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1.
Acta Radiol ; 44(6): 583-9, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14616201

ABSTRACT

PURPOSE: To assess the clinical value of three-dimensional coronary MR angiography (CMRA) in the detection of significant coronary artery stenosis using conventional X-ray angiography as the standard reference. MATERIAL AND METHODS: Sixty-nine patients underwent X-ray coronary angiography and CMRA because of suspected or previously diagnosed coronary artery disease. MRI was performed with a 1.5-T whole body imaging system using ECG-triggered 3D gradient echo sequence with retrospective navigator echo respiratory gating and fat suppression. RESULTS: A total of 276 coronary artery segments were analyzed. The X-ray coronary angiography was normal in 22 patients. Significant proximal stenoses (exceeding 50%) or occlusions were present in 102 coronary artery segments. In all, 120 stenoses or occlusions were identified in CMRA. Sixteen percent of the coronary artery segments had to be excluded because of poor image quality. The overall sensitivity and specificity for MRA for identification of significant stenosis were 75% and 62%, respectively. CMRA correctly detected 89% of patients with at least one vessel disease, but 6 patients with coronary artery disease would have been missed. CONCLUSIONS: Because of the high data exclusion and false- negative case rate, CMRA with retrospective navigator echo triggering is at present not suitable as a clinical screening method in coronary artery disease.


Subject(s)
Coronary Angiography , Coronary Stenosis/diagnosis , Coronary Vessels/pathology , Imaging, Three-Dimensional , Magnetic Resonance Angiography , Adult , Aged , Coronary Stenosis/diagnostic imaging , Electrocardiography , Female , Humans , Male , Middle Aged , Predictive Value of Tests , ROC Curve , Sensitivity and Specificity
2.
Cardiovasc Intervent Radiol ; 26(3): 298-301, 2003.
Article in English | MEDLINE | ID: mdl-14562983

ABSTRACT

This case illustrates successful treatment of a large postoperative intrasellar pseudoaneurysm with a polytetrafluoroethylene (PTFE)-covered stent. The advantages and potential disadvantages of this novel method of treatment are discussed. A previously healthy 59-year-old man underwent transsphenoidal operative treatment for hypophyseal macroadenoma, complicated by bleeding. On the 17th postoperative day the patient had profuse arterial bleeding from his nose requiring posterior tamponade. Subsequent angiography of the left internal carotid artery (ICA) revealed a large pseudoaneurysm located intrasellarly, with the orifice in the anteromedial wall in the ophthalmic segment of the ICA. Surgical treatment of the pseudoaneurysm was considered very risky. A 12-mm PTFE-covered stent (JoMed, Ulestraten, Netherlands), manually compressed on a PTCA-balloon (Maxxum 4.5/13 mm, Boston Scientific, Ireland) was endovascularly delivered covering the orifice of the pseudoaneurysm. Control angiography immediately after the intervention and one year later revealed no flow into the pseudoaneurysm and the ICA was fully patent. In conclusion, deployment of a PTFE-covered stent proved to be feasible and successful in the treatment of an intrasellar iatrogenic ICA pseudoaneurysm. Adequate anticoagulative treatment after the procedure is essential to prevent thrombotic complications.


Subject(s)
Carotid-Cavernous Sinus Fistula/surgery , Sella Turcica/blood supply , Sella Turcica/surgery , Blood Vessel Prosthesis , Carotid Artery, Internal/diagnostic imaging , Carotid Artery, Internal/pathology , Carotid Artery, Internal/surgery , Coated Materials, Biocompatible/therapeutic use , Humans , Male , Middle Aged , Polytetrafluoroethylene/therapeutic use , Sella Turcica/diagnostic imaging , Stents , Tomography, X-Ray Computed
3.
Clin Radiol ; 57(7): 632-9, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12096864

