P2742Right ventricular stroke volume during dobutamine stress magnetic resonance compared to lung perfusion and peak oxygen uptake after arterial switch operation for transposition of the great arteries

Objectives

Abnormal pulmonary perfusion due to stenosis of the central pulmonary arteries is common after neonatal arterial switch operation (ASO) for transposition of the great arteries (TGA). We conducted a monocentric prospective study in young adults after neonatal ASO for TGA to evaluate the effects of abnormal pulmonary perfusion on the increase of the right ventricular stroke volume (RVSV) during dobutamine stress magnetic resonance (DSMR) and on cardiopulmonary exercise capacity.

Methods

68 unselected patients (age 18–29 years) underwent CMR at rest and under dobutamine stress (10 to 40 μg/kg/min). RVSV, pulmonary blood flow distribution (PBFD) and peak flow velocity were derived from phase contrast mapping in the main, right and left pulmonary artery (PA) at rest and each stress level. A cardiopulmonary exercise test (CPET) was performed at the same day. All patients reached maximal exercise effort according to heart rate and respiratory exchange rate.

Results

PBFD at rest: 9/68 patients (13%, ASO-S) had abnormal pulmonary perfusion at rest, defined as PBFD >2:1 (right/left or left/right) and/or relevant stenosis of the main PA (Vmax >2.5 m/s). 59/68 patients (87%, ASO-N) had normal pulmonary perfusion.

PBFD under DSMR: (1) In the whole patient group, there was no increase of PBFD under stress compared to PBFD at rest. On an individual patient level, no relevant worsening of abnormal PBFD was found.

(2) Under low dose dobutamine, ASO-S had a significantly lower RVSV-increase (RVSVstress/RVSVrest) compared to ASO-N (see figure). However, under high dose dobutamine, this effect was no longer significant (see figure).

(3) The RVSV-increase under low and high dose dobutamine did not correlate with peak oxygen uptake during CPET, neither in the total group nor in the subgroups (see table). Peak oxygen uptake was not significantly different between ASO-N and ASO-S (p=0,72).

RVSV-increase compared to CPET peak VO2% ASO-total ASO-S ASO-N RVSV-increase/peak VO2% RVSV-increase/peak VO2% RVSV-increase/peak VO2% low dose dobu high dose dobu low dose dobu high dose dobu low dose dobu high dose dobu Pearson correlation coefficient −0.02 −0.05 0.01 −0.22 −0.05 −0.04 p-value 0.90 0.71 0.98 0.56 0.71 0.78

Figure 1

Conclusion

(1) Patients with relevant stenosis of main PA and/or abnormal peripheral blood flow distribution (ASO-S) exhibit a reduced RVSV-increase under low dose dobutamine compared to patients without stenosis (ASO-N). This effect was not present under high dose dobutamine stress.

(2) These findings did not correlate with peak oxygen uptake during CPET, an objective parameter of cardiopulmonary exercise capacity.

(3) Therefore, a conservative proceeding rather than surgery or catheter intervention should be considered, especially in asymptomatic adult patients.

Acknowledgement/Funding

Supported by Kinderherzen, Fördergemeinschaft Deutsche Kinderherzzentren e.V.

Updating a legacy PACS: experience with hardware and operational integration during transition to a new architecture

The transition of the WVUH PACS to a new configuration that can support filmless radiology has been delayed by several “midcourse” corrections on the part of the primary PACS vendor. If the current product development time lines are reliable, then it will have been an 8 year process that will allow WVUH to be a filmless hospital in time for the next millennium.

Positron emission tomography for preoperative staging of colorectal carcinoma

PURPOSE

Positron emission tomography (PET) is an imaging technique based on in vivo cellular metabolism. Increased glucose metabolism in neoplastic cells is detected by using fluorine-18 deoxyglucose. In an ongoing pilot study to determine the usefulness of this technique, PET is compared with computerized tomography (CT) for the preoperative staging of colorectal carcinoma.

METHODS

Sixteen patients were evaluated with both PET and CT of the abdomen and pelvis. Results were compared with operative and histopathologic findings. Fifteen malignant lesions were found in 16 patients by histology. PET had a positive predictive value of 93 percent and a negative predictive value of 50 percent. By comparison CT had a positive predictive value of 100 percent and a negative predictive value of 27 percent.

