64-slice Multidetector Computed Tomography Research Articles

Multidetector CT and cone-beam CT have substantial agreement in detecting dental and sinus abnormalities in equine cadaver heads.

The performance of cone-beam CT (CBCT) systems compared to conventional helical multidetector CT (MDCT) imaging of the equine head is unknown. The aim of this prospective, method-comparison study was to compare the ability of CBCT and MDCT to detect abnormalities in equine cadaver heads. Eleven equine cadaver heads were scanned using a CBCT scanner and a 64-slice MDCT scanner. Consensus evaluations for CBCT and MDCT scans were performed by three observers. Identified abnormalities were grouped into subcategories with a focus on dental abnormalities. Kappa agreement values between detected abnormalities for CBCT and MDCT methods were calculated. Of 468 teeth evaluated, 122 (26.1%) were found to have abnormalities (including in 58 infundibula and 7 pulps) using MDCT and 105 (22.4%) were found to have abnormalities (including in 52 infundibula and 2 pulps) using CBCT. The agreement between CBCT and MDCT was almost perfect for overall detection of dental abnormalities (k=0.90) with k=1 for diastema k=0.95 for clinical crown abnormalities, and k=0.93 for infundibular abnormalities. However, the detection of pulp changes by CBCT was only moderate k=0.44. Increased scatter radiation, non-calibrated Hounsfield Unit and artefacts in CBCT images made accurate identification of the pulp density difficult. In conclusion, CBCT results were similar to conventional MDCT for the majority of dental abnormalities, however, pulp abnormalities were not reliably identified using CBCT, potentially limiting its clinical use for detecting endodontic disease in its current form. Further comparison with more cases with confirmed dental disease and studies in clinical cases are warranted.

CORONARY ARTERY DISEASE ON CT-CORONARY ANGIOGRAM – COMPARISON BETWEEN DIABETIC AND NON-DIABETIC POPULATION

Objective: To evaluate the CT coronary angiograms of patients presenting with symptoms of coronary artery disease (CAD) as well as to compare the results between the diabetics and non-diabetics. Methodology: This descriptive cross-sectional study was carried out in Cardiology department of Chaudhary Pervaiz Elahi Institute of Cardiology, Multan. One hundred and fifty nine patients with history of symptoms of CAD and no previous history of myocardial infarction or revascularization were included in study. The conventional risk factors were noted and 64 slice multi detector CT coronary angiogram was done on all patients. Total calcium score and number of segments with disease, obstructive disease and non-obstructive disease were noted. Results were compared among diabetic and non-diabetic patients. Results: Mean age of the patients was 50.54±7.90 years. Out of 159 patients 118(74.2%) were males and 41 (25.8%) were females. Diabetic patients were 101(63.5%), 64 (40.3%) were hypertensive, 39(24.5%) were smokers, 24.5% (n=39) had positive family history, 18.2% (n=29) were obese and 13.8% (n=22) had dyslipidemia. There was no coronary artery disease in 40 (25.2%) patients while 91 (57.2%) patients had obstructive and 28 (17.6%) patients had non-obstructive disease. 83. 1% diabetics had obstructive CAD and 12.0% of non diabetic patients had obstructive CAD. Mean number of obstructive segments in diabetic patients are 2.36±1.23. Conclusion: CAD was more prevalent in diabetic patients and CAD is easily predicted by non-invasive technique of CT coronary angiography.

Incidentalomas of the female genital tract on 64-slice MDCT: a clinico-radiological pictorial review.

Sonography is the imaging modality of choice for diagnosing diseases of the female genital tract due to its high resolution, easy availability, low cost and lack of radiation. CT is not advocated for the primary evaluation of the female pelvis. However, with the advent of Multidetector CT (MDCT), females of all ages undergo CT scan of the abdomen and pelvis for myriad non-gynaecological diseases, e.g. subacute intestinal obstruction, abdominal lump, abdominal tuberculosis, appendicitis, ureteric colic, pancreatitis, oncological staging, follow-up, etc. Incidental female genital tract disorders were seen on these scans that are a dilemma for both, the radiologists and the clinicians. The objective of this pictorial review is to characterise the incidentally detected lesions of the female genital tract observed on 64-slice MDCT by correlating with sonography, if necessary, and establishing a clinico-radiological diagnosis. Our aim is to emphasise that the radiologist may be the first person to recognise a gynaecologic disorder and hence can play a significant role in patient management.

