3D CTA Images Research Articles

Preoperative evaluation of the segmental artery of left upper lobe by thin-section CT and 3d-CTA.

Understanding pulmonary artery (PA) branches and their variations is crucial for successful lung resection. We aimed to evaluate the segmental PA branching pattern of the left upper lobe (LUL) using thin-section computed tomography (TSCT) images and 3D-CT angiography (3D-CTA). This study included 108 patients who underwent CTA and left upper lobectomy. The segmental PA branching pattern of the LUL was meticulously identified by two thoracic radiologists using 3D-CTA and TSCT images. The lingular artery branches from the left PA (LPA) were classified into mediastinal type (pars mediastinalis: PM), interlobar type (pars interlobaris: PI), and PI originating from the lower portion (PI'), specifically from A8. The intraoperative findings of the PA branches of the LUL were compared with the preoperatively obtained 3D-CTA and TSCT images in each patient's case. The median (range) number of LPA branches of the LUL was 4.36 (3-8). The most common number of A1 + 2 branches was two, seen in 34 cases (31.5%). One or more branches of A1 + 2c directly originating from the LPA were found in 63 cases (58.3%). The number of branches of A3 was single in 85 cases and the most frequent (78.7%). Instances where one or more branches of A3a directly originated from the LPA were found in seven cases (6.5%). A1 + 2 and A3 origins were separate and independent in 40 cases (37.0%). As the branching pattern of the lingular artery, PI/PI' was most frequent (61.1%). PI´ was observed in 26 cases (24.1%). Inter-observer agreement for A1 + 2, A1 + 2c, A3, A3a, and lingular artery branching patterns was moderate to substantial (κ = 0.53-0.72). Preoperative 3D-CTA and TSCT images identified 99.8% of LPA branches compared to intraoperative findings, except one. The segmental PA branching pattern of the LUL can be evaluated using TSCT and 3D-CTA images, providing precise preoperative information.

3-D Contrast-Enhanced Fusion Ultrasound for Accurate Volume Assessment of Vessel Lumen and Plaque in Carotid Artery Disease as Compared With Computed Tomography Angiography

ObjectiveThree-dimensional contrast-enhanced fusion ultrasound (3D-CEFUS) of atherosclerotic carotid arteries provides spatial visualisation of the vessel lumen, creating a lumenography. As in 3D computed tomography angiography (3D-CTA), 3D-CEFUS outlines the contrast-filled lumen. Plaque and vessel contours are distinguished in 3D-CEFUS, allowing plaque volume quantification as a valid estimate of carotid plaque burden. 3D-CEFUS is unproven in inter-modality studies, vindicating the assessment of 3D-CEFUS applicability and comparing 3D-CEFUS and 3D-CTA lumenography as a proof-of-concept study. MethodsUsing an ultrasound system with magnetic tracking, a linear array transducer, and SonoVue contrast agent generated 3D-CEFUS acquisitions by spatial stitching of serial 2D images. From 3D-CEFUS and 3D-CTA imaging, the atherosclerotic carotid arteries were reconstructed with lumenography in an offline software programme for lumen and plaque volume quantification. Bland-Altman analysis was used for inter-image-modality agreement. ResultsThe study included 39 carotid arteries. Mean lumen and plaque volume in 3D-CEFUS were 0.63 cm3 (SD 0.26) and 0.62 cm3 (SD 0.26), respectively. Lumen volume differences between 3D-CEFUS and 3D-CTA were non-significant, with mean difference of 0.01 cm3 (SD 0.02, p = .26) and limits of agreement range (LoA-range) of ±0.11 cm3. Mean plaque volume difference was -0.12 cm3 (SD 0.19, p = .006) with LoA-range of ±0.39 cm3. ConclusionStrong agreement in lumenography between 3D-CEFUS and 3D-CTA was found. The inter-image-modality difference in plaque volumes was substantial due to challenging vessel wall definition in 3D-CTA. 3D-CEFUS is viable in quantifying carotid plaque volume burden and can potentially monitor plaque development over time.

