Planar Reformation Research Articles

3D planar reformation of vascular central axis surface with biconvex slab

Curved multi-planar reformation (curved MPR) is one of the commonly used vascular visualization methods in clinics. It re-samples and visualizes the vascular central axis surface (VCAS), which is a curved surface passing through the vascular central axis (VCA) or vessel centerline. The rotation of the VCAS along the VCA generates a set of 2D images. In this paper, we introduce a 3D curved MPR method, VCAS planar reformation (VPR) by a convex hull, called a biconvex slab. The entire vessel is enclosed within a biconvex slab and rendered in one image by volume rendering, such as MIP or X-ray. The method is applied to computed tomographic angiography (CTA) data sets. The resulting image is clear and free from obstruction by bones and other adjacent organs.

Femoropopliteal artery centerline interpolation using contralateral shape

Curved planar reformation allows comprehensive visualization of arterial flow channels, providing information about calcified and noncalcified plaques and degrees of stenoses. Existing semiautomated centerline-extraction algorithms for curved planar reformation generation fail in severely diseased and occluded arteries. We explored whether contralateral shape information could be used to reconstruct centerlines through femoropopliteal occlusions. We obtained CT angiography data sets of 29 subjects (16m/13f, 19-86yo) without peripheral arterial occlusive disease and five consecutive subjects (1m/4f, 54-85yo) with unilateral femoropopliteal arterial occlusions. A gradient-based method was used to extract the femoropopliteal centerlines in nondiseased segments. Centerlines of the five occluded segments were manually determined by four experts, two times each. We interpolated missing centerlines in 2475 simulated occlusions of various occlusion lengths in nondiseased subjects. We used different curve registration methods (reflection, similarity, affine, and global polynomial) to align the nonoccluded segments, matched the end points of the occluded segments to the corresponding patent end points, and recorded maximum Euclidean distances to the known centerlines. We also compared our algorithm to an existing knowledge-based PCA interpolation algorithm using the nondiseased subjects. In the five subjects with real femoropopliteal occlusions, we measured the maximum Euclidean distance and the percentage of the interpolation that remained within a typical 3 mm radius vessel. In the nondiseased subjects, we found that the rigid registration methods were not significantly (p<0.750) different among themselves but were more accurate than the nonrigid methods (p<0.001). In simulations using nondiseased subjects, our method produced centerlines that stayed within 3 mm of a semiautomatically tracked centerline in occlusions up to 100 mm in length; however, the PCA method was significantly more accurate for all occlusions lengths. In the actual clinical cases, we found the following [occlusion length (mm):error (mm)]: 16.5:0.775, 42.0:1.54, 79.9:1.82, 145:3.23, and 292:6.13, which were almost always more accurate than the PCA algorithm. We conclude that the use of contralateral shape information, when available, is a promising method for the interpolation of centerlines through arterial occlusions.

Survival in Nonocclusive Mesenteric Ischemia

The aim of the study was to establish a procedure for early diagnosis and treatment of nonocclusive mesenteric ischemia (NOMI). NOMI has a high mortality rate, and early diagnosis and treatment are important for improving survival in patients with this condition. The subjects were 22 patients treated at our hospital over 13 years. Diagnostic criteria for NOMI were established based on the first 13 cases. In the 9 more recent cases, we performed abdominal contrast multidetector row computed tomography (MDCT) upon suspicion of NOMI based on these criteria. Imaging allowed definite diagnosis of NOMI, and continuous intravenous high-dose PGE1 administration was initiated immediately after diagnosis (dose, 0.01-0.03 microg/kg per min; mean administration period, 4.8 days). Nine of the first 13 patients died of multiple organ failure associated with multiple intestinal necrosis. These cases suggested that NOMI may develop when 3 of the following 4 criteria are met after cardiovascular surgery or maintenance dialysis in elderly patients: symptoms of the ileus develop slowly from abdominal symptoms, such as an unpleasant abdominal feeling or pain; a requirement for catecholamine treatment; an episode of hypotension; and slow elevation of the serum transaminase level. In the 9 recent cases, definite diagnosis was made from spasm of the principal arteries in arterial volume rendering and curved planar reformation MDCT images. Early treatment with PGE1 prevented acute-stage NOMI in 8 of the 9 cases. Early diagnosis of NOMI is possible using the above criteria and MDCT, and initiation of PGE1 treatment may increase survival in patients with NOMI.

