Volume-rendering Method Research Articles

Evaluation of the Accuracy of 3D Printed Patient-Specific Brain Biopsy Guide Using 3D Volume Rendering Technique in Canine Cadavers

The objective of this study was to evaluate the accuracy of a CT-based, 3D-printed, patient-specific brain biopsy guide (3D-psBBG) through the application of a transfrontal approach in canine cadavers. A total of ten canine cadavers, with weights ranging from 4.36 to 14.4 kg, were subjected to preoperative CT scans to generate 3D skull models. Customized biopsy guides were created based on these models and manufactured using 3D printing technology. Twenty spinal needle insertions were performed, and the accuracy of needle placement was evaluated through both CT and 3D volume-rendering techniques. The mean needle placement error was 2.1 mm, with no significant differences observed between insertions targeting the fronto-olfactory and piriform lobes. The 3D volume-rendering method demonstrated superior accuracy compared to the CT method, with statistically significant differences in placement errors for both targets. The average time required for the design and manufacture of the guides was 249 min. These findings indicate the high accuracy and potential clinical application of CT-based 3D-psBBG for improving diagnostic outcomes in veterinary neurology.

Real-time volume rendering for three-dimensional fetal ultrasound using volumetric photon mapping

Three-dimensional (3D) fetal ultrasound has been widely used in prenatal examinations. Realistic and real-time volumetric ultrasound volume rendering can enhance the effectiveness of diagnoses and assist obstetricians and pregnant mothers in communicating. However, this remains a challenging task because (1) there is a large amount of speckle noise in ultrasound images and (2) ultrasound images usually have low contrasts, making it difficult to distinguish different tissues and organs. However, traditional local-illumination-based methods do not achieve satisfactory results. This real-time requirement makes the task increasingly challenging. This study presents a novel real-time volume-rendering method equipped with a global illumination model for 3D fetal ultrasound visualization. This method can render direct illumination and indirect illumination separately by calculating single scattering and multiple scattering radiances, respectively. The indirect illumination effect was simulated using volumetric photon mapping. Calculating each photon’s brightness is proposed using a novel screen-space destiny estimation to avoid complicated storage structures and accelerate computation. This study proposes a high dynamic range approach to address the issue of fetal skin with a dynamic range exceeding that of the display device. Experiments show that our technology, compared to conventional methodologies, can generate realistic rendering results with far more depth information.

Evaluation of femoral condyle volumes in patients with trochlear dysplasia: a pilot study

To examine the volumes of the medial and lateral femoral condyles and the trochlear groove, and to determine their relationship with trochlear dysplasia. Computed tomography images of the knees of 21 patients with trochlear dysplasia and 18 healthy individuals were analysed retrospectively. According to the modified Dejour classification, the degree of trochlear dysplasia was recorded, such as type A trochlea being low-grade dysplasia and types B, C, and D trochlea being high-grade dysplasia. Volume of the trochlear groove and medial and lateral femoral condyles were calculated using the three-dimensional (3D) volume-rendering method. The volumes of lateral condyle, medial condyle, and trochlear groove were statistically significantly lower in patients with trochlear dysplasia when compared to healthy participants. When compared according to Dejour types, all parameters were statistically significantly lower in both high- and low-grade dysplasia patients (p<0.05). The correlation between femoral condyle volumes and trochlear groove volume was low in the control group, but there was a moderate positive correlation in the patient group (r=0.50-0.75, p<0.05). In trochlear dysplasia, the volume of the trochlear groove decreases and hypoplasia may occur in both lateral femoral and medial femoral condyles. Therefore, hypoplasia of only one condyle should not be interpreted as trochlear dysplasia. A holistic approach to patients is required.

A Spherical Volume-Rendering Method of Ocean Scalar Data Based on Adaptive Ray Casting

There are some limitations in traditional ocean scalar field visualization methods, such as inaccurate expression and low efficiency in the three-dimensional digital Earth environment. This paper presents a spherical volume-rendering method based on adaptive ray casting to express ocean scalar field. Specifically, the minimum bounding volume based on spherical mosaic is constructed as the proxy geometry, and the depth texture of the seabed terrain is applied to determine the position of sampling points in the spatial interpolation process, which realizes the fusion of ocean scalar field and seabed terrain. Then, we propose an adaptive sampling step algorithm according to the heterogeneous depth distribution and data change rate of the ocean scalar field dataset to improve the efficiency of the ray-casting algorithm. In addition, this paper proposes a nonlinear color-mapping enhancement scheme based on the skewness characteristics of the datasets to optimize the expression effect of volume rendering, and the transparency transfer function is designed to realize volume rendering and local feature structure extraction of ocean scalar field data in the study area.

