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[Analysis of three-dimensional imaging of the right hepatic vein and right portal vein branch using 2D-TOF MR angiography: evaluation of utility of MR angiography in determining puncture course on TIPS].

2D-TOF MR angiographies were performed in seven patients of liver cirrhosis with hepatocellular carcinoma to investigate three-dimensional anatomical relationships of the right hepatic vein and first order of right portal vein branch. The puncture course was set up in three-dimensional rectangular coordinates, and the bend angle and turning angle of the modified Ross needle, and puncture distance were calculated of the data measured on the A-P and L-R projection images of MR angiograms. The utility and limitation of 2 D-TOF MR angiography to determine the puncture course on TIPS were discussed in this study.

Adult↗

Correlation of 3D MR coronary angiography with selective coronary angiography: feasibility of the motion-adapted gating technique.

The aim of this study was to verify the feasibility of a respiratory motion compensation technique (motion-adapted gating, MAG) for visualization of coronary arteries (CA) by correlation with selective coronary angiography (SCA). Fifteen subjects (11 patients, mean age 61.3 years, age range 41-73 years; and 4 healthy volunteers, mean age 32.3 years, age range 31-35 years) were investigated. A Philips Gyroscan ACS-NT was used, operating at 1.5 T, was combined with the PowerTrak 6000 gradient system. An ECG-triggered, respiratory motion-gated 3D turbo field echo sequence was used. The real-time algorithm utilized the concept of k-space weighting in combination with automatic analysis of respiratory motion. The main CA were investigated. Qualitative analysis was performed by three blinded investigators. Visibility was graded on a five-point scale (0=not visualized, 1=insufficient, 2=sufficient, 3=good, 4=excellent). Segments graded 2-4 were defined as adequately visualized. Sixty-two of 88 assessable CA segments in patient, and 22 of 32 in volunteer group were adequately visualized. Visibility of CA was classified as excellent for proximal RCA (avg. 3.6+/-0.5), good for LM, proximal LAD, proximal LCX, middle RCA and sufficient for middle LAD. Sensitivity, specificity, positive and negative predictive values for coronary MRA in detection of CA stenoses with luminal narrowing >/=50% were 88, 94, 83, and 96%, respectively. Magnetic resonance imaging in combination with MAG has proven to be a promising technique for noninvasive imaging of CA due to good image quality and a patient convenient free-breathing technique.

Adult↗

A multicenter, site-independent, blinded study to compare the diagnostic accuracy of contrast-enhanced magnetic resonance angiography using 1.0M gadobutrol (Gadovist) to intraarterial digital subtraction angiography in body arteries.

PURPOSE: Prospective evaluation of diagnostic accuracy of single field-of-view contrast-enhanced MR Angiography (ceMRA) with 1.0M gadobutrol compared to intraarterial DSA in body arteries. MATERIALS AND METHODS: In an European multicenter study 179 patients underwent ceMRA and DSA. For each indication five prospectively defined vessel segments were evaluated by local investigators onsite and by three site-independent blinded readers (BR) independently. RESULTS: The agreement between ceMRA and DSA diagnosis was statistically significant in the onsite (96.6%) and blinded reader (86.6-90.2%) evaluation. Sensitivity, specificity, accuracy, positive (PPV) and negative predictive values (NPV) for detection of relevant stenosis (>50%) were calculated for the right and left internal carotid arteries, and common and external iliac arteries: Sensitivity was 95-98% (onsite) and 76-96% (BR), specificity 94-96% (onsite) and 86-94% (BR), accuracy 96% (onsite) and 87-93% (BR), NPV 98-99% (onsite) and 84-98% (BR), and PPV 79-93% (onsite) and 44-91% (BR), respectively. CONCLUSION: CeMRA of body arteries using 1.0M gadobutrol provides diagnostic information comparable to intraarterial DSA.

Adult↗

Gadolinium-enhanced magnetic resonance angiography, colour duplex and digital subtraction angiography of the lower limb arteries from the aorta to the tibio-peroneal trunk in patients with intermittent claudication.

