Multidetector-row Computed Tomography Images Research Articles

Evaluation of a compact cone beam CT concept with high image fidelity for point-of-care brain imaging.

Cone beam computed tomography (CBCT) has potential advantages for developing portable, cost-effective point-of-care CT systems for intracranial imaging, such as early stroke diagnosis, hemorrhage detection, and intraoperative navigation. However, large volume imaging with flat panel detector based CBCT significantly increases the scattered radiation fluence which reduces its image quality and utility. To address these issues, a compact CBCT concept with enhanced image quality was investigated for intracranial imaging. The new system features a novel antiscatter collimator and data correction method to address the challenges in imaging large volumes with CBCT. A benchtop CBCT prototype was constructed. Imaging studies with anthropomorphic phantoms showed that soft tissue visualization, Hounsfield Unit (HU) accuracy, contrast, and spatial resolution increased significantly with the proposed CBCT concept, and they were comparable to the values measured in the gold standard multidetector-row CT (MDCT) images. Contrast-to-noise ratio (CNR) in CBCT images was within 12-31% of the CNR in MDCT images. These findings indicate that a compact CBCT system integrated with effective scatter suppression techniques may have increased utility in the context of brain imaging, and the proposed approach may enable the development of point-of-care CT systems for head imaging based on flat panel detector based CBCT technology.

Deep Learning Reconstruction to Improve the Quality of MR Imaging: Evaluating the Best Sequence for T-category Assessment in Non-small Cell Lung Cancer Patients.

Deep learning reconstruction (DLR) has been recommended as useful for improving image quality. Moreover, compressed sensing (CS) or DLR has been proposed as useful for improving temporal resolution and image quality on MR sequences in different body fields. However, there have been no reports regarding the utility of DLR for image quality and T-factor assessment improvements on T2-weighted imaging (T2WI), short inversion time (TI) inversion recovery (STIR) imaging, and unenhanced- and contrast-enhanced (CE) 3D fast spoiled gradient echo (GRE) imaging with and without CS in comparison with thin-section multidetector-row CT (MDCT) for non-small cell lung cancer (NSCLC) patients. The purpose of this study was to determine the utility of DLR for improving image quality and the appropriate sequence for T-category assessment for NSCLC patients. As subjects for this study, 213 pathologically diagnosed NSCLC patients who underwent thin-section MDCT and MR imaging as well as T-factor diagnosis were retrospectively enrolled. SNR of each tumor was calculated and compared by paired t-test for each sequence with and without DLR. T-factor for each patient was assessed with thin-section MDCT and all MR sequences, and the accuracy for T-factor diagnosis was compared among all sequences and thin-section CT by means of McNemar's test. SNRs of T2WI, STIR imaging, unenhanced thin-section Quick 3D imaging, and CE-thin-section Quick 3D imaging with DLR were significantly higher than SNRs of those without DLR (P < 0.05). Diagnostic accuracy of STIR imaging and CE-thick- or thin-section Quick 3D imaging was significantly higher than that of thin-section CT, T2WI, and unenhanced thick- or thin-section Quick 3D imaging (P < 0.05). DLR is thus considered useful for image quality improvement on MR imaging. STIR imaging and CE-Quick 3D imaging with or without CS were validated as appropriate MR sequences for T-factor evaluation in NSCLC patients.

The Probability of Multidetector Row Computed Tomography (MDCT) for Assessment of Transmitral Flow Velocities and Transannular flow Velocities in Comparison with 2-Dimensional (2D) Echocardiography

