Multiplanar Reconstruction Images Research Articles

Determination of Inoue Balloon Size by Analysis of Mitral Valve Geometry Using Three-Dimensional Transesophageal Echocardiography in Patients with Mitral Stenosis

In percutaneous mitral balloon commissurotomy (PMBC) for patients with mitral stenosis (MS), the size of the balloon has traditionally been determined using a crude method based on the patient's height or body surface area. We aimed to evaluate the clinical value of balloon size selection by quantitatively analyzing mitral valve (MV) geometry using 3D transesophageal echocardiography (TEE). In 184 consecutive patients who underwent PMBC, the geometry of the MV annulus was analyzed during mid-diastole, including the measurement of lateral-medial diameters obtained from dedicated 3D software (LMD-3d) or from analysis using multiplanar reconstruction images (LMD-mpr). Patients were categorized into three groups: those with successful results after PMBC (SU group), those with residual mitral stenosis (MS, group), and those with significant MR (MR group). The SU, MS, and MR groups included 110, 50, and 17 patients, respectively. We compared three conventional formulas (Formula 1, 2, 3) based on the patient's height or body surface area with two new formulas derived from data in the SU group: balloon size = 0.0684 × LMD-3d + 24.309 (Formula 4) and 0.061 × LMD-mpr + 24.573 (Formula 5). Compared with the calculated balloon sizes using Formula 4, the inflated balloon sizes were significantly smaller (-0.78±1.02; p<0.001) in the MS group, while they were significantly larger (0.56±1.05; p=0.04) in the MR group. This pattern was also consistent in Formula 5. In conclusion, selecting the Inoue balloon inflation size based on the mitral annulus diameter determined by 3D TEE might be a reasonable approach.

Optimization of 3D imaging time reduction by assessing spatial resolution in the slice selective direction using the ladder method

PurposeAssessing spatial resolution in MRI is challenging due to non-linearity. Despite the widespread use of 3D imaging in clinical practice for lesion detection and multi-planar reconstruction (MPR), the extended acquisition time poses a shortcoming. To address this, the “Slice resolution” parameter is utilized; however, its impact on MPR images is unclear. This study aims to assess spatial resolution using the ladder method, investigate the effects of diverse slice resolution settings in various imaging sequences, and propose optimal conditions. MethodsImages were acquired using various 3D imaging sequences—SPACE T1WI, SPACE T2WI, and VIBE T1WI—with different slice resolutions. Axial cross-section images were acquired and reconstructed into coronal cross-sections. The ladder method was employed for objective evaluation, including spatial frequency analysis. Additionally, visual evaluation was conducted and compared with ladder method results. ResultsFor three imaging sequences, the evaluated value of ladder method remained relatively constant from 100 % to 80 % slice resolution. However, the evaluated value decreased in low-spatial frequency for slice resolution below 70 %. ConclusionsResults from both ladder method and visual evaluations indicated image quality remained stable when the slice resolution was decreased to 80 %, potentially enabling a 20 % reduction in imaging time while preserving resolution in other cross-sections reconstructed by MPR.

Skeletal computed tomography findings of upper extremities in middle-aged persons with thalidomide embryopathy.

Individuals with thalidomide embryopathy are now approximately 60 years old. For years, they have been compensating for their hypoplastic limbs in various aspects of daily living, and they face secondary problems such as limb and back pain. Imaging analysis is beneficial for understanding the pathogenesis of these problems. However, previous studies on skeletal imaging were mainly radiographic studies conducted at young ages, and there are few studies on skeletal imaging after aging, with most of them being case reports. In this study, detailed analyses of the skeletons of the upper extremities were performed using three-dimensional computed tomography and multiplanar reconstruction images in five individuals with thalidomide embryopathy aged approximately 60 years. Each individual frequently complained of neck, shoulder, and/or back pain. Dislocation, subluxation, and osteoarthritis were observed in the shoulder joints in some individuals. Hypoplasia of the trochlea and/or capitulum of the humerus, coronoid fossa, olecranon, and coronoid processes was observed in the elbow joints. Fusion and hypoplasia of the carpal bones were frequently observed in wrist joints. Radiocarpal and ulnocarpal synostoses were also observed. The joint instability and osteoarthritis found in this study may have contribute to upper limb pain in individuals with thalidomide embryopathy.

