Multidetector-row Computed Tomography Angiography Research Articles

64-Slice MDCT Angiography of Upper Extremity in Assessment of Native Hemodialysis Access

To compare multidetector row computed tomographic (MDCT) angiography with conventional digital subtraction angiography (DSA) in the evaluation of vascular access stenoses in hemodialysis patients. Twenty-one consecutive patients were imaged with MDCT angiography and subsequent DSA. The superficial vein of leg was used as the route for intravenous administration. The vascular stenosis was assessed in not significant (<50% stenosis), moderate stenosis (50%-74% stenosis), severe stenosis (75%-99%), and total occlusion (100%). The accuracy, sensitivity, specificity, positive, and negative predictive values were calculated for significant vascular stenosis using DSA as the standard reference. The sensitivity and specificity of MDCT angiography for the detection of significant hemodialysis vascular access were 100% (95% CI, 89.3%-100%) and 94.8% (95% CI, 89.1%-97.6%), respectively. The positive and negative predictive values were 84.2% (95% CI, 68.1%-93.4%) and 100% (95% CI, 95.8%-100%), respectively. The accuracy of MDCT angiography for detection of significant stenoses was 95.9% (95% CI, 91.4%-97.0%). MDCT angiography provides excellent correlation in vascular stenosis as compared with DSA in hemodialysis access. Complete assessment of entire vascular segments could be performing with MDCT angiography in planning before endovascular intervention or surgical correction.

The Distribution of the Perforators in the Anterolateral Thigh and the Utility of Multidetector Row Computed Tomography Angiography in Preoperative Planning

This prospective study searches for the clinical relevance of preoperative multidetector row computed tomography (MDCT) angiography (CTA) for anterolateral thigh (ALT) free flap.Preoperative CTA data were collected in 100 patients between November 2004 and April 2008, and data from 139 limbs were evaluated for the number, type, and location of the ALT perforators. This information was used as operative roadmap and correlated with intraoperative findings in 58 patients.The MDCT revealed an average number of perforators of 2.28 per unilateral ALT (range, 0-4) and projected that 23% of the limb have at least 1 septocutaneous perforator. When the reference line connecting the anterior superior iliac spine ASIS and patella was divided into 10 equal parts, most of the perforators were concentrated in 4/10 to 7/10 and the most common was on the proximal 5/10. Two-thirds of septocutaneous perforators were present in the proximal half. Fifty-two of 58 patients had operative findings consistent with CTA, but 4 perforators failed to appear in preoperative CTA and 3 musculocutanenous perforators were initially identified as septocutaneous type but actually had a short intramuscular course.Preoperative mapping using MDCT angiography is fast, simple, and provides fairly accurate information about the location, type, and the course of the perforators. It allows appropriate selection of the sizable perforator with the shortest intramuscular course preoperatively leading to safer and easier operation with optimal outcome.

Correlation between kinking and coiling of the carotid arteries as assessed using MDCTA with symptoms and degree of stenosis

To evaluate whether the presence of kinking and coiling of the carotid arteries is associated with symptoms and an increased degree of carotid artery stenosis. One hundred and fifty-three consecutive patients examined using multidetector-row computed tomography angiography (MDCTA) were studied retrospectively. The arterial phase was obtained by injecting 4-6ml/s of contrast material. A total of 306 carotid arteries were assessed for the presence of tortuosity. The degree of carotid artery stenosis was measured according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Logistic regression analysis was performed to determine whether an independent association existed between the presence of vessel tortuosity, symptoms, and the degree of carotid artery stenosis. Kinking was detected on 37 occasions (12.1%) and coiling on 20 occasions (6.5%). Using Yates's corrected chi-square test, an association between kinking and symptoms (p=0.002) was observed, but not between coiling and symptoms (p=0.31). Logistic regression confirmed that the strongest association was present between stenosis degree and symptoms (p=0.001), but kinking (p=0.009) and age (p=0.001) were also significantly associated with symptoms. A Mann-Whitney test did not demonstrate correlation between coiling (p=0.16) or kinking (p=0.22) and increased degree of carotid artery stenosis. The results suggest that kinking may be associated with symptoms, whereas coiling does not appear to be associated with symptoms. The degree of carotid artery stenosis severity is not related to the presence of vessel tortuosity.

