Effect of MR angiography on the diagnosis and treatment of patients with suspected renovascular disease.

PURPOSE: Although the diagnostic accuracy of renal magnetic resonance (MR) angiography is established, its effect on referring physicians is unknown. The authors prospectively measured the effect of MR angiography results on referring physicians' diagnosis and treatment (plans) of patients with suspected renovascular disease. MATERIALS AND METHODS: Referring physicians prospectively completed questionnaires before and after MR angiography was performed during evaluation of their patients with suspected renovascular disease. The questionnaires asked them to estimate the probability (0%-100%) of their most likely diagnosis before and after receiving the imaging information. They were also asked for their anticipated and final treatment plans. The authors calculated the mean gain in diagnostic percentage confidence and the proportion of patients with changed initial diagnoses or anticipated management. A paired t-test was used to assess significance of the gains in diagnostic percentage confidence. RESULTS: Physicians prospectively completed pre- and post-MR-angiography questionnaires for 30 patients. MR angiography improved mean diagnostic certainty by 35% (P < .0001). MR angiography changed physicians' initial diagnoses in 12 patients (40%). Anticipated treatment plans were changed in 20 patients (67%). Invasive procedures were avoided in eight patients (27%). CONCLUSION: MR angiography has a substantial effect on the diagnostic and therapeutic decision-making of physicians managing patients with suspected renovascular disease.

Pulmonary parenchymal splenosis.

We describe the cytologic findings of a case of pulmonary parenchymal splenosis, a rare condition that follows lacerating trauma to the spleen, and may masquerade as a metastatic neoplasm. Approximately 24 cases of thoracic splenosis have so far been reported, the vast majority presenting as pleural-based nodules, and the cytological features of only two cases, both belonging to the latter group, have been described. We believe our case report to be the first to describe the cytological features of an intrapulmonary splenosis, and its features differ from the prior cases by having a mixed inflammatory cell infiltrate, with a predominance of lymphocytes, plus pulmonary macrophages and occasional endothelial cells. This condition has variable cytological features, but the correct diagnosis can be made in the presence of appropriate history and radiographic findings. Confirmation may require biopsy or radionucleide imaging.

Comparison of treatment plans for lower extremity arterial occlusive disease made with electrocardiography-triggered two-dimensional time-of-flight magnetic resonance angiography and digital subtraction angiography.

BACKGROUND: The purpose of the study was to determine whether preoperative treatment plans for patients with lower extremity ischemia can be made with electrocardiography (EKG)-triggered two-dimensional (2D) time-of-flight (TOF) magnetic resonance angiography (MRA) as accurately as digital subtraction angiography (DSA). METHODS: Forty patients were prospectively evaluated with the combination of EKG-triggered 2D TOF MRA, DSA, and pulse volume recordings. Blinded reviewers graded arterial segments for disease severity. Accuracy of separate MRA- and DSA-based treatment plans was compared with the procedures performed based on all available information. RESULTS: There was an 86% exact match between MRA- and DSA-based plans (92% MRA and 94% DSA accuracy). The MRA-based plan accurately predicted 90% of suprainguinal and 95% of infrainguinal procedures, whereas the DSA-based plan accurately predicted 100% of suprainguinal and 85% of infrainguinal procedures. Two-year primary patency was 83% for all procedures. Radiologists' review of disease severity resulted in a mean exact correlation between studies of 81% (kappa = 0.64). The agreement between radiologists interpreting the MRA was 84% (kappa = 0.7) compared with 82% (kappa = 0.66) for the DSA. CONCLUSIONS: MRA- and DSA-based preoperative management plans were of comparable efficacy. Significant interobserver variability was seen with the interpretations of both preoperative studies. EKG-triggered 2D TOF MRA can be used to plan arterial reconstructions; however, all patients require arterial pressure measurements prior to suprainguinal repair and confirmatory intraoperative angiography during infrainguinal revascularization.

Peripheral vascular disease and renal transplant artery stenosis: a reappraisal of transplant renovascular disease.