Ultra-low-dose lung multidetector computed tomography in children – Approaching 0.2 millisievert

PurposeTo compare objective and subjective parameters in image quality and radiation dose of two MDCTs (helical 64 detector CT vs. axial 256 detector CT) in paediatric lung CT. MethodsRadiation dose and image quality were compared between non-enhanced lung CT from a helical 64-slice multidetector CT (MDCT 1) and a 256-slice scanner (MDCT 2) with axial wide-cone acquisition and using deep learning image reconstruction. In 23 size-matched paediatric studies (age 2–18 years) from each scanner, the radiation exposure, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), image sharpness and delineation of small airways were assessed. Subjective image quality was rated by 6 paediatric radiologists. ResultsWhile MDCT 2 provided higher SNR and CNR, subjective image quality was not significantly different between studies from both scanners. Radiation exposure was lower in studies from MDCT 2 (CTDIvol 0.26 ± 0.14 mGy, effective dose 0.23 ± 0.11 mSv) than from MDCT 1 (CTDIvol 0.96 ± 0.52 mGy, effective dose 1.13 ± 0.58 mSv), p < 0.001. Despite lower radiation dose for the scout images, the relative scout-scan-ratio increased from 2.64 ± 1.42 % in MDCT 1 to 6.60 ± 5.03 % in MDCT 2 (p = 0.001). ConclusionsBy using latest scanner technology effective radiation dose can be reduced to 0.1−0.3 mSv for lung CT in children without compromising image quality. Scout image dose increasingly accounts for substantial portions of the total scan dose and needs to be optimized. In children CT should be performed on state-of-the-art MDCT scanners with size-adapted exposure protocols and iterative reconstruction.

Comparison of Maximum Intensity Projection and Volume Rendering in Detecting Pulmonary Nodules on Multidetector Computed Tomography.

IntroductionLung cancer is the most common cancer overall, and the foremost cause of cancer-related mortality. Almost all lung cancers evolve from pulmonary nodules. As multidetector CT (MDCT) scanners are now widely available, there is an increased rate of detection of pulmonary nodules. It is of utmost importance to evaluate pulmonary nodules to rule out the possibility of neoplastic diseases. With advancements in technology, there are various manual and automatic analytic software providing a wide range of post-processing techniques. Maximum intensity projection (MIP) and volume rendering (VR) techniques have been analyzed previously regarding pulmonary nodules but there is a scarcity of data in terms of low-density nodules. This study aims to delineate the comparison and supremacy of both techniques in terms of low-density nodules.MethodologyThe current prospective study was conducted from June 2019 to June 2020 in the Radiology Department at Dr. Ziauddin Hospital, Karachi. Chest CT scans were performed on 16 slice MDCT (Alexion 16 Multi-slice, Toshiba Medical System Corporation, Houston, TX). A consultant radiologist of six years experience and a postgraduate trainee of three years experience analyzed each patient on a workstation (Vitrea 6.2.0, Vital Images, Minnetonka, MN). SPSS 23.0 (SPSS Inc., Chicago, IL) was incorporated for data analysis. Data were expressed in the median and interquartile range (IQR). Data collected for this study were analyzed using analyzing the median difference in nodule count using Wilcoxon’s signed-rank test. A p-value of <0.05 was considered significant.ResultsAfter informed consent, 236 patients were recruited for the study. MIP outperformed VR in terms of nodule detection and low-density nodules at each evaluated slab thicknesses (p<0.001). A 10-mm MIP was superior to all other techniques in terms of detection of pulmonary nodules and low-density nodules (p<0.001). MIP was also considered an easier technique as there was excellent inter-rater reliability and agreement.ConclusionThis study is robust evidence regarding the supremacy of MIP. MIP outperformed VR on every slab thicknesses. The 10-mm MIP technique was superior to all others evaluated and was recorded to be an easier analyzing technique.

