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ABSTRACT |
Tuesday, May 2, 1:30 PM–3:30 PM
Abstracts 132–143
Moderators: Brian S. Funaki, MD and Gaurav Goswami, MD
1:30 PM
132. Hemodynamic Evaluation of the Cirrhotic Patient: Does it Matter where you Measure the Pressures?
Ferral H.*; Behrens G.; Alonzo M.; Patel N.H.; Interventional Radiology, RUSH Medical Center, Chicago, IL.
Address correspondence to H. Ferral (hferral{at}rushradiology.org)
Objective: The hemodynamic evaluation of the cirrhotic patient is commonly performed in clinical practice. The degree of portal hypertension has prognostic implications and changes in management may be decided based on this information. Gastroenterologists propose the measurement of the wedge hepatic vein to free hepatic vein gradient as the validated standard, however, interventional radiologists commonly report on gradients to the inferior vena cava or right atrium. We undertook this study to determine if these various gradients are different from the statistical standpoint in the patients with biopsy-proven liver cirrhosis.
Materials and Methods: This is a retrospective study. The records of all patients undergoing transjugular liver biopsy with hemodynamic evaluation from June 2004 to September 2005 at our institution were reviewed. A total of 140 patients (87 males, 53 females) with a mean age of 53 (11–86 yr.) were identified. Indications for transjugular liver biopsy were: Coagulation disorders 41% (n = 51), massive ascites in 26% (n = 36), work-up for organ transplantation 9% (n = 12) and other 25% (n = 35). Pressures measured included: wedge hepatic vein (WHV), free hepatic vein (FHV), inferior vena cava (IVC) and right atrium (RA). Wedge pressures were measured with a balloon occlusion catheter using a calibrated Transpac IV (Abbott, Chicago, IL) pressure transducer connected to a Solar 7000 (General Electric, Milwaukee, WI) patient monitor. Findings are specified in means, standard deviation and percentages. Data was analyzed using the two tailed, paired t-student test.
Results: Twenty five cirrhotic patients were identified. All patients had portal hypertension with gradients > 5 mmHg. The mean gradients were: WHV to FHV: 15.88 (± 7.52) mmHg; WHV to IVC: 16.46 (± 7.97) mmHg and WHV to RA: 19.23 (± 8.57) mmHg. The WHV/FHV and WHV/IVC gradients were not different (p = 0.28), however the WHV/FHV and WHV/RA and WHV/IVC and WHV/RA gradients were different (p < 0.001) and (p = 0.001) respectively.
Conclusion: Our results show that WHV/RA gradients were significantly higher than either the WHV/FHV or WHV/IVC gradients. The site of pressure measurement should be specified by the operator as these results may have an impact on patient's management.
133. Dual-injection Contrast-enhanced (DICE) MRA of Peripheral Arteries on a 3T System - Not as Simple as it Seems
Costantino M.M.1*; Szumowski U.1; Baker P.3; Kaufman J.2; Lakin P.1,2; Porras M.2; 1. Diagnostic Radiology, Oregon Health and Science University, Portland, OR; 2. Interventional Radiology, Dotter Interventional Institute, Portland, OR; 3. Diagnostic Radiology, VA Medical Center, Portland, OR.
Address correspondence to M.M. Costantino (costanti{at}ohsu.edu)
Objective: Two segment magnetic resonance arteriography (MRA) of lower extremity peripheral arterial disease has been well described on a 1.5T MRI. Given the increasing utilization of 3T MRA, we have developed important protocol parameters unique to the 3T system. Specifically, due to a smaller field of view on the short bore 3T MRI, four stations are required to provide adequate anatomic coverage. Imaging four stations creates a unique challenge in avoiding distal venous signal contamination given contrast transit time and image acquisition time. To address this problem we have divided the lower extremities into two segments, proximal and distal, of two stations each. The proximal segment includes the pelvis and thigh stations, and the distal segment the knee and calf stations. Development of this protocol allows for widespread use of 3T MRA of the lower extremities.