Multidetector CT Angiography in the Follow-Up of Patients Treated with Renal Artery Stents: Value of Different Reformation Techniques Compared with Axial Source Images

To evaluate the role of 4 different reformation techniques in comparison with axial images from multidetector computed tomographic angiography (MDCTA) in the follow-up of renal artery stents. Data on 40 patients (20 men; mean age 65 years) who underwent MDCTA as part of their routine follow-up after successful primary stenting of a main renal artery were retrospectively analyzed. Multiplanar reformation (MPR), curved planar reformation (CPR), volume rendering threshold (VRT), and virtual angioscopy (VA) were reviewed by 2 independent observers who were blinded to the results of the axial source images, which served as the gold standard. The stenosis degree was scored as I = 0%, II <50%, III = 51%-75%, IV = 76%-99%, or V = occlusion; a stenosis >50% was considered hemodynamically significant. Five hemodynamically significant stenoses were identified on axial images. The correlation with axial images was perfect for both observers using MPR and CPR (kappa = 1 for each observer); corresponding results were kappa = 0.69 and kappa = 0.64 for VRT and kappa = 0.88 and kappa = 0.83 for VA, respectively. The interobserver correlations were excellent for all reformation techniques (kappa = 0.95 to 1). Compared to axial images, MPR and CPR correlated perfectly with axial images; VA performed surprisingly well, while VRT was affected by artifacts and consequently showed inferior results.

Multipath Curved Planar Reformation of the Peripheral Arterial Tree in CT Angiography

The study was approved by the institutional review board, and informed consent was obtained. The purpose of the study was to prospectively quantify the angular visibility range, determine the existence of orthogonal viewing pairs, and characterize the conditions that cause artifacts in multipath curved planar reformations (MPCPRs) of the peripheral arterial tree in 10 patients (eight men and two women; mean age, 69 years; range, 54-80 years) with peripheral arterial occlusive disease. Percentage of segments with the maximal possible visibility score of 1 was significantly greater (odds ratio, 1.42; P<.001) for MPCPRs than for maximum intensity projections. One or more orthogonal viewing pairs were identified for all above-knee arterial segments, and artifactual vessel distortion was observed when the vessel axis approached a horizontal course in MPCPRs.

Automated generation of curved planar reformations from MR images of the spine

A novel method for automated curved planar reformation (CPR) of magnetic resonance (MR) images of the spine is presented. The CPR images, generated by a transformation from image-based to spine-based coordinate system, follow the structural shape of the spine and allow the whole course of the curved anatomy to be viewed in individual cross-sections. The three-dimensional (3D) spine curve and the axial vertebral rotation, which determine the transformation, are described by polynomial functions. The 3D spine curve passes through the centres of vertebral bodies, while the axial vertebral rotation determines the rotation of vertebrae around the axis of the spinal column. The optimal polynomial parameters are obtained by a robust refinement of the initial estimates of the centres of vertebral bodies and axial vertebral rotation. The optimization framework is based on the automatic image analysis of MR spine images that exploits some basic anatomical properties of the spine. The method was evaluated on 21 MR images from 12 patients and the results provided a good description of spine anatomy, with mean errors of 2.5 mm and 1.7° for the position of the 3D spine curve and axial rotation of vertebrae, respectively. The generated CPR images are independent of the position of the patient in the scanner while comprising both anatomical and geometrical properties of the spine.

Usefulness of the long-axis and short-axis reformatted images of multidetector-row CT in evaluating T-factor of the surgically resected pancreaticobiliary malignancies

Purpose To evaluate the diagnostic efficacy of curved planar reformations along the duct (long-axis CPR) and series of reformations perpendicular to the duct (short-axis MPR) in evaluating T-factors of pancreaticobiliary malignancy. Materials and methods Twenty-five patients with surgically proven pancreaticobiliary malignancy (12 bile duct cancers and 13 pancreas cancers) were evaluated. A dynamic study was performed with multidetector-row CT with four detectors, and reconstructed with 1 mm thickness and intervals. Tracing the center of the duct system on axial images, long-axis CPR images and serial short-axis MPR images were obtained. Two radiologists interpreted the T factor of the diseases three times: session (1), axial images only; session (2), axial, coronal and sagittal multiplanar reformation images; and session (3), axial, long-axis CPR, and short-axis MPR images. Receiver operating characteristic curves were analyzed. Results In evaluations of bile duct cancer, Az values of (3) (0.95, 0.92) were higher than those of (1) (0.89, 0.88) and (2) (0.92, 0.89), with some significant differences. In evaluations of pancreas cancer, Az values of all interpretations were almost equal. Conclusion Long-axis CPR and short-axis MPR images were suggested to be useful as additional images to the original axial images in evaluating the local extension of bile duct carcinomas.