OBJECTIVES: To evaluate the sensitivity, specificity, positive and negative predictive value of contrast-enhanced (gadolinium) magnetic resonance imaging (CE-MRA) and colour duplex ultrasound (CDU) of lower limb arteries. DESIGN: Prospective, single centre study. MATERIAL AND METHODS: A consecutive series of 58 patients with intermittent claudication (IC) were examined with CE-MRA and CDU from the infrarenal aorta to the tibio-peroneal trunk with digital subtraction angiography (DSA) as reference. The arterial tree was divided into 15 segments, pooled into three regions; suprainguinal, thigh and knee. Sensitivity, specificity, positive and negative predictive values for significant obstructions were calculated. Cohen Kappa statistics was used to establish agreement between the three methods. RESULTS: The sensitivity (specificity in parentheses) for significant obstructions in the suprainguinal region were 96% (94%) for CE-MRA and 91% (96%) for CDU, in the thigh region 92% (95%) for CE-MRA and 76% (99%) for CDU, and in the knee region 93% (96%) for CE-MRA and 33% (98%) for CDU. CDU failed to visualize 10% of suprainguinal, 2% of thigh and 13% of knee-region arterial segments. CONCLUSIONS: Both CE-MRA and CDU are good alternatives to DSA in the suprainguinal- and thigh-region. In the knee region only CE-MRA can be relied upon as an alternative to DSA. Imaging by CDU is not suited to situations were evaluation of runoff vessels is important.

Aged↗

Comparison of nonsubtracted digital angiography and conventional screen-film angiography for the evaluation of patients with peripheral vascular disease.

Recently, x-ray equipment manufacturers have produced systems capable of generating nonsubtracted digital angiograms (NSDA) of the arteries of the lower extremities with a high-resolution 1,024 x 1,024 matrix. One such system was compared with conventional screen-film angiography (CSFA) for the evaluation of peripheral vascular disease. Both NSDA and CSFA were performed prospectively in an identical fashion on 47 patients. The images were evaluated, and diagnostic adequacy (ie, information sufficient to direct subsequent therapy) and a variety of image quality attributes--vessel opacification, correct timing, complete anatomic coverage, and ease of reading--were compared. CSFA and NSDA provided similar diagnostic information. NSDA was judged superior to CSFA with regard to timing (P less than .001). CSFA was judged superior with regard to anatomic coverage (P less than .001) and ease of reading (P less than .01). NSDA is a promising method for evaluating patients with peripheral vascular disease. Further work is needed to provide more complete anatomic coverage and to improve the quality of the hard-copy images.

Angiography↗

[Contrast media enhanced magnetic resonance angiography for determining patency of a coronary bypass. A comparison with coronary angiography].

AIM: Assessment of graft patency with current non-invasive MRA techniques is particularly difficult for evaluating internal mammary artery grafts. Our aim is to determine the accuracy of a contrast enhanced MRA technique is assessing graft patency. METHODS: We examined 19 patients with a total of 53 grafts (32 venous/21 arterial), using an ultrafast contrast enhanced 3D gradient-echo technique and compared this with the results of selective angiography. RESULTS: Sensitivity of the contrast enhanced method was 95.2% for venous grafts, 94.4% for IMA grafts and 94.8% overall. Specificity was 85.7% overall, 90.9% for venous and 66.7% for IMA grafts. Positive predictive value was 94.4%. CONCLUSION: Compared with previous studies, visualisation of IMA grafts was improved by using contrast enhanced MRA. In this preliminary study, contrast enhanced MRA proved promising for the assessment of graft patency.

Adult↗

Moyamoya disease in an adult with Down syndrome: comparison of magnetic resonance angiography and conventional angiography.

Moyamoya disease, or idiopathic progressive arteriopathy, is a vascular occlusive disease that results in stenosis of the internal carotid arteries, stimulating the development of collaterals and telangiectatic vasculature from basilar and leptomeningeal arteries. Within the past several years, several reports have suggested that children with Down syndrome can develop moyamoya vasculopathy. We present the first reported magnetic resonance angiographic diagnosis of moyamoya disease in an adult with Down syndrome. This was also confirmed by conventional cerebral angiography.