Two-Dimensions (2D) echocardiography using TDI has been used most commonly to evaluate diastolic LV function. Although the role of MDCT imaging for evaluation of coronary atherosclerosis has been explored extensively. Moreover, assessment of LV volumes and systolic function using MDCT were studied before and showing accurate myocardial border delineation despite its clinical significance use regarding radiation and contrast. The probability to evaluate diastolic function using MDCT has not been studied well yet. The present study was aimed to evaluate the probability of cardiac CT for assessment of diastolic function in a direct comparison with 2-dimensional (2D) echocardiography using combined assessment of transmitral velocity and transannular mitral velocity. One hundred and twenty patients’ consecutive patients who had been referred for 64-MDCT imaging were prospectively selected from our clinical registry. After exclusion criteria had been applied, forty patients who had undergone 64-MDCT and 2D echocardiography with TDI were enrolled. MDCT and 2D echocardiography were performed within the same day and no acute coronary events or worsening of angina occurred between the examinations and no changes in the use of medication occurred between both examinations. A good correlation was found for demonstrate the probability of multidetector row computed tomography (MDCT) for assessment of trans-mitral flow velocities and trans-annular flow velocities in comparison with 2-dimensional (2D) echocardiography using tissue Doppler imaging (TDI).

Gumbel distribution-based technique enables quantitative comparison between streak metal artifacts of multidetector row CT and cone-beam CT: a phantom study

Cone-beam computed tomography (CBCT), derived from multidetector row CT (MDCT), has a high spatial resolution and has recently been applied to various organs. One of the severe limitations common to CBCT and MDCT is metal artifacts. In particular, streak metal artifacts (SMAs) between multiple metal materials often hinder diagnosis. However, no studies have quantitatively compared the strength of SMAs in MDCT and CBCT. Nomura et al. reported an evaluation method specialized in SMAs of CBCT using the Gumbel distribution (GD), which can also be applied to SMAs of MDCT (Oral Surg Oral Med Oral Pathol Oral Radiol 131: 494-502,2021, https://doi.org/10.1016/J.OOOO.2020.08.031 ). This study aimed to quantitatively compare SMAs occurring between titanium materials on MDCT and CBCT images using the GD-based method. The SMAs were investigated as follows: A hydroxyapatite block was sandwiched between two titanium rods to generate an SMA. They were placed in an acrylic phantom, simulating a human head, and scanned using an MDCT scanner and two CBCT scanners. The obtained images were analyzed using Gumbel plots and location parameters, and the SMA strength was calculated. The results showed that the SMAs on the MDCT images were significantly weaker than those on the CBCT images. In the CBCT scans, a smaller volume CT dose indexvalue caused stronger SMAs. These results indicate that MDCT is more advantageous than CBCT in terms of SMA reduction when bone morphology between titanium materials must be evaluated. The characteristic should be considered in clinical cases.

Value of MDCT data of mandibular condyle cancellous bone to osteoporosis screening

The purpose of this study was application of age- and gender-related differences in mandibular condyle CT values on multidetector-row computed tomography imaging to osteoporosis screening. The mandibular CT images of 327 patients were analyzed retrospectively. The ovoid-shaped region of interest contouring was manually performed on both sides of the mandibular condyle on axial images to determine the mean CT value. The Klemetti index (KI) for each patient was categorized into C1, C2 and C3 based on coronal CT images. The mean CT values of the mandibular condyle were decreased with age in both males and females. The mean CT values of the mandibular condyle also decreased as the KI progressed. Our result suggested that the mean CT values of the mandibular condyle may be a new predictor for screening osteoporosis on multidetector-row computed tomography images.

Panorama of multidetector-row computed tomography findings of carcinoma gall bladder - A retrospective observational study.

Carcinoma of the gall bladder (Ca GB) has marked ethnic and geographical variations with a broad spectrum of imaging findings on multidetector-row computed tomography (MDCT). We aim to study the spectrum of the imaging findings of Ca GB on MDCT in an Eastern Indian hospital as these imaging findings help in accurate diagnosis and staging of this lethal disease. The MDCT images of 100 biopsy-proven cases of adenocarcinoma of GB performed from January 1, 2017, to December 31, 2018, in our hospital were retrospectively reviewed by two experienced radiologists blinded to the diagnosis. The CT protocol was a plain scan followed by triple-phase contrast-enhanced CT. Reconstructed images in the form of maximum intensity projection, volume-rendered technology, and minimum intensity projection images were also assessed. Descriptive statistics were used for data analysis. Ca GB showed a female predominance (female:male -1.9:1). The mean age of presentation was 54.7 years (females) and 58 years (males). The morphological patterns were a mass replacing the GB (46%), focal or diffuse wall thickening (26%), and an intraluminal polypoidal mass (28%). Direct extension was to liver (76%), duodenum (32%), colon (19%), pancreas (9%), and abdominal wall (1%). Biliary dilatation (53%), vascular invasion (14%), omental involvement (23%), ascites (22%), N1 (40%), and retroperitoneal lymphadenopathy (33%) were common. Distant metastasis comprised of hepatic (42%), pulmonary (7%), Krukenberg's tumor (6%), and osseous (1%) lesions. The stages at diagnosis were I or II (3%), IIIA (4%), IIIB (16%), IVA (10%), and IVB (67%). Ca GB has a broad spectrum of findings on MDCT and it mostly presents at an advanced stage. MDCT with reconstructions is beneficial in the assessment of locoregional and distant spread and cancer staging which has a direct implication on patient management, survival, and mortality.