CONCLUSIONS

These preliminary results indicate that PET has increased sensitivity for staging colorectal carcinoma, whereas CT has higher specificity. The predictive value of a positive PET compares favorably with CT. Furthermore, the predictive accuracy for detection of colorectal carcinoma is 83 percent for PET and 56 percent for CT.

Fluorine-18 and carbon-11 labeled amphetamine analogs--synthesis, distribution, binding characteristics in mice and rats and a PET study in monkey

No-carrier-added (NCA) (+-)-p-[18F]fluoroamphetamine (2a) and (+-)-6-[18F]fluoro-3,4-methylene-dioxy-amphetamine (2b) were synthesized through a multistep synthesis by nucleophilic substitution of the appropriate precursors (p-nitrobenzaldehyde, 1a and 6-nitropiperonal 1b, respectively) with [18F]fluoride followed by condensation with nitroethane and reduction with LAH in 20-30% yield (EOB) in a synthesis time of 90-109 min from EOB. NCA (-)-[11C]methamphetamine (4a) and (+-)-3,4-methylene-dioxy-N-[11C]methamphetamine (4b) were synthesized by methylation of the appropriate desmethyl precursors 3a and 3b with [11C]H3I in 40-60% yield (EOB) in a synthesis time of 30 min from EOB. Animal studies in mouse and rat revealed that the relative tissue uptake of these radiotracers was kidneys > lungs > liver > spleen > brain > heart > blood. The uptakes of these radiotracers in mouse brain were high and similar at 5 min post-injection (approx. 5%/g) but radioactivity then declined rapidly (approx. 1%/g at 60 min post-injection). For compounds 2a and 2b, the activity in the femur did not increase with time indicating in vivo defluorination may not be the major route of metabolism. Monoamine uptake inhibitors (nomifensine, fluoxetine and nisoxetine) did not inhibit but enhance the uptake of (-)-[11C]methamphetamine (4a) in the rat brain by greater than 50%. A PET study in a Rhesus monkey revealed that the uptakes of (-)-[11C]methamphetamine in different brain regions were similar and the retention of the radioactivity in these regions remained constant throughout the study. Analysis of arterial plasma by HPLC showed that 50% of radioactivity remained as 4a at 60 min post-injection.

Diagnostic efficacy of PET-FDG imaging in solitary pulmonary nodules. Potential role in evaluation and management

BACKGROUND

Positron emission tomography (PET), a new noninvasive imaging modality, utilizing 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG), has demonstrated increased FDG uptake in lung tumors.

OBJECTIVE

To determine the diagnostic efficacy of PET-FDG imaging in differentiating benign from malignant solitary pulmonary nodules.

PATIENT SELECTION

A prospective study of 30 patients who presented with indeterminate solitary pulmonary nodules less than 3 cm in size based on chest radiograph and computed tomographic (CT) scan.

SETTING

Two tertiary care medical centers in Omaha, Neb: Creighton University Medical Center and the Omaha Veterans Administration Medical Center.

MEASUREMENTS

Positron emission tomographic imaging of the lung was performed 1 h after intravenous injection of 10 mCi of F-18-FDG. Qualitative analysis of the images was performed independently by two observers by visual identification of the areas of increased FDG uptake in the lung nodules. Semiquantitative analysis was performed using computation of differential uptake ratio (DUR). Histologic specimens were obtained in 29 patients (thoracotomy 20, transthoracic needle aspiration biopsy 8, bronchoscopy 1).

RESULTS

Positron emission tomographic imaging correctly identified 27 of 30 pulmonary nodules. Diagnostic accuracy was high with sensitivity of 95 percent and specificity of 80 percent. The positive and negative predictive value of PET imaging for solitary pulmonary nodules was 90 percent and 89 percent, respectively. The DUR values were significantly higher for malignant nodules (mean +/- SD, 5.55 +/- 2.79) than benign nodules (mean +/- SD, 0.95 +/- 0.99) (p < 0.001). There was one false-negative result in a patient with a 1-cm nodule identified as a scar adenocarcinoma. There were two false-positive cases and both had caseating granulomas with active inflammation and Histoplasma organisms.

CONCLUSION

PET-FDG imaging of the lung, a new noninvasive diagnostic test, has a high degree of accuracy in differentiating benign from malignant pulmonary nodules. PET-FDG imaging could complement CT scanning in the evaluation and treatment of patients with solitary pulmonary nodules.