BACKGROUND: Renal transplant artery stenosis (RTAS) continues to be a problematic, but potentially correctable, cause of post-transplant hypertension and graft dysfunction. Older transplant recipients, prone to peripheral vascular disease (PVD), may have pseudoRTAS with PVD involving their iliac system. METHODS: We retrospectively analyzed 819 patients who underwent kidney transplantation between 1993 and 1997 to determine the contribution of pseudoRTAS to renal transplant renovascular disease. Univariate analyses were performed for donor and recipient variables, including age, weight, gender, race, renal disease, cholesterol and creatinine values, human leukocyte antigen (HLA) matching, cytomegalovirus (CMV) infection, and immunosuppressive medications. Significant variables were then analyzed by a Cox proportional hazards model. RESULTS: Ninety-two patients (11.2%) underwent renal transplant arteriogram (Agram) or magnetic resonance angiography (MRA) for suspected RTAS. RTAS or pseudoRTAS, defined as one or more hemodynamically significant lesions in the transplant artery or iliac system, was evident in 44 patients (5.4%). Variables significantly associated with RTAS by univariate analysis were weight at the time of transplant (p = 0.0258), male gender (p = 0.034), discharge serum creatinine > 2 mg/dL (p = 0.0041), and donor age (p = 0.0062). Variables significantly associated with pseudoRTAS by univariate analysis were weight at the time of transplant (p = 0.0285), recipient age (p = 0.0049), insulin-dependent diabetes mellitus (IDDM; p = 0.0042), panel reactive antibody (PRA) at transplant (p = 0.018), and body mass index (p = 0.04). Weight at transplant and donor age remained significantly associated with an increased risk for RTAS in a multivariate stepwise Cox proportional hazards model. IDDM, transplant PRA, weight at transplant, and donor age were significantly associated with an increased risk for pseudoRTAS in a multivariate stepwise Cox proportional hazards model. Importantly, both RTAS and pseudoRTAS were associated with poorer graft survival (p < 0.007 for each). CONCLUSIONS: Renal transplant renovascular disease encompasses pre-existing PVD acting as pseudoRTAS, as well as classical RTAS. Efforts to identify and correct renal transplant renovascular disease of either nature are important, given its negative impact on graft survival.

Multidisciplinary approach to deep-seated lesions requiring radiologically-guided fine-needle aspiration.

Fine-needle aspiration (FNA) is a diagnostic modality that continues to improve in accuracy as training and experience accumulate. With increasing operator expertise and improved localization techniques, greater numbers of patients are able to benefit from FNAs performed on sites that are otherwise difficult or dangerous to reach by conventional surgery. We present a retrospective review of a 2-yr experience with radiologically-guided deep-seated FNA. In 115 cases involving transthoracic and transabdominal sites, we achieved the following overall figures: 91.9% sensitivity, 100% specificity, 93.9% diagnostic accuracy, 100% positive predictive value, and 80.6% negative predictive value. Our results are compared to those in other series. When properly applied, FNA of deep-seated lesions through image guidance is equivalent to tissue diagnosis obtained by laparotomy or surgical procedures. The benefits of FNA with or without core biopsy vs. scalpel biopsy are readily apparent when one considers the morbidity, cost, turnaround time, and trauma to the patient.

Diagnosis of recurrent desmoplastic small round cell tumor by fine needle aspiration. A case report.

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a recently described neoplasm characterized by aggressive biology, occurrence in body cavities, expression of antigens from multiple cell lineages and a specific translocation between chromosomes 11 and 22. Most of the published information on this neoplasm is histologic. The case presented here enabled presentation of the cytomorphologic and immunocytochemical features of aspirated cytologic material obtained from this unique tumor. CASE: The cytologic, histologic, radiologic and clinical features of a DSRCT from a 17-year-old patient are presented. Although the initial diagnosis in this case was made on histology, recurrence was proven by fine needle aspiration biopsy (FNAB). CONCLUSION: The presence of sheets or clusters of small round malignant cells, associated with shards of dense fibroconnective tissue, in FNAB should lead the cytologist to consider the diagnosis of DSRCT.

CT depiction of experimental liver tumors: contrast enhancement with hepatocyte-selective iodinated triglyceride versus conventional techniques.