Optimizing early cancer diagnosis and detection using a temporal subtraction technique

To optimize the early diagnosis and detection of lung cancer, computer-aided diagnostic (CAD) systems have been a useful tool for analyzing medical images. The temporal subtraction technique, which is a CAD system, performs the subtraction operation between the current image and the previous image on the same patient, and supports observation by emphasizing the temporal changes. However, the temporal subtraction technique for 3D images, such as thoracic CT images, has not yet been established. There is a need to develop efficient and highly accurate 3D nonrigid registration techniques to reduce subtraction artifacts. This study aims to develop a 3D nonrigid registration technique to establish a 3D temporal subtraction technique. In particular, we focus on the Finite Element Method, which is versatile, applicable to a wide range of fields, and capable of handling any shape. Our new method was examined on 46 clinical cases with multidetector row computed tomography images. As a result, the proposed method improved by 6.93% (p = 3.0 × 10−6) compared to the conventional methods in terms of the rate of reduction of artifacts, and the effectiveness was verified. Therefore, this study contributes to the literature on early detection and treatment.

Comparison of cortico-medullary phase contrast-enhanced MDCT and T2-weighted MR imaging in the histological subtype differentiation of renal cell carcinoma: radiology-pathology correlation.

PurposeRenal cell carcinoma (RCC) subtype differentiation is of crucial importance in the management and prognosis of these patients. In this study, we investigated the usefulness of unenhanced and cortico-medullary phase contrast-enhanced multidetector-row computed tomography (MDCT) and T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) modalities in the discrimination of the 3 main subtype RCC patients in correlation with their histopathological findings.Material and methodsA total of 80 pathologically proven RCC patients who had undergone either partial or total nephrectomy were retrospectively investigated in this study. Their histological subtypes were 54 clear cell renal cell carcinoma (ccRCC), 15 papillary renal cell carcinoma (pRCC), and 11 chromophobe renal cell carcinoma (cRCC), based on pathological evaluation. There were 62 male (77.5%) and 18 female (22.5%) patients. Among the 54 ccRCC patients, 29 patients had both non-contrast and cortico-medullary phase CT, 1 had only non-contrast CT, 5 only had cortico-medullary phase CT, and 38 had MRI examination. In the pRCC group, 10 patients had both non-contrast and cortico-medullary phase CT, 1 had only non-contrast CT, 1 had only cortico-medullary phase CT, and 12 had MRI. Finally, in the remaining 11 cRCC patients, 9 had both non-contrast and cortico-medullary phase CT, and only 5 had MRI. We calculated both tumour attenuation values as HU (Hounsfield units) on unenhanced and cortico-medullary phase MDCT images and also tumour mean signal intensity values on FSE T2-weighted MRI images by using the region of interest (ROI) including normal renal cortex measurements. Besides quantitative evaluation, we also performed qualitative visual assessment of tumours on contrast-enhanced MDCT and FSE T2-weighted MRI.ResultsThere was no statistically significant difference among the attenuation values of the 3 tumour subtypes on pre-contrast CT images. ccRCC demonstrated a prominent degree of contrast enhancement compared to the chromophobe and papillary ones on cortico-medullary phase MDCT. We found no statistically significant difference between chromophobe and papillary subtypes, although chromophobe tumours showed slightly higher attenuation values compared to papillary ones. ccRCCs usually demonstrated a heterogenous contrast enhancement on cortico-medullary phase CT images, while the papillary subtype usually had a homogenous appearance on visual assessment. On FSE T2-weighted MR images, the signal intensity values of ccRCC patients were found to be significantly higher than both chromophobe and papillary subtypes. Although cRCC patients had a prominently lower T2 signal intensity than clear cell subtype, there was no statistically significant signal intensity difference between chromophobe and papillary subtypes. Regarding visual assessment, papillary subtype tumours showed a mostly homogenous appearance on T2-weighted images and a statistically significant difference was present. On the other hand, there was no significant difference of visual assessment of the clear cell and chromophobe subtypes.ConclusionsThe measurement of the attenuation values on cortico-medullary phase MDCT and the mean signal intensity values on FSE T2-weighted MRI can provide useful information in the differentiation of RCC main subtypes. Also, visual assessment of tumours on both modalities can contribute to this issue by providing additional imaging properties.