Automated CTA Quantification of Internal Carotid Artery Stenosis:A Pilot Trial

To evaluate the feasibility and accuracy of automated analysis software for use with multidetector computed tomographic angiography (CTA) in the exact grading of internal carotid artery stenosis. A retrospective pilot trial was performed using CTA datasets from 87 stenotic carotid arteries in 46 consecutive patients (34 men; median age 73.5 years) with known cerebrovascular disease. Internal carotid artery (ICA) stenosis was graded according to NASCET criteria by 2 experienced vascular radiologists in consensus using axial source images as well as curved planar reformations and digital subtraction angiography (DSA). These results were then compared to those obtained from the automated CTA analysis software and the results of manually adapted automated CTA analysis. Measurements from automated CTA analysis as well as manually adapted automated CTA analysis correlated significantly to those of axial/reformatted CTA and DSA (r=0.53 and r=0.82, r=0.58 and 0.70, respectively, all p<0.05). Compared to axial/reformatted CTA measurements, automated CTA analysis had a median difference of -16%, while manually adapted automated CTA had a difference of -10%. Corresponding differences in a comparison with DSA were +4% and -2%, respectively. Circumferential calcification or kinking of the ICA origin did not significantly interfere with these differences (all p>0.05). Sensitivities for the detection of ICA stenosis >70% by manually adapted automated CTA analysis and automated measurement were 44.2% and 34.9%, respectively, versus axial/reformatted CTA. Compared with DSA as the gold standard, the sensitivities were 54.2% and 62.5%, respectively. Specificities for both methods and gold standards all exceeded 90%. Commercially available automated CTA analysis is a feasible tool, but sensitivities are still not sufficient for clinical application.

The Adamkiewicz artery: demonstration by intra-arterial computed tomographic angiography

The purpose of this study was to evaluate the feasibility of using multidetector-row CT angiography (CTA) with intra-arterial contrast injection (IA-CTA) to depict the artery of Adamkiewicz (arteria radicularis magna, ARM). We performed IA-CTA in 27 preoperative patients with aneurysm or dissection of the descending thoracic or thoracoabdominal aorta. ARM was examined on multiplanar and curved planar reformation images and on the paging method, and we investigated detectability and visualization of the ARM, the level of branching, and right/left frequency as well as continuity from the origin to the ARM. Furthermore, the bolus characteristic of contrast medium in IA-CTA was investigated and compared with CTA with intravenous contrast injection (IV-CTA). The bolus characteristic of the contrast medium was assessed by the determination of the CT value in the aorta in each of the 16 cases in which both IA-CTA before surgery and intravenous IV-CTA at the time of admission were performed. The ARMs were clearly visualized and at least one ARM to be reserved was determined in all patients (100%). The average number of ARM observed was 1.4+/-0.58 per patient (39/27). Innate origin was determined in 90% (35/39) of ARMs and it ranged between the 8th thoracic vertebra and the 3rd lumbar vertebra levels, and branching from the left accounted for 63.2% (24/38). It was possible to observe the exact continuity from the innate origin to the ARM as well as from the secondary origin to the ARM mediated by collateral vesseles in 61.5% of the total ARMs (24/39). The CT value in the aorta calculated on IA-CTA was significantly higher than that on IV-CTA (p<0.05). As a result, the high bolus characteristic of contrast medium in IA-CTA was confirmed. It was possible to detect the ARM in all patients and to obtain information about the origin by IA-CTA. This method is considered useful for preoperative assessment of a descending thoracic or a thoracoabdominal aorta for aortic aneurysm or dissection.