PURPOSE: To compare findings at computed tomography (CT) enhanced with a hepatocyte-selective contrast agent (iodinated triglyceride) and/or iohexol and at CT during arterial portography (CTAP). MATERIALS AND METHODS: Rabbit livers were directly inoculated with VX2 carcinoma. Results were compared for five helical CT examinations: unenhanced CT, iohexol-enhanced CT (600 mg iodine per kilogram of body weight [mg I/kg]), CTAP (with iohexol [600 mg I/kg]), triglyceride-enhanced CT (126 mg I/kg), and dual-contrast-enhanced CT (triglyceride plus iohexol [425 mg I/kg]). Attenuation of normal liver and tumor were compared with analysis of variance techniques and blinded reader evaluations. RESULTS: Normal liver attenuation was greatest at CTAP (127.3 HU +/- 5.3 [mean +/- standard error of the mean]), followed by dual-contrast-enhanced CT (112.4 HU +/- 1.2), iohexol-enhanced CT (97.9 HU +/- 2.2), triglyceride-enhanced CT (82.3 HU +/- 1.1), and unenhanced CT (54.9 HU +/- 1.8). Liver-to-lesion attenuation difference at triglyceride-enhanced CT was significantly greater than at iohexol-enhanced CT (P < .05), and attenuation differences at dual-contrast-enhanced CT were comparable to those at CTAP. Tumors did not enhance at triglyceride-enhanced CT, which increased conspicuity. Sensitivity values for lesion detection at dual-contrast-enhanced CT were greater than those at iohexol-enhanced CT or at CTAP (P < .05). CONCLUSION: At CT enhanced with triglyceride (especially when combined with iohexol), sensitivity values and liver-to-lesion attenuation differences were greater with lower iodine doses than with iohexol or at CTAP.

The Bird's Nest inferior vena caval filter: review of a single-center experience.

PURPOSE: To examine a large single-center experience with Bird's Nest vena caval filters for indications, clinically evident recurrent thromboembolic disease, and other filter-related complications. MATERIALS AND METHODS: During a 6-year period, 308 patients underwent percutaneous placement of an inferior vena caval filter. The 267 patients who received a Bird's Nest filter are the subject of this retrospective review. The series included 162 men and 105 women who ranged in age from 16 to 88 years (mean, 57.1 +/- 17.0 standard deviation). RESULTS: Indications for filter placement included contraindication to anticoagulation (n = 141), complication of anticoagulation (n = 23), failure of anticoagulation (n = 30), failure of previously placed filter (n = 1), and prophylaxis (n = 82). Ten patients had more than one indication. Acute lower extremity deep venous thrombosis was confirmed in 133 patients, pulmonary embolism (PE) was found in 44 patients, and both were positively diagnosed in 37 other patients. Fifty-three patients had no documented acute thromboembolic disease at the time of insertion. Mean follow-up was 13 months. Thirty-day mortality was 9.7%, including one death from recurrent PE and one major puncture-site bleeding episode that may have contributed to death. Recurrent PE was found at radionuclide scanning or autopsy in three patients (1.1%), whereas another eight patients (3.0%) had suspected recurrent PE without confirmatory studies. Eight patients (3.0%) developed early venous access site thrombosis, including two who progressed to phlegmasia cerulea dolens with fatal complications. Significant nonthromboembolic problems were encountered in 1.9% of patients. CONCLUSIONS: The Bird's Nest filter is a safe and effective device for patients with complicated venous thromboembolic disease.

Preclinical evaluation of an iodinated particulate contrast agent for use during angiography: work in progress.

PURPOSE: To study the feasibility of using an iodinated particulate contrast agent, iodipamide ethyl ester (IDE), for angiography. MATERIALS AND METHODS: IDE at doses of 40-100 mg of iodine per kilogram was diluted to a total volume of 5-20 mL and used for digital subtraction angiography in nine dogs under general anesthesia. Equivalent images were obtained by using water-soluble contrast medium (WSCM) for comparison (iohexol) in seven animals. All images were reviewed by blinded reviewers and graded subjectively on a five-point scale. RESULTS: Angiographic studies of multiple vascular territories performed with IDE yielded images of slightly lower overall quality compared with images obtained with WSCM (P = .14, Mann-Whitney U test). Arterial phase images were subjectively superior with WSCM when compared with IDE (P < .0001, chi 2.) Depiction of the corresponding veins during the venous phase on the IDE angiograms was superior to that on WSCM angiograms in 12 of 21 cases, although this did not reach statistical significance (P > .05 chi 2). Images of the renal vein and portal vein achieved with IDE were graded as superior to those achieved with WSCM in eight of 10 reviews. CONCLUSION: Angiography is feasible with IDE. Compared with WSCM, IDE produced images of lesser quality during the arterial phase, but of equal or superior quality in the venous phase depending on the vessel studied. Because it is excreted slowly in bile and is isotonic, it may prove useful in patients with renal insufficiency, diabetes, multiple myeloma, or severe coronary disease.