An analysis of the left top pulmonary vein and comparison with the right top pulmonary vein for lung resection by three-dimensional CT angiography and thin-section images

PurposeThe right top pulmonary vein (RTPV) is defined as an anomalous branch of the right superior PV (SPV) draining into the PV or left atrium (LA). Several previous reports have described the RTPV, but only a few have mentioned the left top PV (LTPV). The present study aimed to evaluate the branching patterns of the RTPV and LTPV using thin-section CT images and three-dimensional CT angiography (3D-CTA).Materials and methodsThis study included 1437 consecutive patients for evaluation of the right side and 1454 consecutive patients for the left side who were suspected of lung cancer and underwent CTA. We assessed the presence of each RTPV and LTPV and their branching patterns on the CTA images. When the RTPV or LTPV was identified, the maximum short-axis diameter was measured.ResultsRTPV was found in 9.1% (131/1437), whereas LTPV was found in 2.9% (42/1454) of the patients. RTPV was also observed in 17.1% (7/41) of LTPV cases, except for one case in which the right side could not be evaluated. The most common RTPV inflow site was the right inferior PV (IPV) in 64.9% (85/131) of the patients, whereas that of the LTPV was the left IPV in 100.0% (42/42) of the patients. The mean diameter of the RTPV and LTPV was 3.3 mm (range, 1.3–7.5 mm) and 2.4 mm (range, 0.9–6.3 mm), respectively (P < 0.01).ConclusionThe top PV branching pattern variations can be evaluated using thin-section CT and 3D-CTA images. RTPV is not a rare finding, and LTPV should also be identified in lung cancer cases scheduled for resection.

Morphological Analysis of the Sylvian Fissure Stem to Guide a Safe Trans-sylvian Fissure Approach.

The sylvian fissure stem and its deep cisternal part (SDCP) consist mainly of the orbital gyrus (OG) and anterior medial portion of the temporal lobe. SDCP's adhesion has been found to make a trans-sylvian approach difficult due to the various patterns of adhesion. Thus, in this study, we aim to clarify the morphological features of the SDCP, and to guide a safe trans-sylvian approach. We retrospectively classified the morphology of the SDCP in 81 patients into 3 types (tight, moderate, loose type) according to the degree of adhesion of the arachnoid membrane and analyzed the morphological features of the OG and the temporal lobe using intraoperative video images. In addition, we have retrospectively measured each width of the SDCP's subarachnoid space at the three points (Point A, lateral superior portion; Point B, downward portion; Point C, medial inferior portion of SDCP) and analyzed their relationship to the degree of adhesion using the preoperative coronal three-dimensional computed tomography angiography (3D-CTA) images of 44 patients. As per the results, SDCP's adhesions were determined to be significantly tighter in cases with large OG and young cases. The temporal lobe had four surfaces (posterior, middle, anterior, and medial) that adhered to the OG in various patterns. The tighter the adhesion between the OG and each of the three distal surfaces of the temporal lobe, the narrower the width of the subarachnoid space at each point (A, B, C). Understanding of the morphological features of the SDCP, and estimating its adhesion preoperatively are useful in developing a surgical strategy and obtaining correct intraoperative orientation in the trans-sylvian approach.

Feasibility of Preoperative Magnetic Resonance Angiography/Black-Blood Magnetic Resonance Imaging/Computed Tomography Fusion Imaging Without Contrast Agent for Carotid Endarterectomy

Preoperative identification of the carotid bifurcation (CB) location and plaque and stenosis distal end of the cervical internal carotid artery in relation to bony structures is essential for carotid endarterectomy (CEA). However, for patients with contrast contraindications, cervical 3-dimensional computed tomography angiography (3D-CTA) is unavailable. In this study, we created fusion images of magnetic resonance angiography (MRA), black-blood (BB) magnetic resonance imaging (MRI), and CT to determine if these noncontrast agent images are superior to 3D-CTA for preoperative CEA planning. The fusion images showed vascular structures obtained by MRA, plaque observed by BB-MRI, and bone structures shown by CT. Spatial localization accuracy was verified by directly overlaying contrast-enhanced 3D-CTA images on the fusion images. We validated this technique in 50 patients with unilateral ICA stenosis, 28 of whom underwent CEA. The 2D-distance CB MRA-CTA (the 2D distance difference between CB MRA and CB CTA perpendicular to the long axis of the carotid artery) was measured. We also compared the findings of the fusion image regarding the CB location and plaque distal end with the operative findings. The median 2D distance CB MRA-CTA was 1mm. CB MRA was located distal and proximal to CB CTA in 21and 29 patients, respectively. The CB location and fusion-image plaque were consistent with the intraoperative findings in all CEA patients. Fusion images created from MRA, BB-MRI, and noncontrast CT were feasible as an alternative to 3D-CTA for patients with contrast contraindications.