Volume Prediction of Extended Latissimus Dorsi Musculocutaneous Flap for Breast Reconstruction Using a Computed Tomography Volume-Rendering Technique with an X-ray Contrast Thread Marking.

The extended latissimus dorsi (ELD) musculocutaneous flap is one of the surgical techniques used for breast reconstruction. Preoperative preparation to determine the exact amount of flap tissue to be harvested is important to achieve a good outcome with autologous tissue reconstruction. However, few reports exist on objective preoperative volume prediction of ELD flaps. The purpose of this study was to quantify the elevated ELD volume as a preoperative plan. Patients who underwent immediate or delayed breast reconstruction with ELD flap after mastectomy between March 2015 and January 2022 are included. (1) The ELD flap was designed preoperatively, X-ray contrast thread was applied along the design, and CT imaging was performed in the same lateral supine position as the surgical position. 3D images were constructed, and the volume-rendering method was used to obtain the integrated volume. (2) Intraoperative ELD flap volume was calculated using the water displacement method. The correlation between (1) and (2) was examined. (1) The mean preoperative predicted value was 290.2 mL and (2) the mean intraoperative ELD flap volume was 298.3 mL. The correlation coefficient between the two volumes was 0.93, indicating that they were correlated. We could quantify the ELD flap volume using the volume-rendering method with X-ray contrast threads. This study could be a useful method for preoperative prediction planning of the ELD flap in breast reconstruction. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Abstract 10040: Impact of Periaortic Adipose Tissue Detected by Computed Tomography on Aortic Vulnerable Plaques Identified by Non-Obstructive General Angioscopy

Introduction: Periaortic adipose tissue (PAAT) is related to the development of cardiovascular disease. However, the relationship between periaortic adipose tissue (PAAT) and aortic plaque instability has not been elucidated. Hypothesis: We hypothesized that PAAT would be associated with aortic vulnerable plaques derived non-obstructive general angioscopy (NOGA) in patients with cardiovascular disease. Methods: We investigated 117 patients who underwent NOGA of the aorta and CT. PAAT volume was measured using the volume-rendering method by extracting the area from -30 to -190 HU within the thoracic aorta. PAAT volume index (PAAT-I) was defined as PAAT volume divided by the body surface area. We evaluated the number of vulnerable plaques including ruptured plaques, ulcerations, thrombi, intense yellow plaques by NOGA in the whole aorta. All patients were divided into the median value of PAAT-I (16.9 [13.0 - 21.6] ml/m2) Results: The high PAAT-I patients had significantly greater number of vulnerable plaques in the thoracic aorta than the low PAAT-I patients (2 [1-4] vs 1 [0-3], p&lt;0.05). The PAAT-I had a correlation with the number of vulnerable plaques in the thoracic and whole aorta (r=0.44, p&lt;0.001, r=0.35, p&lt;0.01, respectively) Conclusions: PAAT in the thoracic aorta was related to the number of NOGA derived-aortic vulnerable plaques in patients with cardiovascular disease. PAAT may play an important role in the development of aortic plaque instability.

The relationship between patellar volume and trochlear volume in patients with patellofemoral instability

To investigate a possible relationship between both the volume and morphology of the patella and the volume of the trochlea in trochlear dysplasia (TD). Eighteen patients with TD and 18 controls were evaluated retrospectively in two groups using computed tomography (CT). Patellar morphology was evaluated with the standard measurement methods described in the literature. Additionally trochlear sulcus volume (TV) and patellar volume (PV) were measured quantitatively using the three-dimensional volume-rendering method. The relationship between patella dimensions and volume and trochlea volume was evaluated. The length of the medial patellar facet (lMP), patellar width (PW), TV and PV were significantly lower in the patient group. When compared according to Dejour types, PW was statistically significantly lower than the control group in those with high-grade and those with low-grade dysplasia. A positive correlation was found between the TV and PV in both groups (patient group: r=0.583 p=0.011; control group: r=0.485 p=0.042). CONCLUSİONS: PV and the TV are related. Therefore, PV can be used as a determining parameter in the evaluation of TD. This technique can also be used for prosthesis construction and more accurate surgical planning.

Application of 3D reconstruction through CT to measure the abdominal cavity volume in the treatment of external abdominal hernia.