P-007 Initial experience with a combined multi-detector row CT and a biplane angiography suite with a single interactive table for the evaluation and treatment of vascular disease involving the head and neck

Introduction and purposeThe purpose of this study is to present our initial experience with the usefulness of a combined multi-detector row CT and biplane angiographic system with a single interactive...

Significance and Imaging of Lumbar Veins and Early-Branching Arteries in Planning Living-Donor Laparoscopic Nephrectomy: Two Case Reports From 21 Months' Experience

A key aspect in planning laparoscopic living-donor nephrectomy is mapping of vascular variations. Lumbar veins and early-branching renal arteries are of utmost importance. To date, 43 candidates including 18 men and 25 women aged 25 to 67 years have been examined at our clinic using 16-section multidetector-row computed tomography angiography. Each examination was double-checked by an experienced radiologist. Of the 43 patients, 31 underwent surgery. In 29 of 31 patients (93.5%), the anatomy observed during surgery was identical to that demonstrated on the preoperative computed tomography scan. In 1 of 2 patients, 2 separate arteries were found at surgery, rather than the prognosticated early-branching arteries. In this patient, conversion to open surgery was necessary. In the other patient, a lumbar vein running into a retroaortic renal vein was discovered. In this patient, a 6-mm length of the joint stem contained the wall of the aorta and the periaortic tissue; thus, technically they were of separate origins. Careful mapping of the anatomy helps to prevent unexpected operative complications that are difficult to manage. Correct interpretation of the data must always be based on agreement between the radiologist and the surgeon.

Clinical utility of multidetector row computed tomography for diagnosing spinal dural arteriovenous fistulas undiagnosed by magnetic resonance imaging

Two elderly patients with dural arteriovenous fistulas (AVF), the abnormal vessels of which were not presented on magnetic resonance imaging (MRI) are reported. Although spinal AVF was suspected from hyperintensity in the spinal cord, dilated vessels were not detected on MRI. Computed tomography (CT) angiography was performed with a 64-detector row multidetector row CT (MDCT) system in both cases. The draining dilated vein was observed in both cases and they were interpreted as perimedullary AVF. In case 1, axial scan and the dorsal section of the coronal view demonstrated continuity of the radiculomedullary artery and intercostal artery through the spinal branch at the left Th12 level. After intravascular embolization in case 1 and surgical treatment in case 2, neurological improvement was obtained in both cases. MRI findings suggestive of dural AVF have described that intradural perimedullary tortuous low signal intensities posterior to the spinal cord, known as flow void, on T(2)-weighted images is the most consistent. Recently, MDCT angiography confirmed the presence of a fistula previously suspected after MRI. There are no previous reports that describe cases of dural AVF diagnosed by MDCT angiography of which abnormal vessels were undetected by MRI images. MDCT can detect abnormal vessels which were not depicted on MRI. When dural AVF are suspected on MRI, MDCT angiography should be performed before selective angiography to diagnose.

ECHO-COLOR DOPPLER, MAGNETIC RESONANCE ANGIOGRAPHY AND COMPUTED TOMOGRAPHY ANGIOGRAPHY: WHAT IS THE BEST TECHNIQUE TO CHARACTERIZE RENAL ARTERY STENOSIS?: PP.18.209

Purpose: Renal artery stenosis represents the narrowing of the main renal artery that supplies the kidney. Depending on the degree of stenosis, patients can develop hypertension. Our purpose was to compare the role and the diagnostic efficacy of Echo-Color Doppler (ECD), Magnetic Resonance Angiography (MRA) and Multi-Detector-Row CT angiography (MDCTA) in the study of patients with renal artery stenosis (RAS). Materials and Methods: 11 patients (6 males; 5 females, mean age: 49 years) for a total of 22 renal arteries were analysed by using ECD MDCTA and MRA. The following features were analysed: presence or absence of stenosis, stenosis position (ostial, proximal, central, distal, braches) and the degree of the stenosis. CT scans were obtained after intravenous bolus administration of 110–140 mL of non-ionic contrast material using a 3–6 mL/sec flow rate. We assessed every patient by using axial scans, multiplanar reconstruction (MPR), maximum intensity projection (MIP) and volume rendering (VR) techniques. MRA were performed by using a superconducting 1.5 Tesla Magnet. ECD exams were performed by using a dedicated system with a 11 Mhz probe. Results: USECD detected 3 RSA, MRA detected 4 RAS and MDCTA detected 6 RAS The highest number of stenosis found in the ostial localization (p < 0.001). Conclusions: MDCTA is an highly accurate technique to asses renal artery stenosis. Our data underlined that the site where the radiologist has to look for detect RAS is in ostial position. MRA and ECD determine suboptimal results.