A Novel Method for Improving the Accuracy of MR-derived Patient-specific Vascular Models using X-ray Angiography.

MR imaging, a noninvasive radiation-free imaging modality commonly used during clinical follow up, has been widely utilized to reconstruct realistic 3D vascular models for patient-specific analysis. In recent work, we used patient-specific hemodynamic analysis of the circle of Willis to noninvasively assess stroke risk in pediatric Moyamoya disease (MMD)-a progressive steno-occlusive cerebrovascular disorder that leads to recurrent stroke. The objective was to identify vascular regions with critically high wall shear rate (WSR) that signifies elevated stroke risk. However, sources of error such as insufficient resolution of MR images can negatively impact vascular model accuracy, especially in areas of severe pathological narrowing, and thus diminish clinical relevance of simulation results, as local hemodynamics are sensitive to vessel geometry. To improve the accuracy of MR-derived vascular models, we have developed a novel method for adjusting model vessel geometry utilizing 2D X-ray angiography (XA), which is considered the gold standard for clinically assessing vessel caliber. In this workflow, "virtual angiographies" (VAs) of 3D MR-derived vascular models are conducted, producing 2D projections that are compared with corresponding XA images to guide the local adjustment of modeled vessels. This VA-comparison-adjustment loop is iterated until the two agree, as confirmed by an expert neuroradiologist. Using this method, we generated models of the circle of Willis of two patients with a history of unilateral stroke. Blood flow simulations were performed using a Navier-Stokes solver within an isogeometric analysis framework, and WSR distributions were quantified. Results for one patient show as much as 45% underestimation of local WSR in the stenotic left anterior cerebral artery (LACA), and up to a 56% underestimation in the right anterior cerebral artery when using the initial MR-derived model compared to the XA-adjusted model. To evaluate whether XA-based adjustment improves model accuracy, vessel cross-sectional areas of the pre- and post-adjustment models were compared to those seen in 3D CTA images of the same patient. CTA has superior resolution and signal-to-noise ratio compared to MR imaging but is not commonly used in the clinic due to radiation exposure concerns, especially in pediatric patients. While the vessels in the initial model had normalized root mean squared deviations (NRMSDs) ranging from 26% to 182% and 31% to 69% in two patients with respect to CTA, the adjusted vessel NRMSDs were comparatively smaller (32% to 53% and 11% to 42%). In the mildly stenotic LACA of patient 1, the NRMSDs for the pre- and post-adjusted models were 49% and 32%, respectively. These findings suggest that our XA-based adjustment method can considerably improve the accuracy of vascular models, and thus, stroke-risk prediction. An accurate, individualized assessment of stroke risk would be of substantial help in guiding the timing of preventive surgical interventions in pediatric MMD patients.

Low-dose three-dimensional CT angiography for the evaluation of posterolateral protrusion of the vertebral artery over the posterior arch of the atlas: a quantitative anatomical comparison study of the rotational and neutral positions