ABSTRACT

AIM: To identify plain radiographic findings that predict segmental lumbar spine instability as shown by functional flexion-extension radiography. MATERIALS AND METHODS: Plain radiographs and flexion-extension radiographs of 215 patients with clinically suspected lumbar spine instability were analysed. Instability was classified into anterior or posterior sliding instability. The registered plain radiographic findings were traction spur, spondylarthrosis, arthrosis of facet joints, disc degeneration, retrolisthesis, degenerative spondylolisthesis, spondylolytic spondylolisthesis and vacuum phenomena. Factors reaching statistical significance in univariate analyses (P < 0.05) were included in stepwise multiple logistic regression analysis. RESULTS: Degenerative spondylolisthesis (P = 0.004 at L3-4 level and P = 0.017 at L4-5 level in univariate analysis and odds ratio 16.92 at L4-5 level in multiple logistic regression analyses) and spondylolytic spondylolisthesis (P = 0.003 at L5-S1 level in univariate analyses) were the strongest independent determinants of anterior sliding instability. Retrolisthesis (odds ratio 10.97), traction spur (odds ratio 4.45) and spondylarthrosis (odds ratio 3.20) at L3-4 level were statistically significant determinants of posterior sliding instability in multivariate analysis. CONCLUSION: Sliding instability is strongly associated with various plain radiographic findings. In mechanical back pain, functional flexion-extension radiographs should be limited to situations when symptoms are not explained by findings of plain radiographs and/or when they are likely to alter therapy.


Subject(s)
Joint Instability/diagnostic imaging , Lumbar Vertebrae/diagnostic imaging , Spinal Diseases/diagnostic imaging , Adolescent , Adult , Aged , Analysis of Variance , Female , Humans , Intervertebral Disc/diagnostic imaging , Logistic Models , Male , Middle Aged , Radiography , Spondylarthropathies/diagnostic imaging , Spondylolisthesis/diagnostic imaging
4.
Acta Radiol ; 43(2): 116-24, 2002 Mar.
Article in English | MEDLINE | ID: mdl-12010286

ABSTRACT

OBJECTIVE: The aim of the study was to evaluate the ability of CT angiography (CTA) to detect atherosclerosis of the carotid arteries in comparison with 3D time-of-flight MR angiography (3D TOF MRA), using contrast angiography and intravascular ultrasound (IVUS) as a reference. MATERIAL AND METHODS: Contrast angiography and CTA were performed in 31 patients (mean age 65 years, range 45-79). The image quality was evaluated, atherosclerotic lesions were registered, and diameter stenosis degree was visually estimated from axial source images of CTA and 3D TOF MRA (21 patients), and results of interpretations were compared. The comparison of quantitative measurements was performed using IVUS as a reference. RESULTS: Contrast angiography detected 51 lesions (mean diameter stenosis 50%, range 10-100%), and CTA detected all same lesions. CTA provided better image quality and consistency of image interpretation than 3D TOF MRA. IVUS verified 29 atherosclerotic lesions with a mean diameter stenosis of 35%, (range 4-40%). CTA yielded a sensitivity of 96% to 100% (< or =10% or < or =20% diameter stenosis regarded as normal) for the detection of lesions with reference to IVUS. CONCLUSION: CTA seems feasible and accurate for the detection of atherosclerosis in carotid arteries.


Subject(s)
Carotid Artery Diseases/diagnostic imaging , Cerebral Angiography , Tomography, X-Ray Computed , Aged , Angiography, Digital Subtraction , Carotid Artery Diseases/diagnosis , Female , Humans , Magnetic Resonance Angiography , Male , Sensitivity and Specificity , Ultrasonography, Interventional
5.
Radiology ; 218(3): 711-8, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11230644

ABSTRACT

PURPOSE: To evaluate safety and efficacy of endovascular interventions in failing antebrachial Brescia-Cimino hemodialysis fistulas in consecutive patients. MATERIALS AND METHODS: Altogether, 103 interventions were performed in 53 Brescia-Cimino shunts in 51 patients by means of antegrade brachial arterial access. Twelve interventions were initiated with pharmacomechanical thrombolysis and/or thromboaspiration. All interventions included balloon angioplasty that was completed with stent placement in eight cases and with endovascular brachytherapy with an iridium 192 source in five cases. RESULTS: The technical success rate of the primary interventions was 92% (49 of 53) and that for all interventions was 95% (98 of 103). The rate of major complications was 4% (four of 103). Clinical success was achieved in 92% (95 of 103) of the interventions. By including the initial failures, 58% +/- 7 (standard error of the estimate), 44% +/- 8, 40% +/- 8, and 32% +/- 10 primary and 90% +/- 5, 85% +/- 5, 79% +/- 7, and 79% +/- 7 secondary clinical patency rates were registered at 6 months and 1, 2, and 3 years, respectively, by means of Kaplan-Meier analysis. The location of the main treated lesion at the arteriovenous anastomosis (P =.03) was a predictor of poorer long-term patency. CONCLUSION: Endovascular interventions with antegrade brachial arterial access are highly effective in restoring function in failing Brescia-Cimino fistulas.


