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Biomedical subjects

V Raptopoulos

Publications and source records attributed to V Raptopoulos.

At least 73 records · Page 4Linked to original sources
PubMed1991

Factors affecting the development of pneumothorax associated with thoracentesis.

This study is a retrospective survey of the variables that may influence the development of pneumothorax after thoracentesis. In a 30-month period, a computer search of hospital records identified 342 thoracenteses, of which 154 were done with conventional techniques by the clinical services, and 188 were done with sonographic guidance. Other factors surveyed included the patients' age, sex, underlying pulmonary disease, and overall clinical condition; the size of the effusion; the type of tap (diagnostic or therapeutic); the amount and type (exudate or transudate) of fluid acquired; and the size of the needles used. The technique used was the most significant single risk factor affecting the development of pneumothorax (18% for clinical vs 3% for sonography-guided thoracenteses). The incidence of pneumothorax decreased when a smaller amount of pleural fluid was aspirated (mean, 246 ml aspirated from patients who did not vs 472 ml from those who did develop pneumothorax) and when thin needles were used (4% pneumothorax with 20-gauge or smaller and 18% with larger than 20-gauge needles). The other factors surveyed did not influence the development of pneumothorax. Our results show that sonography-guided thoracentesis is complicated by pneumothorax significantly less often than is thoracentesis done with conventional techniques. Use of the smallest possible needle and aspiration of the smallest possible amount of fluid will also result in fewer cases of pneumothorax.

Adult↗
PubMed1991

Value of dual-energy CT in differentiating focal fatty infiltration of the liver from low-density masses.

Focal (irregular, partial) fatty infiltration of the liver may simulate neoplastic or other hypodense masses on CT. On the basis of previous observations of the phenomenon that differences in X-ray attenuation diminish with increasing energy of X-rays used, we performed a preliminary study to determine if dual-energy CT could be used to discriminate between fatty infiltration and hypodense liver masses. Dual-energy CT at 140 and 80 kVp was performed in 14 patients undergoing liver biopsy and in seven control subjects with presumedly normal liver. Attenuation measurements were taken, and the changes in attenuation between 140 and 80 kVp were calculated. The mean changes in attenuation were 3.5 H for normal liver (n = 7), 2.5 H for hypodense liver masses (n = 6), 13 H for fatty liver (n = 5), 0.3 H for fatty liver combined with hemochromatosis or hemosiderosis (n = 3), and 2 H for the spleen (n = 18). The change in attenuation increased as the fat content in the liver increased. Analysis of variance showed a statistically significant difference (p less than .001) between fatty liver and the other groups. A difference greater than 10 H was unique to fatty infiltration. These results suggest that dual-energy CT may help to differentiate focal fatty infiltration of the liver from low-density neoplastic or other lesions, but only if the iron content of the liver is not increased.

Adult↗
PubMed1990

Complications associated with thoracentesis. A prospective, randomized study comparing three different methods.

To determine what role the technique plays in complications associated with thoracentesis performed by physicians in training, we undertook a prospective study of thoracentesis in the medical service at our institution in which the sampling method was randomized among needle, needle with catheter, and needle with direct sonographic guidance. Fifty-two spontaneously breathing, cooperative patients with free-flowing effusions obliterating more than half of the hemidiaphragm on an upright, posteroanterior chest roentgenogram were randomized. When we analyzed those complications that were potentially life-threatening (eg, pneumothorax) and/or placed patients at increased risk for further morbidity (eg, pneumothorax, dry tap, inadequate tap), the sonography-guided method was associated with significantly fewer serious complications (0 of 19) than the needle-catheter (9 of 18) or needle-only methods (5 of 15). The sonography-guided method was associated with fewer pneumothoraces (0 of 19) than the needle-catheter (7 of 18) or needle-only methods (3 of 15). The difference between needle-catheter and needle-only methods was not significant. From our results, we conclude that the method by which thoracentesis was performed significantly influenced the spectrum and frequency of complications, and the sonography-guided method was the safest.

Catheterization↗
PubMed1989

Splenic trauma in adults: impact of CT grading on management.