Synthesis of (+/-)-[18F]BMY 14802, its enantiomers and their anatomical distributions in rodents

A potential antipsychotic drug, BMY 14802 was labeled with 18F and its distribution in rodents was studied. No-carrier-added (NCA) (+/-)-[18F]BMY 14802 (5) was synthesized by two methods in 5-10% radiochemical yield in a synthesis time of 130-140 min from EOB with a specific activity of 0.5-1.5 Ci/microM. (+)- and (-)-[18F]BMY 14802 was synthesized by the chiral reduction of alpha-(4-[18F]fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazine-b utanone (4) with chiral reducing agent, (+)- and (-)-beta-chlorodiisopinocampheylborane [(+)- and (-)-DIP chloride] in 6-10% radiochemical yield in a synthesis time of 150 min from EOB. Animal studies in mouse and in rat revealed that the distribution of 5 in each tissue was high at 5 min, the radioactivity then declined rapidly in all tissues studied except in the liver and in the small intestine. The radioactivity in the femur did not increase with time indicating in vivo defluorination may not occur. The uptakes of (+/-)-[18F]BMY 14802 and its enantiomers, (+)- and (-)-[18F]BMY 14802 in rat cerebellum, brain stem, hippocampus and spinal cord were similar and were significantly reduced by prior treatment of rat with haldol. This suggests that (+/-)-[18F]BMY 14802 and its enantiomers bind to sigma-receptors in a similar fashion.

Clinical applications of positron-emission tomography in cancer

Positron-emission tomography is a unique imaging technique that has shown promise for improving staging, treatment planning, and monitoring of cancer. When used in conjunction with a radioactive glucose analog, positron-emission tomography has proven useful for detecting malignant tissue and quantitating changes in tumor glycolysis during and after treatment. This article reviews the principles of positron-emission tomography and its clinical role in cancer treatment.

Pre-operative staging of colorectal carcinoma using positron emission tomography

Positron emission tomography (PET) is a unique technique for imaging functional metabolism of normal and diseased tissue. Accelerated rate of glucose metabolism typical of malignant tumor cells can be detected by using fluorine-18 deoxyglucose. In this pilot study, PET FDG imaging was compared to computerized tomography for the pre-operative staging of colorectal carcinoma. We prospectively evaluated 16 patients by simultaneously performing PET FDG and CT imaging for lesions in the liver, colon and rectum. The results were compared to the operative findings in all patients. Twenty tumor sites (lymph nodes 5, colon and rectum 13, liver 2) were found on histology in 16 patients. On comparison with histology, sensitivity, specificity and predictive accuracy for detection of tumor sites were 90%, 66% and 87% with PET as compared to 60%, 100%, and 65% with CT. These findings represent increased sensitivity and predictive accuracy for staging of colorectal carcinoma with PET FDG imaging as compared to CT scanning.

Thallium-201 myocardial imaging in patients with coronary artery disease: comparison of intravenous adenosine and oral dipyridamole

OBJECTIVE

To compare thallium-201 (201Tl) myocardial perfusion imaging following intravenous adenosine and oral dipyridamole.

DESIGN

Open-label, randomized, comparison.

SETTING

Outpatient, university-affiliated clinic.

PATIENTS

Fifteen patients with angiographically documented coronary artery disease.

INTERVENTIONS

Planar 201Tl myocardial perfusion imaging following both intravenous adenosine 140 micrograms/kg/min for six minutes and oral dipyridamole suspension 300 mg.

MAIN OUTCOME MEASURES

A comparison between adenosine and dipyridamole was made in the following areas: concordance in interpretation of 201Tl scintigrams, cardiac and noncardiac 201Tl uptake and clearance, hemodynamic and electrocardiographic changes, and adverse effects.

RESULTS

The scintigraphic studies showed perfusion defects in 13 patients (87 percent) after dipyridamole and in 15 patients (100 percent) after adenosine. 201Tl uptake and clearance were quantitated in nine myocardial segments and in four extracardiac segments in each patient. 201Tl uptake was not significantly different between adenosine and dipyridamole studies in most cardiac regions. Extracardiac 201Tl uptake was significantly less in the liver and splanchnic regions following adenosine compared with dipyridamole. 201Tl clearance was not significantly different following adenosine and dipyridamole except in the anterolateral region in the anterior view. Hemodynamic changes following administration of intravenous adenosine and oral dipyridamole were not significantly different. Adverse effects were more common with adenosine than with dipyridamole. Adverse effects with adenosine were transient; however, adverse effects with dipyridamole were prolonged and required reversal with aminophylline in 2 patients. No patients required termination of the adenosine infusion or administration of aminophylline.