Age-related changes in mitral annular disjunction: A retrospective analysis using enhanced cardiac CT

AimsThe current recognition of mitral annular disjunction (MAD) as an anatomical abnormality potentially associated with ventricular arrhythmias has sparked controversy regarding its prevalence and clinical implications. This study aimed to investigate the prevalence and extent of MAD in individuals with no significant structural abnormalities involving the left heart using enhanced cardiac CT, while also exploring potential factors, such as age, that may be associated with MAD. MethodsSystolic datasets of cardiac CT from 742 subjects were retrospectively included. MAD was determined by rotating orthogonal multiplanar reconstruction images around the central axis of the mitral annulus. The maximal distance of disjunction (DMAD) and segments involved (SI, 0 to 5 basal segments at left ventricular wall) was quantified to evaluate the extent of separation. ResultsIn total, 449 (60.5%) had MAD. Subjects with MAD were significantly older (51.3 ± 19.9 years vs. 29.6 ± 20.3 years, P < 0.001). Age was found to be an independent relevant factor for MAD (OR = 1.059; 95%CI: 1.033, 1.085; P < 0.001). Subjects with MAD were then divided into 4 subgroups (G1: ≤20 years, G2: 21–40 years, G3: 41–60 years, G4: ≥61 years). DMAD and SI of each age subgroup were 1.9 ± 0.2 mm, 2.0 ± 1.2 (G1, n = 36), 2.7 ± 0.8 mm, 2.9 ± 1.3 (G2, n = 51), 3.0 ± 0.8 mm, 3.0 ± 1.3 (G3, n = 183), and 3.0 ± 1.0 mm, 3.7 ± 1.1 (G4, n = 179). Age was an independent relevant factor associated with DMAD (R2 = 0.132; β = 0.014; 95%CI: 0.004, 0.024; P = 0.007) and SI (OR = 1.030; 95%CI: 1.005, 1.055; P = 0.016). ConclusionsMAD is a common finding on cardiac CT. Its prevalence and extent increase with age.

Visualisation of dental anatomy in CBCT scans (Part 2).

To the trained eye, every tooth is different. An in-depth understanding of dental anatomy in cross-sectional images is a fundamental basic skill required when interpreting cone beam computed tomography (CBCT) scans. The conventional orthogonal planes of axial, coronal, and sagittal are not always the best planes in which to assess teeth because every tooth is at a slightly different angle to all these planes. In this chapter, the author demonstrates the characteristic anatomy of upper and lower incisors, canines, premolars, and molars in longitudinal and transverse sections, using carefully uprighted images. Some of these teeth are also shown in transverse section at various levels in the crown and root. The chronology of permanent teeth is shown. Developing teeth are discussed and incremental growth lines are mentioned.The author describes three well-known dental notation systems (Palmer, FDI, hybrid).There are four videos accompanying this chapter, including one fascinating video showing a scroll-through of all the cross-arch sections of a synthetic panoramic (curved multiplanar reconstruction) image that includes all the upper and lower teeth in a 16-year-old.

Visualisation of dental anatomy in CBCT scans: Part 1.

To the trained eye, every tooth is different. An in-depth understanding of dental anatomy in cross-sectional images is a fundamental basic skill required when interpreting cone beam computed tomography (CBCT) scans. The conventional orthogonal planes of axial, coronal, and sagittal are not always the best planes in which to assess teeth because every tooth is at a slightly different angle to all these planes. In this chapter, the author demonstrates the characteristic anatomy of upper and lower incisors, canines, premolars, and molars in longitudinal and transverse sections, using carefully uprighted images. Some of these teeth are also shown in transverse section at various levels in the crown and root. The chronology of permanent teeth is shown. Developing teeth are discussed and incremental growth lines are mentioned.The author describes three well-known dental notation systems (Palmer, FDI, hybrid).There are four videos accompanying this chapter, including one fascinating video showing a scroll-through of all the cross-arch sections of a synthetic panoramic (curved multiplanar reconstruction) image that includes all the upper and lower teeth in a 16-year-old.

Modified double-pulley fixation provides better reduction of bone fragments and union compared to single-point fixation in bony Bankart lesions.