Peripheral CT angiography for interventional treatment planning

Lower extremity CT angiography (CTA) has evolved into a very effective, widely available and robust imaging modality for patients with peripheral arterial occlusive disease (PAOD). In this article we briefly review the acquisition and contrast administration techniques for 4- through 64-channel peripheral CTA. Visualization of atherosclerotic disease with CTA in general requires 'angiography-like' 3D images (such as volume rendered or maximum intensity projection images), but-notably in the presence of vessel wall calcifications and stents-cross-sectional views (such as curved planar reformations, CPR) are also required to accurately assess the flow lumen of the aorta down to the pedal arteries. Adequate visualization and mapping of atherosclerotic lesions in patients with PAOD is not only a prerequisite for generating a dictated report, but more importantly, standardized postprocessed images are the key to communicating the findings to the treating physician, and they also serve as a treatment planning tool. Treatment decisions (surgical versus transluminal revascularization, or conservative treatment), and percutaneous treatment planning (access site, antegrade versus retrograde puncture) can be made in the majority of patients with PAOD based on lower extremity CT angiograms.

The Role of Multi-slice Spiral CT Angiography in Patient Management After Endovascular Therapy

To bring out the role of multi-slice spiral CT angiography (MS-CTA) in patient management after endovascular therapy of subclavian artery stenosis. Twenty-one consecutive patients with clinically suspected restenosis after endovascular treatment of subclavian artery stenosis or occlusion were included in the study. Eleven patients had been treated with percutaneous transluminal angioplasty (PTA) alone and 10 with PTA and stenting. The mean follow-up period after PTA or stenting was 57 (+/-27 SD) months. CTA was performed using a bolus-triggered high-resolution protocol with biphasic intravenous contrast medium injection. Axial images and curved planar reformations (CPRs) were rated by three readers with regard to patency of supra-aortic vessels. Imaging findings were correlated with a standardized clinical assessment. All examinations were of diagnostic quality. Of 21 referred patients, 7 had significant reobstruction of the treated subclavian artery. Six of the 7 patients with significant restenosis on CTA were treated conservatively (antiplatelet agents), despite 2 of them being symptomatic on the standardized clinical assessment, which showed a sensitivity and specificity of 86% in predicting stenosis. One patient was treated with PTA and stent deployment because of strong subjective suffering. MS-CTA is useful for exclusion or quantification of clinically suspected restenosis in carefully selected patients after endovascular therapy where ultrasound is inconclusive and/or contrast-enhanced magnetic resonance angiography is contraindicated.

Role of 64-slices spiral CT in acute chest pains

目的 探讨64层螺旋CT在急性胸痛病因鉴别诊断中的临床价值.方法 对36例临床急性胸痛的患者行64层螺旋CT心胸联合血管造影检查.对所有扫描原始数据用冠状、矢状面多平面重组(MPR)、曲面重组(CPR)、容积再现(VR)和最大密度投影(MIP)等方法行冠状动脉、肺动脉和胸主动脉成像.由2名有经验的放射科医生对所有图像进行观察,对疾病进行诊断,其中16例患者同时行选择性血管造影检查.结果 所有行64层螺旋CT心胸联合血管造影的患者1次检查均可清晰显示双侧肺动脉、冠状动脉主干及其主要分支以及胸主动脉,同时均可进行纵隔及肺窗重组,对胸部疾病进行诊断.显示冠状动脉狭窄10例,急性肺动脉栓塞14例,主动脉夹层6例(其中1例同时伴有冠状动脉右支急性血栓形成);并诊断气胸1例、缩窄性心包炎1例;4例未见明显异常.结论 64层螺旋CT 1次心胸联合血管造影检查能清晰地显示冠状动脉、肺动脉及主动脉,对其病变作出正确诊断,还能清晰地显示胸部疾病,是急性胸痛病因诊断无创、可靠的检查方法。

A new 3-D diagnosis strategy for duodenal malignant lesions using multidetector row CT, CT virtual duodenoscopy, duodenography, and 3-D multicholangiography

Recent advances in multidetector row computed tomography (MD-CT) technology provide new opportunities for clinical diagnoses of various diseases. Here we assessed CT virtual duodenoscopy, duodenography, and three-dimensional (3D) multicholangiography created by MD-CT for clinical diagnosis of duodenal malignant lesions. The study involved seven cases of periduodenal carcinoma (four ampullary carcinomas, two duodenal carcinomas, one pancreatic carcinoma). Biliary contrast medium was administered intravenously, followed by intravenous administration of an anticholinergic agent and oral administration of effervescent granules for expanding the upper gastrointestinal tract. Following intravenous administration of a nonionic contrast medium, an upper abdominal MD-CT scan was performed in the left lateral position. Scan data were processed on a workstation to create CT virtual duodenoscopy, duodenography, 3D multicholangiography, and various postprocessing images, which were then evaluated for their effectiveness as preoperative diagnostic tools. Carcinoma location and extent were clearly demonstrated as defects or colored low-density areas in 3-D multicholangiography images and as protruding lesions in virtual duodenography and duodenoscopy images. These findings were confirmed using multiplanar or curved planar reformation images. In conclusion, CT virtual duodenoscopy, doudenography, 3-D multicholangiography, and various images created by MD-CT alone provided necessary and adequate preoperative diagnostic information.