HYPERTENSION AND CAROTID ARTERY STENOSIS. A CORRELATIVE STUDY BY USING MULTI-DETECTOR-ROW CT ANGIOGRAPHY: PP.18.212

Objective: Carotid artery stenosis is the major risk factor for ischemic stroke. Our purpose was test the hypothesis of a correlation between carotid artery stenosis and hypertension by using multi-detector-row CT angiography (MDCTA). Design and Method: 104 consecutive patients studied by using a MDCTA, for an overall number of 208 carotid arteries, were retrospectively studied. The following features were analysed: degree of the stenosis (on the basis of North American Symptomatic Carotid Endarterectomy Trial criteria) the composition of the plaque and course anomalies, and presence of plaque's ulcerations. For each patient we generated post-processed images by using Maximum Intensity Projection (MIP), Multi-Planar Reconstruction (MPR) and Volume Rendering (VR) techniques. Results: We detected seventy-one patients with significant stenosis; patients with hypertension were 55, (43 with stenosis and 12 without stenosis). We did not observe a significant statistical correlation (p = 0.142). Conclusions: Results of our work suggest that there is not a significant statistical association between carotid artery stenosis and hypertension, although there is a visible trend in patients (p = 0.142) with carotid artery stenosis towards hypertension.

Computed Tomographic Angiography in Evaluation of Superficial Temporal to Middle Cerebral Artery Bypass

Catheter-directed digital subtraction angiography (DSA) is considered the standard for evaluation of superficial temporal to middle cerebral artery (STA-MCA) bypass patency. Few clinical investigations have been performed that evaluate the efficacy of computed tomographic angiography (CTA) in the assessment of extracranial-intracranial bypass. Using multi-detector row CTA, STA-MCA bypass patency was assessed in the initial postoperative period and several months afterward and compared with DSA. No significant difference was identified in the evaluation of graft patency between DSA and CTA. Although multiple modalities exist to evaluate STA-MCA bypass graft patency, the multidetector CTA is widely available and allows for rapid, accurate patency assessment.

Dynamic MR perfusion imaging: Capability for quantitative assessment of disease extent and prediction of outcome for patients with acute pulmonary thromboembolism

To compare directly the capabilities of multidetector-row computed tomography (MDCT) and MRI for disease severity assessment and outcome prediction for acute pulmonary thromboembolism (APTE) patients. Fifty consecutive APTE patients underwent MDCT, MR angiography, dynamic perfusion MRI, treatment and follow-up examination. Pulmonary blood flow (PBF), pulmonary blood volume, and mean transit time maps were generated from perfusion MRI, and all segmental parameters were determined by using region of interest measurements. Receiver operator curve analyses were used to determine the most accurate parameter for diagnosis of the APTE segment. Then, APTE index from perfusion MRI (PE(perfusion MRI) index), right ventricle/left ventricle (RV/LV) diameter ratio and APTE indexes from embolic burdens observed on MDCT (PE(CT) index) and MR angiography (PE(MRA) index) were calculated. Finally, ability to differentiate mortality (n = 8) from survival (n = 42) groups and to predict patient outcome were statistically assessed. PBF was a significantly more accurate parameter than others (P < 0.05). When feasible threshold value was applied, specificity and accuracy of RV/LV diameter ratio and PE(Perfusion MRI) index were significantly higher than those of PE(CT) and PE(MRA) indexes (P < 0.05). Logistic regression analysis demonstrated that each index was a significant predictor (P < 0.05). Dynamic perfusion MRI can be effective for disease extent assessment and outcome prediction for APTE patients.