CONCLUSIONS

These preliminary data suggest that adenosine 201Tl imaging may be a useful alternative to dipyridamole 201Tl imaging. Although adenosine produces more frequent adverse effects, they are generally better tolerated than those associated with dipyridamole.

Solitary pulmonary nodules: detection of malignancy with PET with 2-[F-18]-fluoro-2-deoxy-D-glucose

It is estimated that nearly one-third of solitary pulmonary nodules (SPNs) may represent bronchogenic carcinoma. The noninvasive imaging methods used currently (ie, plain radiography, computed tomography) are not reliable for accurate detection of malignancy in most SPNs. The authors prospectively evaluated use of positron emission tomography (PET) with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) for identification of malignancy in 20 patients with noncalcific, radiographically indeterminate SPNs. PET-FDG imaging demonstrated focal hypermetabolism in 13 biopsy-proved malignant nodules, whereas no increased FDG uptake was seen in the seven benign SPNs. Semiquantitative analysis with computation of differential uptake ratios also helped clearly differentiate benign nodules (mean +/- standard deviation, 0.56 +/- 0.27) from malignant nodules (mean +/- standard deviation, 5.63 +/- 2.38) (P less than .001). Thus, PET-FDG imaging may be a potentially useful noninvasive technique for accurate differentiation of benign and malignant SPNs that are radiographically indeterminate.

Considerations in setting up a positron emission tomography center

Clinically oriented imaging with position emission tomography (PET) has come of age. Given an adequate referral base and physician interest, a compelling argument can be made at all levels of the review process for setting up a PET program in a clinical setting. PET is expensive. It is obvious that the cost of running a PET service depends heavily on an institution's ability to obtain reasonable financing. Educational institutions have the opportunity to acquire special funding through a variety of sources. On the other hand, money can be expensive for private entrepreneurs. It appears that in the near future PET centers will probably remain at educational institutions or large well-financed community hospitals able to raise money at reasonable rates until reimbursement issues are better resolved. Finally, the future of clinical PET may hinge significantly on the ability of commercial radiopharmaceutical suppliers to provide regional fluorodeoxyglucose distribution. As an institutional program development, PET offers opportunities by providing unique clinical data aiding the referral pattern. PET may serve as a magnet for recruitment in many areas and may promote interdisciplinary cooperation. A clinical PET center serves both as a model for future and more widespread use of PET and as a training ground for medical personnel. Finally, the unique capabilities of PET may facilitate grant opportunities.

Adenosine in myocardial perfusion imaging using positron emission tomography

Because of its unique ability to demonstrate the metabolic consequences of myocardial ischemia, positron emission tomography (PET) is extremely valuable in assessing myocardial viability. PET imaging can identify the myocardial segments that are likely to improve after revascularization and may be more sensitive and specific for the detection of coronary artery disease compared with thallium perfusion imaging. Adenosine has several advantages over dipyridamole as a pharmacologic stress agent for use with PET. It produces maximal vasodilation in a significantly greater percentage of patients, is a more potent coronary vasodilator, and its very short half-life may be ideal for use with the very short half-life radioactive tracers used in PET. When combined with metabolic studies, adenosine may be useful for the assessment of patients who received thrombolytic therapy for an acute myocardial infarction.

The reproducibility of measuring the anorectal angle in defecography

Dynamic proctography is a radiographic procedure that has become widely used in the evaluation of pelvic floor function. The anorectal angle (ARA) is one parameter which is usually quantified during this examination. To determine the accuracy with which this measurement can be made, three physicians independently measured the resting and squeezing ARAs of 22 women. The coefficient of variation and the kappa statistic were used to describe the degree of agreement among the three examiners. These analyses revealed poor agreement among examiners for all 22 patients taken as individuals, (kappa less than or equal to 0.40; mean coefficient of variation at rest = 18 percent; mean coefficient during squeezing = 21 percent). These results suggest that measurements of ARAs will vary among examiners for any particular patient, even though individual examiners may demonstrate consistency in recording ARA data. There is wide interobserver variation in the measurement of the ARA from lateral radiographs, making quantification an exercise of only limited clinical value.