To investigate the changes in relevant anatomical parameters of posterolateral protrusion of the vertebral artery (VA) between head-neck rotational and neutral positions using low-dose three-dimensional computed tomography angiography (3D-CTA). Low-dose 3D-CTA images obtained for various craniocervical diseases in 36 non-dominant VA side patients with neutral, left and right head-neck rotational positions were evaluated. The relevant parameters from superior and inferior views, including external diameter (ED), internal diameter (ID), transverse diameter (TD), heights and diameters of posterolateral protrusion of the VA over the posterior arch of the atlas in the neutral and rotational positions, were recorded and compared. There was no significant differences in the rotational angle (left/right: 31.23±6.60/29.94±6.09°, p>0.05). There were no significant differences in heights and diameters of bilateral VA between rotational and neutral positions (all p>0.05). The contralateral ID, ED, and TD of the rotational positions were significantly shorter than those of the neutral position (all p<0.05), while there were no significant differences in the three ipsilateral diameters (all p>0.05). Posterolateral protrusion of the VA is not uncommon in the population, and surgeons should be aware of its presence, especially the increased possibility of injury to the VA caused by head-neck rotation, during the operation; thus, preoperative evaluation by low-dose 3D-CTA should be considered.

A Simple Method to Estimate the Trajectory to the Genu of the Corpus Callosum in the Interhemispheric Approach for Distal Anterior Cerebral Artery Aneurysms.

In the interhemispheric approach (IHA) for the distal anterior cerebral artery (DACA) aneurysms, the surgical trajectory to a DACA aneurysm is very important because surgeons sometimes encounter the intraoperative disorientation and the premature rupture. The purpose of this study was to clarify the anatomical landmarks indicating the trajectory to the genu of the corpus callosum (GCC) at the early stage of dissection for the correct intraoperative orientation. “Point A” was defined as the crossing point between the frontal bone and the line connecting the projected external acoustic opening (EAO) and the GCC on the midline slice of the sagittal three-dimensional computed tomography angiography (3D-CTA) images. We measured the distance from the nasion to Point A using midline sagittal slice images from 50 patients who underwent 3D-CTA at our institution. The average distance was 7.0 cm (±0.3 cm). Therefore, the direction of the spatula inserted in the direction of the EAO from Point A (7 cm above the nasion) corresponds to the trajectory to the GCC. In DACA aneurysms of the A3 segment, the pericallosal artery distal to the aneurysm can be safely identified by dissecting the interhemispheric fissure distal to the trajectory to the GCC. In DACA aneurysms of the A4 or A5 segment, the parent artery of the aneurysm can be safely identified by dissection along the trajectory to the GCC. Point A and the EAO can be used as landmarks indicating the trajectory to the GCC for the correct intraoperative orientation in the IHA for DACA aneurysms.

Patient-Specific Coronary Artery Bypass Graft 3D Printing: Implications for Procedural Planning in Complex Percutaneous Coronary Interventions.

Three-dimensional (3D) printing technology has seen tremendous growth in augmenting didactics, research, and preprocedural planning with structural heart procedures. Limited investigative efforts have been made in other areas of the cardiovascular spectrum. 3D-printed models (PMs) of anatomically complex coronary artery bypass graft (CABG) patients from coronary computed tomography angiography (CCTA) have implications for adaptive learning and preprocedural planning. Five patients with CCTA who underwent subsequent coronary angiography were 3D printed for retrospective comparisons. Standard slicer software was used to create a computer-aided image of the ascending aorta, native coronary arteries, bypass grafts, aortic arch, and great vessels and 3D printed using polylactic acid filament. The models were painted with acrylic paint to highlight anatomical features and comparison was made with coronary angiography and 3D-CTA images. All occluded vein grafts, left and right internal mammary artery (IMA) grafts, patent saphenous vein grafts, along with distal graft anastomotic sites, were accurately 3D printed. In cases with chronic total occlusions (CTOs), ambiguous ostial caps, mid or distal vessel chronic occlusions, and occlusions seen as CTOs on coronary angiography were 3D printed showing either distal vessel reconstitution via collaterals or complete arterial filling seen in a setting of calcification, microchannels, and collateral flow. Lastly, 3D printing of the aortic root and great vessels allowed for better appreciation of vessel tortuosity to aid in the cannulation of IMA grafts and optimizing engagement with diagnostic and guiding catheters. 3D printing of anatomically complex CABG patients has the potential to assist with preprocedural planning and operator understanding of complex coronary anatomy.

Efficacy of CO₂ Infusion for Preoperative Computed Tomographic Angiography with Computed Tomographic Colonography.