Adult↗

Time-of-flight MR angiography with Gd-DTPA hexamethylene diamine co-polymer blood pool contrast agent: comparison of enhanced MRA and conventional angiography for arterial stenosis induced in rabbits.

Vascular stenoses were induced in the external iliac arteries of New Zealand white rabbits by a combination of hypercholesterolemic diet and repeat balloon injury. Two-dimensional (2D) and three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) was performed with a specifically designed phased array coil in a 1.5 T system. Enhancement with gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) hexamethylene diamine co-polymer (Nycomed: NC 22181), a blood pool MR contrast agent, was measured after contrast administration and compared with pre-contrast images at the same levels. Vessel diameter measurements were obtained at multiple levels and compared with comparable levels on conventional angiograms of the same animals. Stable enhancement, averaging 227% above baseline, was observed with the 3D TOF MRA over the 40 minutes of this study. Enhancement was not observed with the 2D TOF technique. Measurement of the smallest vessels in this study with 3D TOF MRA was slightly improved following contrast enhancement, although both pre- and post-contrast diameter measurements tended to underestimate the assumed true vessel diameter. Thus, Gd-DTPA hexamethylene diamine co-polymer (Nycomed: NC 22181), a blood pool MR contrast agent, produces significant, stable enhancement with the 3D TOF technique and may improve MRA measurement of small vessels.

Angioplasty, Balloon↗

Effects of angiographic contrast medium on left ventricular function: evaluation by contrast angiography and radionuclide angiography.

The purpose of this study was to evaluate the effect of angiographic contrast medium on left ventricular (LV) function in 26 patients undergoing diagnostic cardiac catheterization. Beat-by-beat analysis during contrast ventriculography showed that the ejection fraction (EF) was lower in the last beats than in the first beats (P less than .02). Radionuclide angiograms were obtained the day before, as well as 15 to 65 minutes after catheterization, which included contrast ventriculography and coronary anteriography. The EF by radionuclide angiography was lower after catheterization than before (43 +/- 14% vs 47 +/- 17%, P less than .01). The EF decreased by greater than or equal to 5% in 11 of the 26 patients (42%) after catheterization. The decrease in EF in some patients was observed up to 65 minutes after catheterization and was not associated with symptoms or ST-T changes. The EF decreased in only one of nine patients who received nitroglycerin during catheterization, whereas it decreased in 10 of 17 patients who did not receive nitroglycerin (P less than .05). The EF decreased in 9 of 14 patients (64%) who had normal resting LV function, whereas it decreased in only 2 of 12 patients (17%) who had abnormal resting function (P less than .05). Thus, contrast material may depress LV function up to 1 hr and is more frequent in patients with normal resting EF. The use of nitroglycerin during catheterization may mask this effect.

Adult↗

ECG changes during cerebral angiography. An analysis of 334 patients--942 cerebral angiographies.

We have analyzed HR changes greater than 20% among 334 patients and 942 cerebral angiographies. A tachycardial effect was seen in 14.9% of patients, while a bradycardial effect was seen in 7.1% including two patients having cardiac standstill (0.5%). These two patients were examined without atropine premedication after subarachnoid hemorrhage. Patients under 19 years of age, unpremedicated with atropine sulfate and suffering from subarachnoid hemorrhage secondary to ruptured aneurysm or arteriovenous malformation showed a significantly high incidence of bradycardia. On the other hand, patients with the neoplastic disease and having an initial sinus bradycardia showed a significantly high incidence of a tachycardial effect.

Adolescent↗

Magnetic resonance angiography of extracranial carotid and vertebral arteries, including their origins: comparison with digital subtraction angiography.