Iopamidol as a gastrointestinal contrast agent. Lack of peritoneal reactivity

The ideal contrast agent in patients suspected of having gastrointestinal perforation is an iso-osmolar, or nearly iso-osmolar substance, that causes no peritoneal reaction. Iopamidol is a nonionic water-soluble contrast medium that may be considered in such situations. Intraperitoneal injections of ionic and nonionic contrast agents were compared in rats to study potentially harmful peritoneal inflammation. Only intraperitoneal barium injection produced any significant tissue reaction, such as adhesions and ascites. There was no difference between iopamidol and the other water-soluble contrast agents. Iopamidol may satisfy the need for nonreactive and nearly iso-osmolar contrast agents for evaluating patients with possible bowel perforation. However, the high cost of this agent may make its clinical application impractical.

Myocardial uptake and clearance of T1-201 in healthy subjects: comparison of adenosine-induced hyperemia and exercise stress

Pharmacologic stress testing with dipyridamole is useful in patients undergoing thallium-201 myocardial perfusion scintigraphy who cannot adequately exercise. Because dipyridamole increases coronary blood flow by reducing the metabolism of adenosine, the authors compared the uptake and clearance of T1-201 following exercise stress testing (EST) and resting intravenous infusion of adenosine (AI) in crossover fashion in 20 healthy men. No perfusion defects or areas of redistribution were noted in any of the scans. Mean absolute myocardial T1-201 uptake was 1.3 times greater with AI than with EST. Mean absolute extracardiac uptake was 2.0 times greater with AI. Mean T1-201 myocardial clearance was virtually the same in all AI and EST views. During AI, 70% of the subjects experienced subjective side effects, mean arterial blood pressure decreased by 15%, and heart rate increased by 48%. The effects of adenosine on T1-201 kinetics in the myocardium are similar to those of EST. Adenosine may be useful as a pharmacologic stress agent in patients undergoing T1-201 myocardial perfusion scintigraphy.

A calcified vascular mediastinal mass

We report the incidental finding of a late post-traumatic pseudoaneurysm of the thoracic aorta in a patient being treated for subarachnoid hemorrhage from a motorcycle accident. The diagnosis of calcified vascular mediastinal masses may be suspected from routine chest roentgenograms and confirmed by aortography. Computed tomography and magnetic resonance imaging are helpful when the diagnosis remains obscure. The recognition of chronic pseudoaneurysms is clinically important.

Progressive CT appearance of hepatic metastases from colorectal carcinoma

An 8-year retrospective review of 106 serial computed tomographic (CT) examinations performed on 32 patients with colorectal carcinoma metastatic to the liver was done to determine if the CT appearance of such metastases changed with a favorable response to chemotherapy or with progression of disease. Of these 32 patients, 15 underwent placement of an infusion pump for delivery of chemotherapy directly into the hepatic artery, 3 underwent partial hepatectomy, 1 underwent both procedures, and 13 underwent neither. Regression of hepatic metastases (7 patients), only seen following infusion pump placement, was associated with a decrease in size and an increase in margination of lesions. In two of these patients regression of metastases was seen in one area of the liver with subsequent progression or development of metastases in another region, presumably due to preferential delivery of chemotherapeutic agent. Progression of disease (23 patients) was associated with an increase in both size and number of lesions that became progressively less well marginated. Development of poorly marginated or infiltrative characteristics at the periphery of the lesion was associated with a poor prognosis. Thus, the CT characteristics of hepatic metastases from colorectal carcinoma differ with a favorable response to chemotherapy and with progression of disease.

The retropsoas recess. Demonstration using computed tomography

The retropsoas recess, a previously undescribed normal anatomic variant, is reported. In most individuals, the space posterior to the belly of the psoas muscle contains fat within the posterior pararenal space. However, a retrospective review of 250 consecutive CT examinations of the abdomen revealed 11 cases (4.4%) in which bowel loops extended at least partially posterior to the psoas muscle. Unilateral left-sided occurrence was present in seven, with four bilateral. Colon was invaginated in five, small intestine in four, and both colon and small intestine in one. There was no age or sex predominance. A paucity of retroperitoneal fat is the primary predisposing factor for development of a retropsoas recess. Although recognition of this normal variant is generally not difficult, the CT appearance may mimic a retroperitoneal mass or abscess in less-than-ideal examinations or targeted studies. The potential presence of bowel loops in this location should be considered during interventional procedures.