Materials and Methods: Twenty patients were examined using a short bore 3T MRI (Philips Medical Systems). A transmit/receive whole body coil was used for the proximal segment (pelvis/thigh stations) and a body coil or a receive-only spine coil wasused for the distal segment (knee/calf stations). 3D fast-field echo images were acquired in a coronal plane with TR/TE/flip 4.1/1.3/20, 50–70 partitions, FOV 32–34, matrix 304 x 512 reconstructed to 512 x 512. Over-contiguous slices, 1.2 mm in proximal and 1.5 mm in distal segment stations, were used with imaging times of 17–21s per station. All stations were acquired using elliptic-centric k-space acquisition (CENTRA) except the knee station of the distal segment, acquired with Reversed CENTRA. The distal segment stations were acquired following 12–15 ml of IV gadolinium contrast (Omniscan) at 0.7ml/sec. The proximal segment stations were acquired following 25–28 ml of IV Omniscan at 1.4 ml/sec. Two radiologists analyzed the images for venous signal using a 4-grade scale.
Results: We had no non-diagnostic studies due to venous contamination. Our initial images resulted in several non-diagnostic studies given patient motion. After the first few studies, as our familiarity with the protocol and software improved, we were able to complete a study in approximately 45 minutes, down from 90 minutes for the initial study. This eliminated patient motion artifact.
Conclusion: We have developed and evaluated a modified dual injection contrast enhanced (DICE) MRA technique that minimizes venous contamination and provides the basis for a practical diagnostic exam of the lower extremities using a short bore 3T MRI.
134. MR Venography to Detect Occult Deep Venous Thrombosis (DVT) in Patients Suspected of Paradoxical Embolism and Stroke
Kalva S.P.*; Danti M.; Sahani D.V.; Geller S.C.; Greenfield A.J.; Waltman A.C.; Curvelo M.; Fan C.; Wicky S.; Radiology, Massachusetts General Hospital, Boston, MA.
Address correspondence to S.P. Kalva (skalva{at}partners.org)
Objective: To study the clinical utility of imaging the deep veins of the pelvis and legs in patients suspected of paradoxical embolism and brain ischemia.
Materials and Methods: 142 patients (80M:62F; mean age:51y) with brain ischemia (TIA/stroke) and patent foramen ovale (PFO) (confirmed on contrast echocardiography) were included in this study. All patients underwent compression ultrasonography of the lower extremities, contrast-enhanced MR venography of the pelvis and IVC and CTA of the carotid arteries within 48hrs of clinical presentation. 12 patients were excluded from the study because a source for brain ischemia was found (significant carotid stenosis [n = 5], atrial fibrillation [n = 7]). The presence and location of deep venous thrombosis (DVT), the presence of venous anomalies and associated risk factors for DVT were recorded. All patients were clinically followed for a mean 60 day-period.
Results: Three of 130 (2%) had DVT. Two had popliteal vein thrombosis and the other had thrombus in the IVC. Two of the three patients had risk factors for DVT. Compression of the left common iliac vein by the right common iliac artery (May-Thurner's syndrome) was found in 9; none of these patients had thrombus identified. Risk factors for DVT were present in 57 (hypercoagulability [n = 40]; cancer [n = 5]; trauma [n = 1]; others [n = 11]). Anticoagulation was started when DVT was detected. During follow-up, 74 patients had closure of the PFO and 3 had recurrent stroke.
Conclusion: The prevalence of DVT in patients suspected of paradoxical embolism and brain ischemia is very low. Imaging is relevant to exclude DVT as this can alter the management. MR venography was useful to exclude DVT prior to catheterization.
135. CT Angiography in the Evaluation of Trauma to the Lower Extremities: Diagnostic Accuracy and Interobserver Agreement
Munera F.; Patel R.*; Munoz R.; Radiology, University of Miami/Jackson Memorial Hospital, Miami, FL.
Address correspondence to R. Patel (rpatel{at}um-jmh.org)
Objective: To evaluate the interobserver agreement and accuracy of multidetector row CT angiography (MDCTA) as the initial diagnostic examination in patients suspected of having focal arterial injury of the lower extremities following penetrating or blunt trauma.
