Transjugular intrahepatic portosystemic shunt: accuracy of helical CT angiography in the detection of shunt abnormalities.

PURPOSE: To determine the sensitivity, specificity, and accuracy of helical computed tomographic (CT) angiography in the detection of transjugular intrahepatic portosystemic shunt (TIPS) stenoses or occlusions. MATERIALS AND METHODS: Thirty-seven patients underwent 50 helical CT angiographic examinations and, within 2 weeks of each examination, portography with measurement of the portosystemic pressure gradient. Helical CT angiograms were independently interpreted by three radiologists who were blinded to the results of portography. Results of helical CT angiography and portography were compared. Sensitivity and specificity of helical CT angiography were separately calculated for the demonstration of morphologic abnormalities and the determination of their hemodynamic significance. RESULTS: Of the 50 portograms, 31 (62%) demonstrated morphologic TIPS abnormalities, 24 (77%) with and seven (23%) without elevated portosystemic pressure gradients. Helical CT angiograms correctly demonstrated 30 (97%) of the 31 morphologic abnormalities and allowed correct diagnosis of 22 (92%) of the 24 hemodynamically significant abnormalities. Nineteen (38%) portograms were normal; helical CT angiograms correctly demonstrated the absence of abnormality in 17 (90%) of these cases. Sensitivity and specificity of helical CT angiography for all morphologic abnormalities were 97% and 89%, respectively, and, for hemodynamically significant abnormalities, 92% and 77%. CONCLUSION: Helical CT angiography holds promise as a screening modality for the detection of TIPS stenoses or occlusions.

Mesenteric, omental, and retroperitoneal edema in cirrhosis: frequency and spectrum of CT findings.

PURPOSE: To determine the frequency and CT imaging spectrum of mesenteric, omental, and retroperitoneal edema in patients with cirrhosis. MATERIALS AND METHODS: Eighty patients were identified with liver cirrhosis and no other cause of edema. Five radiologists jointly reviewed the abdominal CT scans of these patients to assess, by majority decision, the presence, severity, distribution, and configuration of mesenteric edema and the presence of omental and retroperitoneal edema. Subcutaneous edema, ascites, pleural effusion, splenomegaly, varices, portal venous thrombosis, and serum albumin levels were also documented. RESULTS: Mesenteric edema was present in 69 (86%) patients. Mesenteric edema occurred alone in 26 (38%) and with omental or retroperitoneal edema in 40 (58%) of the 69 patients with edema. No patient had omental or retroperitoneal edema alone. Mesenteric edema was mild in 51 (74%) and moderate to severe in 18 (26%), patchy in 47 (68%) and diffuse in 22 (32%), purely infiltrative in 60 (87%) and infiltrative with superimposed masslike nodules in nine (13%) patients. These parameters had significant associations among themselves and with ascites, pleural effusions, subcutaneous edema, and low mean serum albumin levels but not with splenomegaly or varices. CONCLUSION: Mesenteric, omental, and retroperitoneal edema occur commonly in patients with cirrhosis. The appearance of mesenteric edema varies from a mild infiltrative haze to a severe masslike sheath that engulfs the mesenteric vessels.

Diverticulitis versus colon cancer: differentiation with helical CT findings.

PURPOSE: To retrospectively determine the computed tomographic (CT) signs associated with diverticulitis or colon cancer, and to prospectively apply these signs in the differentiation of these diseases. MATERIALS AND METHODS: Fifty-eight CT scans in cases of proved diverticulitis (n = 27) or colon cancer (n = 31) were evaluated retrospectively by radiologists (blinded to the proved diagnosis) for the presence or absence of previously reported CT findings. These findings were correlated with the pathologic or final clinical diagnosis. The retrospective findings were applied in a prospective evaluation with a new set of 72 CT scans. The same five radiologists rendered a diagnosis according to a five-point confidence scale from definitely benign to definitely malignant. Individual and consensus readings were correlated with the final diagnosis. RESULTS: Retrospectively, pericolonic inflammation (P < .01) and segment involvement greater than 10 cm (P < .012) were the most significant findings for diverticulitis; pericolonic lymph nodes (P < .0001) and luminal mass (P < .003) were the most significant findings for colon cancer. Prospectively, an unequivocal diagnosis was made correctly in 16 (40%) of 40 cases of diverticulitis and 21 (66%) of 32 cases of colon cancer. CONCLUSION: When there are no pericolonic lymph nodes adjacent to a segment of colonic wall thickening, with pericolonic inflammatory changes, the most likely diagnosis is diverticulitis. When pericolonic lymph nodes are present, with or without pericolonic edema, the most likely diagnosis is colon cancer.