To evaluate 3D reconstruction through CT in the measurement of abdominal cavity volume. From January 1, 2019 to December 31, 2019, 61 patients diagnosed as external abdominal hernia were included in this prospective study. Multislice computed tomography (MSCT) was applied to patients scanning, and the images were transferred to post-processing workstation for further analysis. We measured the abdominal cavity volumes using volume rendering (VR) method and diameter rendering (DR) method, and the results were used to test whether there is a correlation between them. In addition, the time required for the measurement was recorded and analyzed. In this study, we found that there was no significant difference in the abdominal cavity volumes between these two groups (VR vs. DR = 7857.316 ± 2035.786cm3 vs. 7967.268 ± 2925.792cm3, P > 0.05). Besides, the correlation analysis between the measured values of VR method and DR method showed there was a significant positive correlation (r = 0.922, P < 0.01). The linear regression equation based on the scatter plot was established as follows: y = 0.6417x + 2745, R2 = 0.8504. Furthermore, this regression equation was simplified as follows: y = 0.64x + 2800, R2 = 0.8499. Meanwhile, the time required for measurement of VR was significantly longer than that of DR (VR vs. DR = 64.3 ± 7.1min vs. 2.6 ± 0.6min, P < 0.01). In conclusion, the DR method can quickly measure and calculate the abdominal cavity volume, and its accuracy can more suitable for clinical requirement.

Three‐dimensional volumetric measurement of the aortic root compared to standard two‐dimensional measurements using cardiac computed tomography

Two-dimensional measurements are self-evidently limited when seeking accurately to represent the three-dimensional complexity of the aortic root. Volumetric measurement, therefore, seems an ideal alternative for a more accurate assessment. We retrospectively analyzed 123 individuals undergoing cardiac computed tomography. We measured the dimensions of the sinuses of Valsalva using routine multiplanar short axis imaging. Three conventional two-dimensional methods were applied to measure the dimensions of the sinuses. These involved bisecting center of sinus-to-center of interleaflet triangle measures, along with center of sinus-to-center of sinus, and largest sinus-to-sinus measurements. We then quantified the volumes of the root using the volume-rendering method. The mean dimensions of the sinuses were significantly greater when measured using the largest sinus-to-sinus method as opposed to center of sinus-to-center of interleaflet triangle and center of sinus-to-center of sinus methods (33.6 ± 3.6 mm vs. 31.1 ± 3.1 mm and 30.9 ± 3.3 mm, p < .0001). The mean root volume of 13.6 ± 4.2 ml showed the strongest correlation with the mean dimensions of the sinuses of Valsalva measured using the bisecting method (R2 = .8401, p < .0001). By using two- and three-dimensional measurements, we have provided average data for the structurally normal aortic root. The differences and correlations encountered should be noted when evaluating and following changes in the diseased root.

Sacral Anatomical Orientation in the Lebanese Population

Introduction PI is currently used as the gold standard measurement in spinopelvic anatomy. There is a need for a reliable method to calculate sacral anatomic orientation (SAO) independent of posture and to establish its association with PI, which was previously established in a single study (Peleg et al., 2007). Therefore, the aim of our study is the application and verification of this association on a Lebanese sample. Methods Methods for measuring SAO and PI on living individuals are described. The study was carried out on 200 adult individuals using CT 3D images (volume-rendering method). Reliability (intratester and intertester) was evaluated using the intraclass correlation test. A regression analysis was carried out to evaluate the association between the two measurements. Results There were 103 females (51%) and 97 males (49%) with a mean age of 58.68 ± 19.6 years (min = 20; max = 93). The mean SAO and PI in our population were found to be 52.65° (SD = 8.16°) and 59.08° (SD = 12.53°), respectively. SAO and PI measurements were highly correlated (Pearson correlation test; r = −0.296, P < 0.0001 for our general population). PI can be predicted via SAO, i.e., SAO = (−0.193 × PI) + 64.057. Conclusions SAO may be an important tool, alongside PI, in defining the sagittal shape of the spine and useful for understanding its association with spinal diseases as they are not affected by postural changes.