Imaging of the superficial inferior epigastric vascular anatomy and preoperative planning for the SIEA flap using MDCTA

The superficial inferior epigastric artery (SIEA) flap consists of skin and subcutaneous fat with limited donor-site morbidity and has the potential to be very versatile - either as a thin flap without excessive fat tissue or as a voluminous flap for breast reconstruction. However, anatomical inter-individual variability often makes the choice of a free SIEA flap difficult. Imaging of small-calibre vessels is possible with the multi-detector-row computed tomography angiography (MDCTA) and to obtain the characteristics of the superficial inferior epigastric vascular anatomy, we investigated the superficial inferior epigastric system using MDCTA. We investigated 17 patients who had abdominal wall MDCTA in preparation for a free flap procedure using either the deep inferior epigastric perforator (DIEP), SIEA or the groin flap. The visibility and anatomical characteristics including the branching pattern, the diameter, course of travel and layers were noted. The SIEA was visible in 64.7% and, of these, 36.4% had a common trunk formation with the superficial circumflex iliac artery (SCIA), while 63.6% arose independently. The measured diameters were SIEA 1.6 ± 0.4mm, SCIA 1.4 ± 0.4mm, deep circumflex iliac artery (DCIA) 2.4 ± 0.4mm, DIEA 2.9 ± 0.4mm and superficial inferior epigastric vein (SIEV) 3.1 ± 0.5mm. The SIEA consistently coursed lateral to and deeper than the SIEV and also lateral to the DIEA. MDCTA provided detailed three-dimensional information of the superficial inferior epigastric vascular system including the course and size of the SIEA. The information on vascular anatomy obtained with the MDCTA is valuable in the preoperative planning of the free SIEA flap and should be performed routinely.

The use of multi detector computed tomography in assessing the retroaortic left renal vein and accompanying vessel anomalies.

Because renal venous variations possess potential hazards during abdominal aortic surgery or laparoscopic donor nephrectomy, the detailed preoperative evaluation of the renal vessels with angiography should be performed to avoid vascular injuries. We present multidetector row computed tomography (MDCT) findings of the retroaortic left renal vein (RLRV) with other vascular variations. Twenty-two patients with RLRV were evaluated with MDCT using multiplanar images, MIP images, and 3D volume rendering. The RLRVs with accessory renal vessels and other variant veins draining into the left renal vein were effectively evaluated in all patients. MDCT angiography is an effective technique for evaluating abdominal vessels, and it presents adequate images of renal vessels and vascular variations, which pose importance before abdominal surgery.

Coronary artery fistula: multidetector row computed tomography angiography in young child

Coronary artery fistula: multidetector row computed tomography angiography in young child

Accuracy and pitfalls of multidetector-row computed tomography in detecting spinal dural arteriovenous fistulas

The purpose of this study was to evaluate the accuracy of multidetector-row CT angiography (MDCTA) in demonstrating spinal dural arteriovenous fistulas (SDAVFs). The authors studied 10 patients with SDAVFs, including 2 with spinal epidural AVFs, who underwent preoperative MR imaging, MDCTA, and digital subtraction angiography (DSA). In the evaluation of coronal sections of multiplanar reformation MDCTA images, inspection was focused on the presence of the following findings: 1) dilated perimedullary veins in the spinal canal; 2) focal enhancement of the nerve root, suggesting the location of the AVF, around the dural sleeve; and 3) a radicular vein that drains the AVF into perimedullary veins. The utility of MDCTA was assessed by comparing its findings with those of DSA in each case. Digital subtraction angiography confirmed that the AVFs were located in the thoracic spine in 4 patients and in the lumbar spine in 6 patients, and MDCTA detected dilated perimedullary veins in all 10 patients. In 8 patients, there was focal enhancement of the nerve root. The radicular vein that drains the AVF into the perimedullary veins was found in 8 cases. In 8 cases, the MDCTA-derived level and side of the AVF and its feeder corresponded with those shown by DSA. In 2 patients, however, the MDCTA-derived side of the feeder was on the side contralateral to the feeding artery confirmed by DSA. These lesions were interpreted as spinal epidural AVFs with perimedullary drainage. In 2 cases, MDCTA could not detect the multiplicity of their feeders. The use of MDCTA preceding DSA can be helpful to focus the selective catheter angiography on certain spinal levels. However, one should keep in mind that epidural AVFs with perimedullary drainage may resemble SDAVFs and also that MDCTA cannot exclude the possibility of multiple feeders. Further research should elucidate how broadly selective angiography should explore around the MDCTA-suggested target.