Preoperative computed tomography-guided disease-free survival prediction in gastric cancer: a multicenter radiomics study.

Preoperative and noninvasive prognosis evaluation remains challenging for gastric cancer. Novel preoperative prognostic biomarkers should be investigated. This study aimed to develop multidetector-row computed tomography (MDCT)-guided prognostic models to direct follow-up strategy and improve prognosis. A retrospective dataset of 353 gastric cancer patients were enrolled from two centers and allocated to three cohorts: training cohort (n=166), internal validation cohort (n=83), and external validation cohort (n=104). Quantitative radiomic features were extracted from MDCT images. The least absolute shrinkage and selection operator penalized Cox regression was adopted to construct a radiomic signature. A radiomic nomogram was established by integrating the radiomic signature and significant clinical risk factors. We also built a preoperative tumor-node-metastasis staging model for comparison. All models were evaluated considering the abilities of risk stratification, discrimination, calibration, and clinical use. In the two validation cohorts, the established four-feature radiomic signature showed robust risk stratification power (P=0.0260 and 0.0003, log-rank test). The radiomic nomogram incorporated radiomic signature, extramural vessel invasion, clinical T stage, and clinical N stage, outperforming all the other models (concordance index=0.720 and 0.727) with good calibration and decision benefits. Also, the 2-yr disease-free survival (DFS) prediction was most effective (time-dependent area under curve=0.771 and 0.765). Moreover, subgroup analysis indicated that the radiomic signature was more sensitive in risk stratifying patients with advanced clinical T/N stage. The proposed MDCT-guided radiomic signature was verified as a prognostic factor for gastric cancer. The radiomic nomogram was a noninvasive auxiliary model for preoperative individualized DFS prediction, holding potential in promoting treatment strategy and clinical prognosis.

How to assess a CTA of the abdomen to plan an autologous breast reconstruction.

The deep inferior epigastric perforator (DIEP) flap is recognised as the most popular option for autologous breast reconstruction. Planning of the DIEP flap involves pre-operative assessment of abdominal vascular anatomy with imaging, of which computed tomographic angiography (CTA) has become the mainstay. CTA enables detailed planning of a range of surgical steps, leading to reduced operative times and improved surgical outcomes. The value of CTA is only demonstrated when the relevant vascular anatomy is able to be demonstrated and appraised. For optimal analysis, a 64-slice multi-detector row CT scanner and imaging software including OsiriX™, Siemens InSpace™ or Horos™ are required. The seven major steps to consider include: (I) perforator size; (II) perforator angiosome; (III) intramuscular course; (IV) deep inferior epigastric artery (DIEA) pedicle; (V) venous anatomy; (VI) superficial inferior epigastric artery (SIEA) and superficial inferior epigastric vein (SIEV); and (VII) abdominal wall structure. These steps should also be reviewed when marking the patient and planning the flap intra-operatively. While CTA has superior sensitivity and specificity in mapping perforator anatomy it also faces challenges due to ionising radiation exposure, contrast-induced allergy and potential nephrotoxicity. Despite these challenges, the benefits of CTA to the individual patient has maintained its role in pre-operative planning of the DIEP flap.