P1828Aortic calcification detected by computed tomography and aortic vulnerable plaques: aortic angioscopy study

Abstract Background Aortic calcification is associated with atherosclerotic risk factors and an increased risk of death and cardiovascular disease. However, the relationships aortic calcification and aortic plaque instability are not yet elucidated. Recently, some reports showed non-obstructive aortic angioscopy seemed to visualize atherosclerotic changes of aortic wall more clearly compared with computed tomography (CT). The purpose of this study was to evaluate whether aortic calcification is associated with aortic vulnerable plaques in patients with cardiovascular disease. Methods We investigated 60 consecutive patients with confirmed or suspected coronary artery disease who underwent both aortic angioscopy and CT. The AC volume (ACV) was measured using the volume-rendering method by extracting the area &gt;130 HU within the whole aorta. ACV index (ACVI) was defined as ACV divided by the body surface area. We evaluated the number of ruptured plaque (RP), ulceration and fissure by aortic angioscopy in the whole aorta. We excluded 4 hemodialysis patients. All patients were divided into the median value of ACVI. Results The mean age of patients was 68±10. The median of ACVI was 10.7 ml/m2 [3.9–22.7]. High ACVI patients had significantly greater number of RP, ulceration and atheromatous plaques detected by aortic angioscopy compared with those of low ACVI (2.2±2.7 vs 0.8±1.1, p=0.033, 1.6±1.2 vs 0.9±1.0, p=0.041, 4.0±3.1 vs 1.9±1.8, p=0.009, respectively). Furthermore, the patients without aortic calcification did not have RP at all. In a multivariate model, the number of the atheromatous plaques was independently associated with high ACVI (odds ratio 1.57, 95% confidence interval 1.07–2.69, p=0.018) Conclusions Aortic calcification detected by CT was related to aortic vulnerable plaques in patients with cardiovascular disease.

Volume Rendering Method Applied to 3D Edge Impurity Emission in LHD to Produce Projection Image in Arbitrary Plane

Volume Rendering Method Applied to 3D Edge Impurity Emission in LHD to Produce Projection Image in Arbitrary Plane

The Fast Contour Tree-Based Medical Volume Rendering Method

The Fast Contour Tree-Based Medical Volume Rendering Method

Serum phosphate is an independent predictor of the total aortic calcification volume in non-hemodialysis patients undergoing cardiovascular surgery

BackgroundA high serum phosphate level is a well-known risk factor for vascular calcification (VC) in patients on hemodialysis (HD). However, the association between the serum phosphate level and VC in non-HD patients is unclear. Our aim was to assess the impact of serum phosphate level on aortic calcification (AC) volume in non-HD patients undergoing cardiovascular surgery. MethodsA total of 117 patients who underwent thoracoabdominal computed tomography as a preoperative general evaluation before cardiovascular surgery were enrolled. The total AC volume was quantified using the volume-rendering method by extracting the area ≥130HU within the entire aorta. The total AC volume index (AC-VI) was estimated as the total AC volume divided by the body surface area. ResultsIn the 117 patients (64.7±13.1 years, 39% women), the median total AC-VI was 1.23mL/m2. The mean estimated glomerular filtration rate (eGFR), adjusted serum calcium levels, and serum phosphate levels were 63.8±19.9mL/min/1.73m2, 9.1±0.4mg/dL, and 3.6±0.6mg/dL, respectively. When the patients were classified into four quartiles based on their total AC-VI value, the serum phosphate level showed a positive correlation with a probability of being in the highest AC-VI quartile (R2=0.0146, p=0.0383) whereas the adjusted serum calcium level did not show a significant correlation (R2=0.0040, p=0.2615). A similar relationship between the serum phosphate level, adjusted serum calcium level, and AC-VI was confirmed when the total AC-VI was divided into the thoracic AC-VI and abdominal AC-VI. Multivariate analysis indicated that the serum phosphate level was an independent positive predictor of higher total AC-VI quartiles (β=0.8013, p=0.0160). ConclusionsAn increase in serum phosphate level was associated with an increased AC burden in non-HD patients undergoing cardiovascular surgery.

Association of a Subperiosteal Hematoma With Minor Injury.

An intraorbitalsubperiosteal hematoma is a rare clinical entity that is usually caused by head trauma. The authors experienced a patient involving an intraorbital hemorrhage that was associated with minor injury in the forehead and that required surgical decompression. The authors describe this rare case involving an intraorbitalsubperiosteal hematoma that occurred in a conscious young boy who had no remarkable head injury and who had sudden onset of proptosis. Three-dimensional computed tomography, which was conducted with a volume-rendering method, was very useful, and the transorbital approach that was used to remove the hematoma was very effective. The patient showed good recovery. The pathogenesis of the intraorbitalsubperiosteal hemorrhage could not be fully explained, and, thus, the authors suggest that a possible pathogenesis involved the migration of the hemorrhage from the forehead into the intraorbital region.