Subject(s)
Arteriovenous Shunt, Surgical/methods , Brachial Artery/surgery , Renal Dialysis/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Prospective Studies , Reoperation , Safety , Thrombolytic Therapy , Treatment Outcome , Vascular Patency
6.
Methods Mol Med ; 52: 177-86, 2001.
Article in English | MEDLINE | ID: mdl-21340941

ABSTRACT

A number of imaging modalities have been used for evaluating the severity of atherosclerotic lesions in vivo. X-ray angiography, using iodine contrast agent, has been the standard imaging technique so far, in spite of its limitations. The severity of lumen-narrowing lesions is generally underestimated in X-ray angiography when compared to operative and histological findings, especially in cases of diffuse atherosclerosis or concentric stenosis. Because of compensatory enlargement of the vessel, human atherosclerotic plaques do not encroach on the lumen until the lesion occupies up to 40% of the combined arterial wall and lumen volume (1). Contrast angiography provides only indirect signs of atherosclerosis on the basis of analysis of the longitudinal silhouette of the vessel lumen, but does not give information about the structure of the vessel wall or morphology of the atherosclerotic lesions, with the exception of heavy calcifications. Magnetic resonance angiography (MRA) is already competing with X-ray angiography in many clinical applications (2). Preliminary data have suggested that magnetic resonance imaging (MRI) is able to provide information about the vessel wall and plaque characteristics ex vivo (3,4) and in vivo (5), but poor spatial and temporal resolution impairs thus far the utility of MR techniques in quantitation of atherosclerosis in animal models (6,7).

7.
Eur Radiol ; 10(11): 1754-62, 2000.
Article in English | MEDLINE | ID: mdl-11097403

ABSTRACT

Intravascular ultrasound (IVUS) imaging provides useful additional information to X-ray angiography in selected cases of balloon angioplasty and stent placement with complex vascular anatomy and unclear findings at angiography. It facilitates accurate measurements of the vessel dimensions and reveals the extent of the disease for the selection of proper angioplasty balloon size, as well as confirms full expansion and attachment of the stent or stent graft to the arterial wall. Intravascular US imagining contributes useful information for the basis of planning surgical or endovascular therapy of aortic dissection and is valuable for guiding percutaneous fenestration of the dissection flap. This imaging modality facilitates placement of vena cava filter without cavography and/or fluoroscopy in patients with contraindication for iodine contrast media and/or X-ray fluoroscopy. Technical development may further increase utility of IVUS imaging in interventional radiology.


Subject(s)
Radiology, Interventional , Ultrasonography, Interventional , Aortic Dissection/therapy , Angioplasty, Balloon , Aortic Aneurysm/therapy , Blood Vessel Prosthesis Implantation , Humans , Stents
8.
J Vasc Interv Radiol ; 11(8): 1021-31, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10997465

ABSTRACT

PURPOSE: To evaluate the safety and efficacy of infrapopliteal percutaneous transluminal angioplasty (PTA) as a primary treatment of chronic critical limb ischemia in a prospective trial. MATERIALS AND METHODS: Infrapopliteal PTA was performed on 72 limbs of 60 patients (mean age, 72 y; range, 38-92 y) and patients were followed for 12-24 months. RESULTS: The primary angiographic success rate for the stenoses was 84% (102 of 121) and that for the occlusions was 61% (41 of 67) with corresponding restenosis rates of 32% and 52% at follow-up angiography performed a mean of 10 months after primary PTA. The rate of major complications was 2.8% (access site pseudoaneurysms in two patients). The primary clinical success was 63% (45 of 72). A 48% cumulative primary patency rate, a 56% secondary patency rate, and a 80% cumulative limb salvage rate were registered at 18 months, as determined with use of Kaplan-Meier analysis. Lack of angiographic improvement at the site of the most severe ischemia and renal insufficiency (serum creatinine level > 130 micromol/L) were independent predictors of poorer long-term clinical results, as determined with use of Cox multiple regression analysis. CONCLUSIONS: Infrapopliteal PTA is a feasible primary treatment of chronic critical limb ischemia with moderate primary angiographic and clinical success, a low complication rate, and a cumulative limb salvage rate comparable with surgical techniques.