Although carotid bifurcation stenoses are not the only lesions of the extracranial cerebral arteries, magnetic resonance angiographic (MRA) studies to date have concentrated on the carotid bifurcation. We compared digital subtraction angiography of the extracranial portions of the cerebral arteries with MRA using an ordinary body coil, the time-of-flight method, and multiple transverse slabs which covered the arteries down to the aortic arch. Twenty-two patients (15 with arteriosclerotic diseases, 4 with aortitis, and 3 with tumours) had MRA using a 1.5 T magnet system with a three-dimensional fast imaging with steady state precession (FISP) technique. Thirty-nine carotid and 39 vertebral arteries were assessed by three radiologists with regard to stenoses or occlusions, graded as normal, mild (< 30%), moderate (30-60%) or severe (> 60%) stenosis, or occluded. Grading corresponded well in 81%; stenoses appeared more marked on MRA in 14% and were seen less clearly on MRA in 5%. When 26 carotid bifurcations were assessed separately, grading corresponded well in 95%. MRA is the only method which can display the whole course of the extracranial carotid and vertebral arteries non-invasively and satisfactorily.

Adolescent↗

[Conventional magnetic resonance angiography and contrast enhanced magnetic resonance angiography of extracranial blood vessel segments].

The introduction of fast gradient systems allows a reliable visualization of the extracranial carotid vessels by the magnetic resonance angiography (MRA) which meanwhile is implemented into clinical routine. By the mainly applied time-of-flight (TOF) technique, vessels can be imaged without contrast agent (CA). Due to the application of ultra-fast gradient-echo-sequences, the first-pass evaluation of an intravenous bolus-injection of Gadolinium in the carotids from the aortic arch up to the skull base can be performed in less than 30 s. In this study. Advantages and disadvantages of both techniques are discussed. For a qualitatively optimal contrast enhanced MRA (CE-MRA) timing parameters like injection delay, flow rate and the adjustment of sequence parameters have to be considered in relation to the fast venous return from the sinus to the jugular veins. First, the optimal time point of the data acquisition have been determined at a model and with a computer simulation in reference to the presence of CA in the arteries. As a result, 90% of the contrast contribution is defined by 16% of the symmetrically acquired central k-space lines. A measuring protocol for clinical use was obtained by a gradual variation of spacial resolution, measuring time and CA-injection parameters and was proved in normal volunteers and patients. An exact determination of the bolus-arrival-time by means of a test-bolus injection was acquired. The best qualitative results were achieved by a double-dose- injection at 2 ml/s injection rate. The temporal reserves of ultra-fast sequences should be invested in the improvement of the spatial resolution. To date, further investigations related to the problem of optimal CA-application may improve the potentials of CE-MRA procedures.

Carotid Arteries↗

Contrast-enhanced MR angiography of abdominal vessels: is there still a role for angiography?

The purpose of this review article is to describe recent advantages in contrast-enhanced (CE) three-dimensional (3D) magnetic resonance angiography (MRA) in comparison with other vascular imaging techniques, and to discuss their current clinical applications for the imaging of abdominal vessels. Principles and technical considerations are presented and clinical applications are reviewed for different vascular diseases. In ruptured aortic aneurysms and acute dissections CT is the method of first choice. Contrast-enhanced 3D MRA can be well used for therapeutic planning and follow-up in patients with stable disease. A comprehensive MR examination including CE 3D MRA, MR urography and MR nephrogram has the potential to replace the conventional studies for the evaluation of renal vascular disease. It is an accurate method for imaging the origins of coeliac and superior mesenteric arteries, although the image resolution is too low for reliable assessment of the inferior mesenteric artery. Contrast-enhanced 3D MRA has emerged as the method of choice for studying the portal venous system in liver transplant recipients, in patients with portal hypertension and in cases with abdominal tumours for preoperative evaluation. Additional non-invasive flow measurements are useful in monitoring portal hypertension. The abdominal veins can be well imaged using unenhanced MR techniques. Imaging may be facilitated with intravascular contrast media. Contrast-enhanced 3D MRA can replace intra-arterial DSA for diagnosis, therapy planning and follow-up in patients with abdominal vascular disease. Catheter-based arteriography will still be used for interventional procedures such as percutaneous transluminal angioplasty, stent placement and embolisation.

Abdomen↗

Intraarterial digital subtraction angiography vs conventional angiography of abdominal diseases.