Low Radiation Dose Implications in Obese Abdominal Computed Tomography Imaging

The aim of this study was to evaluate the implications of low radiation dose in abdominal computed tomography (CT) when combined with noise reduction filters and to see if this approach can overcome the challenges that arise while scanning obese patients. Anthropomorphic phantoms layered with and without 3-cm-thick circumferential animal fat packs to simulate different sized patients were scanned using a 128-slice multidetector CT (MDCT) scanner. Abdominal protocols (n = 12) were applied using various tube currents (150, 200, 250, and 300 mA) and tube voltages (100, 120, and 140 kVp). MOSFET dosimeters measured the internal organ dose. All images were reconstructed with filtered back projection (FBP) and different iterative reconstruction (IR) strengths (SAFIRE 3, SAFIRE 4, and SAFIRE 5) techniques and objective noise was measured within three regions of interests (ROIs) at the level of L4–L5. Organ doses varied from 0.34–56.2 mGy; the colon received the highest doses for both phantom sizes. Compared to the normal-weighted phantom, the obese phantom was associated with an approximately 20% decrease in effective dose. The 100 kVp procedure resulted in a 40% lower effective dose (p &lt; 0.05) compared to at 120 kVp and the associated noise increase was improved by increasing the IR (5) use, which resulted in a 60% noise reduction compared to when using FBP (p &lt; 0.05). When combined with iterative reconstruction, the low-kVp approach is feasible for obese patients in order to optimize radiation dose and maintain objective image quality.

English

BACKGROUND The craniovertebral junction is a complex articulation between occiput, atlas, axis and supporting ligaments enclosing the soft tissue structures of cervicomedullary junction which includes medulla, spinal cord and lower cranial nerves. The incidence of different types of CVJ anomalies varies with demographic environment &amp; ill-defined genetic factors. CVJ anomalies are more frequently found in Indian subcontinent than anywhere else in the world. Even in India, these anomalies are more frequently documented from Bihar, Uttar Pradesh, Rajasthan and Gujarat. The reason for this geographical clustering is more speculative. The CVJ anomalies can be either due to bony or soft tissue anomalies. They are common in all age groups and almost equal in both sex groups. The anomalies can be due to congenital or acquired causes. There has been a renewed interest in the normal anatomy &amp; pathological lesions of CVJ anomalies with dynamic xrays, computed tomography (CT) and magnetic resonance imaging (MRI). The clinical features are often delayed up to 2 nd or 3rd decade, since they are subtle and often missed. Various congenital anomalies and acquired disease processes can affect the craniovertebral junction. They often cause diagnostic dilemmas. Only few studies have been conducted in this regard. This study is an attempt to define importance of precise diagnosis for pre-treatment evaluation and systematic classification of CVJ abnormalities with MRI and multi-detector computed tomography (MDCT). METHODS We conducted this cross-sectional descriptive study with 55 patients, who had been referred to us for CT / MRI from Department of Neurology. 3 Tesla MRI (GE Healthcare) and 16 slice MDCT (Philips) were used in this study. RESULTS In our study, congenital anomalies were the most common type of CVJ abnormality followed by degenerative changes and trauma. MRI proved to be better at detecting soft tissue abnormalities and assessing spinal cord compression, although CT was very much accurate at demonstrating bony lesions with short scan times and ability to reconstruct in three orthogonal planes. CONCLUSIONS CT and MRI cannot be compared in imaging the craniovertebral junction and should be complementary to each other. KEYWORDS Craniovertebral Junction, MRI, MDCT

Radiation dose reduction in CT-guided cryoablation of renal tumors.