Subject(s)
Angioplasty, Balloon , Ischemia/therapy , Leg/blood supply , Popliteal Artery , Adult , Aged , Aged, 80 and over , Angiography , Arterial Occlusive Diseases/therapy , Chi-Square Distribution , Female , Humans , Logistic Models , Male , Middle Aged , Popliteal Artery/diagnostic imaging , Popliteal Artery/surgery , Proportional Hazards Models , Prospective Studies , Statistics, Nonparametric , Treatment Outcome , Vascular Patency
9.
J Comput Assist Tomogr ; 24(3): 375-81, 2000.
Article in English | MEDLINE | ID: mdl-10864071

ABSTRACT

The purpose of this study was to evaluate the technical quality of 3D coronary MR angiography (CMRA) with navigator echo and the consistency of image interpretation in repeated imaging sessions. Fourteen subjects underwent CMRA, 10 of whom were imaged twice. The coronary arteries (96 segments) were analyzed twice for hemodynamically significant stenoses. Signal-to-noise and contrast-to-noise ratios varied considerably between the two imagings. Fat saturation was poor or satisfactory in 37%; in 15% of the slabs, the severity of artifacts was moderate; and the overall quality was good to excellent in only 42% of the imagings. The intraobserver reproducibility was good (kappa = 0.54), but the consistency of interpretation for repeated CMRA was only satisfactory (kappa = 0.43). Sensitivities of 84 and 84% and specificities of 70 and 62% were obtained for the two readings. Although the reproducibility of image reading is good, 3D CMRA with navigator echo provides only fair technical consistency, and the frequently compromised image quality impairs the clinical utility of this technique.


Subject(s)
Coronary Vessels/anatomy & histology , Magnetic Resonance Angiography/standards , Adult , Aged , Coronary Angiography , Coronary Disease/diagnosis , Female , Humans , Magnetic Resonance Angiography/methods , Male , Middle Aged , Observer Variation , Reproducibility of Results
10.
Radiology ; 212(2): 483-92, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10429707

ABSTRACT

PURPOSE: To compare endovascular stent placement with percutaneous transluminal angioplasty (PTA) of carotid arteries with respect to distal embolization and findings at intravascular ultrasonography (US), magnetic resonance (MR) imaging, and histopathologic analysis. MATERIALS AND METHODS: PTA was performed in situ in one carotid artery, and stent placement was performed in the other, in ten cadavers (age range, 57-82 years; mean age, 68 years) with severe atherosclerosis by using fluoroscopic and intravascular US guidance. The carotid artery was connected to a pressurized tubing system in which a pulsatile pump circulated water. The effluent water was collected during the interventions, and after filtration and staining, the embolic material was analyzed histologically. After the interventions, the arteries were excised and 1.5-T spin-echo MR imaging was performed. RESULTS: No difference in severity of distal embolization during stent placement versus during PTA was found. The embolic particles were composed mainly of intimal strips and cellular constituents of the atherosclerotic plaques. MR imaging accurately depicted postinterventional changes, and the findings correlated closely with those of intravascular US and histopathologic analysis. CONCLUSION: Although stent placement and PTA were associated with equal distal embolization, the smooth surface and fully patent arterial lumen depicted at intravascular US and MR imaging postinterventionally may indicate that stent placement is preferable to PTA.


Subject(s)
Angioplasty, Balloon , Carotid Stenosis/therapy , Embolism, Cholesterol/pathology , Intracranial Arteriosclerosis/therapy , Stents , Aged , Cadaver , Carotid Stenosis/diagnostic imaging , Carotid Stenosis/pathology , Embolism, Cholesterol/etiology , Female , Humans , Intracranial Arteriosclerosis/diagnostic imaging , Intracranial Arteriosclerosis/pathology , Magnetic Resonance Imaging , Male , Ultrasonography, Interventional
11.
Cardiovasc Intervent Radiol ; 22(3): 219-23, 1999.
Article in English | MEDLINE | ID: mdl-10382053