Sonographic findings in cases of missed gallstones.

UNLABELLED: PURPOSE. We retrospectively evaluated sonographic findings in 946 cases of gallstones to determine whether the false-negative rate for gallstone detection by sonography has decreased as a result of technologic advances over the past 15 years. METHODS: We reviewed preoperative sonographic reports, operative notes, and pathologic reports for 614 women and 332 men (ages 22-78 years) seen over a 2.5-year period and compared sonographic findings with surgical pathologic findings after cholecystectomy. Sonograms for patients whose gallstones were missed on sonography were reviewed by 3 board-certified radiologists. RESULTS: Preoperative sonography of the gallbladder accurately predicted the presence of gallstones in 934 cases (98.7%). Gallstones were not identified by sonography in the remaining 12 cases. In those cases, sonography revealed polyps in 5, sludge in 5, sludge plus a polyp in 1, and neither stones nor polyps in 1. Thus, the false-negative rate was 1.3%. CONCLUSIONS: Despite improvements in sonographic technology, detection of small gallstones remains difficult in some cases. Adherent gallstones can mimic gallbladder polyps. Our false-negative rate for detection of gallstones was no different from that in earlier studies.

Pericolic mesenteric lymph nodes: an aid in distinguishing diverticulitis from cancer of the colon.

OBJECTIVE: This study was done to determine if the detection of pericolic lymph nodes on CT scans could be used to differentiate cancer of the colon from diverticulitis. MATERIALS AND METHODS: We retrospectively evaluated 58 CT scans from 57 patients with proven diverticulitis or cancer of the colon. The CT scans were evaluated by five board-certified radiologists who were unaware of the proven diagnosis. Consensus opinions regarding the presence and size of pericolic lymph nodes were recorded. These data were correlated with the proven diagnoses to determine the correlation between the observed findings and the type of colonic abnormality. Fisher's exact test was used to determine statistical significance. RESULTS: Lymph nodes were seen in 22 (71%) of 31 cases of colonic cancer and in four (15%) of 27 cases of diverticulitis. The lymph nodes were 0.5-2.5 cm in short-axis diameter. We saw no difference in node size for patients with colonic cancer versus patients with diverticulitis. The nodes were most commonly located along the blood vessels in the mesenteric fat. Statistical analysis showed a significant difference (p < .001) in the frequency but not in the size of nodes between the two groups of patients. The detection of nodes resulted in a diagnostic sensitivity and specificity for colonic cancer of 71% and 85%, respectively. CONCLUSION: Pericolic lymph nodes are seen much more frequently in patients with colonic cancer than in patients with diverticulitis. The detection of pericolic lymph nodes in patients suspected of having diverticulitis should raise the suspicion of underlying colonic cancer that should, in turn, prompt additional evaluation.

Computed tomography of the normal appendix and acute appendicitis.

The aim of this article is to present pictorially the spectrum of appearances of the appendix and appendicitis on CT. The images presented were selected from the database of our hospitals. The various appearances of the normal appendix on CT are shown. Appendicitis can be divided into four categories on the basis of CT findings. Examples of each category are shown.

Esophageal hemangioma.

We report a case of esophageal hemangioma presenting with dysphagia and odynophagia. To our knowledge, very few cases have been reported in the radiological literature.

Incidence and significance of subdiaphragmatic air following laparoscopic cholecystectomy.