Detection of intracranial aneurysms using three-dimensional multidetector-row CT angiography: Is bone subtraction necessary?

Purpose The aim of this study was to evaluate the usefulness of three-dimensional CT angiography (3D CTA) with bone subtraction in a comparison with 3D CTA without bone subtraction for the detection of intracranial aneurysms. Materials and methods Among 337 consecutive patients who had intracranial aneurysms detected on 3D CTA, 170 patients who underwent digital subtraction angiography (DSA) were included in the study. CTA was performed with a 16-slice multidetector-row CT (MDCT) scanner. We created the 3D reconstruction images with and without bone subtraction by using the volume rendering technique. Three neuroradiologists in a blinded fashion interpreted both 3D CTA images with and without bone subtraction. The diagnostic accuracy of both techniques was evaluated using the alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive value were also evaluated. Results A total of 200 aneurysms (size: 2–23 mm) were detected in 170 patients. The area under the receiver operating characteristic curve (Az) for 3D CTA with bone subtraction (mean, Az = 0.933) was significantly higher than that for 3D CTA without bone subtraction (mean, Az = 0.879) for all observers ( P < 0.05). The sensitivity of 3D CTA with bone subtraction for three observers was 90.0, 92.0 and 92.5%, respectively, while the sensitivity of 3D CTA without bone subtraction was 83.5, 83.5 and 87.5%, respectively. No significant difference in positive predictive value was observed between the two modalities. Conclusions 3D CTA with bone subtraction showed significantly higher diagnostic accuracy for the detection of intracranial aneurysms as compared to 3D CTA without bone subtraction.

Cortical vein thrombosis: the diagnostic value of different imaging modalities

Cortical vein thrombosis (CVT) is a rare disorder, and its diagnosis is challenging. The aim of our study was to evaluate the value of different imaging modalities for the detection of CVT. Thirteen patients with CVT, either isolated (n = 3) or in combination with sinus thrombosis (n = 10), and 20 control patients without any venous pathologies were included in this study. The analysis was performed independently by three blinded readers who evaluated the following imaging modalities and sequences separately: non-enhanced computed tomography (NCCT); multi-detector row CT angiography (MDCTA); diffusion-weighted (DWI), T1-weighted (T1w), PD-weighted (PDw), T2*-weighted (T2*w), and fluid-attenuated inversion recovery-weighted (FLAIRw) magnetic resonance (MR) sequences; as well as venous MR angiography (vMRA). The sensitivity, specificity, positive (PPV) and negative predictive values, and interobserver agreement of the different modalities were calculated. T2*w showed the highest sensitivity for the detection of CVT (97.4%), followed by T1w (70%). FLAIRw and vMRA had a sensitivity of 50% and 41.7%, respectively, whereas the sensitivity of NCCT, MDCTA, DWI, and PDw was below 30%. The specificity and PPV of all modalities was 100%, with good to perfect interobserver agreement. T2*w was the superior MR imaging sequence for diagnosing CVT. Besides T2*w, only T1w reached a sensitivity of over 50% for CVT, followed by FLAIRw, and vMRA. On the contrary, our results suggest that NCCT but also MDCTA might not be suitable for diagnosing CVT.

Association of plaque in the carotid and coronary arteries, using MDCT angiography

ObjectiveAssociations between various plaque types in coronary and carotid arteries using multidetector row computed tomography (MDCT) have not yet been reported. We evaluated MDCT correlation of total plaque and various plaque subtypes in carotid and coronary arteries. MethodsWe studied 62 patients who had both carotid and cardiac computed tomography angiography (CTA). The plaque in each vascular segment was classified as non-calcified, calcified or mixed. ResultsThe average age of this population was 68±22 years, 63% males. Total plaque in the carotid artery correlated with total, calcified and mixed plaque in the coronary artery (all P<0.001). Calcified plaque in the carotid artery was associated with total and calcified plaque in the coronary bed (P<0.001). Non-calcified coronary plaque was not associated with carotid plaque. ConclusionTotal plaque in coronary and carotid arteries are highly correlated.