ABSTRACT

PURPOSE: To evaluate the angiographic patterns of clinically manifest recurrent disease after infrainguinal percutaneous transluminal angioplasty (PTA) of stenoses and total occlusions. METHODS: Among 326 infrainguinal PTAs on 263 consecutive patients, selective angiography was performed on 61 limbs of 52 patients 1-60 months after the primary intervention because of clinically suspected recurrent disease. Lesion-specific and patient-related factors were analyzed for 75 angiographically confirmed recurrent lesions in 57 limbs of 48 patients. RESULTS: Recurrent disease was more frequently a stenosis when the original target lesion was a stenosis (92%, 44/48) than when the original lesion was a total occlusion (59%, 16/27; p < 0.001). When the original target lesion was a stenosis, the total length of the recurrent disease was longer than that of the original lesion [3.9 +/- 3.9 cm (mean +/- standard deviation) vs 2.8 +/- 2.7 cm; p = 0.03], while in the subgroup of original total occlusions the length of the recurrent lesion was shorter than that of the original occlusion (7.1 +/- 5.0 cm vs 9.9 +/- 6.9 cm; p = 0.02). Half the restenosis (22/44) extended beyond one or both ends of the original stenosis and 38% (6/16) of the reocclusions extended beyond the distal end of the original occlusion. CONCLUSIONS: The type of recurrent disease depends on the original lesion type and the restenotic lesion frequently extends beyond one or both ends of the original target lesion.


Subject(s)
Angioplasty, Balloon , Arterial Occlusive Diseases/therapy , Intermittent Claudication/therapy , Ischemia/therapy , Aged , Arterial Occlusive Diseases/diagnostic imaging , Constriction, Pathologic/diagnostic imaging , Constriction, Pathologic/therapy , Female , Humans , Intermittent Claudication/diagnostic imaging , Ischemia/diagnostic imaging , Leg/blood supply , Male , Radiography , Recurrence
12.
Acta Radiol ; 40(3): 291-5, 1999 May.
Article in English | MEDLINE | ID: mdl-10335967

ABSTRACT

PURPOSE: To compare iodixanol 270 mg I/ml with iohexol 300 mg I/ml in infrapopliteal arteriography by measuring digital densitometric vessel opacification and by visually assessing angiographic enhancement. MATERIAL AND METHODS: In a double-blind, dual-balanced, 4-sequence cross-over design, 50 claudicant patients received two contrast media injections (10 min interval) in the superficial femoral artery. Digital angiography was performed at 8 frames/s and time-density curves with a circular region of interest over a distal calf artery were generated. A mixed, linear model was used to identify effects influencing the density measurements. Subjective evaluation of the image quality was made independently by two observers. RESULTS: No statistically significant difference between the contrast media was revealed in the analysis of the densitometric measurements (p=0.14) nor in the subjective visual evaluation (p=0.74). However, the mean density at the time of maximum opacification was higher after the first injection than that after the second injection (p=0.02). There was a tendency towards lower intensity of warmth during injection of iodixanol 270 than during injection of iohexol 300. CONCLUSION: In patients with severe occlusive atherosclerotic disease, iodixanol yielded the same image quality as iohexol in infrapopliteal arteriography, in spite of the 30 mg I/ml lower iodine concentration.


Subject(s)
Absorptiometry, Photon , Angiography , Contrast Media , Iohexol , Leg/blood supply , Radiographic Image Enhancement , Triiodobenzoic Acids , Adult , Aged , Aged, 80 and over , Cross-Over Studies , Double-Blind Method , Female , Humans , Intermittent Claudication/diagnostic imaging , Male , Middle Aged
13.
Stroke ; 30(4): 827-33, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10187887

ABSTRACT

BACKGROUND AND PURPOSE: Our aim was to evaluate the usefulness of 3-dimensional time-of-flight magnetic resonance angiography (3-D TOF MRA) in detection and quantification of mild atherosclerotic changes of carotid arteries with reference to intravascular ultrasound (IVUS) and contrast angiography. METHODS: TOF MRA at 1.5 T, IVUS, and selective digital subtraction angiography were performed on 31 extracranial carotid arteries of 27 patients (mean age, 52 years; age range, 17 to 75 years) undergoing neuroendovascular interventions. The atherosclerotic lesions were registered, and quantitative measurements of plaque thickness, luminal diameters, and diameter stenosis were independently performed for the imaging modalities. RESULTS: Among 170 arterial segments analyzed, IVUS revealed a total of 48 atherosclerotic lesions (mean diameter stenosis, 17%; range, 4% to 40%), only 25 of which were depicted on digital subtraction angiography. Analysis of the axial source images of TOF MRA resulted in sensitivity of 77% to 83% and specificity of 71% to 80% in lesion depiction for the 2 readers with reference to IVUS. The values of diameter stenosis measured from MRA and IVUS were closely interrelated (r=0.53 to 0.61, P<0.001). CONCLUSIONS: Three-dimensional TOF MRA is feasible and moderately accurate for evaluation of mild atherosclerotic changes of carotid arteries.