Seventy-five patients with various abdominal diseases were studied by intraarterial digital subtraction angiography (IA DSA) during conventional abdominal angiographic examinations. The image quality, tumor stain, and arterial encasements were evaluated and diameters of vessels visualized by IA DSA were measured. The vessels greater than 2.0 mm or more in diameter were equally well demonstrated on IA DSA. IA DSA demonstrated tumor stains and portal system to good advantage. Real time imaging was also advantageous during an embolization procedure.

Abdominal Neoplasms↗

Comparison of visibility and diagnostic capability of noninvasive coronary angiography by eight-slice multidetector-row computed tomography versus conventional coronary angiography.

The usefulness of multidetector-row computed tomography (MDCT) for visualization of coronary arteries has been reported; however, little is known about the diagnostic capability of noninvasive coronary angiography (CA) using 8-detector row CT. We investigated the visualization and diagnostic values of 8-slice MDCT-CA. Twenty-five consecutive patients who underwent conventional CA were investigated. The entire heart was scanned for approximately 20 seconds. Images were created using different reconstruction methods (half-scan and multisectors) followed by image creation during different time windows of the cardiac cycle. The data set containing the fewest artifacts was selected, then reformatted images were created and evaluated. In 348 segments in 25 subjects as determined by conventional CA, 258 segments (74.1%) were judged visible by MDCT-CA. Lower visibility was observed in segments with smaller diameters. Visibility in segments with diameters of > or =2.0 mm was 85.8% (212 of 247 segments). Patients with higher mean heart rates and a larger range of heart rate alteration during the breath-holding scan time had lower visibility. The most frequent cause for invisibility was "adjacent structure" (47%), followed by "small diameter" (33%), and "motion artifact" (16%), suggesting that motion artifacts were reduced by multisector reconstruction and search for the best-optimized time window. MDCT-CA detected 27 of 37 significant stenotic lesions (73%) that had a diameter reduction of >50% and correctly judged 226 of 311 segments (72.7%) as normal. Sensitivity, specificity, and accuracy of the visualized segments by MDCT-CA was 90% (27 of 30 segments), 99.1% (226 of 228 segments), and 98.1% (253 of 258 segments), respectively. Low visibilities in the left circumflex artery and distal and small segments are limitations of 8-slice MDCT-CA because of limited spatial resolution.

Adult↗

[Use of a new tiltable angiography table for diagnostic and interventional CO2 angiography].

A new tiltable angiographic table was tested for its applicability during carbon dioxide angiography in 11 patients. A change of position could be performed easily without delaying the procedure time and improved image quality in 8 patients while carbon dioxide was applied as contrast agent. The new tiltable angio table--originally designed for surgical procedures performed within the angiosuite--proved to be of use also during percutaneous diagnostic procedures, particularly with carbon dioxide as a contrast agent.

Angiography↗

[Digital subtraction angiography and large-film angiography of the pelvic and leg arteries].

The diagnostic information and image quality of 1153 DSA studies of pelvic and lower limb arteries and of 104 conventional large film angiograms have been analysed. Using intra-arterial contrast, all large film angiograms and all DSA studies of the iliac, femoral, popliteal and upper calf arteries were satisfactory. For demonstrating the distal calf vessels and vessels in the foot, intra-arterial DSA was superior to large film angiography. Using intravenous DSA, 98% of the iliac, femoral and popliteal arteries were adequately demonstrated, although image quality was reduced.

Angiography↗

Assessment of left ventricular volumes by magnetic resonance in comparison with radionuclide angiography, contrast angiography and echocardiography.

The present study shows that for assessment of LVEF, MRI and the standard methods seem to provide information of similar value. For absolute volume measurements, MRI and RNA are superior to single plane angiography and 2 DE using the modified Simpson-rule. The time consuming transversal MRI method does not seem to be superior to the oblique multislice method, when apical aneurysms can be ruled out. MRI thus seems to be an accurate method for determination of LV stroke volume as well as for determination of LVEF and hence for diastolic and systolic volumes. MRI, however, depends of a good image quality, which is crucial especially in dilated ventricles containing stagnant or slowly moving blood.

Adult↗