The impact of computed tomographic (CT) grading of splenic injury on case management was evaluated in 64 adult patients who underwent abdominal CT within 24 hours of blunt abdominal trauma. Severity of splenic parenchymal disruption and the presence of hemoperitoneum were each graded on a scale of 0-3 (maximal total score = 6). The splenic injury was graded retrospectively (stage 1) in 29 patients and prospectively (stage 2) in 35 patients. Patients who were treated surgically had a significantly higher score than those who were treated conservatively (3.8 vs 1.9 in stage 1, 4.1 vs 1.7 in stage 2, P less than .001 for both stages). Data analysis showed that patients with a splenic score of less than 2.5 can be treated safely without surgery, while patients with a splenic score of 2.5 or more are more likely to need surgery. In the latter group of patients, CT scoring did not change the operative rate (74% vs 75%) but did prompt earlier surgical intervention in stage 2. This significantly increased the rate at which spleen-saving operations were performed (from 21% to 67%, P less than .032) and the overall rate of splenic salvage. The CT scoring system used in this study appears to be a simple, reproducible, and useful method for quantitating splenic injury in blunt abdominal trauma.

Adolescent↗
PubMed1989

The value of non-contrast-enhanced CT in blunt abdominal trauma.

The usefulness of non-contrast CT, limited to the upper abdomen, in conjunction with conventional IV contrast-enhanced scanning was studied prospectively in 190 patients who had sustained blunt abdominal trauma. In 78, visceral injuries were confirmed at surgery or at follow-up CT. Of the patients with injuries, 14 (18%) had hyperdense hematomas on the non-contrast studies that became isodense after IV administration of contrast material. These hematomas generally were small and posed an immediate threat to life in only one patient (0.5% of all subjects). In 13% of patients with injury (5% of the total), the additional information did influence treatment planning (surgery in two and intensive conservative treatment in eight). Compared with conventional contrast scanning, the combined non-contrast-contrast technique increased the scanning time only by about 5 1/2 min, but it improved the sensitivity and accuracy of CT in detecting visceral injuries from 74% and 84% to 92% and 91%, respectively (p less than or equal to .003 and p less than or equal to .04). Although contrast-enhanced scanning alone accurately depicts visceral injuries requiring surgical treatment, the incorporation of a non-contrast sequence can detect a subgroup of patients who require intensive conservative management with bed rest and close observation. This additional information can be obtained expeditiously, with minimal additional effort or intervention. The use of non-contrast scanning alone is not recommended.

Abdominal Injuries↗
PubMed1989

Increased prevalence of cholelithiasis in patients with abdominal aortic aneurysm: sonographic evaluation.

We performed a prospective study to determine the prevalence of cholelithiasis in patients with abdominal aortic aneurysm. Over an 18-month period, the gallbladder and the abdominal aorta were evaluated routinely in all consecutive patients referred to us for sonography of the abdomen and retroperitoneum. The patients were divided into two groups: those with an abdominal aortic aneurysm (aorta greater than 3 cm in transverse diameter) (n = 96) and those whose aorta measured less than 3 cm in transverse diameter (n = 538), who served as control subjects. Cholelithiasis was found in 50% of patients with and 26% of patients without aneurysm (p less than .0001). A stepwise logistic regression analysis found age alone to be predictive of cholelithiasis (p = .030). However, age was not predictive of cholelithiasis when included with abdominal aortic aneurysm in a multivariate model. Diabetes mellitus and gender were not predictive of cholelithiasis. We found cholelithiasis in approximately half of the patients who had abdominal aortic aneurysms. This is almost double the prevalence in the general elderly population. A pathophysiologic explanation for this observation remains to be found.

Aged↗
PubMed1989

Technical principles in CT evaluation of the gut.

Computed tomography (CT) of the abdomen is a sophisticated, multifaceted, and expensive test that requires meticulous attention to technique and extensive pretest planning. Evaluation of the gut is an integral part of every abdominal CT, and a successful examination requires knowledge of the characteristics of oral and intravenous contrast materials, the available technology, and the ways these factors interact and influence the quality of the images. Careful tailoring of the examination and flexibility to combine the various techniques ensures a successful CT examination not only of the gastrointestinal tract but of the entire abdomen as well.