Preoperative Multidetector-Row Computed Tomography-Guided Prognostic Prediction for Disease-Free Survival: A Multicenter Study in Gastric Cancer

Background: Preoperative noninvasive evaluation of clinical outcomes remains challenging for gastric cancer. Herein, we identified a multidetector-row computed tomography (MDCT)-guided prognostic radiomic signature for disease-free survival (DFS), with the purpose of constructing a convenient nomogram for clinical need. Methods: A retrospective dataset of 353 gastric cancer patients were enrolled from two centers totally and allocated to three cohorts: training cohort (n=166), internal validation cohort (n=83), and external validation cohort (n=104). Quantitative feature extraction was derived from portal venous phase MDCT images. The least absolute shrinkage and selection operator penalized Cox regression was adopted to construct a radiomic signature. A radiomic nomogram integrated radiomic signature and significant clinical risk factors. We also built a preoperative tumornode-metastasis staging model for comparison. All models were evaluated considering risk stratification, discrimination, calibration, and clinical use. Findings: In the two validation cohorts, the established four-feature radiomic signature showed robust risk stratification power (P=0.0260 and 0.0003, log-rank test). The radiomic nomogram incorporated radiomic signature, extramural vessel invasion, clinical T stage, and clinical N stage, outperforming the other models (concordance index = 0.720 and 0.727) with good calibration and decision curves. The 2-year DFS prediction was also most effective (time-dependent AUC = 0.771 and 0.765). Moreover, subgroup analysis indicated radiomic signature was more sensitive in stratifying patients with advanced clinical T/N stage. Interpretation: The proposed MDCT-guided radiomic signature was verified as a prognostic factor for gastric cancer. The radiomic nomogram provided a noninvasive model for individualized DFS prediction, holding potential in promoting preoperative clinical prognosis and treatment strategies. Funding Statement: This work was supported by the National Key R&D Program of China (2017YFC1308700, 2017YFA0205200, 2017YFC1309100), National Natural Science Foundation of China (81971776, 81771924, 81501616, 81227901, 81671851, 81527805, 81771912), the Beijing Natural Science Foundation (L182061), the Bureau of International Cooperation of Chinese Academy of Sciences (173211KYSB20160053), the Instrument Developing Project of the Chinese Academy of Sciences (YZ201502), and the Youth Innovation Promotion Association CAS (2017175). Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: This retrospective analysis was ethically granted by the Institutional Review Board of Peking University People's Hospital (PKUPH) and Guangdong General Hospital (GDGH) in compliance with the Health Insurance Portability and Accountability. Informed consent was not required from patients.

Computed Tomography Imaging Findings of Acute Aortic Pathologies.

Acute aortic syndromes (AAS) encompass a spectrum of life-threatening conditions characterized by acute aortic pain. AAS include acute aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, and aneurysm rupture. The prognosis of AAS is clearly related to prompt diagnosis and appropriate management. The different types of AAS cannot be reliably differentiated solely based on clinical presentation since the clinical features are indistinguishable. Multidetector-row computed tomography (MDCT) with electrocardiographic gating (ECG-gated MDCT) has been used in the acute emergency setting as a powerful clinical tool, which enables rapid and specific diagnosis of aortic pathologies. ECG-gated MDCT significantly reduces motion artifact and avoids potential pitfalls in the diagnosis of AAS. The aim of this review is to evaluate the role of MDCT imaging in the assessment of AAS and to discuss the differentiation of this spectrum of aortic diseases with reference to the key imaging findings.

Validated Multidetector-Row Computed Tomography-Based Radiomic Analysis for Preoperative Survival Prediction in Gastric Cancer: A Multicenter Study