BackgroundComputed tomographic colonography (CTC) is useful for patients for whom colonoscopy may be difficult to perform and is widely employed to examine the vasculature prior to colorectal cancer surgery. Computed tomographic angiography (CTA) was shown to be beneficial intraoperatively to manipulate blood vessels and prevent vascular injury. Three-dimensional (3D)-CTA combined with CTC (3D-CTA with CTC) is useful for preoperative evaluations of the anatomy of mesenteric vessels, colon, and lymph nodes. We observed that when the intestine was dilated with carbon dioxide (CO2), the arteriovenous delineation was often more pronounced than without CO2. To clarify the effects of gas injection with and without CO2 on hemodynamics and vascular passage, we compared the effect of contrast for blood vessels.Material/MethodsThirty patients with resectable colorectal cancer who underwent a preoperative CT examination at our institution from January to October 2019 were study participants. Of these, 15 underwent 3D-CTA and 15 had 3D-CTA with CTC. Three board-certified radiologists independently and blindly evaluated 18 blood vessels. CT values for each blood vessel were measured on each image.ResultsCT values for 3D-CTA with CTC were significantly higher with CO2 than without CO2. The quality of 3D-CTA with CTC images for visualization of blood vessels was also significantly greater than that of 3D-CTA, especially those of arterial and intramesenteric venous systems.ConclusionsBased on the higher image quality and CT values obtained by 3D-CTA with CTC for vessels, compared with by 3D-CTA imaging, 3D-CTA with CTC imaging might be useful in evaluating colorectal cancers.

Three-Dimensional Virtual Reality Simulation to Safe Planning Neurosurgical Procedure in Brain Aneurysms, Latin American Single-Center Experience: Advantages and Limitations

Abstract Background The neurosurgical approach to clipping cerebral aneurysms has been a complex challenge for all neurosurgeon experts in cerebrovascular surgery. The three-dimensional computed tomography angiography (3D-CTA) allows identifying bone and vascular structures close to an aneurysm to simulate in virtual 3D images, the appropriate and safest approach to cerebral aneurysm clipping. Objectives This study aims to share our experience using 3D simulation as a support to the safe planning for cerebrovascular disease surgery. Materials and Methods We reviewed the surgical outcomes from a cerebrovascular neurosurgeon using the 3D-CTA images in 360-degree reconstruction in the planning of the preoperative surgical procedure for the treatment of brain aneurysm. In all patients, the virtual surgical approach was replicated in real-time surgery. Results We analyzed 34 patients around 51 ± 8 years of age. Of these, 76.5% (n = 26) and 23.5% (n = 8) were males and females, respectively. Saccular aneurysms were the most frequent (85%), the Arteries affected by aneurysms were middle cerebral artery (n = 6), basilar tip (n = 6), vertebral artery in V3 and V4 (n = 6), and posterior cerebral artery (n = 5). The virtual surgical pterional approach was the most frequently used (50%), followed by fronto-orbito-zigomático (29%) and far lateral (15%) approaches. There were no intraoperative complications in any patient. Conclusion Preoperative 3D virtual reality simulation is a great support tool to perform a safe surgical procedure in real-time for the treatment of simple and complex brain aneurysms.

In Reply: Three-Dimensional Evaluation and Classification of the Anatomy Variations of Vertebral Artery at the Craniovertebral Junction in 120 Patients of Basilar Invagination and Atlas Occipitalization.