Contrast Media↗
PubMed1988

CT of the pancreas with a fat-density oral contrast regimen.

Visualization of the head of the pancreas by CT was prospectively evaluated in two groups of 100 patients who did not have pancreatic disease. Patients were given either a fat-density oral contrast material (12.5% corn-oil emulsion and metoclopramide) or a conventional high-density oral contrast material (barium suspension or iodinated solution). There was no statistically significant difference in the subjects' tolerance to the two regimens. There was, however, a significant improvement in ability to distinguish the head of the pancreas from the duodenal C-loop when the fat-density contrast material was given. When pancreaticoduodenal discrimination was graded, patients given corn-oil emulsion and metoclopramide received an average score of 0.94, whereas those given the high-density agent received an average score of 0.74, with 1.00 being the highest possible score (p less than .005). These data suggest that for routine CT evaluation of the head of the pancreas, a combination of corn-oil emulsion and metoclopramide may be superior to the conventional high-density oral contrast agents given without metoclopramide.

Administration, Oral↗
PubMed1988

Nonoperative treatment of adult splenic trauma: development of a computed tomographic scoring system that detects appropriate candidates for expectant management.

We reviewed the charts of 87 patients with documented splenic injuries resulting from blunt trauma admitted to a regional trauma referral center during the 32-month period beginning in January 1984. Delayed celiotomy was defined as surgical intervention for splenic injury after a trail of nonoperative management lasting at least 24 hours. Delayed celiotomy was not required in any of the 16 cases in the pediatric age group (age less than or equal to 17 years) who were initially managed nonoperatively. In contrast, of the 27 adults who were initially treated nonoperatively, ten (37%) ultimately required celiotomy. Although splenorrhaphy was successfully performed in 21 of 44 patients undergoing early operation, all ten of the patients requiring celiotomy after an unsuccessful trial of observation underwent splenectomy rather than a spleen-preserving procedure. Of the 27 adults who were initially managed nonoperatively, 24 had abdominal computed tomography (CT) performed during their initial diagnostic evaluation. Twenty-three of these scans were reviewed by one of the authors. A CT scoring system was developed, based on the degree of splenic parenchymal and capsular injury and the amount of fluid in the abdomen and the pelvis. Adult patients who were successfully treated without operation had a significantly (p = 0.011) lower total CT score than did patients who required delayed celiotomy. No adult with a total CT score less than 2.5 required delayed operative intervention. These data support

Adolescent↗
PubMed1987

Computed tomography of life-threatening complications of abdominal aortic aneurysm. The disrupted aortic wall.

A localized disruption of the conspicuity of the wall of the aorta was noted on intravenous contrast-enhanced computed tomography (CT) scans of ten patients with ruptured abdominal aortic aneurysm (n = 6) or aortoenteric fistula (n = 4). Subsequently, we reviewed 84 scans of patients with uncomplicated aneurysm (n = 70) or aneurysm graft repair (n = 14) to determine if a disrupted wall has diagnostic implications. In this control group, the wall of the aneurysm was conspicuous throughout in 95% of 64 patients who received iodinated contrast material intravenously and in 55% of 20 patients who did not. In the proper clinical setting, CT scans performed with intravenous administration of iodinated contrast material can provide direct evidence of disruption of the wall of an abdominal aortic aneurysm. In selected cases, this may be important for the diagnosis of rupture. Disrupted conspicuity of the wall, in combination with effacement of the fat plane between an aneurysm and the juxtaposed intestine, increases the accuracy of CT for the diagnosis of aortoenteric fistula.

Aorta, Abdominal↗
PubMed1987

Saline microbubbles monitoring sonography-assisted abscess drainage.

The objective of this study was to assess the use of saline microbubbles as a sonographic contrast medium in monitoring abscess drainage. Seven abscesses were localized and drained with sonographic guidance. Four were in the brain and three were small abscesses in the liver, the subhepatic region, and the pancreas. After aspiration of the purulent material, irrigation with saline produced a highly echogenic sonographic pattern that was free of artifacts and distinctly different from the abscess contents and capsule, and the surrounding parenchyma. In one case, previously unsuspected loculation was detected, requiring repositioning of the needle for complete drainage. All abscesses were resolved and no untoward effects, such as sepsis, were encountered. In one additional patient, microbubble sonographic evaluation was used to monitor the progress of an abscess in which a percutaneous catheter was placed. Saline microbubbles may be used as a sonographic contrast medium to monitor sonography-assisted abscess drainage.