Background: Preoperative noninvasive evaluation of clinical outcome remains challenging for gastric cancer. Herein, we identified a multidetector-row computed tomography (MDCT)-based radiomic signature as a novel prognostic factor in survival prediction for gastric cancer patients. Methods: A retrospective dataset of 326 gastric cancer patients were enrolled from two centers and allocated to three cohorts: training cohort (n=166) and internal validation cohort (n=83) from one center, and external validation cohort (n=77) from another. Quantitative feature extraction was derived from portal venous phase MDCT images. The least absolute shrinkage and selection operator penalized Cox regression was adopted to construct a radiomic signature. A radiomic nomogram integrating radiomic signature and significant clinical risk factors was developed. A preoperative tumor-node-metastasis staging model was also built for comparison. All models were evaluated in terms of risk stratification, discrimination, calibration, and clinical use. Findings: A four-feature radiomic signature was established and showed robust prognosis power in both the internal and external validation cohorts. Subgroup analysis indicated radiomic signature could well risk stratify gastric cancer patients with advanced clinical stage. The radiomic nomogram combining radiomic signature, extramural vessel invasion, and alpha fetoprotein surpassed the other models in disease-free survival prediction with a concordance index of 0.768 in training cohort and 0.721 in internal validation cohort. Meanwhile, the area under two-year time-dependent receiver operating characteristic curve achieved 0.785 and 0.809 in both cohorts, respectively. Interpretation: The proposed MDCT-based radiomic signature was verified as a prognostic factor of gastric cancers, holding potential in promoting preoperative clinical prognosis and treatment strategies. Funding: This work was supported by the National Key R&D Program of China (2017YFC1308700, 2017YFA0205200, 2017YFC1309100), National Natural Science Foundation of China (81771924, 81501616, 81227901, 81671851, 81527805), the Beijing Natural Science Foundation (L182061), the Bureau of International Cooperation of Chinese Academy of Sciences (173211KYSB20160053), the Instrument Developing Project of the Chinese Academy of Sciences (YZ201502), and the Youth Innovation Promotion Association CAS (2017175). Declaration of Interest: The authors declare no conflicts of interest. Ethical Approval: This retrospective analysis was ethically granted by the Institutional Review Board of Peking University People's Hospital (PKUPH) and Guangdong General Hospital (GDGH) in compliance with the Health Insurance Portability and Accountability. Informed consent was not required from patients.

Reliability and accuracy of cone beam computed tomography versus conventional multidetector computed tomography for image-guided craniofacial implant planning: An in vitro study.

To assess the reliability and accuracy of linear measurements on three-dimensional (3D) cross-sectional images, both acquired with cone beam computed tomography (CBCT) and multi-detector row CT (MDCT). Bone thickness was evaluated with regard to image-guided planning of craniofacial implant surgery. Five dry human skulls were used. Cuts were made with a circular bone saw at the ideal implant positions in the nasal, orbital, and temporal regions prior to acquisition of CBCT and MDCT scans. After imaging examination, bone width was assessed by three independent observers using a caliper and defined as a reference. In the next step, cross-sectional images of the regions with the aforementioned cuts were reconstructed from 3D virtual models generated from the digital DICOM datasets with the use of 3D image-based planning software. Subsequently, linear measurements were performed. The systematic difference and interobserver and intraobserver variation of MDCT and CBCT linear measurements were compared with the physical measurements at different locations in the nasal, orbital, and temporal region, respectively. Also, the potential influence of different gray-level values was investigated. The quantitative accuracy of distance measurements was performed using a two-way analysis of variance (ANOVA) and variance component analyses. Only differences with P values < .05 were considered significant. All radiologic measurements showed a significant overestimation of the bony dimensions, reaching more than the used voxel sizes of 0.3 mm for CBCT and 0.5 mm for MDCT. For CBCT, an average measurement bias of 0.39 to 0.53 mm and for MDCT of 0.57 to 0.59 mm was found. MDCT images showed less interobserver variation in linear measurements on cross-sectional images from 3D virtual models compared with CBCT images. Contrast settings statistically significantly influenced linear measurements of bone width for CBCT images (P < .0015) and interobserver variation on MDCT imaging (P < .029). Both CBCT images (KaVo 3D eXam Imaging System) and MDCT images (Aquilion ONE, Toshiba) showed a highly consistent submillimeter overestimation of the anatomical truth in assessing bone thickness of nasal, orbital, and temporal regions of ex vivo specimens. When using CBCT and MDCT images for presurgical assessment, one should be aware of the overestimation of the cortical bone thickness.