Materials and Methods: During a 3 year period, 46 patients (41 M, 5 F, age range 10–79 years) who sustained penetrating injury or blunt trauma to the lower extremities were referred for conventional or computed tomographic angiography owing to clinical suspicion of arterial injury. Within the patient population, 51 arterial segments were studied by means of multidetector row CT angiography performed with a four channel multislice CT unit (Marconi MX8000). Three radiologists with different levels of expertise independently interpreted CT angiographic studies. Conventional angiography, surgery, or 6 month clinical follow-up served as the standard of reference for determining the sensitivity and specificity of multislice CT angiography.
Results: Overall sensitivity and specificity of MDCTA were 100 and 92 %, respectively, with positive and negative predictive values of 93 and 100%. Overall diagnostic accuracy was 96%. Surgery or conventional angiography showed arterial injury in 23 patients (25 of 51 arterial segments). Angiographic findings included arterial occlusion (n = 16), pseudoaneurysm (n = 6), arteriovenous fistula (n = 2), intimal flap / dissection (n = 3), transection (n = 5), and normal arteries (n = 26). These segments were treated either with surgery, endovascular intervention, or were observed. Good to excellent interobserver and intraobserver agreement were observed.
Conclusion: CT angiography is an accurate and reliable imaging modality as an initial study for stable patients with trauma and suspected arterial injury to the lower extremities. CT angiography provides high interobserver agreement amongst different levels of expertise.
136. Vascular Disorders of the Hand: High-resolution Three-Dimensional Contrast-Enhanced MR Angiography Assessment
Abdel Razek A.1*; Saad E.2; Soliman N.1; Abou Elatta H.1; 1. Diagnostic Radiology, Mansoura University Hospital, Mansoura, DK, Egypt; 2. Vascular Surgery, Mansoura University Hospital, Mansoura, DK, Egypt.
Address correspondence to A. Abdel Razek (arazek{at}mans.eun.eg)
Objective: To assess the usefulness of high-resolution three-dimensional contrast enhanced MR angiography in vascular disorders of the hand.
Materials and Methods: Three-dimensional contrast enhanced MR angiography (CE-MRA) was performed for 34 hands in 31 patients (17 M, 14F mean age 34ys) with clinically suspected vascular disorders of the hand. This study was conducted on 1.5 tesla MR unit (Symphony-Siemens). The parameters used: TR = 7 msec, TE = 3 msec, Flip angle = 40 °, F FF OV = 230 mm, matrix = 256 x 256. Bolus of gadolinium-DTPA was injected in the forearm (0.2 mmol/kg at rate of 2 ml/sec followed by 20 ml saline flush at the same rate). Images acquired in coronal plane using dedicated surface coil. The first acquisition served as, a mask, which was subtracted from the second acquisition, the contrast run. Conventional angiography was done for 21 hands within 2–7 days after CE-MRA.
Results: All CE-MRA examinations were technically adequate for analysis with high signal noise ratio. Vessel anatomy and stenotic areas detected with CE-MRA correlated well with those on conventional angiography. No vascular abnormality could be detected in 2 patients. In vasculitis (n = 12), multiple stenotic or occluded regions involving the digital arteries and arch of the hands. In Burger disease (n = 4), there was corrugated vessel with corkscrew collaterals. Multiple occluded vessels were seen in emboli (n = 3). Rayounds disease (n = 3) showed gradual narrowing and tapering of proper digital arteries with capillary congestion. Steal syndrome of the hand (n = 3) was seen in patients with forearm dialysis graft. Vascular supply of the arterio-venous malformation (n = 2). Various types of hemangiomas (n = 3) and aneurysm (n = 2) can be easily diagnosed with CE-MRA.
Conclusion: These preliminary results indicated that high resolution three dimensional contrast enhanced-MR angiography is a promising diagnostic imaging modality for assessment of vascular disorders of the hand as it creates arterial map similar to that provided with conventional angiography.