We aimed to evaluate the effect on the radiation dose to the patient by reducing the tube current during the placement of the ablation needles (reduced dose group) compared with the patient doses delivered when scanning at the standard fully diagnostic level (full dose group) in computed tomography (CT)-guided percutaneous cryoablation. We conducted a retrospective study of 103 patients undergoing cryoablation in a tertiary cancer center. Overall, 62 patients were scanned with standard exposure parameters (full dose group) set on a 64-slice multidetector CT scanner, while 41 patients were scanned on a reduced dose protocol. Dose levels were retrieved from the hospital picture and archiving communication system including the volumetric CT dose index (CTDIvol), total dose length product (DLP), length of cryoablation procedure, number of cryoablation needles and patient size. Wilcoxon Mann-Whitney (rank-sum) tests were used to compare the median DLP, CTDIvol and skin dose between the two groups. Median total DLP for the full dose group was 6025 mGy•cm (1909-13353 mGy•cm) compared with 3391 mGy•cm (1683-6820 mGy•cm) for the reduced dose group. The reduced dose group had a 44% reduction in total DLP and 42% reduction in total CTDIvol (p < 0.001). The estimated skin doses were 384 mGy for the full dose group and 224 mGy for the reduced dose group (42% reduction) (p < 0.001). At 12-month follow-up, the technical success for the full dose (n=62) was 97% with 2 patients requiring a further cryoablation treatment for residual tumor. The technical success for the reduced dose group (n=41) was 100%. CT dose reduction technique during image-guided cryoablation treatment of renal tumors can achieve significant radiation dose reduction whilst maintaining sufficient image quality.

Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study

The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p &gt; 0.05) observed between the protocols and image metrics.

The utility of a novel approach to quantify dyssynchrony by multidetector computed tomography

Abstract Funding Acknowledgements Type of funding sources: None. Background Quantification of left ventricular (LV) dyssynchrony is of great interest for resynchronization therapy (CRT). Recently, cardiac computed tomography (CCT) is feasible for evaluation of dyssynchrony. Our aim was to assess a novel simplified approach using CCT to quantify LV dyssynchrony. Methods We studied 346 consecutive patients with a wide range of QRS width and ejection fractions (EF). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT (Brilliance 256 iCT, Philips Medical Systems) was performed before CRT. After CCT scan, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and a time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software "Myocardial Contraction Map" (Argus, Inc Ehime, Japan). The standard deviation of all segments modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT. Results %SD was feasible in all patients, respectably. %SD was significantly different between the different QRS duration groups; narrow QRS (&amp;lt;120ms): 9 ± 5%, relatively wide QRS (120-150 ms): 11 ± 6%, and significantly wide QRS (&amp;gt;150 ms): 14 ± 7% (p &amp;lt;0.001). Moreover, there was significantly difference in %SD between the different morphology groups; normal: 9 ± 7%, Non-left bundle branch block (Non-LBBB): 10 ± 6%, LBBB: 17 ± 7% (p &amp;lt;0.001). Conclusion This novel simplified approach by CCT can quantify dyssynchrony in different QRS duration and morphology groups. This method has promise for clinical applications to the evaluation of patients for CRT. Abstract Figure.