Subject(s)
Arteriosclerosis/diagnostic imaging , Carotid Artery Diseases/diagnostic imaging , Cerebral Angiography/standards , Magnetic Resonance Imaging/methods , Ultrasonography, Interventional/standards , Adolescent , Aged , Artifacts , Carotid Arteries/diagnostic imaging , Carotid Arteries/pathology , Female , Humans , Magnetic Resonance Imaging/standards , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
14.
Cardiovasc Intervent Radiol ; 21(5): 361-6, 1998.
Article in English | MEDLINE | ID: mdl-9853140

ABSTRACT

PURPOSE: To evaluate complications and their predictors in percutaneous transluminal angioplasty (PTA) of lower-limb arteries. METHODS: Complications in 410 angioplasty procedures in 295 consecutive patients (192 claudicants and 103 suffering from chronic critical ischemia) were prospectively analyzed. RESULTS: The total complication rate was 10.5% (43/410). There were 21 major complications (5%), eight of which required surgical treatment, including four hematomas, two arteriovenous fistulae, and two pseudoaneurysms at the puncture site, two retroperitoneal hematomas, and 11 thrombotic/thromboembolic complications. There were significantly more complications with treatment of occlusions compared with stenoses (18% vs 7%, p = 0.002). Women had significantly more bleeding complications than men (15% vs 6%, p = 0.032). The 30-day mortality rate in patients with critical ischemia was 10%. CONCLUSION: In lower-limb PTA a few target lesion- and patient-related determinants of complications could be identified. In patients with critical ischemia, the 30-day mortality was rather high and mainly due to associated coronary and cerebrovascular diseases.


Subject(s)
Angioplasty, Balloon/adverse effects , Peripheral Vascular Diseases/therapy , Adult , Aged , Aged, 80 and over , Analysis of Variance , Angioplasty, Balloon/methods , Angioplasty, Balloon/mortality , Female , Follow-Up Studies , Hemorrhage/etiology , Humans , Incidence , Leg , Logistic Models , Male , Middle Aged , Peripheral Vascular Diseases/diagnosis , Prospective Studies , Risk Factors , Survival Rate , Thromboembolism/etiology , Treatment Outcome , Vascular Diseases/etiology
15.
Ann Thorac Surg ; 66(4): 1289-94, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9800822

ABSTRACT

BACKGROUND: There are few data about angiographic determinants of functional graft patency and native artery disease progression after coronary artery bypass grafting operation with arterial grafts compared with venous grafts. METHODS: Baseline and follow-up coronary angiograms at a mean of 2 years after operation in 91 patients with 194 arterial and 204 venous graft anastomoses were analyzed. RESULTS: Ninety-two percent of the arterial and 87% of the venous graft anastomoses were patent at follow-up angiography (p = 0.05, odds ratio = 2.63). Unlike that of arterial grafts, the patency rate of venous graft anastomoses correlated negatively with decreasing severity of the bypassed lesion. In contrast to venous grafts, in which angiographic graft function was basically dichotomous (fully patent or occluded), compromised flow of the arterial graft anastomoses was registered in 12%. Progression of the disease was more common in segments bypassed with venous grafts than with arterial grafts (p = 0.001, odds ratio = 2.03). CONCLUSIONS: Angiographic determinants of functional graft patency and progression of occlusive changes in the bypassed artery segments are different for arterial and venous grafts.


