Accuracy of Orthodontic 3D Printed Retainers versus Thermoformed Retainers

Background: The integration of the current technology of CBCT and 3D CAD/CAM technology has great potential in the field of orthodontics, which is not yet fully investigated. The purpose of this article is to evaluate the accuracy of 3D printed retainers in comparison to vacuum formed retainers. Methods: Alginate impressions were taken for ten patients who have a CBCT scan. A 3D printed retainer and vacuum formed retainer were fabricated. Linear measure-ments were measured by two assessors using digital caliper. Every measure-ment on the 3D printed retainer was compared to the corresponding measure-ment on the thermoformed retainer. The linear measurements were Inter-canine width, Inter-premolar width (first and second premolars), Inter-molar width, Canine-midline length (both sides) and Canine-molar length (both sides). Intra-observer, and inter-observer reliability measurements were done. Results: Results showed excellent intra-observer reliability for the thermoformed retainer and the 3D printed retainer. Inter-observer measurements showed strong agreement between the measurements of the two assessors, for both retainers. The comparison of the thermoformed retainer to the 3D printed retainer showed high statistical agreement, except for the canine-molar on the right side, but with no clinical significance, p value of 0.038 and mean difference 0.19. Conclusions: The new method for fabricating a 3D printed retainer is accurate and reliable in comparison to the vacuum formed retainer (conventional method). CBCT proved to be efficient for fabrication of a custom made appliances.

Effect of Atrial Fibrillation on Acute Ischemic Stroke Severity

Objectives: To assess the impact of atrial fibrillation on stroke severity and short-term (1 month) mortality. Materials and Methods: Totally 200 patients admitted to Ain Shams University Specialized Hospital were recruited and diagnosed clinically to have acute ischemic stroke within 3 days. Patients with hemorrhagic infarctions were excluded. History taking about previous heart disease was taken, full general and neurological examinations were done. Full metabolic profile, full cardiac investigations, carotid duplex, MRI brain stroke protocol with initial clinical evaluation and after 1 month re-evaluation using (NIHSS ) scale. Results: All patients underwent transthoracic echocardiography which revealed absence of “A” wave corresponding to atrial fibrillation in 33 patients (16.5%). Those Patients with atrial fibrillation had a median NIHSS score of 11.00 with IQR of 6.00 - 18.50 at admission and 6.00 with IQR of 2.00 - 14.50 after one month. Patients with atrial fibrillation showed significantly higher NIHSS at admission than patients in sinus rhythm, P < 0.05. Magnetic resonance imaging findings showed that MRA showed significant intracranial vessel stenosis in 117 (79.1%) patients. 51 (34.4%) patients had lacunar infarction, 65 (43.9%) patients had partial anterior circulation infarction, 25 (16.2%) patients had posterior circulation infarction and 7 (4.7%) patients had total anterior circulation infarction. 111 (75%) patients showed leucoaraiosis. Conclusion: Atrial fibrillation was found not to have significantly statistical effect on stroke severity and short term mortality.

Diffusion Tensor Imaging and Its Application to Traumatic Brain Injury: Basic Principles and Recent Advances

Traumatic axonal injury is a progressive process evoked by shear forces on the brain, gradually evolving from focal axonal alteration and cumulating in neural disconnection. Clinical classifiers and conventional neuroimaging are limited in traumatic axonal injury detection, outcome prediction, and treatment guidance. Diffusion weighted imaging is an advanced magnetic resonance imaging (MRI) technique that is sensitive to the movement of water molecules, providing additional information on the micro-structural arrangement of tissue. Quantitative analysis of diffusion metrics can aid in the localization of axonal injury and/or de(dys)myelination caused by trauma. Diffusion MRI tractography is an extension of diffusion weighted imaging, and can provide additional information about white matter pathways and the integrity of brain neural networks. Both techniques are able to detect the early micro-structural changes caused by Traumatic Brain Injury (TBI), and can be used to increase understanding of the mechanisms of brain plasticity in recovery after brain injury and possibly optimize treatment planning of patients with Traumatic Brain Injury. This review focuses on the theoretical basis and applied advanced techniques of diffusion weighted imaging, their limitations and applications, and future directions in the application to TBI.