Liver allograft transplantation: postoperative CT findings

The CT findings in the abdomen after liver transplantation as seen on 72 examinations in 23 allograft recipients are described. CT was most useful in the evaluation of the gross structural integrity of the allograft and in the detection of extrahepatic fluid collections. Low-density foci within the allograft parenchyma were seen in 10 patients (43%) and were associated with infarction and necrosis, infection, malignancy, and rejection. Localized extrahepatic fluid collections (hematomas, bilomas, and seromas) were present in 16 patients (70%); four of the focal fluid collections detected by CT were infected. Since the nature of these fluid collections could not always be determined by CT characteristics, fine-needle aspiration was sometimes required for a specific diagnosis. Prominence of the portal structures was associated with previous or ongoing episodes of rejection in eight of nine patients, likely reflecting increased resistance to portal flow. CT occasionally showed low, dense, and calcified thrombi in the donor aorta and inferior vena cava. CT also showed biliary obstruction in four patients (17%) without identifying its cause. CT is a noninvasive means of imaging the hepatic allograft recipient; providing data on the hepatic parenchyma, vasculature, and biliary system; and identifying the presence of intraabdominal fluid.

Ultrasound and computed tomographic evaluation in hepatic transplantation

Ultrasound and CT are valuable in the non-invasive evaluation of complications of hepatic transplantation. Ultrasound is particularly helpful in detecting biliary obstruction and in documenting vascular patency. As with renal transplantation, the value of US in the assessment of rejection will likely increase with time. Computed tomography is most valuable in identifying large parenchymal abnormalities and abdominal fluid. Both US and CT can be used to guide diagnostic and therapeutic percutaneous procedures in hepatic transplant recipients.

Hydrophilic-lipophilic balance as predictor of mucus coating with barium sulfate

In order to improve barium coating of the mucus layer covering the alimentary tract, various surface active substances are added to commercially available contrast media. The action of additives can be expressed in part by their hydrophilic-lipophilic balance (HLB). In an experimental study using human colonic mucus and barium sulfate USP, surfactants of varying HLB (range, 3-11) were used to study the range of HLB resulting in optimal coating. The best coating occurred with an HLB of 7. Quality of coating may be predicted based on knowledge of the HLB of various surface active additives.

Catheter drainage of the left posterior subphrenic space: a reliable percutaneous approach

Catheter drainage of left posterior subphrenic collections can be difficult because of lack of a safe access route. We have found that manual compression of the soft tissues of the posterior left flank can create a safe route for catheter drainage, which otherwise would not be possible. This report describes the technique we have used successfully in 8 cases.

Evaluation of right subphrenic fluid collections with emission computed tomography: an experimental study

An animal model to study subphrenic fluid collections is presented. Performance of single photon emission computed tomography (SPECT) for detection of subphrenic fluid collections was compared to that of liver-lung scintigraphy and transmission computed tomography (TCT). TCT detected a water volume of 25 ml in the right subphrenic space. This volume was barely seen using SPECT and not detectable on scintigraphy. Differences in performance of the three imaging modalities are discussed.

CT of pancreas transplantation

Thirty-eight abdominal CT examinations obtained on 20 patients after pancreas transplantation were reviewed to determine the CT findings associated with pancreas transplantation and to assess the clinical utility of CT in this setting. Visualization of the transplanted pancreas was variable and was strongly influenced by adequacy of gastrointestinal opacification with contrast material. In four cases, linear high-density material was present within the graft, which, depending upon the surgical technique for handling exocrine secretions, represented either pancreaticojejunal stents or silicone within the pancreatic duct. Abdominal fluid collections were identified in 19 patients and were the most common complication identified by CT. Four of these collections were drained percutaneously. The major value of CT in pancreas transplantation is the identification and management of abdominal fluid collections in patients with abdominal pain and fever.

The plain abdominal radiograph in acute gastrointestinal graft-vs.-host disease

The plain abdominal radiographs of 28 patients with acute gastrointestinal graft-vs.-host disease (GVHD) were examined to determine the plain radiographic findings associated with this disorder. These findings, in order of decreasing frequency, included air-fluid levels, bowel wall/mucosal fold thickening, gasless abdomen, bowel dilatation, pneumatosis intestinalis, and ascites. When a number of these findings are present, the plain abdominal radiographs may be sufficiently characteristic to suggest gastrointestinal GVHD. Differentiating acute gastrointestinal GVHD from small-bowel obstruction is often of major clinical importance. Fortunately, the bowel gas pattern in acute gastrointestinal GVHD rarely suggests obstruction and, thus, bowel obstruction can usually be excluded on the basis of plain radiographs alone.

