A subtraction technique comparing pre- and post-contrast medium enhancement CT scans.
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Brain Neoplasms↗
Biomedical subjects
V Raptopoulos
Publications and source records attributed to V Raptopoulos.
Computed tomographic patterns of pseudohypertrophic muscular dystrophy: preliminary results.
At present, the diagnosis of pseudohypertrophic muscular dystrophy (PHMD) rests on the clinical picture and the pattern of inheritance and is supported by electrodiagnostic, histologic, and histochemical techniques. In this report we describe the observed computed tomography (CT) changes in six patients with PHMD and compare these abnormal CT scans with scans of the same anatomic region in 16 normal individuals. Scans of patients with polymyositis and sarcoid myopathy are shown for comparison. Two CT patterns, frequently observed in our series, are described.
Absorptiometry, Photon↗
Sonographic findings in glomus tumor of the stomach.
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Adult↗
Liver regeneration after living adult right lobe transplantation.
BACKGROUND: The purpose of this study was to describe liver regeneration in patients undergoing living-adult liver transplantation. METHODS: This prospective study included 10 donors and eight recipients who had a total of 65 computed tomographic (CT) scans. All patients had preoperative CT ( n = 18), and follow-up CT scans ( n = 47) were obtained for up to 14 months after transplantation. Liver and spleen volumes were measured by hand tracing each organ on the axial portal venous phase images. RESULTS: Both donors and recipients showed immediate increases in liver volume. However, liver regeneration was significantly faster and reached a higher peak in recipients than in donors. Splenic volume in donors demonstrated an initial increase followed by a decline, reaching the preoperative volume after 1 year. Splenic volume in recipients demonstrated immediate decline postoperatively. CONCLUSION: Restoration of liver volume occurred rapidly after transplantation, but followed different patterns in donors and recipients. Deviation from these patterns warrants further investigation.
Adult↗
Is CT angiography sufficient for prediction of resectability of periampullary neoplasms?
The optimal preoperative evaluation of periampullary neoplasms remains controversial. The aim of this study was to analyze the accuracy of helical computed tomography (CT) and CT angiography with three-dimensional reconstruction in predicting resectability. Between March 1996 and May 1999, a total of 100 patients with periampullary neoplasms were prospectively staged by helical CT and CT angiography with three-dimensional reconstruction. Vascular involvement was graded from 0 to 4, with grade 0 representing no vascular involvement and grade 4 total encasement of either the superior mesenteric vein or artery. Patients with grade 4 lesions were considered unresectable. Sixty-eight patients underwent surgical exploration with intent to perform a pancreaticoduodenectomy. Forty-four lesions were grade 0, five were grade l, eight were grade 2, and 11 were grade 3. Resectability for grades 0 to 3 was 96%, 100%, 50%, and 9%, respectively, for an overall resectability rate of 76%. Resectability in patients with vascular encroachment (grade 2) is usually determined by the extent of local disease rather than the presence of extrapancreatic disease. Resection is rarely possible in patients with evidence of vascular encasement (grade 3). Additional imaging modalities such as diagnostic laparoscopy are superfluous in patients with no evidence of local vascular involvement on CT angiography (grades 0 and 1) because of the high resectability rate and infrequency of unsuspected distant metastatic deposits.
Adenoma↗
The effect of time and cholecystectomy on experimental biliary tree dilatation. A multi-imaging evaluation.
The changes of the biliary tree following distal bile duct obstruction and its release were confirmed by biliary scintigraphy and monitored by serial ultrasonography, computed tomography, and values of serum bilirubin and alkaline phosphatase in 14 mongrel dogs. The degree and rate of biliary dilatation were independent of cholecystectomy. The most rapid rate of extrahepatic dilatation occurred within the first 48 hours, while dilated intrahepatic ducts were first recognized three to six days after obstruction. Following release of the obstruction, the degree and rate of resolution of the biliary dilatation were independent of the duration of ligation (one vs. two weeks) and cholecystectomy. The dilatation resolved slowly. Dilated intrahepatic ducts were recognized for as long as eight to 13 days, while extrahepatic biliary dilatation was still present for 13 weeks, at which time the experiment was terminated. It is postulated that the extrahepatic biliary dilatation will approach a plateau approximately one month after total biliary obstruction. It appears that if the obstruction lasts more than one week, it results in irreversible damage to the elasticity of the extrahepatic ducts. Thus, after release of the obstruction, serial biliary imaging is indicated until a new baseline of the biliary tree diameter has been established.
Alkaline Phosphatase↗
High resolution CT mammography of surgical biopsy specimens.
PURPOSE: Our goal was to assess the performance of high resolution CT on breast biopsy specimens before considering the reevaluation of refined CT techniques in patients with breast abnormalities. METHOD: High resolution CT was done in 44 surgical biopsy specimens following conventional X-ray specimen mammography. The specimens comprised 38 palpable and nonpalpable soft tissue abnormalities with mean size of 19 mm and 6 specimens with clustered microcalcifications only. There were 21 carcinomas, 10 fibroadenomas, and 13 other benign conditions. Evaluation of CT and conventional images was done separately, and a feature-grading list was used to compare the two modalities. RESULTS: In fatty specimens, grading of morphologic features of masses and the confidence to detect a soft tissue abnormality were equal with both techniques. CT significantly improved the confidence to detect a mass in 17 specimens with dense tissue: On a scale of 0-10, the mean score for detection was 3.8 with radiography and 5.8 with CT (p<0.008). For clustered microcalcifications, X-ray was superior to CT. The mean CT attenuation of 18 malignant masses (82 HU) was significantly lower than the mean attenuation of 10 fibroadenomas (131 HU; p = 0.003). CT scans of the American College of Radiology test phantom met the requirements for X-ray accreditation. CONCLUSION: For soft tissue abnormalities, CT specimen mammography performed equally as or better than specimen radiography. These in vitro results suggest potential advantages for increased sensitivity and specificity with CT and justify further investigations.