Subject(s)
Coronary Angiography , Coronary Artery Bypass , Coronary Disease/diagnostic imaging , Graft Occlusion, Vascular/diagnostic imaging , Coronary Artery Bypass/methods , Coronary Circulation/physiology , Coronary Disease/surgery , Disease Progression , Female , Follow-Up Studies , Humans , Male , Middle Aged , Saphenous Vein/transplantation , Time Factors , Vascular Patency/physiology
16.
Invest Radiol ; 33(8): 464-71, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9704286

ABSTRACT

RATIONALE AND OBJECTIVES: The authors compare the usefulness of intravascular ultrasound (IVUS) and magnetic resonance imaging (MRI) for quantitation of atherosclerosis in hyperlipidemic rabbits, correlated with histopathology. METHODS: Magnetic resonance imaging with T1- and T2-weighted spin echo sequences and three-dimensional time-of-flight MR angiography of the abdominal aorta was performed on seven rabbits using a 1.5 T MR imager and a standard head coil. X-ray angiography and IVUS examination (3.5 F/30 MHz imaging catheter) was performed via carotid artery access. RESULTS: Time-of-flight MR angiography source images provided the best resolution and plaque-lumen contrast in visual comparison between the different MRI sequences. Intra- and interobserver reproducibilities of the lesion thickness and area measurements were similar in IVUS and MRI (Pearson correlations 0.52-0.97; P < 0.01). The measurements from IVUS and MRI correlated closely with each other as well as with those made from histopathologic specimens (Pearson correlations 0.50-0.79; P < 0.001). The measurements from IVUS were somewhat more accurate than those made from MRI. CONCLUSIONS: Both MRI and IVUS with clinically available imaging equipments are feasible and accurate for the quantitation of experimental atherosclerosis of rabbit aorta.


Subject(s)
Aortic Diseases/diagnosis , Arteriosclerosis/diagnosis , Magnetic Resonance Imaging , Ultrasonography, Interventional , Animals , Aorta, Abdominal/diagnostic imaging , Aorta, Abdominal/pathology , Aortic Diseases/diagnostic imaging , Aortic Diseases/pathology , Arteriosclerosis/complications , Arteriosclerosis/diagnostic imaging , Arteriosclerosis/pathology , Hyperlipidemias/complications , Hyperlipidemias/pathology , Magnetic Resonance Angiography , Observer Variation , Rabbits
17.
J Comput Assist Tomogr ; 22(4): 533-40, 1998.
Article in English | MEDLINE | ID: mdl-9676442

ABSTRACT

PURPOSE: Our goal was to evaluate CT angiography (CTA) in diagnosing renal artery stenosis (RAS). METHOD: Thirty-seven patients underwent digital subtraction angiography (DSA) and CTA. Visual interpretation and stenosis measurements were made from maximum intensity projection (MIP) and multiplanar reformation (MPR) laser film prints of 78 renal arteries. RESULTS: Visual reading of MIP films showed good diagnostic performance by receiver operating characteristic curve analysis, with 100% sensitivity in the assessment of > or = 50% RAS but only 42-54% specificity (overall accuracy 60-75%). The false-positive rate decreased when MIP and MPR films were read together, but the excess of false negatives among the calcified lesions disabled this diagnostic algorithm. Combining visual interpretation of MIP films with quantitative measurements yielded the best diagnostic performance: 92% sensitivity, 80% specificity, and 84% overall accuracy. Renal cortical enhancement measurements (26 patients) had 81% overall accuracy. CONCLUSION: The overall accuracy of CTA with MIP film reading can be enhanced by quantitative measurement of stenosis or reviewing MPRs.


Subject(s)
Angiography/methods , Renal Artery Obstruction/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Aged, 80 and over , Algorithms , Angiography/statistics & numerical data , Angiography, Digital Subtraction/instrumentation , Angiography, Digital Subtraction/methods , False Negative Reactions , False Positive Reactions , Female , Humans , Kidney/diagnostic imaging , Male , Middle Aged , Observer Variation , ROC Curve , Renal Artery/diagnostic imaging , Sensitivity and Specificity , Statistics, Nonparametric , Tomography, X-Ray Computed/statistics & numerical data
18.
Radiology ; 206(1): 65-74, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9423653

ABSTRACT

PURPOSE: To establish the intravascular ultrasound (US) morphology of the arterial wall in various segments of the carotid artery and to evaluate atherosclerotic changes correlated with angiographic and in vitro histopathologic findings. MATERIALS AND METHODS: A total of 67 carotid arteries were imaged with a 3.5-F, 30-MHz intravascular US catheter: Twenty-four arteries were studied in vivo in 22 patients during neuroendovascular interventional procedures, in situ in 10 cadaveric arteries, and in vitro in 33 fresh excised arteries. RESULTS: In vivo, none of 10 calcifications and five (29%) of 17 intimal thickenings detected at intravascular US were seen at contrast material-enhanced angiography. At intravascular US, the arterial wall morphology was consistently three layered in the internal carotid artery above the bulb, either vaguely three layered or homogeneous in the bulb and in the carotid bifurcation, and homogeneous in the majority of common carotid arteries. The medial-adventitial interface was distinct in 21 (88%) of 24 arteries in vivo. Histopathologic and intravascular US classifications of the plaque agreed for 31 (82%) of the 38 arterial specimens in vitro. CONCLUSION: In vivo intravascular US was feasible in carotid arteries with mild atherosclerosis and often revealed intimal thickenings and concentric plaques in angiographically normal segments.