Role of Triple Phase Computed Tomography in the Evaluation of Liver Lesions

Introduction: Wide range of benign and malignant tumours can occur in the liver, the largest organ in our body. So far, the histopathological diagnosis was considered the gold standard with the limitation of it being invasive. However, the advances in the radiological imaging techniques would surpass this difficulty, as well helps in coming to a close, if not many times the definitive diagnosis, thus preventing these invasive diagnostic procedures. Aim: To assess the role of triple phase Computed Tomography (CT) in the evaluation of liver lesions by evaluating the enhancing characteristics and comparing the findings with ultrasound, Magnetic Resonance Imaging (MRI), Biopsy and follow-up as applicable during the study period. Materials and Methods: This is a longitudinal prospective study conducted at Kamineni Institute of Medical Sciences, Narketpally, on 60 selected subjects for a period of 12 months, during July 2017 to July 2018. Patients of age more than 20 years of both gender with clinical suspicion or inconclusively diagnosed liver lesions were selected. These patients are evaluated using standard triple phase contrast CT liver protocol on 16 slice multidetector CT scan. The different enhancing patterns were inspected and compared to USG, MRI and Biopsy as applicable. All the collected data were tabulated in Microsoft excel sheet and were analysed in SPSS Software version 21. Results: The study consisted of 60 patients with 35 male and 25 female and assessed a total of 200 individual liver lesions. Out of which, 141 were malignant and 59 benign. Metastasis being the most common (n=113), followed by Hepatocellular Carcinoma (HCA) (n=26) and intrahepatic Cholangiocarcinoma (CCA) (n=2) in malignant lesions and Haemangioma (n=26) was the commonest benign lesion followed by cysts (n=20), abscess (n=10), Focal Nodular Hyperplasia (FNH) (n=2) and adenoma (n=1). In total, there were 112 (56%) hypovascular lesions and 88 hypervascular lesions (44%), with 11 enhancement patterns which are correlated to standards of reference satisfactorily. The study shows triple phase CT is 100% sensitive in diagnosing abscess, simple cysts, FNH and intrahepatic CCA and showed varied sensitivities with other lesions like HCC (sensitivity-79%), Haemangioma (sensitivity-92.3%), Metastasis (sensitivity- 91.1%), however, it showed 100% specificity in diagnosing all the cases when there was typical enhancement pattern for the individual lesion concerned. The four benign enhancement patterns and five malignant enhancement patterns were noted along with hypo/hypo/hypo, hypo/hypo/hyper and hyper/A/A patterns which needs cautious interpretation. Conclusion: We recommend triple phase CT scan as a standard first line procedure with high sensitivity, specificity and accuracy in differentiating benign and malignant liver lesions and avoiding unnecessary biopsies. Hepatic Arterial Phase (HAP) is used in identifying small hypervascular lesions and Porto-Venous Phase (PVP) in detecting small hypovascular lesions. Particularly in HCC, triple phase CT provides additional information of vascular invasions, arterioportal shunts, capsular delineation and vascular road map for pre-surgical evaluation.

Usando a tomografia computadorizada 3D na descrição anatômica do olho e do órgão vestibulococlear de arara-canindé (Ara ararauna Linnaeus, 1758) e tucano (Ramphastos toco Statius Muller, 1776)

The aim of this study was to evaluate the use of Computed Tomography to study the anatomy of the eye and the vestibulocochlear organ of the wild birds. For this purpose, formaldehyde-embalmed specimens of a toucan and of a blue-and-yellow macaw were submitted to a whole-body scan by a 64 slice-Multidetector CT yielding 0,7mm-thick transversally oriented images. These were reconstructed by specific software that produced additional images in dorsal, transversal, and sagittal planes, as well as three-dimensional images, which were obtained by two techniques: Maximum Intensity Projection and Volume Rendering. Our study found that the eye bulbs in the orbit occupy a proportionally large space in the skull, highlighting the important role that vision plays in these animals. CT provided gross anatomic information about the size and shape of the eye, such as lenses and scleral rings of these birds. Regarding the vestibulocochlear organ, CT was less likely to identify the inner ear structures, especially the ones of the membranous labyrinth. The bony semicircular canals were clearly seen and in the middle ear, thecolumellawas identified. Our results demonstrate that the vestibulocochlear organ of birds is less complex than that of mammals, although, as expected, the semicircular canals are very well developed, being adapted to the accurate balance present in these animals.CT can be used as a good technique to evaluate eye and ear structures on these birds, and can be useful to study them in vivofor pathological conditions or for comparisons between different species.

Role of multidetector computed tomography (MDCT) in evaluation of main and right portal vein branching patterns and its clinical significance