The purpose of this study was to compare clinical scores and imaging outcomes of bony Bankart lesions that underwent single-point and modified double-pulley fixation after at least 2 years of follow-up. Patients who underwent surgery to treat bony Bankart injuries were included and divided into groups A and B. A total of 69 patients were included (32 in group A and 37 in group B). Patients in group A underwent arthroscopic modified double-pulley fixation and patients in group B underwent arthroscopic single-point fixation. Three-dimensional computed tomography (3D-CT) was used to assess glenoid reduction one day after surgery. Postoperative bony union was assessed using 3D-CT and multiplanar reconstruction images 6 months after surgery. Constant-Murley, Rowe rating system, visual analogue scale and University of California at Los Angeles and American Shoulder and Elbow Surgeons scores were recorded before and after surgery. In terms of imaging measurements, there was no significant group difference in the preoperative size of the glenoid defect, the size of the bony fragment or the expected postoperative size of the glenoid defect. The sizes of the actual postoperative glenoid defects differed significantly between the groups (p = 0.027), as did the absolute difference between the expected and actual glenoid defect sizes (p < 0.001). At 6 months postoperatively, 50.0% of group A patients and 24.3% of group B patients exhibited complete bony union (p = 0.027); the rates of partial union were 37.5% and 56.8%, respectively. At the final follow-up, all clinical scores were significantly better than the preoperative scores (all p < 0.05), with no significant group differences (not significant). The use of the modified double-pulley technique with two anchors to treat bony Bankart injuries provides a better reduction of bone fragments than single-point fixation with two anchors and was associated with a higher rate of early bone union. Level III.

Prediction of Pharyngeal 3D Volume Using 2D Lateral Area Measurements During Swallowing.

This study evaluated the validity of pharyngeal 2D area measurements acquired from the lateral view for predicting the actual 3D volume in healthy adults during swallowing. Seventy-five healthy adults (39 females, 36 males; mean age 51.3years) were examined using 320-row area detector computed tomography (320-ADCT). All participants swallowed a 10mL honey-thick barium bolus upon command while seated in a 45° semi-reclining position. Multi-planar reconstruction images and dynamic 3D-CT images were obtained using Aquilion ONE software. Pharyngeal 2D area and 3D volume measurements were taken before swallowing and at the frame depicting maximum pharyngeal constriction. Pharyngeal volume before swallowing (PVhold) was accurately predicted by 2D area (R2 = 0.816). Adding height and sex to the model increased R2 to 0.836. Regarding pharyngeal volume during maximum constriction (PVmax), 2D area also exhibited acceptable predictive power (R2 = 0.777). However, analysis of statistical residuals and outliers revealed a greater tendency for prediction errors when there is less complete constriction of the pharynx as well as asymmetry in bolus flow or movement. Findings highlight the importance of routinely incorporating anterior-posterior views during VFSS exams. Future work is needed to determine clinical utility of pharyngeal volume measurements derived from 320-ADCT.

The prognostic significance of extramural venous invasion detected via contrast-enhanced computed tomography colonography in colon cancer.

167 Background: The precise effects of extramural venous invasion (EMVI) and Spiculation on colon cancer recurrence remain poorly understood. This study investigated the clinical significance of ctEMVI and ctSpiculation as diagnosed via preoperative contrast-enhanced CT colonography (CTC) using three-dimensional multiplanar reconstruction (3D MPR) images. Methods: Patients with stage I–Ⅲ colon cancer (T2 or deeper) diagnosed via CTC at the National Cancer Center Hospital in Japan between 2013 and 2018 were retrospectively evaluated for ctEMVI and ctSpiculation, diagnosed by two observers using 3D MPR images of slices 0.5 mm thick. The interobserver reliability was assessed with Cohen’s kappa statistic, and recurrence-free survival (RFS) was analyzed using Kaplan–Meier curves. Preoperative clinical factors were subjected to Cox regression analysis in relation to RFS. Results: Of 922 patients, 544 eligible cases were analyzed. There were 50 (9.2%) ctEMVI-positive cases and 494 (90.8%) ctEMVI-negative cases, along with 186 (34.2%) ctSpiculation-positive cases and 358 (65.8%) with negative findings. Kappa coefficients for ctEMVI and ctSpiculation were 0.830 and 0.718, respectively. Kaplan–Meier analysis and log-rank tests demonstrated lower RFS in ctEMVI- and ctSpiculation-positive cases (p&lt;0.001). In multivariable analysis, ctT4 (HR 2.95, 95% CI 1.73–5.02) and ctEMVI (2.97, 1.81–4.87) were independent factors associated with RFS. When stratifying TNM stages based on ctEMVI status, in N(+) (i.e., Stage III), ctEMVI-positive group had worse prognoses than negative group (5-year RFS rates; 52.0% vs. 78.5%, p=0.003). Similarly, in N(–) (i.e., Stage I and II), T3N0EMVI(+) cases had significantly worse prognoses than T3N0EMVI(–) and Stage I cases (50.6% vs. 89.3% and 90.1%) and were comparable to the T4N0 group (50.6% vs. 46.7%, p=0.844). Conclusions: Both ctEMVI and ctSpiculation are associated with RFS. ctEMVI is an independent predictor of recurrence and may be valuable in combination with preoperative TNM staging to identify patients at high risk for recurrence. [Table: see text]