Subdiaphragmatic free-air may be indicative of a perforated viscus; however, it is normally present after open abdominal surgery. The objective of this study was to determine the significance and incidence of subdiaphragmatic free air following laparoscopic cholecystectomy (LC). Cases of intestinal perforation following laparoscopic cholecystectomy from 1991 to 1995 at The University of Texas Health Science Center at San Antonio were reviewed and their association with subdiaphragmatic free air was determined. Twenty-five patients undergoing LC and 20 patients undergoing open cholecystectomy (OC) were prospectively evaluated with chest radiographs to determine the incidence and quantity of nonpathologic postoperative free air. Four cases of intestinal perforation resulting from trocar injuries or electrocautery burns occurred among 1603 LCs during this study period, for an incidence of 0.2 per cent. Three of the four patients with perforations were diagnosed postoperatively (2-5 days), and two patients had a moderate volume of subdiaphragmatic free air that aided the diagnosis. The incidence of subdiaphragmatic air following LC was 24 per cent, compared to 60 per cent for OC (P < 0.05). Eighty-three per cent of patients with retained air after LC had a minimal volume, compared to 67 per cent of patients after OC (P < 0.05). Nonpathologic subdiaphragmatic free air may normally be present following laparoscopic cholecystectomy but is uncommon 24 hours after the operation. When present, only a small volume is usually detectable. In the rare situation of intestinal perforation resulting from LC, subdiaphragmatic free air may be an important diagnostic finding.

Transjugular intrahepatic portosystemic shunts: assessment with helical CT angiography.

To evaluate diagnostic computed tomographic (CT) angiograms of transjugular intrahepatic portosystemic shunts (TIPS), helical CT angiography was performed in 10 patients with (n = 7) or without (n = 3) shunt dysfunction. CT angiography was performed with 3-mm-thick sections, pitch of 1, 120 kV, and 180-220 mA, after injection of 150 mL nonionic contrast material at 5 mL/sec, with a 50-second scanning delay after initiation of injection. All patients underwent transjugular portography within 1 week after CT angiography. In all cases, CT angiography correctly showed the presence or absence of the abnormality. These preliminary data suggest that CT angiography can provide diagnostic images of normal and abnormal TIPS.

Sonography: the undiscovered jewel of interventional radiology.

Because most radiologists in the United States have been taught that fluoroscopy and computed tomography (CT) are the best guidance techniques for nonvascular interventional procedures, sonography has been greatly underused in this regard. Recently, sonography has been gaining recognition as a highly useful and versatile guidance technique. It has many advantages over CT and fluoroscopic guidance, including real-time imaging with vessel visualization, decreased procedure time and cost, portability, and lack of ionizing radiation. Sonography should be the primary guidance technique for many nonvascular interventional procedures, and use of sonography as an adjunct guidance technique increases the ease and speed with which many other interventional procedures are performed. Sonography should generally be used instead of CT for guidance of abdominal and pelvic biopsy and drainage. Sonographic guidance should replace CT and fluoroscopic guidance for biopsy and drainage of accessible peripheral thoracic and mediastinal masses. Use of sonographic guidance should be integrated into all interventional radiology suites to reduce radiation exposure and facilitate the performance of many nonvascular and some vascular interventional procedures that have traditionally been performed under fluoroscopic guidance.

Is sonographic flow imaging useful in the differential diagnosis of adrenal masses?

This prospective study was carried out to assess the ability of colour Doppler ultrasound (CDUS) and power flow imaging to differentiate between benign and malignant adrenal masses. We examined 56 adrenal masses, discovered at CT, in 47 patients who had undergone CT for known extraadrenal malignancy or unrelated benign conditions. The nature of the masses was confirmed by histopathology or assessed for likelihood of malignancy by CT appearance, MRI appearance, recent development or increase in size. In none of the adrenal masses was blood flow detected by colour Doppler or power imaging, despite optimizing scanning parameters for the detection of slow flow. We conclude that colour Doppler ultrasound and power imaging do not help in differentiating benign from malignant adrenal masses.