Volumetric Assessment of Corticospinal Tract Infiltration by Astrocytoma Using Diffusion Tensor Tractography

Objectives: The aim of the study is to assess volumetric Corticospinal Tract infiltration by Astro-cytoma using Diffusion Tensor Tractography. Material and Methods: Preoperative, anatomic (T1- and T2-weighted) and diffusion tensor MRI were performed in 9 patients with supratentorial gliomas (WHO grade II and III). The tumors were manually segmented from the T1- and T2-weighted MRI, and their volume calculated. A three-dimensional tractography was performed in each case. A second segmentation and volume measurement was performed on the tumor regions intersecting adjacent white matter fiber tracts. Results: We identified that white matter tracts were infiltrated by 6 Astrocytoma tumors. The median tumor volume (±standard deviation) in our patient population was 33 ± 26.82 ml. The median tumor volume (±standard deviation) infiltrating white matter fiber tracts was 4.15 ± 9.23 ml. The median fraction of tumor volume infiltrating white matter fiber tracts was 26.3% ± 10.1%. Conclusions: Diffusion tensor MR Tractography is a reliable preoperative assessment tool since it detects extensive white matter infiltration by Astrocytoma irrespective of brain tumors volume. Recommendations: Prospective large population studies are required to clarify how infiltration relates to tumor location.

Inhibition of the Oversensing of Cardiac Pacemakers in Chest CT

Objectives: The purpose of this study is to identify how to manage oversensing of pacemakers in chest CT. Methods: Four different models of pacemakers were examined to select the pacemaker generating oversensing. To the pacemaker with oversensing, intermittent switching X-ray was exposed using ECG-gated CT helical scan system at prospective CTA mode. IVY Model was used to synchronize the ECG. Only during in the alert period that is non-refractory and sensing is available, intermittent switching X-ray (300 msec/sec) was exposed in chest CT. For comparison, the same intermittent switching X-ray (300 msec/sec) was exposed in the refractory period when sensing was not available. Results: Oversensing was detected only in one of the four pacemakers tested. In this pacemaker, oversensing was generated by exposure of the intermittent switching X-ray in the alert (non-refractory) period, but oversensing was not observed in the refractory period. Conclusion: A pacemaker has alert and refractory periods. Oversensing of a pacemaker was found to be inhibited by selective ECG-synchronized exposure in the refractory period. Since all pacemakers have the refractory period, the results of this study can be widely applied to the patients with pacemakers in chest CT, and their chest CT can be operated safely.

Performance Evaluation of Super-Resolution Methods Using Deep-Learning and Sparse-Coding for Improving the Image Quality of Magnified Images in Chest Radiographs

Purpose: To detect small diagnostic signals such as lung nodules in chest radiographs, radiologists magnify a region-of-interest using linear interpolation methods. However, such methods tend to generate over-smoothed images with artifacts that can make interpretation difficult. The purpose of this study was to investigate the effectiveness of super-resolution methods for improving the image quality of magnified chest radiographs. Materials and Methods: A total of 247 chest X-rays were sampled from the JSRT database, then divided into 93 training cases with non-nodules and 154 test cases with lung nodules. We first trained two types of super-resolution methods, sparse-coding super-resolution (ScSR) and super-resolution convolutional neural network (SRCNN). With the trained super-resolution methods, the high-resolution image was then reconstructed using the super-resolution methods from a low-resolution image that was down-sampled from the original test image. We compared the image quality of the super-resolution methods and the linear interpolations (nearest neighbor and bilinear interpolations). For quantitative evaluation, we measured two image quality metrics: peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). For comparative evaluation of the super-resolution methods, we measured the computation time per image. Results: The PSNRs and SSIMs for the ScSR and the SRCNN schemes were significantly higher than those of the linear interpolation methods (p p p Conclusion: Super-resolution methods provide significantly better image quality than linear interpolation methods for magnified chest radiograph images. Of the two tested schemes, the SRCNN scheme processed the images fastest;thus, SRCNN could be clinically superior for processing radiographs in terms of both image quality and processing speed.