Assessment of Intracranial Arterial Stenosis with Multidetector Row CT Angiography: A Postprocessing Techniques Comparison

It was demonstrated the some patients with stroke have intracranial stenosis of 50% or greater and the identification of intracranial arterial stenosis is extremely important in order to plan a correct therapeutical approach. The aim of this study was to assess the image quality and intertechnique agreement of various postprocessing methods in the detection of intracranial arterial stenosis. Eighty-five patients who were studied by using a multidetector row CT scanner were retrospectively analyzed. A total of 2040 segments were examined in the 85 subjects. Intracranial vasculature was assessed by using MPR, CPR, MIP, and VR techniques. Two radiologists reviewed the CT images independently. Cohen weighted kappa statistic was applied to calculate interobserver agreement and for image accuracy for each reconstruction method. Sensitivity, specificity, PPV, and NPV were also calculated by using the consensus read as the reference. Two hundred fifteen (10.5%) stenosed artery segments were identified by the observers in consensus. The best intermethod kappa values between observers 1 and 2 were obtained by VR and MIP (kappa values of 0.878 and 0.861, respectively), whereas MPR provided the lowest value (kappa value of 0.282). VR showed a sensitivity for detecting stenosed segments of 88.8% and 91.6% for observers 1 and 2, respectively. The highest positive predictive value was also obtained by VR at 95% and 99% for observers 1 and 2, respectively. Image accuracy obtained by using VR was the highest among all reconstruction methods in both observers (185/255 and 177/255 for observers 1 and 2, respectively). The results of our study suggest that VR and MIP techniques provide the best interobserver and intertechnique concordance in the analysis of intravascular cranial stenosis.

ACQUIRED PORTAL COLLATERAL CIRCULATION IN THE DOG AND CAT

We describe patterns of acquired portal collateral circulation in dogs and in a cat using multidetector row computed tomography angiography. Large portosystemic shunts included left splenogonadal shunts in patients with portal hypertension. Small portal collaterals were termed varices; these collaterals had several patterns and were related either to portal vein or cranial vena cava obstruction. Varices were systematized on the basis of the venous drainage pathways and their anatomic location, namely left gastric vein varix, esophageal and paraesophageal varices, gastroesophageal and gastrophrenic varices, gallbladder and choledocal varices, omental varices, duodenal varices, colic varices, and abdominal wall varices. As reported in humans and in experimental dog models, esophageal and paraesophageal varices may result from portal hypertension that generates reversal of flow, which diverts venous blood in a cranial direction through the left gastric vein to the venous plexus of the esophagus. Blood enters the central venous system through the cranial vena cava. Obstructions of the cranial vena cava can lead to esophageal and paraesophageal varices formation as well. In this instance, they drain into the azygos vein, the caudal vena cava, or into the portal system, depending on the site of the obstruction. Gallbladder and choledocal varices, omental varices, duodenal varices, phrenico-abdominal varices, colic varices, abdominal wall varices drain into the caudal vena cava and result from portal hypertension. Imaging plays a pivotal role in determining the origin, course, and termination of these vessels, and the underlying causes of these collaterals as well. Knowledge about these collateral vessels is important before interventional procedures, endosurgery or conventional surgery are performed, so as to avoid uncontrollable bleeding if they are inadvertently disrupted.

Multidetector-row CT Angiography of Lower Extremities: Usefulness in the Diagnosis of and Intervention for Peripheral Arterial Disease

CT angiography (CTA) based on the data acquired by multidetector-row CT (MDCT) is an established, minimally invasive modality for imaging peripheral arteries. CTA has been used to assess peripheral arterial disease before treatment, and it has replaced conventional angiography for the diagnostic evaluation of peripheral arteries. MDCT can optimize both the long scan length and spatial resolution. CTA using MDCT depicts the fine structures of vessels. Recently, automated CTA analysis software has been developed for measurement of the vascular lumen. The software can automatically measure the diameters of short axial sections at the post-processing workstation. Measurement of the vascular lumen is useful in the planning of intravascular treatment for peripheral arterial disease. CTA is also utilized in assessing the intravascular lumen after metallic stent placement.