137. Computerized Bruit Analysis for Detection of Hemodialysis AV Fistula Stenosis
Patel N.H.1*; Mansy H.A.2; Hoxie S.J.2; Sandler R.H.2; 1. Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL; 2. Pediatric Gastroenterology, Rush University Medical Center, Chicago, IL.
Address correspondence to N.H. Patel (nhpatel{at}rushradiology.org)
Objective: A stenosis in the hemodialysis AV fistula circuit causes vascular sound changes that are detectable using computerized data acquisition and analysis.
Materials and Methods: Prospectively patients with AV fistula or AV graft dysfunction were enrolled and acoustic measurements were acquired with two electronic stethoscopes both before and after the interventional procedure. The correlation coefficient was used to evaluate the strength of the linear relationship between the percent diameter change (PDC) of the stenosis before and after angioplasty, and the acoustic parameter true root mean square (tRMS) of the spectral difference.
Results: Twenty-two patients (7M, mean age 56 years) with 18 AV grafts and 4 AV fistula were enrolled in the study. The correlation between the PDC and tRMS was excellent (R= 0.858 for PDC > 10%, p < 0.001 and R = 0.882 for PDC > 20%, p < 0.001). After PDC climbed over 20% we found a linear relationship between PDC and tRMS; PDC = (1.62*tRMS)+17.17.
Conclusion: Computerized auscultation of vascular sounds may be clinically valuable for predicting stenosis severity as well as changes in stenosis over time.
138. Imaging of Aortal Lesions with Contrast-Enhanced Ultrasound versus CT and MRT
Clevert D.A.1*; Stickel M.2; Flach P.1; Strautz T.1; Jung E.M.3; Becker C.1; Schoenberg S.O.1; Reiser M.1; 1. Department of Clinical Radiology, University of Munich, Munich, Germany; 2. Department of Surgery, University of Munich, Munich, Germany; 3. Department of Clinical Radiology, Passau, Passau, Germany.
Address correspondence to D.A. Clevert (Clevert{at}web.de)
Objective: To evaluate and compare the diagnostic accuracy of low-mechanical-index (low MI) contrast enhanced ultrasound (CUS) with MR angiography (MRA) and CT-Angiography (CTA) in pathological aortal lesions.
Materials and Methods: Prospectively 26 patients with in CTA or MRA detected aortal lesions were examined with CUS in low MI-technique using 1.6 to 2.4 ml intravenous injection of SonoVue (Bracco, Italy). The contrast enhancement was examined in the arterial, venous, and late venous phase. As gold standard to compare the results CTA or MRA were performed.
Results: In all patients a contrast enhanced US could be performed with a relevant diagnosis of the aortal pathologies. In total one covered rupture, 8 aortal dissections, one aorto-caval fistula, two type 3 endoleaks after y-prosthesis and 14 suspect aortal aneurysms were detected in the follow up. For pre-surgery planning in addition to the per-fundated true and false lumen the perfusion of the renal arteries were examined.
Conclusion: CUS with SonoVue allows an early evaluation of aortal lesions. It is an additional examination to CTA and MRA. It may allow a more rapid and non-invasive diagnosis, especially in critical patients from the intensive care unit because of its bed-side availability. Due to the dynamic examination additional information about blood-flow in the true and false lumen and the renal perfusion after dissections can be evaluated.
139. MDCT Angiography of Renal Artery Anatomy in 100 Patients with Atherosclerotic Renal Artery Stenosis: Implications for Renal Artery Stenting with Distal Protection.
Alper H.J.; Talenfeld A.*; Schwope R.; Cohen E.; Lookstein R.A.; Radiology, Mount Sinai Medical Center, New York, NY.
Address correspondence to A. Talenfeld (arizonaadam{at}yahoo.com)
Objective: Renal artery stent procedures using embolic protection devices require detailed anatomic planning including the diameter of the main renal artery proximally and distally as well as the length from the stenosis to the bifurcation. MDCT angiography currently offers a non-invasive alternative to conventional angiography with excellent spatial resolution. This study examines the normal anatomy relevant to renal artery stent procedures using MDCT angiography in patients with renal artery stenosis.