Prognostic impact of extramural venous invasion detected by contrast-enhanced CT colonography in colon cancer.

The impact of computed tomography (CT)-detected extramural venous invasion on the recurrence of colon cancer is not fully understood. The aim of this study was to investigate the clinical significance of extramural venous invasion diagnosed before surgery by contrast-enhanced CT colonography using three-dimensional multiplanar reconstruction images. Patients with colon cancer staged greater than or equal to T2 and/or stage I-III who underwent contrast-enhanced CT colonography between 2013 and 2018 at the National Cancer Center Hospital in Japan were retrospectively investigated for CT-detected extramural venous invasion. Inter-observer agreement for the detection of CT-detected extramural venous invasion was evaluated and Kaplan-Meier survival curves were plotted for recurrence-free survival using CT-TNM staging and CT-detected extramural venous invasion. Preoperative clinical variables were analysed using Cox regression for recurrence-free survival. Out of 922 eligible patients, 544 cases were analysed (50 (9.2 per cent) were diagnosed as positive for CT-detected extramural venous invasion and 494 (90.8 per cent) were diagnosed as negative for CT-detected extramural venous invasion). The inter-observer agreement for CT-detected extramural venous invasion had a κ coefficient of 0.830. The group positive for CT-detected extramural venous invasion had a median follow-up of 62.1 months, whereas the group negative for CT-detected extramural venous invasion had a median follow-up of 60.7 months. When CT-TNM stage was stratified according to CT-detected extramural venous invasion status, CT-T3 N(-)extramural venous invasion(+) had a poor prognosis compared with CT-T3 N(-)extramural venous invasion(-) and CT-stage I (5-year recurrence-free survival of 50.6 versus 89.3 and 90.1 per cent respectively; P < 0.001). In CT-stage III, the group positive for CT-detected extramural venous invasion also had a poor prognosis compared with the group negative for CT-detected extramural venous invasion (5-year recurrence-free survival of 52.0 versus 78.5 per cent respectively; P = 0.003). Multivariable analysis revealed that recurrence was associated with CT-T4 (HR 3.10, 95 per cent c.i. 1.85 to 5.20; P < 0.001) and CT-detected extramural venous invasion (HR 3.08, 95 per cent c.i. 1.90 to 5.00; P < 0.001). CT-detected extramural venous invasion was found to be an independent predictor of recurrence and could be used in combination with preoperative TNM staging to identify patients at high risk of recurrence.

Computed Tomography of Transcatheter Aortic Valve Replacement-Related Complications

Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of severe aortic stenosis, with an impressive reduction in mortality and complication rates over the last decade, becoming a safer alternative in patients at high/moderate risk for surgical treatment. Complications are rare but can be life-threatening; thus, cardiac imagers must be familiar with their imaging findings. TAVR-related complications often require multimodality imaging, although ECG-gated cardiac computed tomography (CCT) is the technique of choice, given its high spatial resolution and multiplanar image reconstruction. This review will discuss the imaging findings of the most important post-TAVR complications and novel preventive measures.

Image Quality and Lesion Detection of Multiplanar Reconstruction Images Using Deep Learning: Comparison with Hybrid Iterative Reconstruction.