Introduction: Knowledge of the normal portal vein anatomy and its variations is imperative for various hepatic interventional procedures and liver surgeries like during creation of transjugular intrahepatic portosystemic shunt (TIPS), partial hepatectomy and Liver transplantation. Aims and Objective: The aim of our study was to determine and analyse the spectrum of variations in the main and right portal vein anatomy and their prevalence in Indian population using MDCT. Materials and Methods: Triple phase abdomen CT of 688 patients done on a 64 slice MDCT scanner between February 2012 and March 2014, were retrospectively evaluated by two radiologists independently. Out of these, 500 patients met the inclusion criteria. Axial images of portal and venous phase along with the maximum-intensity-projection and volume rendered images were reviewed and branching patterns of main and right portal vein were recorded. Results: Normal portal vein anatomy was present in 67% of the patients. Main portal vein (MPV) variations were seen in 15.2% of the patients. The most common variant was Z-type pattern (7.6%). Next common was trifurcation pattern (6.6%). Right portal vein (RPV) variations were seen in 17.8% of patients and the most common pattern was early segmental branching (6.8%). Other RPV branching variations were RPV trifurcation (3.6%), RPV quadrification (3.6%), and superior-inferior division (1.4%). Miscellaneous branching variations of RPV were seen in 2.4% of all patients. Conclusion: Variations in the main portal vein and right portal vein anatomy are quite common and can be clearly detected with MDCT. Keywords: Portal vein branching, Portal vein MDCT, MPV variation, RPV variation.

Quantitative analysis of dyssynchrony assessed by multidetector computed tomography can predict clinical outcome after cardiac resynchronization therapy

Abstract Background The degree of mechanical dyssynchrony has been suggested as a predictor for long-term survival after cardiac resynchronization therapy (CRT). There have been little reports of dyssynchrony assessment with the use of cardiac computed tomography (CCT). Methods We studied 35 heart failure (HF) patients (average age 67±10 years) referred for CRT with NYHA III-IV heart failure, left ventricular (LV) ejection fraction (EF) 20±10% (all ≤35%), and QRS duration 156±22 ms (all ≥120ms). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT was performed before CRT. Based on CCT, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and the time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software “Myocardial Contraction Map”. The standard deviation modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT. The predefined primary end-point was the first HF hospitalization or death over 2 years. Results %SD was feasible in all patients, respectably. There were 16 events over 2 years; 11 HF hospitalizations and 5 deaths. Patients with %SD ≥22% (optimal cutoff for outcome by ROC curve analysis) had a better clinical outcome than patients with %SD &amp;lt;22% (p=0.01, Figure). Conclusion Patients who had %SD ≥22% assessed by MDCT had a particularly favorable event-free survival following CRT, and this appears to be an important prognostic marker. Funding Acknowledgement Type of funding source: None

Evaluation of Impact of Factors Affecting CT Radiation Dose for Optimizing Patient Dose Levels

The dose metrics and factors influencing radiation exposure for patients undergoing head, chest, and abdominal computed tomography (CT) scans were investigated for optimization of patient dose levels. The local diagnostic reference levels (DRLs) of adult CT scans performed in our hospital were established based on 28,147 consecutive examinations, including 5510 head scans, 9091 chest scans, and 13,526 abdominal scans. Among the six CT scanners used in our hospital, four of them are 64-slice multi-detector CT units (MDCT64), and the other two have detector slices higher than 64 (MDCTH). Multivariate analysis was conducted to evaluate the effects of body size, kVp, mAs, and pitch on volume CT dose index (CTDIvol). The local DRLs expressed in terms of the 75th percentile of CTDIvol for the head, chest, and abdominal scans performed on MDCT64 were 59.32, 9.24, and 10.64 mGy, respectively. The corresponding results for MDCTH were 57.90, 7.67, and 9.86 mGy. In regard to multivariate analysis, CTDIvol showed various dependence on the predictors investigated in this study. All regression relationships have coefficient of determination (R2) larger than 0.75, indicating a good fit to the data. Overall, the research results obtained through our workflow could facilitate the modification of CT imaging procedures once the local DRLs are unusually high compared to the national DRLs.

