy of MR imaging and of CT (85% for each) are better for evaluation of liver metastases; lower sensitivities (62% and 70%, respectively) than specificities (97% and 94%, respectively) were demonstrated for both modalities. CONCLUSION: CT was more accurate than MR imaging in detection and characterization of transmural penetration of rectal tumors. Recent technologic advances in MR imaging may affect these results.

Aged↗
PubMed1996

Peripheral portal venous blood flow alterations induced by hepatic masses: evaluation with color and pulsed Doppler sonography.

We examined 29 patients with intra- and extrahepatic masses and 10 normal volunteers with duplex and color Doppler ultrasonography. Portal blood flow adjacent to the masses was categorized as anterograde, retrograde, or nondetectable and was correlated with lesion size, character, and location. Anterograde flow was documented in the main portal vein and in the central right and left portal veins in all patients and volunteers. Flow in the peripheral portal veins near the lesion examined was retrograde in 17, anterograde in 10, and nondetectable in two of the patients. Retrograde peripheral flow was seen only in solid lesions, abscesses, and large subcapsular hematomas. Peripheral portal flow was anterograde in all of the volunteers. This study confirms that color Doppler sonography can detect alterations in portal flow induced by intra- and extrahepatic masses. The relatively common presence of peripheral portal flow reversal in patients with metastases and hepatocellular carcinomas indicates that it is not a reliable sign for differentiation between these entities.

Adult↗
PubMed1995

Dynamic contrast-enhanced MR imaging of the liver: parenchymal enhancement patterns.

A retrospective study of 164 patients undergoing dynamic contrast-enhanced magnetic resonance (MR) imaging was performed to assess hepatic parenchymal enhancement patterns and to correlate these patterns with hepatic function and disease. Rapid T1-weighted images were acquired before and after gadolinium administration. Hepatic enhancement patterns were analyzed blindly by two observers. Medical records were reviewed to document known liver pathology and liver function test results. A total of 72% of patients had homogeneous enhancement of the liver parenchyma; 28% had heterogeneous enhancement. Of the latter group, 61% of patients had enhancement conforming to segmental or lobar boundaries. Patients with heterogeneous enhancement patterns were more likely to have abnormal liver function test results and hepatic morphological abnormalities on their MR examinations than patients with homogeneous enhancement patterns. Heterogeneous hepatic enhancement on dynamic MR images is associated with a higher likelihood of liver disease and biochemical evidence of hepatic dysfunction than homogeneous enhancement.

Adult↗
PubMed1995

Acute pancreatitis in children: CT findings of intra- and extrapancreatic fluid collections.

PURPOSE: To determine the location and importance of fluid collections in children with acute pancreatitis. MATERIALS AND METHODS: The authors retrospectively reviewed the abdominal computed tomographic (CT) scans of 28 children with acute pancreatitis. CT scans were evaluated for pancreatic size and distribution of intra- and extrapancreatic fluid collections. Extrapancreatic fluid was classified as (a) peritoneal, (b) retroperitoneal, (c) mesenteric, or (d) ligamentous. RESULTS: Fourteen children (50%) had complicated pancreatitis associated with fluid collections. Intrapancreatic fluid was identified in only two patients (7%), whereas extrapancreatic fluid was seen in 14 (50%). Extrapancreatic fluid was most often seen in the anterior pararenal space, followed by the lesser sac, lesser omentum, and transverse mesocolon. The fluid collections diminished spontaneously in 11 patients (78%). Three patients with persistent fluid collections required surgical intervention for associated abnormalities. CONCLUSION: Intrapancreatic fluid collections are rare in children with pancreatitis. Extrapancreatic fluid collections tend to be extensive, but most diminish spontaneously.

Acute Disease↗