We assessed and compared the image quality of normal and pathologic structures as well as the image noise in chest computed tomography images using "adaptive statistical iterative reconstruction-V" (ASiR-V) or deep learning reconstruction "TrueFidelity". Forty consecutive patients with suspected lung disease were evaluated. The 1.25-mm axial images and 2.0-mm coronal multiplanar images were reconstructed under the following three conditions: (i) ASiR-V, lung kernel with 60% of ASiR-V; (ii) TF-M, standard kernel, image filter (Lung) with TrueFidelity at medium strength; and (iii) TF-H, standard kernel, image filter (Lung) with TrueFidelity at high strength. Two radiologists (readers) independently evaluated the image quality of anatomic structures using a scale ranging from 1 (best) to 5 (worst). In addition, readers ranked their image preference. Objective image noise was measured using a circular region of interest in the lung parenchyma. Subjective image quality scores, total scores for normal and abnormal structures, and lesion detection were compared using Wilcoxon's signed-rank test. Objective image quality was compared using Student's paired t-test and Wilcoxon's signed-rank test. The Bonferroni correction was applied to the P value, and significance was assumed only for values of P < 0.016. Both readers rated TF-M and TF-H images significantly better than ASiR-V images in terms of visualization of the centrilobular region in axial images. The preference score of TF-M and TF-H images for reader 1 were better than that of ASiR-V images, and the preference score of TF-H images for reader 2 were significantly better than that of ASiR-V and TF-M images. TF-M images showed significantly lower objective image noise than ASiR-V or TF-H images. TrueFidelity showed better image quality, especially in the centrilobular region, than ASiR-V in subjective and objective evaluations. In addition, the image texture preference for TrueFidelity was better than that for ASiR-V.

Usefulness of sectional images in dural AVF for the interpretation of venous anatomy.

Knowledge of the venous anatomy is essential for appropriately treating dural arteriovenous fistulas (AVFs). It is challenging to determine the overall venous structure despite performing selective angiography for dural AVFs with feeder from multiple selected arteries. This is because only a part of the veins can be observed through the shunt in the selected artery. Therefore, after performing selective angiography of all vessels to understand the approximate venous anatomy, the venous anatomy can be easily understood by closely examining the source image of computed tomographic angiography or magnetic resonance angiography. Through this, it is possible to specify the vein that is to be blocked (target embolization), thereby avoiding extensive blocking of the vein and avoiding various complications. In the case of dural AVF with feeder from single selected artery, if the multiplanar reconstruction image of the three-dimensional rotational computed tomography obtained by performing angiography is analyzed thoroughly, a shunted pouch can be identified. If embolization is performed by targeting this area, unnecessary sinus total packing can be avoided.

Diagnostic Role of Bronchoscopic Brush Biopsy Guided by Thin-Section Computed Tomography in Peripheral Pulmonary Lesions

Objective: The diagnosis of peripheral pulmonary lesions (PPLs) is important as they may be malignant. It is difficult to diagnose PPLs in the absence of a diagnostic guiding tool. Computed tomography (CT) thin-section multiplanar reconstruction (MPR) images have been used as an alternative guide for bronchoscopic diagnosis of PPL. In this study, we aimed to investigate the diagnostic efficacy of MPR image guidance for PPL. Methods: Patients with PPL who underwent bronchoscopic brush biopsy guided by thoracic CT thin-section MPR images at our center were retrospectively reviewed. The distance of the lesion to the distal bronchus, the presence of the CT-Bronchus sign, the location of the PPL, and the size of the PPL were recorded from the hospital image record archive. The diagnosis rate was obtained from the procedure records. Results: The study included 92 cases. The mean PPL size was 40 ± 21 mm and the mean distal bronchial lesion distance was 27 ± 19 mm. A total of 49 (53.3%) patients had a positive CT-Bronchus sign. The diagnostic yield of the method was 48.9%. The diagnosis rate was significantly higher in patients with positive CT-Bronchus sign (67.3%) compared to those without (26.7%) (P = 0.001). Factors affecting the diagnosis in the logistic regression analysis were distal bronchial lesion distance, presence of CT-Bronchus sign,and localization of the lesion. Conclusion: CT thin-section MPR images can be used for bronchoscopy guidance in cases with PPL larger than 20 mm and positive CT-Bronchus sign in centers where an interventional radiology unit and other guidance tools are not available.

Insights Into the Standard Echocardiographic Views From Multimodality Imaging: Ventricles, Pericardium, Valves, and Atria

The widespread use of cardiac computed tomography and cardiac magnetic resonance imaging in patients undergoing echocardiography presents an opportunity to correlate the images side by side. Accordingly, the aim of this report is to review aspects of the standard echocardiographic examination alongside similarly oriented images from the two tomographic imaging modalities. It is hoped that this exercise will enhance understanding of the structures depicted by echocardiography as they relate to other structures in the thorax. In addition to reviewing basic cardiac anatomy, the authors take advantage of these correlations with computed tomography and cardiac magnetic resonance imaging to better understand the issue of foreshortening, a common pitfall in transthoracic echocardiography. The authors also highlight an important role that three-dimensional echocardiography can potentially play in the future, especially as advances in image processing permit higher fidelity multiplanar reconstruction images.