Computational Fluid Dynamics and Its Impact on Flow Measurements Using Phase-Contrast MR-Angiography

Rationale and Objectives: Computational fluid dynamic (CFD) simulations are discussed with respect to their potential for quality assurance of flow quantification using commercial software for the evaluation of magnetic resonance phase contrast angiography (PCA) data. Materials and Methods: Magnetic resonance phase contrast angiography data was evaluated with the Nova software. CFD simulations were performed on that part of the vessel system where the flow behavior was unexpected or non-reliable. The CFD simulations were performed with in-house written software. Results: The numerical CFD calculations demonstrated that under reasonable boundary conditions, defined by the PCA velocity values, the flow behavior within the critical parts of the vessel system can be correctly reproduced. Conclusion: CFD simulations are an important extension to commercial flow quantification tools with regard to quality assurance.

Mode B Ultrasound in the Study of the Posterior Segment in the Medical Clinic “Marie Curie” in Bamako

Introduction: The study of the posterior segment of the eye has nowadays become one of the most frequent indications for diagnostic ultrasound in the ophthalmological field. The objective of this work is to contribute to the improvement of the diagnostic management of pathologies of the posterior segment of the eye in the radiology department of the medical clinic “Marie Curie” in Bamako. Material and Methods: This was a cross-sectional study carried out in the medical imaging department from January 2020 to January 2022. It concerned all patients who presented for the study of the ocular posterior segment on ultrasound. Results: Fifty-two (52) patients out of a total of 109 were included in the study, i.e. a frequency of 47.70%. The average age was 33.90 with the extremes ranging from 05 years to 75 years. The male sex dominated with a frequency of 69.23%. Ocular ultrasound was prescribed mainly by ophthalmologists (100%). In the study of the posterior segment, preoperative assessment represented the most frequent indications with respectively 55.76% and 23.10%. Retinal detachment and vitreous hemorrhage were the most found lesions on ultrasound with 50% and 34.61% respectively. Conclusion: Ocular ultrasound is accessible in Bamako and has allowed the study of the posterior segment of the eye. It occupies an important place in the study and management of ocular pathologies of the posterior segment.

Evaluation of CT Scans Reports in Pancreatic Tumors at Ouagadougou (Burkina Faso)

Background: There are no recommendations for the use of standardised CT reports in oncology in our country. The aim of this study was to evaluate CT reports of pancreatic tumors in the city of Ouagadougou. Materials and Methods: Descriptive, multicenter, cross-sectional study conducted from 1st January 2013 to 31 December 2021. It concerned CT scan reports from five public and private imaging centers in the city of Ouagadougou. During the study period, 41 reports of pancreatic tumors were collected. We evaluated the reports using the standardized model developed by the Society of Abdominal Radiology and the American Pancreatic Association as a reference. Results: CT scan reports were not standardised. The writing style was free. Concerning the lesion, the aspect of the tumor at the pancreatic time was the item with the least information (24.4%). The status of the superior mesenteric artery was mentioned in 17%, the celiac trunk and the portal trunk in 12.2% of cases and 9.7% for the superior mesenteric vein. No report noted the appearance of the common hepatic artery. The status of the lymph nodes, liver and peritoneal cavity was mentioned in all reports. The exact location of the lymph nodes was not specified. The analysis of the reports classified them into two groups: potentially resectable tumours in the absence of secondary locations in 31.7% of cases and locally advanced tumours or presence of metastases in 68.3% of cases. Conclusion: The CT reports were not standardized. The items allowing evaluating the loco-regional extension of the tumor were the least specified. This may suggest the high rate of potentially resectable tumours in our study.

Markerless Respiratory Motion Tracking Using Single Depth Camera

The aim of this study is to propose a novel system that has an ability to detect intra-fractional motion during radiotherapy treatment in real-time using three-dimensional surface taken by a depth camera, Microsoft Kinect v1. Our approach introduces three new aspects for three-dimensional surface tracking in radiotherapy treatment. The first aspect is a new algorithm for noise reduction of depth values. Ueda’s algorithm was implemented and enabling a fast least square regression of depth values. The second aspect is an application for detection of patient’s motion at multiple points in thracoabdominal regions. The third aspect is an estimation of three-dimensional surface from multiple depth values. For evaluation of noise reduction by Ueda’s algorithm, two respiratory patterns are measured by the Kinect as well as a laser range meter. The resulting cross correlation coefficients between the laser range meter and the Kinect were 0.982 for abdominal respiration and 0.995 for breath holding. Moreover, the mean cross correlation coefficients between the signals of our system and the signals of Anzai with respect to participant’s respiratory motion were 0.90 for thoracic respiration and 0.93 for abdominal respiration, respectively. These results proved that the performance of the developed system was comparable to existing motion monitoring devices. Reconstruction of three-dimensional surface also enabled us to detect the irregular motion and breathing arrest by comparing the averaged depth with predefined threshold values.