Is it possible to derive a reliable estimate of human visceral and subcutaneous abdominal adipose tissue from simple anthropometric measurements?

The aim of the study was to generate equations predicting visceral (VAT) and subcutaneous (SAT) abdominal adipose tissue (AT) from simple anthropometric measurements. Magnetic resonance imaging (MRI) was used to measure VAT and SAT cross-sectional areas at the level of L4 in 49 subjects (19 men and 30 women) with a large range of age and body mass index (BMI). BMI, waist and hip circumferences, waist to hip ratio (WHR), subscapular and paraumbilical skinfolds (i.e., "simple" anthropometric measurements), total body fat content by the isotope-dilution method, and abdominal sagittal diameter by MRI (i.e., "nonsimple" anthropometric measurements) were also measured. Equations to estimate VAT and SAT from age and simple anthropometric measurements (i.e., excluding total body fat and abdominal sagittal diameter) were developed. These equations were then used in 24 subjects (nine men and 15 women) to cross-validate them. The best regression equations, including waist circumference in men and waist circumference and age in women, explained 56% and 68% of VAT variability, respectively. The corresponding standard error of the estimate (SEE) in men was approximately 40% and in women approximately 37% of the mean value of VAT measured by MRI. The best regression equations developed to predict SAT had a higher explained variability (approximately 87% in both men and women) and a lower SEE (< 20% of the mean values of SAT measured by MRI). In men, the equation included BMI and hip circumference, and in women, BMI and age. The inclusion of a higher number of simple anthropometric parameters in the predictive models neither significantly increased the explained variability of VAT or SAT nor significantly decreased the SEE of VAT or SAT. Also, inclusion in the multiple regression analysis of total body fat content and abdominal sagittal diameter did not improve prediction. In the cross-validation study, differences between predicted and observed values of VAT were large, with a tendency to overestimation in both men and women. In contrast, differences between predicted and observed values of SAT were small. We suggest that SAT but not VAT can be estimated from age and simple anthropometric measurements. Direct methods (MRI, computed tomography [CT], or other options) should be used for assessment of VAT.

Pulmonary function after laparoscopic cholecystectomy.

BACKGROUND: The purpose of this study was to prospectively compare the effect of laparoscopic cholecystectomy (LC) versus open cholecystectomy (OC) on postoperative pulmonary function. METHODS: Forty consecutive patients (20 in each group) who were evenly matched in terms of pulmonary risk factors were assigned to either elective LC or OC. Pulmonary function studies, oxygen saturation, and chest radiography were performed on both groups before and after the operation until baseline levels were reached. Narcotic requirements and pulmonary complications were compared. The t test, ANOVA, and chi-squared analysis were used. RESULTS: Compared to the patients who underwent OC, patients who underwent LC had a significant reduction in postoperative pulmonary impairment (30% to 38%) in all areas studied including forced vital capacity; forced expiratory volume in 1 second; forced expiratory flow, mid-expiratory phase; maximum forced expiratory flow; maximum voluntary ventilation; total lung capacity; and oxygen saturation. Pulmonary function returned to baseline levels 4 to 10 days sooner after LC. Pulmonary complications including atelectasis and hypoxia were less frequent after LC. An eight-fold decrease was noted in postoperative pain medication requirement in the LC group. CONCLUSIONS: Compared to OC, laparoscopic cholecystectomy results in a significantly reduced compromise in pulmonary function and narcotic requirement leading to fewer postoperative pulmonary complications. Laparoscopic cholecystectomy should be considered the procedure of choice for elective cholecystectomy.

Virulent diverticular disease in young obese men.

Recent treatment of young patients (aged 40 years or less) with complicated diverticulitis prompted us to review our experience. During a 9-year period ending in December 1990, 61 of 238 patients treated for acute diverticulitis were 40 years of age or younger. The younger patients were primarily obese Hispanic males in whom the correct diagnosis was frequently missed. Younger patients more frequently required an operation on an urgent basis for complications of diverticulitis during the initial hospitalization. The most common indication for operation in young patients was perforation compared with recurrent disease for the older age group. The younger group had a sevenfold incidence of enteric fistulas complicating their acute episode of diverticulitis. Our data suggest that diverticular disease in young patients is more common and more likely to require early surgical intervention than previously noted. In addition, obesity may represent an important etiologic factor in the development of diverticular disease.