To the Editor: We appreciate the comments of Sardhara et al1 regarding our paper entitled “Three-Dimensional Evaluation and Classification of the Anatomy Variations of Vertebral Artery at the Craniovertebral Junction in 120 Patients of Basilar Invagination and Atlas Occipitalization” published in Operative Neurosurgery.2 We regretted not citing the research by Sardhara et al3 in our paper, as there were so many papers concerning the vertebral artery (VA) variations at the craniovertebral junction (CVJ). We could not cite all the information in the literatures. In your study, the anatomical parameters between VA variations and bony deformity were measured and a total score for risk stratification of VA injury during surgery was calculated.3 Your paper had given many useful and beneficial clinical experiences. However, the preventive strategies of different type of VA injury and clinical value of anatomical parameters were majorly discussed in our paper.2 There might be some misunderstanding of the comments of Sardhara et al.1 In our study,2 the traditional three-dimensional (3D) computed tomography angiography (CTA) was used just as most of the literature reported. The limitation of the traditional 3D reconstruction software is that the circumambient osseous of VA cannot be transparent and the special course of VA variations in the osseous deformities cannot be clearly recognized. In our study, the separating, fusing, opacifying and false-coloring-volume rendering technique was used to process the traditional 3D-CTA image. Based on our experiences, it only takes another 5 to 10 min to realize the differentiation of anatomical structures with a different opacity value. Therefore, we concluded that such technique is a convenient and concise method for preoperative evaluation of safety screw placement and for identifying the risk of VA injury in congenital anomalies at the CVJ. In our center, we have treated CVJ anomalies since the 1980s and have accumulated experience of over 3000 cases. We started the VA research very early. As early as 2005, we had reported a kind of VA entering subarachnoid space at the C2 to C3 intervertebral level,4 which is consistent with the abnormal VA as a C3 segmental artery mentioned in the author's letter. With the number of cases increased over the years, we did further study with the biggest cohort. Although the abovementioned kind of VA variations is rare, we found it in 3 patients in our study. The result we reported was still earlier than those reported by Moon et al.5 Patients with basilar invagination and atlas occipitalization usually present abnormal anatomy of the VAs at the CVJ. In managing such complex diseases, spine surgeons are greatly challenged with issues regarding how to intraoperatively address the VA. Failure to recognize them may lead to catastrophic complications. In fact, multiple modalities have been routinely used to detect the aberrant VA, like the 3D imaging reconstruction technique, mixed reality technique and 3D printed technique. With the assist of these techniques, the risks of VA injury would be reduced and the optimal surgical results would be achieved for patients. Funding This study did not receive any funding or financial support. Disclosures The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.

Efficacy of non-rigid registration technique for misregistration in 3D-CTA fusion imaging.

To assess whether fusion 3D-CTA images can be corrected using non-rigid registration (NRR) for gastroenterology imaging. This study included 55 patients before gastroenterology surgery who underwent preoperative 3D-CTA prior to gastroenterological surgery. We recorded the coordinate of measurement points on the arterial vessels (X, Y, and Z) in each portal phase, original image of the arterial phase, and arterial phase with NRR. The distance of misregistration between the two points was calculated with the coordinate of the original image with NRR and that of the portal phase as true value. The distance of misregistration between the two points in the original arterial and portal phase images was significantly higher than that in the arterial phase image with NRR on all directions (p < 0.01). This study showed that NRR may correct misregistration on fusion 3D-CTA imaging. Hence, it can visualize correctly the anatomy of the vessel.

Improved Depictions of the Anterior Choroidal Artery and Thalamoperforating Arteries on 3D-CTA Images Using Model-based Iterative Reconstruction

To evaluate the depictability of intracranial small arteries using high-resolution CTA with model-based iterative reconstruction (MBIR). We retrospectively analyzed 21 patients who underwent brain 3D-CTA. Axial and volume-rendered (VR) images were reconstructed from the 3D-CTA raw data using adaptive statistical image reconstruction (ASIR) and MBIR. As a quantitative assessment, intra-arterial CT values of the ICA and contrast-to-noise ratio were measured to evaluate vessel enhancement. Additionally, CT values and standard deviations (SDs) of CT values and signal to noise ratio in white matter parenchyma were measured to evaluate background noise. As a qualitative assessment, the degree of vessel depictability in the anterior choroidal artery (AchoA) and the perforating branches of thalamoperforating arteries (TPA) on VR images using two different reconstruction algorithms was visually evaluated using a 3-point grading system. The CT value of the ICA [605.27± 89.76 Hounsfield units (HU)] was significantly increased and the SD value (i.e., image noise) of the white matter parenchyma [6.79 ± 0.81(HU)] was decreased on MBIR compared with ASIR [546.76 ± 85.27 (HU)] and [8.04 ± 1.08 HU)] (p <.05 for all). Contrast-to-noise ratio of ICA [84.48 ± 20.17] and signal to noise ratio of white matter [6.18 ± 0.75] with MBIR were significantly higher than ASIR [65.98 ± 13.08] and [5.28 ± 0.78] (p < 0.05 for all). In addition, depictions of the AchoA and TPA on VR images were significantly improved using MBIR compared with ASIR (p < 0.05). MBIR allows depiction of small intracranial arteries such as AchoA and TPA with better visibility than ASIR without increasing the dose of radiation and the amount of contrast agent.