Subject(s)
Arteriosclerosis/diagnostic imaging , Carotid Arteries/diagnostic imaging , Carotid Stenosis/diagnostic imaging , Ultrasonography, Interventional , Adult , Aged , Angiography, Digital Subtraction , Arteriosclerosis/pathology , Cadaver , Carotid Arteries/pathology , Carotid Stenosis/pathology , Cerebral Angiography , Feasibility Studies , Female , Humans , Male , Middle Aged , Reference Values
19.
Neuroradiology ; 39(10): 728-32, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9351111

ABSTRACT

The suitability of the cerebrospinal fluid (CSF) in the lumbosacral dural sac as an internal signal-intensity reference was studied on magnetic resonance imaging (MRI) of the lumbar spine using a surface coil and motion artefact suppression technique. A signal-intensity reference is needed when signal is compared between images, studies or subjects. Homogeneity of the CSF was estimated visually on T2-weighted images of 60 subjects at 1.5 T and of another 60 subjects at 0.1 T. Spines with a severely narrowed dural sac or marked scoliosis were excluded from the study to avoid partial volume effect. CSF was homogeneous in 82% and 73% of the examinations at 1.5 T and 0.1 T, respectively. The type and location of the local inhomogeneities did not relate to local narrowings of the dural sac. The signal intensity of CSF was measured in 108 examinations at 0.1 T after correcting the spatially-dependent signal-intensity non-uniformities with a phantom-based method. The signal-intensity difference between the CSF in the upper and lower lumbar dural sac was less than 10% in 73% of the examinations. The CSF in the lumbosacral dural sac can be a useful signal-intensity reference for estimation of the signal of the adjacent structures in patients without severe narrowing of the dural sac or marked scoliosis. It may contribute to assessing spinal disease processes.


Subject(s)
Cerebrospinal Fluid/physiology , Dura Mater/pathology , Lumbar Vertebrae/pathology , Magnetic Resonance Imaging , Sacrum/pathology , Spinal Diseases/diagnosis , Adult , Aged , Diagnosis, Differential , Humans , Intervertebral Disc Displacement/diagnosis , Male , Middle Aged , Phantoms, Imaging , Reference Values , Scoliosis/diagnosis , Sensitivity and Specificity , Spinal Nerve Roots/pathology
20.
Cardiovasc Intervent Radiol ; 20(5): 353-8, 1997.
Article in English | MEDLINE | ID: mdl-9271645

ABSTRACT

PURPOSE: To evaluate the suitability of transbrachial access for endovascular renal artery interventions. METHODS: During 37 consecutive endovascular renal artery interventions, the transbrachial approach was used on nine patients (mean age 63 years; range 41-76 years) for 11 renal artery procedures on native kidneys and one percutaneous transluminal angioplasty (PTA) on a transplanted kidney. The reason for using transbrachial access was a steep aorta-renal angle in five, and severe aorta-iliac atherosclerosis in the remaining patients. In addition to the intervention catheter in the left brachial artery, an additional nonselective catheter for controlling the procedure was inserted transfemorally (six patients) or via the contralateral brachial artery. RESULTS: Eleven interventions (six PTAs, five stents) were successfully completed. The one failure resulted from impenetrable subclavian artery stenosis. The only major complication was a brachial artery pseudoaneurysm requiring surgical treatment. CONCLUSION: Transbrachial access is an effective and relatively safe technique for renal artery interventions when transfemoral access is not possible.


Subject(s)
Angioplasty, Balloon/methods , Brachial Artery , Renal Artery Obstruction/therapy , Aged , Female , Humans , Hypertension, Renovascular/therapy , Male , Middle Aged , Radiography , Renal Artery Obstruction/diagnostic imaging , Stents
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