Abdomen↗
PubMed1987

Fat-density oral contrast agent for abdominal CT.

To overcome the problem of inadequate mixing of gastrointestinal (GI) tract contents with conventional high-density oral contrast agents in abdominal computed tomography (CT), a flavored 12.5% corn oil emulsion (COE) was tested as an oral contrast agent in 62 patients. The results were compared with those obtained from 105 patients who received high-density oral contrast agents. A simple patient preparation regimen for the COE was developed, which appears to be reasonably well tolerated by the patients and yields diagnostic studies comparable to those obtained with conventional agents. Use of the COE resulted in consistent discrimination of the GI tract and depiction of the GI wall. Preliminary data suggest that it may be particularly useful for CT evaluation of the stomach, duodenum, and pancreas; in patients suspected of having solid tumors; and in thin people.

Barium Sulfate↗
PubMed1987

Clinicians' appraisal of sonography.

The perceived efficacy of sonography in making diagnostic and management decisions in clinical practice was determined through a questionnaire survey of physicians who had recently referred patients to a university radiology department. Of 2,178 questionnaires sent, 1,611 were returned (74%). Sensitivity and specificity of sonography, corrected for verification bias, were 72% and 84%. Referring physicians considered the studies to be of value in arriving at the final diagnosis and in the clinical management of patients in approximately two-thirds of the cases. Results were considered of no value and misleading in 4% of the cases. Sonography was more accurate and was reported to be valuable by approximately 10% more physicians when a specific indication for an examination could be identified rather than when indications were vague and when sonographic findings were abnormal rather than normal (P less than .005). In general, sonography was of equal value to both specialists and nonspecialists. The results of this study suggest that sonography is, and is perceived by clinicians to be, an accurate and valuable clinical diagnostic modality.

Attitude of Health Personnel↗
PubMed1986

The anatomical basis for retrorenal extensions of pancreatic effusions: the role of the renal fasciae.

Retrorenal extension of pancreatic inflammatory processes are considered to involve invasion of the posterior pararenal space. Analysis of computed tomographic (CT) images demonstrates preservation of posterior pararenal fat in most patients, implicating some other mechanism. We have examined the anatomical basis for these retrorenal extensions in static and functional studies of 12 cadavers using CT imaging, dissection and histological techniques. We observed that the posterior renal fascia was thicker than the anterior, that it could be easily separated into two layers by manual dissection and injections of liquid latex, that the inner (anterior) layer of the posterior fascia was continuous with the anterior fascia and the outer layer continuous with the lateroconal fascia. The point at which the two layers of the posterior fascia separated laterally and the medial extent of the posterior fascia varied considerably in CT scans of 100 patients. These data are interpreted to mean that pancreatic effusions extend posterior to the kidney by separating the two layers of the posterior renal fascia.

Fascia↗
PubMed1986

Imaging of the bowel wall. Computed tomography and fat density oral-contrast agent in an animal model.

In this study, we reassessed the problems encountered in computed tomographic (CT) examinations performed with conventional bowel preparations, and developed a fat density oral contrast in dogs. Conventional high-density agents, water, fat (negative) density, and air were administered using a nasogastric tube to eight dogs (25 separate CT scans). Optimal and consistent identification of the gastrointestinal (GI) tract and mural visualization were achieved with 400 ml of 12.5% to 50% corn oil emulsions administered in four hourly divided doses. Mild diarrhea was observed with the 50% concentration only, but no untoward effect was noted clinically with 25% and 12.5% emulsions. Mixing the negative (fat) density oral contrast with the GI contents produced conditions optimal for high-CT contrast resolution of the GI wall. Standard intravenous administration of iodinated contrast agent enhanced mural visualization and, in conjunction with dynamic scanning, time density curves. This suggests that vascular perfusion could be portrayed. This animal model may be used for the experimental evaluation of a number of GI abnormalities, including ischemic, neoplastic, and inflammatory conditions.

Administration, Oral↗