Automated curved planar reformation of 3D spine images

Traditional techniques for visualizing anatomical structures are based on planar cross-sections from volume images, such as images obtained by computed tomography (CT) or magnetic resonance imaging (MRI). However, planar cross-sections taken in the coordinate system of the 3D image often do not provide sufficient or qualitative enough diagnostic information, because planar cross-sections cannot follow curved anatomical structures (e.g. arteries, colon, spine, etc). Therefore, not all of the important details can be shown simultaneously in any planar cross-section. To overcome this problem, reformatted images in the coordinate system of the inspected structure must be created. This operation is usually referred to as curved planar reformation (CPR). In this paper we propose an automated method for CPR of 3D spine images, which is based on the image transformation from the standard image-based to a novel spine-based coordinate system. The axes of the proposed spine-based coordinate system are determined on the curve that represents the vertebral column, and the rotation of the vertebrae around the spine curve, both of which are described by polynomial models. The optimal polynomial parameters are obtained in an image analysis based optimization framework. The proposed method was qualitatively and quantitatively evaluated on five CT spine images. The method performed well on both normal and pathological cases and was consistent with manually obtained ground truth data. The proposed spine-based CPR benefits from reduced structural complexity in favour of improved feature perception of the spine. The reformatted images are diagnostically valuable and enable easier navigation, manipulation and orientation in 3D space. Moreover, reformatted images may prove useful for segmentation and other image analysis tasks.

Magnetic resonance imaging study of lumbosacral spinal cord nerves before artificial somatic-central nervous system-autonomic reflex pathway establish ment

目的 探讨MRI在人工体神经-内脏神经反射弧建立术前腰骶部脊神经评估的价值.方法对10例神经源性膀胱患者均采用常规MRI、稳态构成干扰序列(constructive inference in steady state,CISS)成像,并对T2W CISS三维(3D)原始数据进行多平面重组(multiple planar reformation, MPR).结果 MRI发现,脊髓栓系综合征5例,其中1例合并脊髓血管畸形,脊神经返折走行,出硬脊膜处脊神经数目异常;脊髓损伤4例,椎管内占位病变1例,脊神经漂浮下行,神经根数目正常.结论常规MRI及T2W CISS 3D检查对人工体神经-内脏神经反射弧建立术前脊神经的评估具有重要价值.MPR可以清晰的显示脊神经的走行及前后根的排列。

Vascular Mapping of the Leg with Multi–Detector Row CT Angiography prior to Free-Flap Transplantation

To retrospectively evaluate multi-detector row computed tomographic (CT) angiography in determining donor- and recipient-site arterial suitability for successful vascularized free-flap transplantation. The institutional review board granted approval; informed consent was waived, and the study was HIPAA compliant. Lower extremities of 20 (12 male, eight female; mean age, 51 years; range, 10-84 years) patients undergoing vascularized free-flap procedures were examined at multi-detector row CT angiography. In five patients, legs were assessed as potential fibular free-flap donors for mandibular, maxillary, or radial reconstruction. In 15 patients, legs were assessed as recipient sites for free flaps. Vascular maps obtained with volume rendering, maximum intensity projections, and curved planar reformations were generated, and assessment was made in the depiction of calf vessels and presence of stenosis, occlusion, and anatomic anomaly. Findings of CT angiography, physical examination, and surgery were compared, where applicable, and successful CT-based prediction of the surgical intervention was assessed. Immediate and long-term (>70 days) viability of the graft was assessed in all patients. CT angiography depicted the entirety of all four major calf arteries in 29 of 32 legs scanned. In three legs, external-fixation hardware obscured some segments. There were no discrepancies between CT findings and those identified at the time of surgery. Arterial abnormalities, including stenosis, occlusion, and variant anatomy, were seen in 12 lower extremities in 10 patients. Only two were suspected on the basis of physical examination findings. In five of 20 patients, CT findings resulted in changes to the surgical plan. There was a 100% immediate viability of all grafts, which remained well vascularized between 70 days and 37 months after the procedure. Multi-detector row CT angiography provides a noninvasive means of preoperatively assessing lower extremity arteries for abnormalities, which could jeopardize graft viability or pedal arterial supply after free-flap procedures.