Additive value of split-bolus single-phase CT scan protocol for preoperative assessment of lung cancer patients referred for video-assisted thoracic surgery.

We aimed to assess the additive value of the split-bolus single-phase computed tomography (CT) scan protocol to preoperatively assess patients with lung cancer, who were referred for video-assisted thoracic surgery, when compared to a standard staging CT protocol. We included 160 patients with lung cancer who underwent a split-bolus single-phase CT scan protocol (split-bolus protocol), which can acquire whole-body staging CT and pulmonary artery-vein separation CT angiography (PA-PV CTA) in a single acquisition and 160 patients who underwent whole-body staging CT (standard protocol). We compared the quality of the staging CT images of hepatic parenchyma, portal vein, and hepatic vein between both protocols. We also investigated image quality on PA-PV CTA images in the split-bolus protocol and recorded the number of patients that underwent the 3D PA-PV CTA imaging process. The split-bolus protocol for staging CT images demonstrated a slightly higher enhancement with regard to the hepatic parenchyma (p = 0.007) and hepatic vein (p = 0.006) than the standard protocol. There was no significant difference in the quality of the staging CT images between both protocols (p = 0.067). The mean CT number for the main pulmonary artery and the left atrium for the PA-PV CTA images in the split-bolus protocol were 289.1HU and 172.8HU, respectively. Among the images associated with the split-bolus protocol, 98.1% were of appropriate quality for 3D PA-PV CTA imaging. The split-bolus protocol is a dose-efficient protocol to acquire the staging CT and PA-PV CTA images in a single session and provides sufficient image quality for preoperative assessment in patients with lung cancer.

Utility of Split-bolus Single-phase Protocol for Pulmonary Artery and Vein Separation Preoperative 3D-CTA in Lung Cancer Video-assisted Thoracic Surgery

There are many variations in branching and running of pulmonary artery (PA) and pulmonary vein (PV). It is desirable to separate as a surgical simulation of lung cancer and important to grasp before video-assisted thoracic surgery (VATS) to perform quick and safe. Therefore, the purpose of this study was to evaluate objective and subjective image quality (contrast attenuation, separation ability, and vascular visualization) of PA and PV of splitbolus single-phase protocol (SBSPP) in preoperative three-dimensional computed tomography angiography (3DCTA). CT value of PA was 410.2±71.0 Hounsfield unit (HU), PV was 245.1±24.8 HU, difference between CT value of PA and CT value of PV was 164.5±60.9 HU. Subjective image quality of PA and PV could be visualized until more than the segmental branch level. SBSPP can obtain sufficient CT value for separate visualization of PA and PV, and before VATS useful PA and PV 3D-CTA imaging.

Accurate liver vessel segmentation via active contour model with dense vessel candidates

Background and objectiveThe purpose of this paper is to propose a fully automated liver vessel segmentation algorithm including portal vein and hepatic vein on contrast enhanced CTA images. MethodsFirst, points of a vessel candidate region are extracted from 3-dimensional (3D) CTA image. To generate accurate points, we reduce 3D segmentation problem to 2D problem by generating multiple maximum intensity (MI) images. After the segmentation of MI images, we back-project pixels to the original 3D domain. We call these voxels as vessel candidates (VCs). A large set of MI images can produce very dense and accurate VCs. Finally, for the accurate segmentation of a vessel region, we propose a newly designed active contour model (ACM) that uses the original image, vessel probability map from dense VCs, and the good prior of an initial contour. ResultsWe used 55 abdominal CTAs for a parameter study and a quantitative evaluation. We evaluated the performance of the proposed method comparing with other state-of-the-art ACMs for vascular images applied directly to the original data. The result showed that our method successfully segmented vascular structure 25%-122% more accurately than other methods without any extra false positive detection. ConclusionOur model can generate a smooth and accurate boundary of the vessel object and easily extract thin and weak peripheral branch vessels. The proposed approach can automatically segment a liver vessel without any manual interaction. The detailed result can aid further anatomical studies.