Qualitative and Quantitative Perfusion Parameters Determined by 3D Single-Shot GRASE ASL MR Imaging

Rationale and Objectives: A particular arterial spin (ASL) labeling technique, called 3D-single-shot GRASE ASL is discussed with respect to the ability and limits of quantifying perfusion parameters. Materials and Methods: The technique enables the acquisition of perfusion weighted signal at multiple delay times (TI) in one scan. The readout part is a gradient and spin-echo combination (GRASE) that uses switched gradient rephrasing of signals to produce several times as many signals as turbo-spin-echo, which translates into faster imaging time and higher signal-to-noise ratio (SNR) per imaging time. The technique provides the possibility for model based quantification of cerebral blood flow and the determination of the bolus arrival information without use of contrast agent and thus the characterization and determina-tion of regions that are supported by collaterals. Results: Whereas for a quantification of the permeability using ASL the SNR is not high enough, at least qualitative permeability maps can be determined, if an optimal homogenous SNR was guaranteed. This was accomplished in brain regions with a high blood supply, typically given in tumors, and by using a correction for coil sensitivity at the highest possible additional scaling. Conclusion: The single-shot 3D GRASE ASL can provide information about the principal blood supply, the transit delay of the blood flow due to a stenosis or collaterals and a qualitative measure of the permeability.

Effect of the Energy Window Width on the Estimation of Renal Function from Dynamic Renal Scintigraphy with ^99mTc-MAG3

Objective: The width of the photopeak energy window influences the image quality and quantitative accuracy of gamma camera imaging. We compared 20% and 15% energy windows in renal scintigraphy with 99mTc-mercaptoacetyltriglycine (MAG3), especially in terms of camera-based quantitative estimation of renal function. Materials and Methods: Forty patients who underwent dynamic renal scintigraphy with 99mTc-MAG3 were enrolled in this study. Images were acquired simultaneously using two energy windows centered at 140 keV and with widths of 20% and 15%. Fractional renal uptake was calculated as the ratio of initial renal uptake estimated by patient imaging to injected dose estimated by syringe imaging, and was converted to MAG3 clearance using an empirical equation determined previously from data obtained with a 20% energy window. Relative function of the right kidney was also assessed. Visual evaluation was performed to compare image quality between the 20% and 15% energy windows. Results: Both total kidney MAG3 clearance and relative function of the right kidney were identical between the 20% and 15% energy windows. Image quality was also similar irrespective of the energy window width. Conclusions: The camera-based method established using a 20% energy window is applicable for the estimation of renal function using a 15% energy window, and data obtained using 20% and 15% windows are interchangeable.

Breast Density: Does It Vary among the Main Ethnic Groups in Malaysia?

Breast cancer is one of the common cancers among Malaysians and there are associated risk factors which include breast density. Therefore, this study was done to determine the association of breast cancer risks among ethnic groups in relation to breast density. Mammography was done on 300 women with equal numbers of Malays, Chinese and Indians with a mean age of 53.35 ± 7.4 years. Mammograms were evaluated using BI-RADS (Breast Imaging Reporting and Data System) protocol by two independent radiologists for breast density categorization. Chi-square analysis showed an association between breast density and age factor (p 0.05) whereas body mass index (BMI) was inversely associated with breast density (p > 0.05). There was significant difference in number of children and menopausal status (p 0.05). Results showed that 65% of Chinese subjects had denser breast density composition as to 50% in Malays and 35% in Indians. There was significant difference between breast density of three ethnic groups (p 0.05) with Chinese having 2.4 times denser breast (OR = 2.45, 95% CI: 1.466 - 3.948) followed by Malays (OR = 1.020, 95% CI: 0.681 - 1.689) and lowest in Indians (OR = 0.406, 95% CI: 0.247 - 0.668). Based on breast density, the Chinese are at a higher risk of developing breast cancer followed by Malays and lastly Indians.