Materials and Methods: A retrospective review was performed of all MDCT angiograms (n = 218) between 6/2002 to 9/2005 to identify patients with ostial atherosclerotic renal artery stenosis. All studies were performed on a 16 or 64 slice MDCT scanner Patients with a > 50% stenosis were included in the study. Data sets were analyzed on a Vital Images Workstation utilizing multiplanar reformats with a vessel analysis software package. The variables measured included: length of the stenosis (L1), length of the main renal artery from the stenosis to the main bifurcation (L2), maximum diameter immediately distal to the stenosis (D1), and the maximum diameter 1 cm proximal to the bifurcation (D2). These variables were analyzed using student's t-Test for gender differences and differences between the left and right renal arteries.
Results: 127 arteries in 108 patients were reviewed [76 males (age 58–97, mean 77) 32 females (ages 57–92, mean 79)]. Significant differences were seen between the left (n = 72) and right (n = 55) renal arteries for L1 (10.44 mm +/- 4.66 vs. 12.39 mm +/- 5.90; p < 0.05), L2 (28.01 mm +/- 12.42 vs. 36.27 mm +/- 15.56; p < 0.01), and A1 (0.26 cm2 +/- 0.11 vs. 0.23 cm2 +/- 0.07; p < 0.05). There were also significant differences between men and women in the left A1 (0.28 cm2 +/- 0.11 vs. 0.21 cm2 +/- 0.11; p < 0.01) and D2 (6.9 mm +/- 1.34 vs. 5.73 +/- 1.34; p < 0.01). Significant differences were seen in men when comparing left to right L2 (27.98 mm +/- 12.87 vs. 35.83 mm +/- 15.65; p < 0.05), A1 (0.28 cm2 +/- 0.11 vs. 0.24 mm +/- 0.07; p < 0.05), and D2 (6.93 mm +/- 1.34 vs. 6.30 mm +/- 1.02; p < 0.05). Differences were seen in female left vs. right L2 (28.1 mm +/- 11.46 vs. 37.0 +/- 15.77; p < 0.05).
Conclusion: There are significant anatomic differences between left and right renal arteries in patients with ostial renal artery stenosis. There are also significant gender differences in renal artery anatomy. These differences are relevant for planning percutaneous renal artery stent procedures using embolic protection devices.
140. Comparison of Dynamic Expiratory CT with Bronchoscopy in Diagnosing Airway Malacia
Lee K.S.1*; Sun M.1; Ernst A.2; Feller-Kopman D.2; Majid A.2; Boiselle P.M.1; 1. Radiology, Beth Israel Deaconess Medical Center, Boston, MA; 2. Division of Pulmonary Medicine, Beth Israel Deaconess Medical Center, Boston, MA.
Address correspondence to K.S. Lee (kslee{at}bidmc.harvard.edu)
Objective: Bronchoscopy, an invasive procedure, is the current gold standard for diagnosing airway malacia. Our purpose was to compare dynamic expiratory CT with this reference gold standard in the diagnosis of airway malacia.
Materials and Methods: A computerized hospital information system was used to retrospectively identify all patients with bronchoscopically proven airway malacia referred for CT airway imaging at our institution during a 19-month period. CT scans were performed within 1 week of flexible bronchoscopy. All patients were scanned with a standard protocol, including end inspiratory and dynamic expiratory volumetric imaging on an eight-detector multislice helical CT scanner. An experienced thoracic radiologist, who was blinded to the bronchoscopic results, initially reviewed the CT images for malacia by using an analysis tool to measure the cross-sectional area of the airway lumen at inspiration and expiration. For both CT and bronchoscopy, malacia was defined as > 50% expiratory reduction in cross-sectional area of the airway lumen. CT and bronchoscopic findings were subsequently jointly reviewed by the radiologist and bronchoscopist for concordance. Risk factors for malacia and presenting symptoms were also recorded.