Fractional Flow Reserve Derived from Coronary Computed Tomography Angiography Datasets: The Next Frontier in Noninvasive Assessment of Coronary Artery Disease.

Fractional flow reserve (FFR) derived from coronary CTA datasets (FFRCT) is a major advance in cardiovascular imaging that provides critical information to the Heart Team without exposing the patient to excessive risk. Previously, invasive FFR measurements obtained during a cardiac catheterization have been demonstrated to reduce contrast use, number of stents, and cost of care and improve outcomes. However, there are barriers to routine use of FFR in the cardiac catheterization suite. FFRCT values are obtained using resting 3D coronary CTA images using computational fluid dynamics. Several multicenter clinical trials have demonstrated the diagnostic superiority of FFRCT over traditional coronary CTA for the diagnosis of functionally significant coronary artery disease. This review provides a background of FFR, technical aspects of FFRCT, clinical applications and interpretation of FFRCT values, clinical trial data, and future directions of the technology.

The diagnostic value of three-dimensional CT angiography for patients with acute coronary artery disease.

Computed tomography angiography (CTA) is an efficient method for the diagnosis of heart disease. However, few contemporary studies have evaluated the prognostic value of three-dimensional (3D)-CTA for patients with acute coronary artery disease. The aim of the present study was to investigate the diagnostic value of 3D-CTA for patients with acute coronary artery disease. A total of 136 patients with suspected acute coronary artery disease were recruited and received conventional coronary angiography (CCA) and 3D-CTA. 3D-CTA was used to assess calcified plaques in the coronary arteries (CCTA), the ratio of calcified plaque volume to vessel circumference (RVTC) and diagnostic accuracy. The results revealed that 3D-CTA was a more effective diagnostic method for identifying calcified plaques in patients with acute coronary artery disease compared with CCA. 3D-CTA demonstrated a significantly better area under curve, sensitivity, specificity, positive predictive value and negative predictive value compared with CCA (P<0.01). In the present study, 3D-CTA was used to successfully diagnose 86 patients with acute coronary artery disease, 34 with myocardial infarction and 16 with stable angina. 3D-CTA images clearly showed global noise levels and target-to-background ratios determined by manually delineated coronary plaque lesions compared with CCA. Furthermore, 3D-CTA was significantly better for discriminating ischemia compared with CCA (P<0.01). In conclusion, the results of the present study suggest that 3D-CTA provides superior diagnostic performance compared with CCA alone in patients with acute coronary artery disease.

Editor's Choices

This study aimed to investigate the application of 3-dimensional computed tomography angiography (3D-CTA) for defining cavernous sinus aneurysms and intradural aneurysms involving the internal carotid artery around the anterior clinoid process.Results from 42 patients with an aneurysm of the internal carotid artery around the anterior clinoid process who underwent 3D-CTA were reviewed and compared with those of observed clinical operations.Among the 42 patients, there was a total of 45 aneurysms of the internal carotid artery around the anterior clinoid process. After surgery, 33 of the 45 aneurysms were confirmed as intradural aneurysms, and the other 12 were confirmed as aneurysms in the cavernous sinus. 3D-CTA imaging of the medial sagittal plane showed that 31 out of 31 (100%) intradural aneurysms of the internal carotid artery were above the virtual line between the inferior border of the anterior clinoid process and the tuberculum sellae, and 12 out of 14 (86%) cavernous sinus aneurysms were below the virtual line (P < 0.0001).The virtual line between the inferior border of the anterior clinoid process and the tuberculum sellae on 3D-CTA indicates the proximal dural ring of the internal carotid artery. This line helps differentiate cavernous sinus aneurysms from intradural aneurysms involving the internal carotid artery around the anterior clinoid process.