Grading of Brain Tumors by Mining MRS Spectrums Using LabVIEW <br/>—Metabolite Peak Height Scanning Method

In this paper, we attempt to resolve the problem of grading of brain tumors as grade 2, grade 3, grade 4, using information from magnetic resonance spectroscopy (MRS) image, to assist in clinical diagnosis. This paper proposes a novel approach to extract metabolite values represented in a graphical form in MR Spectroscopy image. Metabolites like N-acetyl aspartate (NAA), Choline (CHO) along with the metabolite ratios NAA/CHO and presence/absence of LACTATE peak play the most important role in deciding the tumor type. The proposed approach consists of several steps including preprocessing, metabolite peak height scanning and classification. Proposed system stores the metabolite values in dataset instead of storing MRS images;so reduces the image processing tasks and memory requirements. Further these metabolite values and ratios are fed to a BPN classifier. Experimental results demonstrate the effectiveness of the proposed approach in classifying the brain tumors.

Image Reconstruction from Fan-Beam Projections without Back-Projection Weight in a 2-D Dynamic CT: Compensation of Time-Dependent Rotational, Uniform Scaling and Translational Deformations

In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent backprojection weight which compensates for the time-dependent translational, uniform scaling and rotational deformations occurring in the object of interest during the data acquisition process. We shall also compare the computational cost of the proposed reconstruction algorithm with the existing one which has position-dependent weight. To accomplish the objective listed above, we first formulate admissibility conditions on deformations that is required to exactly reconstruct the object from acquired sequential deformed projections and then derive the reconstruction algorithm to compensate the above listed deformations satisfying the admissibility conditions. For this, 2-D time-dependent deformation model is incorporated in the fan-beam FBP reconstruction algorithm with no backprojection weight, assuming the motion parameters being known. Finally the proposed reconstruction algorithm is evaluated with the motion corrupted projection data simulated on the computer.

Lymphoscintigraphy Using Dynamic Imaging and SPECT/CT in Chylothorax

Lymphoscintigraphy readily provides confirmation of chylothorax but not detailed localization of the leakage site. A 77-year-old woman developed traumatic chylothorax and underwent lymphoscintigraphy with radiolabeled albumin to identify the site of lymph leakage. Dynamic imaging demonstrated appearance of focal activity presumably in the upper mediastinum, followed by spread to the left hemithorax. Subsequently, SPECT/CT showed that the leakage site was located in the left side of the upper mediastinum, and this location was confirmed during video-assisted thoracoscopic surgery. Dynamic imaging demonstrated the site of first appearance of abnormal activity, and SPECT/CT enabled detailed localization of the abnormal activity with anatomic correlation. The combination of dynamic imaging with SPECT/CT appears to be recommendable for lymphoscintigraphic assessment of chylothorax.

Reliability of Medical Imaging in the Pre-Therapeutic Assessment of Acute Intestinal Obstruction at the Centre Hospitalier Universitaire Du Point “G”.

Introduction: Acute intestinal obstruction is a serious pathology, a surgical emergency for which medical imaging plays an important role in the management. We initiated this work in order to study the contribution of imaging in the diagnosis of acute intestinal obstruction at the Point-G University Hospital. Patients and Methods: This was a prospective, descriptive and analytical study of 96 patients collected at the radiology and medical imaging department of CHU Point-G from January 2018 to January 2019. Results: The age of our patients varied from 11 to 86 years, with an average of 36 years old. There was a male predominance of 64.6% against 35.4% for women, i.e., a sex ratio of 1.82. Previous surgery was found in 61.5% of our patients. The pain was present in all patients. An unprepared abdominal X-ray was performed in 89.6% of patients. Hydroaerobic levels were found in 96.5% of patients. Abdominopelvic CT scans were performed on 12 patients, all of whom were diagnosed with occlusion. These positive diagnostic findings were consistent with intraoperative findings in 92% of cases. The causes were dominated by bridges in 46 patients and tumors in 9 patients. Signs of severity on CT were dominated by signs of distress of the upstream bile ducts in 8.3%. Exactly 8% of our patients spontaneously resumed transit, 91% received surgical treatment and 1% died before surgery. The outcome was favorable in 80 patients (83.3%) and poor with death in 16 patients (16.7%). Conclusion: Acute intestinal obstruction remains a serious pathology for which the X-ray of the PSA is often the only radiological examination performed in an emergency. However, abdominopelvic CT seems to us to be widely indicated thanks to its contribution both to the positive diagnosis and to the diagnosis of severity and etiology. However, this imaging technique is widely underused in our practice because of its high cost and lack of availability.