Hepatic artery thrombosis after liver transplantation: temporal accuracy of diagnosis with duplex US and the syndrome of impending thrombosis.

PURPOSE: To determine how the interval between ultrasonography (US) and a definitive diagnosis affects the accuracy of duplex US for the diagnosis of hepatic artery thrombosis after transplantation. MATERIALS AND METHODS: Retrospective chart review was performed in 202 patients with liver transplants. Results of duplex US were compared with those of angiography, surgery, or autopsy. RESULTS: Sensitivity for US was 54% up to 1 month before and 82% on the day of the definitive diagnostic study. Specificity remained relatively constant over time (86%-87%). Accuracy reached 85%, and negative predictive value reached 93%. Qualitative changes on the sonogram enabled prediction of subsequent thrombosis. Rejection, recurrent hepatitis, aberrant anatomy, hypotension, arterial collaterals, and operator error caused false-positive or false-negative results. CONCLUSION: Although duplex US remains a good screen for hepatic artery thrombosis, angiography is strongly recommended. Serial US studies are necessary for diagnosis. Sensitivity improves over time as the clinical picture clarifies. Qualitative changes on the sonogram (the syndrome of impending thrombosis) enable prediction of subsequent hepatic artery thrombosis.

Lesion visualization by targeted computed tomography liver enhancement in dogs.

RATIONALE AND OBJECTIVES: We conducted a pilot study to determine the potential advantages of using liver-specific targeted computed tomography (CT) contrast agents for lesion detection. METHODS: Eight dogs had liver infarcts created by percutaneous injections of ethanol. Each dog underwent CT scans with four imaging techniques: unenhanced, intravenous contrast enhanced (IVCE), CT arterial portography (CTAP), and targeted liver enhancement with iodipamide ethylester (IDE) particles. Lesions were assessed quantitatively to determine liver-to-lesion density differences and the drop in density across liver edge as a quantitative measure of edge sharpness. Expert readers subjectively analyzed data to determine lesion visibility and edge sharpness. RESULTS: Liver-to-lesion density differences were greatest with CTAP (56.4 +/- 35.5 Hounsfield units [H]) followed by IDE (41.1 +/- 7.0 H), i.v. (22.7 +/- 6.0 H), and unenhanced scans (13.6 +/- 4.1 H; ps < .05 for CTAP versus unenhanced and IDE versus unenhanced). Edges were best defined both subjectively and quantitatively on IDE-enhanced scans. CONCLUSION: Targeted liver-specific contrast agents have potential to increase lesion visibility when compared with standard i.v. contrast enhancement of the liver by increasing lesion edge definition and liver-to-lesion attenuation differences. Further work in animal tumor models, and clinical trials as agents become available, appears justified.

Musculoskeletal neoplasms: preoperative evaluation with MR angiography.

PURPOSE: To assess the ability of magnetic resonance (MR) angiography to depict vascularity of musculoskeletal neoplasms. MATERIALS AND METHODS: Two-dimensional (2D) time-of-flight (TOF) MR angiography was compared with conventional arteriography during staging of musculoskeletal tumors in 23 prospective examinations. Phase-contrast (PC) MR angiography was also performed in 19 cases and evaluated as a possible supplement to 2D TOF imaging. RESULTS: Of named vessels, 92% in proximity to tumor were noted by blinded readers. The PC technique provided supplemental data in 47% of cases, usually related to better delineation of in-plane feeder vessels and areas with pulsatile blood flow. Of the 28 branch feeder vessels, 23 were noted on both conventional arteriograms and MR angiograms in a nonblinded review, but 16 were difficult to distinguish as feeders because of lack of associated tumor blush. CONCLUSION: MR angiography has promise to replace conventional arteriography for orthopedic preoperative planning.

Thrombolysis versus surgery as the initial management for native artery occlusion: efficacy, safety, and cost.