Pancreatic and Peripancreatic Diseases Mimicking Primary Pancreatic Neoplasia

A variety of anatomic variants and pathologic conditions in and around the pancreas may simulate primary pancreatic neoplasia at routine abdominal cross-sectional imaging. An ambiguous lesion whose appearance suggests a pancreatic origin requires a broad differential diagnosis that can subsequently be narrowed on the basis of both clinical history and features at optimal computed tomography (CT) and magnetic resonance (MR) imaging. Pancreas-specific multidetector CT and MR imaging techniques with thin collimation, multiplanar and multiphasic scans, and newly introduced curved planar reformation may help avoid potential diagnostic pitfalls. These techniques can help identify and characterize a mass in multiple viewing planes, thereby helping distinguish a true pancreatic neoplasm from peripancreatic adenopathy or from a tumor of the adjacent duodenum or small bowel. They can also help determine the cause of a tumor. It is important that the radiologist be familiar with the wide spectrum of anatomic variants and disease entities that can mimic primary pancreatic neoplasia in order to initiate the appropriate lesion-specific work-up and treatment and avoid unnecessary tests or procedures, including surgery.

Value of curved planar reformations in MDCT of abdominal pathology.

Value of curved planar reformations in MDCT of abdominal pathology.

MDCT in Pancreatic adenocarcinoma: prediction of vascular invasion and resectability using a multiphasic technique with curved planar reformations.

The objective of our study was to determine the negative predictive value of MDCT with curved planar reformations for detecting vascular invasion and predicting overall resectability in patients with pancreatic adenocarcinoma. Imaging findings related to vascular invasion and overall tumor resectability in 25 patients who underwent contrast-enhanced biphasic MDCT evaluation were correlated with actual vessel invasion and overall resectability determined at surgery and pathologic examination. The presence of vascular invasion was assessed in 110 major peripancreatic vessels in 22 patients who underwent resection. On MDCT, 23 (92%) of 25 patients were deemed to have resectable pancreatic adenocarcinoma. The tumors in the remaining two (8%) were considered not resectable because of the presence of vascular invasion (which was confirmed in only one patient at surgery). Of those 23 patients deemed to be candidates for curative resection on the basis of MDCT results, 20 were found to have resectable adenocarcinoma at time of surgery, yielding a negative predictive value for MDCT of 87% (20/23 patients) for overall resectability. In the other three patients, adenocarcinoma was deemed to be unresectable because of small metastases to the liver (two patients) or to the peritoneum (one patient) discovered at surgery. For detection of vascular invasion, MDCT yielded a negative predictive value of 100% (108/108 vessels) with no false-negative findings and an accuracy of 99% (109/110 vessels) with 108 true-negative findings, one true-positive finding, and one false-positive finding. Our preliminary data on MDCT show that the technique has excellent negative predictive value for vascular invasion and good negative predictive value for overall tumor resectability in patients with pancreatic adenocarcinoma, suggesting an improvement over previous results reported using single-detector CT. The problem of undetected micrometastases to the liver and peritoneum remains.

Clinical Usefulness of Virtual Angioscopy Using 3D MR Angiography DICOM Images

Objective : To evaluate of virtual angioscopy was implemented using MR(magnetic resonance) angiography image of carotid artery. Methods : The endoscopy system provides a 3D volume rendered image as a navigation map and has the multi planar reformation image along the path and a 2D axial image as a reference image. We segmented the common carotid artery and internal, external carotid artery from the MR angiography image. We used the coordinates as a navigation path for virtual camera that were calculated from medial axis transformation. We used the perspective projection and marching cube algorithm to render the surface from volumetric MR angiography image data. Results : The virtual angioscopy is highly recommended as a diagnosis tool with which the specific place of stenosis can be identified and the degree of stenosis can be measured qualitatively. Conclusion : Virtual angioscopy is one of the powerful tool for non-invasive carotid artery and many in-vitro, in-vivo studies have shown the artery stenosis detection. Inside of the carotid artery is one of the body region not accessible by real optical endoscopy but can be visualized with virtual endoscopy.