Automatic Classification of Magnetic Resonance Histology of Peripheral Arterial Chronic Total Occlusions Using a Variational Autoencoder: A Feasibility Study.

The novel approach of our study consists in adapting and in evaluating a custom-made variational autoencoder (VAE) using two-dimensional (2D) convolutional neural networks (CNNs) on magnetic resonance imaging (MRI) images for differentiate soft vs. hard plaque components in peripheral arterial disease (PAD). Five amputated lower extremities were imaged at a clinical ultra-high field 7 Tesla MRI. Ultrashort echo time (UTE), T1-weighted (T1w) and T2-weighted (T2w) datasets were acquired. Multiplanar reconstruction (MPR) images were obtained from one lesion per limb. Images were aligned to each other and pseudo-color red-green-blue images were created. Four areas in latent space were defined corresponding to the sorted images reconstructed by the VAE. Images were classified from their position in latent space and scored using tissue score (TS) as following: (1) lumen patent, TS:0; (2) partially patent, TS:1; (3) mostly occluded with soft tissue, TS:3; (4) mostly occluded with hard tissue, TS:5. Average and relative percentage of TS was calculated per lesion defined as the sum of the tissue score for each image divided by the total number of images. In total, 2390 MPR reconstructed images were included in the analysis. Relative percentage of average tissue score varied from only patent (lesion #1) to presence of all four classes. Lesions #2, #3 and #5 were classified to contain tissues except mostly occluded with hard tissue while lesion #4 contained all (ranges (I): 0.2-100%, (II): 46.3-75.9%, (III): 18-33.5%, (IV): 20%). Training the VAE was successful as images with soft/hard tissues in PAD lesions were satisfactory separated in latent space. Using VAE may assist in rapid classification of MRI histology images acquired in a clinical setup for facilitating endovascular procedures.

Imaging findings of hepatocellular carcinoma with portal vein tumor thrombosis secondary to hepatic portal vein collateral circulation: a cross-sectional study.

Hepatic portal vein collateral circulation plays an important role in maintaining the perfusion of hepatic portal vein. However, at present, there is little research on collateral circulation of hepatic portal vein. Our study aims to analysis the imaging types and clinical value of hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) invading and completely blocking different branches of portal vein, secondary to hepatic portal vein collateral circulation. This study retrospectively analyzed Hepatocellular carcinoma (HCC) with PVTT diagnosed with enhanced CT examination of the upper abdomen in our hospital from May 2020 to October 2021.The inclusion criteria for patients were the following: (I) ultimately diagnosed with HCC, (II) accompanied by complete obstruction of the main portal vein or left/right branches, and (III) with collateral circulation of the hepatic portal vein established. All images were postprocessed by multiplanar reconstruction (MPR), maximum intensity projection (MIP), and other reconstruction techniques to obtain images of the abnormal portal vein system and the collateral vessels running toward the hepatic portal veins. Three physicians jointly judged the imaging anatomical classification of each collateral vessel. The qualitative variables were compared by chi-squared test. A total of 125 hepatic portal vein collateral vessels were observed in MPR and MIP reconstruction images of 71 patients with portal vein cancer thrombosis with established hepatic portal vein collateral circulation. Common hepatic collateral branches in patients with PVTT mainly include the biliary collateral branch, gastric collateral branch, mesenteric collateral branch, accessory portal vein system and the splenic branch. The incidence rate was respectively 77.5%, 36.6%, 32.4%, 28.2%, 1.41%. The correct understanding of the imaging anatomical classification of the collateral vessels of the hepatic portal vein can provide clinicians with more information for diagnosis and treatment planning.