Prognostic factors for maxillary sinus mucosal thickening following Le Fort I osteotomy: a retrospective analysis

BackgroundLe Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined.MethodsUsing MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery.ResultsThe mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery.ConclusionsOperative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.

Optimal diagnostic method using multidetector-row computed tomography for predicting lymph node metastasis in colorectal cancer

BackgroundPrediction of nodal involvement in colorectal cancer is an important aspect of preoperative workup to determine the necessity of preoperative treatment and the adequate extent of lymphadenectomy during surgery. This study aimed to investigate newer multidetector-row computed tomography (MDCT) findings for better predicting lymph node (LN) metastasis in colorectal cancer.MethodsSeventy patients were enrolled in this study; all underwent MDCT prior to surgery and upfront curative resection for colorectal cancer. LNs with a short-axis diameter (SAD) ≥ 4 mm were identified on MDCT images, and the following measures were recorded by two radiologists independently: two-dimensional (2D) SAD, 2D long-axis diameter (LAD), 2D ratio of SAD to LAD, 2D CT attenuation value, three-dimensional (3D) SAD, 3D LAD, 3D SAD to LAD ratio, 3D CT attenuation value, LN volume, and presence of extranodal neoplastic spread (ENS), as defined by indistinct nodal margin, irregular capsular enhancement, or infiltration into adjacent structures.ResultsForty-six patients presented 173 LNs with a SAD ≥ 4 mm, while 24 patients exhibited pathologically confirmed LN metastases. Receiver operating characteristic analysis revealed that 2D LAD was the most sensitive measure for LN metastases with an area under the curve of 0.752 (cut-off value, 7.05 mm). When combined with CT findings indicating ENS, 2D LAD (> or ≤ 7 mm) showed enhanced predictive power for LN metastases (area under the curve, 0.846; p < 0.001).ConclusionsLAD in axial MDCT imaging is the most sensitive measure for predicting colorectal LN metastases, especially when MDCT findings of ENS are observed.

Computer-Aided Diagnosis of Pancreas Serous Cystic Neoplasms: A Radiomics Method on Preoperative MDCT Images.

Objective:Our aim was to propose a preoperative computer-aided diagnosis scheme to differentiate pancreatic serous cystic neoplasms from other pancreatic cystic neoplasms, providing supportive opinions for clinicians and avoiding overtreatment.Materials and Methods:In this retrospective study, 260 patients with pancreatic cystic neoplasm were included. Each patient underwent a multidetector row computed tomography scan and pancreatic resection. In all, 200 patients constituted a cross-validation cohort, and 60 patients formed an independent validation cohort. Demographic information, clinical information, and multidetector row computed tomography images were obtained from Picture Archiving and Communication Systems. The peripheral margin of each neoplasm was manually outlined by experienced radiologists. A radiomics system containing 24 guideline-based features and 385 radiomics high-throughput features was designed. After the feature extraction, least absolute shrinkage selection operator regression was used to select the most important features. A support vector machine classifier with 5-fold cross-validation was applied to build the diagnostic model. The independent validation cohort was used to validate the performance.Results:Only 31 of 102 serous cystic neoplasm cases in this study were recognized correctly by clinicians before the surgery. Twenty-two features were selected from the radiomics system after 100 bootstrapping repetitions of the least absolute shrinkage selection operator regression. The diagnostic scheme performed accurately and robustly, showing the area under the receiver operating characteristic curve = 0.767, sensitivity = 0.686, and specificity = 0.709. In the independent validation cohort, we acquired similar results with receiver operating characteristic curve = 0.837, sensitivity = 0.667, and specificity = 0.818.Conclusion:The proposed radiomics-based computer-aided diagnosis scheme could increase preoperative diagnostic accuracy and assist clinicians in making accurate management decisions.