Total body fat content and fat topography are associated differently with in vivo glucose metabolism in nonobese and obese nondiabetic women.

In this study, total body fat content and fat topography were related to glucose metabolism in the basal and insulin-stimulated states in 18 nonobese and 18 obese premenopausal nondiabetic women. All subjects received a euglycemic insulin (20 mU.min-1.m2) clamp study in combination with [3-3H]-D-glucose infusion and indirect calorimetry to quantitate total body glucose uptake, glucose oxidation, and nonoxidative glucose disposal. Total body fat content was determined with tritiated water, whereas body fat distribution was estimated from the WHR, the STR, and the VSR (measured by magnetic resonance imaging). In the postabsorptive state, total body glucose utilization, glucose oxidation, and nonoxidative glucose disposal rates were similar in nonobese and obese women, whereas during the insulin clamp all three metabolic parameters were reduced significantly in the obese group. In nonobese women, total body fat content was related inversely to both total and nonoxidative glucose disposal during the insulin clamp, whereas no relationship was found between glucose metabolism (total, oxidative, and nonoxidative) and WHR, STR, or VSR. In contrast, in obese women, no relationship was observed between total body fat content and any measure of insulin-mediated glucose metabolism. However, both WHR and VSR were related inversely to total, oxidative, and nonoxidative glucose disposal rates during the insulin clamp. These results suggest that total body fat content and body fat topography are associated differently with insulin-mediated glucose metabolism in nonobese and obese women. In the nonobese women, total body fat mass appears to be a primary determinant of tissue sensitivity to insulin, whereas in obese women, body fat topography exerts a more dominant effect.

Systematic transrectal ultrasound guided prostate biopsy after negative digitally directed prostate biopsy.

The diagnostic accuracy of digitally directed prostate biopsies was evaluated by performing systematic ultrasound guided biopsies on 44 patients who had previously had a negative prostate biopsy by systematic digitally directed technique. All 44 patients still had palpable abnormalities. Core biopsies (2 to 4) were obtained from each lateral lobe of the prostate with 2 additional cores directed at hypoechoic lesions. Only 4 of the 44 ultrasound directed biopsies (9.1%) were positive for cancer. These results confirm the postulate that random systematic digitally directed biopsy is highly accurate in making the diagnosis of prostate cancer. They also suggest that performing biopsies in a systematic pattern is more important than the method used to guide the biopsy needle.

Gastric villous adenoma: radiologic features.

The high incidence of malignant transformation of gastric villous adenoma requires prompt diagnosis of this rare tumor. We have reported the case of such a tumor in a 29-year-old man. The radiologic appearance of a gastric soft tissue mass with a reticular pattern is highly diagnostic.

Measurement of abdominal fat with T1-weighted MR images.

The cross-sectional area of visceral and subcutaneous fat in the abdomen was measured with T1-weighted spin-echo images acquired with a 1.5-T magnetic resonance (MR) imager. Four axial images centered on L-4 were acquired in each patient. Outline regions of interest (ROIs) were drawn manually for subcutaneous and visceral fat. The subcutaneous fat cross-sectional area was calculated from the ROIs drawn around the outer and inner margins of subcutaneous fat. Several adaptive processing methods were evaluated for measuring fat in the complex structure of the viscera. These methods were compared with an existing MR imaging measurement method for abdominal fat in 18 patients. The adaptive method that uses the valley between the fat and nonfat distributions in the average histogram curve was judged best for research evaluations because it reduces the effects of volume averaging while using a more natural division between fat and nonfat data. Another adaptive method that yielded comparable measurements was thought to be more suitable for clinical applications. Cross-sectional area measurements of abdominal fat were compared in 18 nonobese and 17 obese women to illustrate the utility of these measurements.