Results: 29 patients, including 12 men and 17 women, with mean age of 60 years (range, 36–79 years) comprised the study cohort. CT correctly diagnosed malacia in 28 (97%) of 29 patients. In the one false-negative case, CT was interpreted as "borderline malacia" but did not meet strict 50% criteria for diagnosis. The most common presenting symptoms were dyspnea in 20 (69%) patients, severe or persistent cough in 16 (55%) patients, and recurrent infection in 7 (24%) patients. Identifiable risk factors for malacia were present in 20 (69%) of 29 patients, including COPD in 11 (55%), relapsing polychondritis in 6 (30%), prior tracheostomy in 4 (20%), and prior lung resection and/or radiation therapy in 2 (10%) patients.
Conclusion: Dynamic expiratory CT is a highly sensitive method for detecting airway malacia. Thus, this method can potentially serve as a noninvasive diagnostic examination in patients with risk factors and symptoms of malacia.
141. MRI of Aortic Stent Grafts Using SSFP to Diagnose Endoleaks and Endotension: Single Center Experience
Lookstein R.A.; Honig S.*; Cohen E.I.; Nowakowski F.S.; Stangl P.A.; Ellozy S.H.; Carroccio A.; Jacobs T.; Radiology, Mount Sinai Medical Center, New York, NY.
Address correspondence to S. Honig (shaunhonig{at}mssm.edu)
Objective: To report a single centers experience in the use of steady state free procession imaging for the post–operative surveillance of aortic stent grafts.
Materials and Methods: Between January 2001 and September 2005, 132 patients with nitinol based aortic stent grafts underwent MRI examinations as part of routine postoperative surveillance. The patients were 104 male and 28 females age 54 – 90 (mean 74). 78 patients had steady state free procession imaging of the aortic aneurysm. The contents of the aneurysm sac were reviewed and characterized as uniformly low, heterogeneous, or uniformly bright signal. These results were compared to the contents of the aneurysm sac following intravenous contrast administration. These results were characterized as either positive or negative for endoleak based on the presence or absence of gadolinium in the aneurysm sac.
Results: All patients tolerated the MRI examinations. There were no major or minor complications. Of the 78 patients, 12 patients had significant artifacts related to stainless steel embolization coils placed at the time of surgery in either the internal iliac or common iliac arteries. The remaining 66 patients SSFP results were: 6 patients with uniformly low signal, 53 patients with heterogeneous signal, and 7 patients with uniformly bright signal. All patients with low signal had no evidence of endoleak follow-ing the administration of intravenous contrast. All patients with heterogeneous signal had evidence of endoleak following contrast administration. The seven patients with bright signal had no evidence of endoleak following contrast administration but were noted to have enlarging aneurysm sacs. Direct sac puncture in one patient with bright signal on SSFP revealed a plasma filled aneurysm sac or hygroma confirming a diagnosis of endotension.
Conclusion: These results suggest that SSFP imaging has excellent correlation with contrast enhanced MRA for the presence or absence of endoleak following EVAR. This pulse sequence may have a role in the diagnosis of endotension or sac hygroma.
142. Peripheral MR Angiography with MultiHance: Results of Large-Scale Multicenter Experience
Thurnher S.1; Schneider G.2; Schoenberg S.3; Herborn C.4; Pirovano G.5*; 1. Department of Radiology, University of Vienna, Vienna, Austria; 2. Department of Diagnostic Radiology, Homburg University Hospital, Homburg/Saar, Germany; 3. Institute of Clinical Radiology, Ludwig Maximilians University, Munich, Germany; 4. Department of Diagnostic and Interventional Radiology, University Hospital Essen, Essen, Germany; 5. Worldwide Medical Affairs, Bracco Diagnostics Inc., Princeton, NJ.
Address correspondence to G. Pirovano (gianpaolo.pirovano{at}diag.bracco.com)
Objective: To assess the accuracy of MultiHance®-enhanced (CE)-MR angiography in detecting peripheral artery disease using DSA as the gold standard.