Biopsy↗
Delayed intravenous contrast medium washout from the small bowel in patients with pancreatic carcinoma and splanchnic venous invasion.
PURPOSE: Our goal was to determine whether splanchnic venous invasion by pancreatic carcinoma causes any detectable delay in contrast medium clearance from the small bowel, reflected in alterations in small bowel (SBe), portal vein (PVe), or hepatic (He) enhancement on contrast-enhanced spiral CT. METHOD: The values of SBe, PVe, and He were determined from axial images obtained during performance of an abdominal spiral CT in 20 patients with pancreatic adenocarcinoma. SBe/PVe and SBe/He, felt to reflect intravenous contrast agent washout from the small bowel wall, were also calculated. Nine patients had splanchnic venous invasion (Group 1), and 11 were free of splanchnic venous involvement (Group 2) as determined by surgery or angiography. Similar measurements and ratios were performed in 10 patients with normal spiral CT scans to serve as controls (Group 3). RESULTS: A significant increase in SBe (p < 0.05), SBe/PVe (p < 0.01), and SBe/He (p < 0.05) and decrease in PVe (p < 0.01) were found in patients with invasion when compared with those without invasion and controls, while these parameters were similar in the last two groups. Individual SBe/PVe ratios in Group 1 were consistently elevated when compared with even the highest individual values in Groups 2 and 3. CONCLUSION: A detectable increase in SBe and decrease in PVe exist when comparing patients with and without splanchnic venous invasion by pancreatic adenocarcinoma. This is possibly the result of splanchnic congestion causing a delay in contrast medium washout from the small bowel wall. The SBe/PVe ratio, felt to be an indicator of contrast agent washout, may be used as an aid during spiral CT for pancreatic adenocarcinoma to determine the status of the splanchnic vasculature in equivocal cases.
Adenocarcinoma↗
Percutaneous CT-guided biopsy: improved confirmation of sampling site and needle positioning using a multistep technique at CT fluoroscopy.
We describe a new multistep procedure for CT fluoroscopy-guided core biopsy, which allows confirmation of the biopsy-sampling trough and the final needle tip position prior to sampling. Twelve lesions measuring < or =2 cm or in close proximity to vital structures were biopsied using commercially available biopsy systems. Diagnostic biopsies were obtained in all cases. Mean fluoroscopy time was 11.1 +/- 2.8 s per biopsy. This technique may have the potential to improve the accuracy and safety of CT-guided biopsy.
Biopsy, Needle↗
Current concepts in splenic trauma.
Despite its protected location inside the rib cage, the spleen remains the most commonly injured organ after blunt abdominal trauma. The clinical decision-making process of splenic injury management continues to evolve due to improvements in surgical technique and noninvasive assessment. Splenic preservation techniques and splenic injury grading systems using computerized tomography were developed due to an increased understanding of the spleen's importance in the body's immunological defense system and awareness of the spleen's resiliency after injury. The concept of splenic salvage using splenorrhaphy and nonoperative management was initially applied to the pediatric population during the 1970s, with great success. Application of splenic salvage to hemodynamically stable adult patients with known or unknown splenic injury has demonstrated that adults can be less predictable in their clinical course. Despite the rigorous attention splenic trauma has received, it remains a controversial subject in the surgical and the radiological literature.
Abdominal Injuries↗
Ultrasonography of a plexiform neurofibroma of the popliteal fossa.
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Adult↗
Screening admission CT scans in patients with AIDS--a randomized trial.
OBJECTIVE: To determine if the length of hospital stay could be reduced for patients with AIDS by performing screening head and abdominal-pelvic computed tomography (CT) scans within 24 hours of admission, regardless of presenting signs and symptoms. DESIGN: Randomized, prospective trial. SETTING: Tertiary, academic medical center. PATIENTS: On presentation to the emergency department, 42 patients with AIDS were identified as being eligible to participate in our study. Twenty-two patients consented to participate and were assigned to screening CT or control group. INTERVENTION: Patients assigned to the screening CT group had head and abdominal-pelvic CT scans within 24 hours of admission, regardless of presenting signs or symptoms. The findings of the screening CT scans were immediately communicated to the patient's referring physician. Patients assigned to the control group had CT studies done solely at the discretion of their physician. MAIN OUTCOME MEASURE: Length of stay for patients in the screening CT and control groups. RESULTS: The average length of stay for patients in the screening CT group was 1.3 days longer than the average length of stay for patients in the control group (95% CI, 1.4 days shorter to 4 days longer). The study was terminated after 22 patients were enrolled. CONCLUSION: Screening CT scans of the head and abdomen and pelvis at the time of hospital admission do not reduce the length of stay for patients with AIDS.
Acquired Immunodeficiency Syndrome↗