Assessment of the structural features of the hard palate in endonasal surgery

To study the anatomical structure of the hard palate from the point of view of rhinosurgery, using vector analysis of multispiral computed tomography (MSCT), and to establish anatomical features that should be taken into account when performing surgical interventions on the nasal septum. 107 patients (30 men, 77 women) were examined without congenital cleft palate and surgical interventions on the structures of the nasal cavity and hard palate. All patients underwent MSCT of the nose and paranasal sinuses (PNS) followed by multiplanar image reconstruction. The key point relative to which the measurements were carried out was the posterior wall of the incisor canal from the side of the nasal cavity. The line corresponding to the bottom of the nasal cavity was chosen as the main vector. In the work, measurements of the thickness of the hard palate (THP) at the level of the palatal suture and the width of the palatal suture (WPS) were carried out. Statistical analysis of the obtained results showed that the THP is 1.74 mm [min 0.28; max 6.46], the WPS is 0.9 mm [min 0.2; max 2.51] (conditional norm). In 19 patients (17.8%), the THP was 0.82 mm, in 2 patients (1.9%) - 0.2 mm. In 3 patients (2.8%), the WPS was equal to 2.5 mm. Thus, the data obtained by us indicate that the surgical anatomy of the hard palate is characterized by significant variability, while in some patients the THP can be reduced by 8.8 times, and the WPS increased by 2.7 times compared to normal values. Such anatomical features of the structure of the hard palate should be taken into account when planning septoplasty, since this contingent of patients has an increased risk of developing iatrogenic perforation of the nasal floor during surgical intervention on the lower floor of the nasal septum.

Creation of 3D Stereo and MPR Color Anatomical Charts in the Hepatic Segments

We used the Voronoi diagram of a computed tomography (CT) application (i.e., CT liver volume measurement) to depict the liver area, and we obtained depictions of the hepatic segments as a three-dimensional (3D) image based on clinical data; this information can be used for the patient's education and for surgical planning. The hepatic segments use the inter-relationships among the eight subsegments illustrated by Couinaud, those indicated by the portal veins and those provided by hepatic veins. The liver has dual portal and arterial innervation, with the thick portal vein intertwined with thin arteries similar to the intertwining of ivy plants. Couinaud divided the liver into eight segments (S1 to S8) based on portal vein casts. The Voronoi diagram estimates the dominant region of the portal vein, divides the liver into segments, and produces 3D images and multiplanar reconstruction (MPR) images in color. To support understanding of Couinaud's eight hepatic segments (which are explained only in the illustration of the frontal view of the liver), using 3D images created by the Voronoi diagram, we created 3D stereo color anatomical charts of the liver that Couinaud's eight hepatic segments can be confirmed from multiple directions. In addition, we created the MPR color anatomical charts of the liver (S1 to S8) that can be confirmed by color from three directions: axial images, coronal images, and sagittal images in the same way. We converted the data of this anatomical chart into an electronic file that provides a tool that can be easily used in radiological examinations, and we were able to make improvements based on requests from users.

A token-mixer architecture for CAD-RADS classification of coronary stenosis on multiplanar reconstruction CT images

Background and objectiveIn patients with suspected Coronary Artery Disease (CAD), the severity of stenosis needs to be assessed for precise clinical management. An automatic deep learning-based algorithm to classify coronary stenosis lesions according to the Coronary Artery Disease Reporting and Data System (CAD-RADS) in multiplanar reconstruction images acquired with Coronary Computed Tomography Angiography (CCTA) is proposed. MethodsIn this retrospective study, 288 patients with suspected CAD who underwent CCTA scans were included. To model long-range semantic information, which is needed to identify and classify stenosis with challenging appearance, we adopted a token-mixer architecture (ConvMixer), which can learn structural relationship over the whole coronary artery. ConvMixer consists of a patch embedding layer followed by repeated convolutional blocks to enable the algorithm to learn long-range dependences between pixels. To visually assess ConvMixer performance, Gradient-Weighted Class Activation Mapping (Grad-CAM) analysis was used. ResultsExperimental results using 5-fold cross-validation showed that our ConvMixer can classify significant coronary artery stenosis (i.e., stenosis with luminal narrowing ≥50%) with accuracy and sensitivity of 87% and 90%, respectively. For CAD-RADS 0 vs. 1–2 vs. 3–4 vs. 5 classification, ConvMixer achieved accuracy and sensitivity of 72% and 75%, respectively. Additional experiments showed that ConvMixer achieved a better trade-off between performance and complexity compared to pyramid-shaped convolutional neural networks. ConclusionsOur algorithm might provide clinicians with decision support, potentially reducing the interobserver variability for coronary artery stenosis evaluation.