Three-dimensional quantification and visualization of aortic calcification by multidetector-row computed tomography: A simple approach using a volume-rendering method

Objective: Three-dimensional (3-D) visualization and quantification of vascular calcification (VC) are important to accelerate the multidisciplinary investigation of VC. Agatston scoring is the standard approach for evaluating coronary artery calcification. However, regarding aortic calcification (AC), quantification methods appear to vary among studies. The aim of this study was to introduce a simple technique of simultaneous quantification and 3-D visualization of AC and provide validation data. Methods: The main study comprised of 126 patients who underwent the thoracoabdominal plain computed tomography scan as preoperative general evaluation. AC was quantified using a volume-rendering (VR) method (VR AC volume) by extracting the volume with a density ≥130 HU within the total aorta. The concordance and reproducibility of the VR AC volume were validated in comparison with the conventional slice-by-slice voxel-based AC quantification (volumetric AC score) using the Agatston scoring software. Results: Excellent concordance between the VR AC volume and volumetric AC score was confirmed (Spearman correlation coefficient = 0.9997, mean difference = −0.05 ± 0.23 mL, p <0.0001). Excellent intraobserver and interobserver reliabilities were demonstrated using the Bland–Altman analysis as the mean intraobserver difference was 0.00 mL (p = 0.9863) and the mean interobserver difference was −0.01 mL (p = 0.6612). Conclusion: The VR method was validated to be feasible. This simple approach could overcome the limitation of the current method based on slice-by-slice pixel or voxel summation, which lacks 3-D visual information. Accordingly, this approach would be promising for accelerating the investigation of VC.

Volume Rendering Method for Spatial Seismic Data Based on GPU

Volume rendering is one of the focuses in the research and application of computing visualization. On basis of the spatial data volume formally defined,principles and methods are introduced on the division of volume data, computation of resampling and composition of image in the ray casting algorithm. By resampling and compositing with shader, the algorithm is successfully improved in performance by GPU. The application of the algorithm in seismic interpretation is implemented for visualization of spatial seismic data in gray and pseudo-color and a transfer function is designed to highlight the characteristics of stratums in seismic data field, overcoming limitations in the visualization of profiles, slices and surface rendering of seismic data.

AB1273 Virtual anatomy of cervical nerve roots by 3-D MRI/CT fusion imaging

BackgroundBoth CT and MRI are widely known to be important tools in diagnosing spinal disorders. However, even when three-dimensional data are collected, images are often presented in two dimensions and...

A Pitfall of the Volume Rendering Method with 3D Time-of-Flight MRA: A Case of a Branching Vessel at the Aneurysm Neck

We present a case in which the origin of the branching vessel at the aneurysm neck was observed at the wrong place on the volume rendering method (VR) with 3D time-of-flight MRA (3D-TOF-MRA) with 3-Tesla MR system. In 3D-TOF-MRA, it is often difficult to observe the origin of the branching vessel, but it is unusual for it to be observed in the wrong place. In the planning of interventional treatment and surgical procedures, false recognition, as in the unique case in the present report, is a serious problem. Decisions based only on VR with 3D-TOF-MRA can be a cause of suboptimal selection in clinical treatment.

Virtual reality surgical anatomy of the sphenoid sinus and adjacent structures by the transnasal approach

ObjectiveTo examine the three-dimensional virtual anatomical features of the sphenoid sinus and adjacent structures during virtual surgery and explore their relevance to actual transsphenoidal surgery. MethodsCT images of the sphenoid sinus and surrounding structures from 28 Chinese adult patients were measured using a 16-slice helical CT scanner. Image analysis was performed using the volume-rendering method. Two experienced neurosurgeons wearing stereoscopic glasses performed virtual transsphenoidal surgery by the transnasal approach. ResultsThe virtual anatomical features of the sphenoid sinus and the adjacent structures during virtual surgery were described. The distance from the sphenopalatine foramen to the left and right sphenoid ostium was 10.1 ± 2.7 mm and 10.5 ± 3.2 mm, respectively, to the left and right sphenoidal crest 12.9 ± 2.0 mm and 12.8 ± 2.2 mm, respectively, and to the left and right uncinate process 24.0 ± 1.9 mm and 23.9 ± 2.0 mm, respectively. The distance from the uncinate process to the medial and lateral edge of the most prominent part of the anterior bend of the cavernous internal carotid artery (ICA) was 33.7 ± 3.7 mm and 34.8 ± 3.7 mm, respectively, and the angle between the two lines was 9.7 ± 1.9°. ConclusionThe study provides virtual anatomical information about the sphenoid sinus and important surrounding structures that is essential for successful real life transsphenoidal surgery.