Quantitative Analysis of the Deltoid Ligament Degradation in Chronic Ankle Instability Patients using the CT Value

Category:Ankle; OtherIntroduction/Purpose:Chronic lateral ankle instability (CLAI) that is developed after multiple lateral ankle ligament injury lead to ankle osteoarthritis. Although isolated deltoid ligament injury is rare compared to lateral ankle ligament injury, deltoid ligament tear, especially deep posterior tibiotalar ligament (PTT) can be observed arthroscopically in CLAI patients. Unphysiological loading of the ankle joint with CLAI might cause degradation of the deltoid ligament. This study aimed to investigate image findings of the deltoid ligament using computed tomography (CT) value for quantitative analysis of degenerative ligament changes in CLAI patients.Methods:Among the enrolled patients who underwent ankle magnetic resonance imaging (MRI) and CT scans of the ankle, this retrospective analysis included 24 ankles without ankle osteoarthritis, osteochondral lesion of the talus (OLT), flatfoot and ankle fractures (14 males and 10 females; mean age, 42.8 years) as a control group, and 14 CLAI ankles without OLT (7 males and 7 females; mean age, 31.1 years) as CLAI group. The CT scans were performed using a 64-slice multidetector row CT. Deep PTT was detected on coronal T2-weighted MR images. Both the coronal MR and CT images were matched for analysis, then average CT values were measured using the region of interest that was applied to the detected area of deep PTT on the CT images.Spearman’s correlation coefficient was used to evaluate the correlation between age and CT value in the control group.Results:The strong negative correlation was identified between age and CT value in the control group (Spearman ρ= -0.88; p< 0.001). The CT value of the deep PTT are degraded with aging. Mean CT value of deep PTT in participants under 60 years old were 79.9 HU (95% CI, 75.1-84.8) in the control group (18 ankles), and 66.5 HU (95% CI, 58.6-74.5) in the CLAI group (14 ankles) (Welch’s t test; p = 0.005).Conclusion:MRI techniques and protocols recently have been developed, however, some limitations remain such as a quantitative evaluation of the ligament. Our findings suggest that the CLAI can lead to degradation of the deltoid ligament via an overloading of medial ankle structures. Additionally, CT values should be useful for quantitatively evaluating ligament status including degenerative changes.

Preoperative evaluation of the segmental artery by three-dimensional image reconstruction vs. thin-section multi-detector computed tomography.

Background“Exoview” is a three-dimensional (3D) image reconstruction software developed by our medical team independently. The aim of this retrospective study was to compare the use of 3D image reconstruction, and thin-section multi-detector computed tomography (MDCT) in the preoperative evaluation of the segmental artery (SA).MethodsFrom May 2018 to May 2019, 52 patients received anatomical segmentectomy in our department. All patients received computed tomography pulmonary angiography (CTPA) by use of a 64-slice MDCT before operation. Then the 2D CT data were converted into 3D format by use of Exoview. We compared the intraoperative findings of the SA branches with 3D images and thin-section MDCT.ResultsThe study cohort of 52 patients included 31 women and 21 men and the operative factors include operation time (148.75±53.56 min), blood loss (57.31±79.68 mL), postoperative hospitalization days (6.42±3.48 days), lymph node sampling (3.00±1.50 stations) and postoperative complications (5 patients, 10%). The adenocarcinoma in situ with microinvasion was the predominant type (25 cases, 48%). There were 7 patients accepted for video-assisted thoracoscopic surgery (VATS) lobectomy with radical lymph nodes dissection because invasive adenocarcinoma was confirmed by intraoperative frozen-section analysis. One other patient was confirmed for conversion from VATS segmentectomy to an open operation because of bleeding of the bronchial artery. According to intraoperative findings, 95.7% (132 of 138) and 100% (138 of 138) of these SA branches were precisely identified on preoperative 3D image reconstruction and thin-section MDCT images. The 6 missed branches were less than 1.4 mm in actual diameter.ConclusionsBoth 3D image reconstruction and thin-section MDCT provided precise preoperative information about SA. The 3D image reconstruction software “Exoview” could visualize SA for surgeons. However, the thin-section MDCT provided a better evaluation of small SA branches.