Materials and Methods: Of the 287 recruited patients with Fontain's stage peripheral disease IIa to IV, 272 underwent both MRA and DSA. MRA was acquired at 1.5T using a 2D-TOF before and a 3D-SPGRE sequence after the administration of 0.1 mmol/kg MultiHance® covering from the aortic bifurcation to the trifurcation. Three experienced radiologists for MRA and one for DSA, blinded to all patient information, evaluated the images. Sensitivity, specificity, accuracy, technical failure rate and inter-reader agreement for detection of significant disease (= 50%) using DSA as gold standard were calculated for both TOF and CE-MRA and compared using McNemar's and Chi-square tests.
Results: A total of 983 vessels with significant disease (597 stenoses and 386 occlusions) were identified by the DSA reader. Sensitivity for detection of significant disease ranged from 33.2% to 62.8% and from 54% to 80.9% for TOF-MRA and CE-MRA, respectively. Specificity increased from 74.3–88.9% to 89.7–95.3% and accuracy from 68–77.3% to 85–87.5. All the increases were statistically significant (p < 0.001). Significant decreases (p < 0.001) in technical failure rate from 6.2%–18% for TOF-MRA to 2.5%–3.4% for CE-MRA approaching the values obtained for DSA (1.4%). Significantly better reproducibility (p < 0.00001) was obtained for CE-MRA (82% agreement, k-value: 0.66) compared to TOF MRA (65.2% agreement; k-value: 0.47).
Conclusion: Significant increases in diagnostic performance and reproducibility were demonstrated for MultiHance-enhanced MRA of peripheral vessels in comparison with TOF MRA.
143. Failing Arteriovenous Hemodialysis Fistulas: Assessment with Multidetector CT Angiography and Three-Dimensional (3D) Techniques
Karadeli E.1*; Tarhan N.C.1; Kayahan E.M.1; Tutar N.1; Basaran O.2; Tutal E.3; Coskun M.1; 1. Radiology, Baskent University Faculty of Medicine, Ankara, Turkey; 2. General Surgery, Baskent University Faculty of Medicine, Ankara, Turkey; 3. Nephrology, Baskent University Faculty of Medicine, Ankara, Turkey.
Address correspondence to E. Karadeli (elifkaradeli{at}gmail.com)
Objective: To evaluate the patency of failing arteriovenous hemodialysis fistulas and complications with multidetector CT angiography (MDCTA) and 3D reconstruction techniques.
Materials and Methods: Between September 2003 – July 2004, 30 patients (16M and 14F-aged between 27–79 years old), with suspected hemodialysis access dysfunction had 31 MDCTA (Sensation 16, Siemens, Erlangen, Germany). All fistulas were in the upper extremity. Contrast was administered from a peripheral vein of contralateral arm as a bolus of 150–200ml at a flow rate 5 cc/s. Axial scans were viewed in the arterial phase with reconstruction at 1 mm intervals. Axial MIP, coronal MIP, and VRT images were constituted. AV fistula sites, venous system complications were evaluated for each 3D planes, axial source images and all of the reconstruction and source images together separately and results were compared. Fistulography served as the gold standard for comparison. Statistical analysis was performed with McNemar test.
Results: 14 fistulas were in the wrist, 17 fistulas were in the antecubital fossa. There were 27 native, 4 graft fistulas. When fistula sites were evaluated, the highest sensitivity (93%) was obtained in axial MIP and VRT. In evaluation of venous stenosis, the highest sensitivity, specifity and accuracy (35%, 96%, 84%) were observed in coronal MIP. In detection of aneurysms, the highest sensitivity and accuracy was 100% detected with VRT and all of them. In evaluation of venous occlusion, the highest sensitivity was in all of them (61%), and axial MIP (53%), accuracy results were calculated as 91–93%. In detection of collateral formation, the highest sensitivity was 85% with axial MIP and VRT. Low sensitivity was obtained with only venous stenosis especially on axial source and axial MIP images because there were limitations in evaluation of central veins due to surrounding structures. When diagnosis of the venous pathologies was compared between MDCTA and fistulography, no statistically significant difference was found (p > 0.05).
Conclusion: MDCTA is a non-invasive, fast and effective imaging method to evaluate hemodialysis vascular access and complications. The accuracy of MDCT angiography is high but sensitivity varies with the pathology and 3D-rendering technique employed.
* Will present paper
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