Significance of balloon pressure recording during angioplasty. An experimental study

During angioplasty of artificial stenoses, atherosclerotic human cadaver arteries, and normal canine arteries, pressure and volume of the dilatation balloons were continuously recorded. We found that a sudden yield of a lesion corresponded to a sudden drop in the pressure curve and an increase of the balloon volume. Volume monitoring was insensitive, but pressure recording was very precise. Continuous pressure recording, using a non-compliant inflation system, correctly demonstrated small breaks and ruptures of atherosclerotic vessels, changes not seen on fluoroscopy.

Radiologic diagnosis of wandering spleen complicated by splenic volvulus and infarction

Wandering spleen is a rare condition caused by malattachment of the dorsal mesogastrium. This condition is prone to torsion of the splenic pedicle leading to splenomegaly, hypersplenism, and infarction. Preoperative diagnosis can be suggested radiologically. A case of wandering spleen is reported and its embryologic, clinical, and radiographic features are discussed.

Computed tomography of neutropenic colitis

Four patients developed neutropenic colitis as a complication of acute leukemia (three) or aplastic anemia (one). On computed tomography (CT), neutropenic colitis was characterized by cecal wall thickening (four) and pneumatosis (one). Intramural areas of lower density presumably reflected edema or hemorrhage. Clinical improvement and return of adequate numbers of functioning neutrophils coincided with decrease in cecal wall thickening on CT. Prompt radiologic recognition of this serious condition is crucial, since surgical intervention is probably best avoided.

Percutaneous aspiration and drainage for suspected abdominal infection

Percutaneous drainage (PCD) of abdominal infection is a therapeutic modality whose role is not well defined. Surgical literature on abdominal infection cites a cumulative mortality rate in the range of 20% to 30%, markedly dissimilar from the 80% to 90% cure rates reported in the literature on PCD. We reviewed the PCD experience at a tertiary teaching hospital from 1981 to 1983. Fifty-five patients were suspected to have localized abdominal infection and underwent 66 procedures. PCD was attempted after percutaneous needle aspiration produced drainable fluid. Cure is defined by complete resolution of the abdominal process without any surgical intervention. Palliation is defined as acute decompression of the abdominal process permitting an elective corrective procedure to be performed. Failure is defined as false diagnosis, unsuccessful drainage requiring operation, or recurrence of infection. Diagnosis of the abdominal process was successfully made by aspiration in 59/66 (89%) attempts. PCD was curative in 31/66 (47%) attempts and failed or was palliative in 35/66 (53%). Simple nonfungal, nonfistulous abdominal abscesses were cured with PCD in 25/26 attempts (96%). PCD failure was encountered in 10 infected organized hematomas or thick phlegmons, nine fungal infections, nine abscesses with enteric communication, and five infected necrotic tumors. Abscesses with an underlying enteric communication were cured in 28%, were palliated in 32% and failed in 32% of PCD attempts. Abscesses with yeast as a major component or with necrotic tumor were never cured with PCD. PCD is a valuable diagnostic and therapeutic tool that is curative in simple abdominal abscesses. Its therapeutic role in complex abdominal infections seems to be limited.

Sonography of abdominal posttransplant lymphoma

Five patients developed abdominal lymphoma an average of 89 months after successful renal transplantation. Sonographically, the lymphomas presented as bulky intraperitoneal masses or focal deposits in the liver. These lesions exhibited good sound transmission and intrinsic patterns ranging from sparse, soft echoes to coarse trabeculations. Prompt diagnosis of this serious late complication of renal transplantation is crucial.

Obliteration of the gallbladder without formal cholecystectomy. A feasibility study

Obliteration of the gallbladder without formal cholecystectomy was attempted in 36 rabbits, using an open technique for cannulation of the gallbladder during laparotomy. The gallbladder was cannulated, the proximal cystic duct was occluded with cyanoacrylate-nitrocellulose 2% wt/wt, and the gallbladder mucosa was exposed to various sclerosing agents to induce fibrosis. Heated 60% diatrizoate meglumine and absolute alcohol induced a controllable chronic cholecystitis with transmural fibrosis within two weeks, a result not seen with morrhuate sodium or in the control groups. All animals survived without complications, and no instances of common bile duct damage or occlusion was noted. The results reported are promising and indicate the need for further studies of this technique for its efficacy and safety.