BACKGROUND: A controversy has evolved as to which therapy, thrombolysis or thromboembolectomy, represents the optimal initial treatment for acute native artery occlusion. METHODS: Forty-eight cases of acute class I or II limb ischemia caused by native artery occlusion were retrospectively analyzed between 1988 and 1993. Nineteen of the patients were initially treated with thrombolysis (group 1), and 29 underwent thromboembolectomy (group 2). RESULTS: Initial clinical improvement was seen in 11 (57.9%) of 19 extremities in group 1, with complete clot resolution in 21%, partial lysis in 47.4%, and no angiographic improvement in 31.6%. Significantly superior results were achieved in group 2; 28 (97%) of 29 limbs showed clinical improvement after initial surgical therapy (p = 0.001). Limb salvage was 88.2% in group 1 and 96.6% in group 2 (p = 0.5). Adjunctive procedures for limb salvage were necessary in 10 (52.6%) of 19 limbs in group 1 compared with only five (17.2%) of 29 limbs in group 2 (p = 0.013). Perioperative mortality was 10.5% and 10.3% (p = 1.0), whereas major postoperative complications occurred in 63.2% and 37% of patients in groups 1 and 2, respectively (p = 0.14). Hospital and professional patient charges were analyzed for the 12 most recent patients from each group. Total mean charges per patient were higher in group 1 ($45,171) than in group 2 ($24,898) (p = 0.046). CONCLUSIONS: Patients initially treated surgically achieved better immediate clinical results with significant cost savings and without significant differences in morbidity, mortality, or limb salvage compared with patients treated initially by thrombolysis.

Portal hypertension: surgical management in the 1990s.

BACKGROUND: Although liver transplantation offers definitive treatment for portal hypertension with end-stage liver failure, surgical portosystemic shunts avoid the risks of transplantation and immunosuppressive therapy, and transjugular intrahepatic portosystemic shunt (TIPS) creates a portosystemic shunt with minimal operative risk. The appropriate applications of these modalities are discussed. METHODS: All adults undergoing primary liver transplantation alone (PLT, n = 265), PLT after TIPS (n = 34), PLT after surgical shunts (n = 12), surgical shunt alone (n = 13), TIPS alone (n = 35), or surgical shunt after PLT (n = 5) served as the basis of this study. RESULTS: In contrast to surgical shunts before PLT, TIPS before PLT increased the 1-year graft survival. Surgical shunts alone were done in 18 patients with normal or near normal liver function with 100% survival. TIPS alone offered effective symptomatic relief to most patients, all of whom were judged not to be surgical candidates. CONCLUSIONS: TIPS, surgical shunts, and liver transplantation each have a logical role in management of portal hypertension. Surgical candidates with Child's B or C liver failure should be treated with liver transplantation, and TIPS offers effective treatment for nonsurgical candidates. Surgical shunts can be performed with excellent results in patients with Child's A liver disease. Portal vein occlusion with normal liver function can be successfully treated with surgical shunts.

Transcatheter embolization of the marginal artery of Drummond as treatment for life-threatening retroperitoneal hemorrhage complicating heparin therapy.

We report a case in which life-threatening retroperitoneal hemorrhage complicated heparin therapy. The bleeding originated from the marginal artery of Drummond which was catheterized with a 3-Fr coaxial catheter system (Tracker-18 catheter) and embolized with microcoils. Bleeding stopped and no ischemic complications developed for 3 years after embolization.

MR angiography of the pelvis with variable velocity encoding and a phased-array coil.

PURPOSE: To evaluate the feasibility of an automated variable velocity-encoding sequence and improve the signal-to-noise ratio (S/N) on magnetic resonance angiograms with use of phase contrast and a pelvic phased-array coil. MATERIALS AND METHODS: Three cardiac-gated, two-dimensional (2D), phase-contrast (PC) sequences were evaluated in 10 healthy subjects. A 2D gated PC sequence with variable velocity encoding (velocity-optimized phase contrast [VOPC]) was compared with gated 2D PC sequences performed with high or low constant velocity encoding. S/Ns in VOPC images obtained with a pelvic phased-array coil were compared with those in VOPC images obtained with a body coil. RESULTS: Two blinded readers preferred VOPC for simultaneous display of large and small blood vessels in one acquisition compared with constant low (P = .0105) and high (P = .0067) velocity encoding and for overall image interpretation. VOPC images obtained with the pelvic coil had a 68%-100% better S/N compared with those obtained with the body coil. CONCLUSION: Use of a phased-array coil and variable velocity encoding improves depiction of segmental vascular anatomic structures of the pelvis.