Application of a three-dimensional print of a liver in hepatectomy

Background: Hepatectomy is performed according to the recognition of liver anatomy obtained by preoperative radiological images. Such recognition often differs between operator and assistants. To conquer difference of anatomical recognition, we are going to develop three-dimensional (3D) model navigation for open hepatectomy. Material and methods: Digital segmentation of anatomical structures from multidetector-row computed tomography images utilized the original software “PLUTO”, which was developed by Graduate School of Information Science, Nagoya University. After changing the final segmentation data to the stereolithography files, a 3D printed liver at a 70% scale was produced. The support material was washed and mold charge was removed from 3D printed hepatic veins. The surface of 3D printed model was abraded and coated with urethane resin paint. After natural drying, 3D printed hepatic veins were colored by injection of a dye. The 3D printed portal veins were whitish because mold charge remained. All procedures after 3D printing were performed by hand work. We used 3D print of a liver to hepatectomies for 14 patients. Results: In all study patients, hepatectomy was performed referring to 3D printed model. The planned resections were successful with histologically negative surgical margins. Conclusions: Application of 3D printed liver to hepatectomy is easy and suitable procedure. In the future, diffusion of 3D printing technology in hepatectomy requires further improvement and automatization of hand work after 3D printing.

Efficacy of Automated Supplying Artery Tracking Software Using Multidetector-Row Computed Tomography Images for Emergent Transcatheter Arterial Embolization.

To assess the reliability of a prototype automated supplying artery tracking software (ASATS) using multidetector-row CT (MDCT) images in emergent TAE. Consecutive 53 patients underwent 57 sessions of emergent TAE during 7months. Twenty-one cases were excluded due to a lack of CT data (n = 12) or negative angiographic findings (n = 9). Remaining 34 sessions of TAE and MDCT images in 32 patients (mean age 62.9years; age range 37-92years) were enrolled. ASATS was retrospectively conducted for the identification of supplying arteries which were confirmed with angiography (automated method). Manual modification was added as needed (semi-automated method). Two observers independently reviewed the MDCT images to detect supplying arteries (manual method). Detectability of supplying artery and time to analysis were compared among the automated, semi-automated, and manual methods by both observers. A total of 64 bleeding sites were demonstrated on angiography. The detectability was 28 (43.8%) for automated method, 53 (82.8%) for semi-automated method, 55 (85.9%) for observer 1, and 58 (90.6%) for observer 2. Detectability of semi-automated method was significantly better than of automated method (P = 0.000) and comparable with manual method by both observers (P = 0.193 and 0.081). Average time to analysis was 185.4s for automated method, 297.2s for semi-automated method, 186.2s for observer 1, and 243.7s for observer 2. ASATS has a sufficient ability to identify supplying arteries of bleeding by adding manual modification as needed and can be used for emergent TAE. Level 4, Case Control Study.

Impact of Biliary Drainage on Multidetector-Row Computed Tomography on R0 Resection of Perihilar Cholangiocarcinoma.

Although multidetector-row computed tomography (MDCT) before biliary drainage is useful for the assessment of the resectability of perihilar cholangiocarcinoma (PHC), the impact of biliary drainage on MDCT images before surgical resection for PHC has been poorly studied, and its possible consequences for R0 resection of PHC remain unclear. This study was performed to compare the surgical outcomes of patients with PHC who underwent MDCT before versus after biliary drainage. All consecutive patients who underwent major hepatectomy extending to segment 1 with extrahepatic bile duct resection for PHC from 2009 to 2016 were retrospectively evaluated. R0 resection was defined as no residual cancer at all surgical margins. Patients with pathological stage IV PHC were excluded. Of 142 patients who underwent major hepatectomy, 108 were eligible for this study. Of these 108 patients, 64 (59%) and 44 (41%) underwent MDCT before and after biliary drainage, respectively. The total bilirubin concentration at presentation was lower in patients who underwent MDCT before than after biliary drainage (4.1 ± 5.9 vs. 8.0 ± 7.1mg/ml, respectively; p = 0.002). Although there were no significant differences in the surgical characteristics or pathological stages between the two groups, R0 resection was more frequently achieved in patients who underwent MDCT before than after biliary drainage [46/64 (72%) vs. 22/44 (50%), respectively; p = 0.03]. On multivariate analysis, MDCT before biliary drainage was independently associated with R0 resection of PHC (risk ratio: 2.38, 95% CI 1.05-5.41; p = 0.04). In selected patients, MDCT should be performed before biliary drainage to achieve R0 resection of PHC.