The adhesiometer: a simple device to measure adherence of barium sulfate to intestinal mucosa

A simple, inexpensive device assessing barium sulfate adherence to alimentary tract mucosa was tested in an animal study using pigs and dogs. Interaction of gastric, intestinal, and colonic mucosal lining with three different barium preparations was studied. In both pigs and dogs, barium adherence to gastric mucosa was significantly stronger when compared with colonic mucosa.

Sonography of the gallbladder in bone marrow transplant patients

Nonshadowing opacities in the gallbladder (sludge) occurred in nine of 44 bone marrow transplant patients as a nonspecific finding. Sludge occurring within 2 wk of bone marrow transplant was transient. Later, sludge accompanied hepatic graft versus host disease in seven of 10 patients with this complication of bone marrow transplant. During the course of graft versus host disease, disappearance of sludge matched clinical improvement. Persistence of sludge in patients with hepatic graft versus host disease was associated with a poor prognosis. The gallbladder of one patient who underwent cholecystectomy exhibited histopathologic findings of graft versus host disease.

CT of abdominal lymphoma after renal transplantation

Six patients aged 33-68 years developed posttransplant lymphoma of the abdomen an average of 105 months after successful renal transplantation. On computed tomography (CT), five lymphomas presented as bulky masses in intra- (four) or retroperitoneal (one) location. Infiltrative growth into transplanted kidney (three), colon (two), and retroperitoneum (one) resulted in poorly defined margins on CT. Central areas of lower attenuation presumably reflected tumor necrosis. Metastatic deposits in liver (two) and renal transplant (one) were of a focal nature. Prompt radiologic recognition of this serious late complication of renal transplantation is crucial.

Pancreas imaging by computed tomography after endoscopic retrograde pancreatography

A method using CT after endoscopic retrograde pancreatography (CT-ERP) is described for pancreatic imaging. When using an ERP technique in the canine model comparable to that used in humans, small amounts of contrast material in peripheral pancreatic radicles resulted in enhancement of the pancreas on CT scans. Nine patients were also studied by CT-ERP. In normal patients (n = 5) there was opacification of the entire pancreas on CT-ERP images. The main pancreatic duct was seen on delayed images. In cases of chronic pancreatitis (n = 2), pancreatic opacification was patchy and heterogeneous. There was no contrast-material enhancement in areas of pancreatic carcinomas (n = 2). CT-ERP showed the true extent of carcinoma better than ERP alone.

Symptomatic inguinal hernia: association with intraabdominal mass lesions

In a 10-year period, barium enema showed that 25 patients with symptomatic hernias harbored an intraabdominal mass. Of these masses, 92% were malignant and 88% were situated in the pelvis.

Lymphoma after organ transplantation: radiologic manifestations in the central nervous system, thorax, and abdomen

The radiographic findings of post-transplantation lymphoma in 15 patients are demonstrated. Variations in patterns from those of lymphomas in nonimmunosuppressed patients, etiologic factors, histologic features, and differential diagnosis are discussed. The common finding of central lucency of masses seen on CT scans correlated with necrosis seen at histologic examination. In the post-transplant patient, single or multiple masses, particularly if centrally lucent, should suggest post-transplantation lymphoma. Histologic proof with anatomic localization is important, however, to determine appropriate therapy.

The value of endoscopic retrograde cholangiopancreatography in patients with suspected carcinoma of the pancreas and indeterminate computed tomographic results

Endoscopic retrograde cholangiopancreatography was used to evaluate 26 patients with clinically suspected pancreatic malignant growths and indeterminate compute tomographic result. Endoscopic retrograde cholangiopancreatography benefited preoperative diagnosis or clinical management in 25 of 26 patients by diagnosing carcinoma in six, chronic pancreatitis in ten or normal pancreas in nine. Endoscopic retrograde cholangiopancreatography missed one carcinoma in a chronically inflamed pancreas. Endoscopic retrograde cholangiopancreatography is useful in evaluating patients with indeterminate pancreatic computed tomographic results prior to exploratory laparotomy.