Pre-Operative Perihepatic Lymph Node Assessment in Colorectal Cancer Liver Metastasis—A Review of Current Literature

Objective: Perihepatic lymph node involvement in colorectal cancer liver metastases is a negative prognostic factor. Resection of certain nodal stations around the liver has been shown to possibly improve survival. The aim of this review is to interrogate current literature on pre-operative investigations in diagnosing lymph node involvement. Method: A systematic review was conducted of articles published since 2006 to determine usefulness of pre-operative imaging in diagnosing lymph node involvement in colorectal cancer liver metastases. Results: Only 2 papers met the inclusion criteria for this study. Computed tomography (CT) scans were found to have sensitivities of 33% and 40%, specificities of 94% and 92%, positive predictive values (PPV) of 56% and 30%, and negative predictive values (NPV) of 85% and 95%. Positron emission tomography (PET) was studied in one of the paper and was found to have sensitivity, specificity, PPV and NPV of 57%, 100%, 100%, and 88% respectively. Conclusion: There is a significant lack of research on pre-operative investigations of perihepatic lymph node involvement in colorectal cancer liver metastases. Pre-operative CT and PET scans in assessing perihepatic lymph nodes were shown to be inaccurate. Newer pre-operative imaging modalities and research would be needed.

On Wavelet Transform General Modulus Maxima Metric for Singularity Classification in Mammograms

Continuous wavelet transform is employed to detect singularities in 2-D signals by tracking modulus maxima along maxima lines and particularly applied to microcalcification detection in mammograms. The microcalcifications are modeled as smoothed positive impulse functions. Other target property detection can be performed by adjusting its mathematical model. In this application, the general modulus maximum and its scale of each singular point are detected and statistically analyzed locally in its neighborhood. The diagnosed microcalcification cluster results are compared with health tissue results, showing that general modulus maxima can serve as a suspicious spot detection tool with the detection performance no significantly sensitive to the breast tissue background properties. Performed fractal analysis of selected singularities supports the statistical findings. It is important to select the suitable computation parameters-thresholds of magnitude, argument and frequency range-in accordance to mathematical description of the target property as well as spatial and numerical resolution of the analyzed signal. The tests are performed on a set of images with empirically selected parameters for 200 μm/pixel spatial and 8 bits/pixel numerical resolution, appropriate for detection of the suspicious spots in a mammogram. The results show that the magnitude of a singularity general maximum can play a significant role in the detection of microcalcification, while zooming into a cluster in image finer spatial resolution both magnitude of general maximum and the spatial distribution of the selected set of singularities may lead to the breast abnormality characterization.

Ultrasound Diameter of the Portal Vein to Healthy Adult in Parakou (Benin)

Introduction: The portal vein (PVD) diameter is one of the predictive variables of portal hypertension. This diameter can differ according to the population. The objective of this study was to determine the PVD in a healthy adult population in Parakou using ultrasonography. Methods: A cross-sectional descriptive study was conducted in the medical imaging department of the Borgou and Alibori University-affiliated Hospitals in Parakou from July 1st to October 1st, 2019. The study population consisted of 201 healthy adults. The ultrasound diameter of the portal vein was measured at the level of the hepatic hilum on a cross-sectional epigastric view and on an oblique intercostal view. An association was sought between the PVD and sociodemographic and anthropometric factors. Results: The mean age was 28.97 ± 10.56 years and the sex ratio (M/F) was 0.79. The mean PVD in regular breathing (FB) was 9.83 ± 0.95 mm with a 95% confidence interval of [9.70;9.97], a 95th percentile of 11.49 mm with extremes of 7.50 mm and 12.23 mm. PVD was correlated with age, sex, weight, height and abdominal girth. After multiple linear regressions (r = 0.19), there was correlation between the PVD in normal breathing with age (p = 0.0090), weight (p = 0.0026), body mass index (p = 0.0171) and body surface (p = 0.004). Conclusion: A PVD greater in normal adults is less than 12 mm and seems to be correlated to the subject age, weight, body mass index and body surface. A more than 13 mm PVD should lead to the suspicion of portal vein hypertension in adults in our populations.