Unclassified variants of hepatic artery discovered on a 40 slice multidetector CT scanner

CT angiography is a common modality used to study the anatomy of hepatic arterial system. Literature reports various unclassified variants of hepatic artery, which prompted us to take this study to see the same in our cohort of population. CT angiograms were performed using 40 slice CT scanner on 110 patients for the investigation of arterial variants in case of hepatic donors and patients for aortic evaluation with angiography. The Results were analyzed as per Michels as well as Modified Michels / Hiatt classification of Hepatic artery variants. The typical/classical most common anatomy (type I variant) as proposed by Michels in 1955, was Right and left hepatic artery arising from common hepatic artery which is a branch of celiac artery. In our study we did not find any type X variant and more so vascular anatomy in 5 patients (8%) did not fit into Michels' classification or Modified Michels/Hiatt classification. These variants have not been reported before, and its importance lies in the fact that variants can predispose to increased risk of surgical complications during liver transplantation and hepatobiliary surgery. It may also influence the choice of vascular technique and materials used in interventional procedures.

Evaluation of Ultra-High-Resolution Cone-Beam CT Prototype of Twin Robotic Radiography System for Cadaveric Wrist Imaging

Cone-beam CT (CBCT) applications possess potential for dose reduction in musculoskeletal imaging. This study evaluates the ultra-high-resolution CBCT prototype of a twin robotic X-ray system in wrist examinations compared to high-resolution multidetector CT (MDCT). Sixteen wrists of body donors were examined with the CBCT scan mode and a 384 slice MDCT system. Radiation-equivalent low-dose (CTDIvol(16cm) = 3.3 mGy) and full-dose protocols (CTDIvol(16cm) = 13.8 mGy) were used for both systems. Two observers assessed image quality on a seven-point Likert scale. In addition, software-assisted quantification of signal intensity fractions in cancellous bone was performed. Fewer pixels with intermediate signal intensity were considered to indicate superior depiction of bone microarchitecture. Subjective image quality in CBCT was superior to dose equivalent MDCT with p ≤ 0.03 for full-dose and p < 0.001 for low-dose scans, respectively. Median Likert values were 7/7 (reader 1 / reader 2) in full-dose CBCT, 6/6 in full-dose MDCT, 5/6 in low-dose CBCT and 3/3 in low-dose MDCT. Intraclass correlation coefficient was 0.936 (95% confidence interval, 0.897-0.961; p < 0.001), indicating excellent reliability. Objective analysis displayed smaller fractions of "indecisive" pixels with intermediate signal intensity for full-dose CBCT (0.57 [interquartile range 0.13]) compared to full-dose MDCT (0.68 [0.21]), low-dose CBCT (0.72 [0.19]), and low-dose MDCT (0.80 [0.15]) studies. No significant difference was observed between low-dose CBCT and full-dose MDCT. The new CBCT prototype provides superior image quality for trabecula and bone marrow in cadaveric wrist studies and enables dose reduction up to 75% compared to high-resolution MDCT.

Pericardial adiposity versus body adiposity measured by BMI in the assessment of coronary atherosclerosis burden in patients with hypertension

ABSTRACT Objectives The link between obesity and hypertension with coronary atherosclerosis is complex. We aimed to assess the association of cardiac fat deposition measured by pericardial fat volume(PFV) using by multi-detector CT(MDCT) and general obesity measured by BMI with subclinical coronary atherosclerotic markers (coronary artery calcium score (CAC), coronary plaque and stenosis) in patients with hypertension and suspected coronary artery disease. Methods Among 496 patients presenting with chest pain who underwent 64-slice MDCT angiography to exclude occlusive coronary disease, 261 patients with hypertension (age: 57 ± 8 years, 45% males) enrolled in the present study. Results PFV showed a significant association with CAC(r = 0.2,P = .001),coronary stenosis severity(PFV median(IQR) 88(63–161) in patients with coronary stenosis<50% compared to PFV median(IQR) 125(85–140) in patients with coronary stenosis ≥ 50%, P = .001) and coronary plaque presence (PFV median (IQR) 89(65–128) in patients without plaque compared to PFV median (IQR) 115(74–150) in patients with plaque presence = 0.03).the significant association of PFV with CAC[odds ratio(95% confidence interval = 0.5(0.19–0.97),P = .001] and coronary stenosis severity [odds ratio(95% confidence interval = 1.1(1.00–1.01),P = .01]persisted after adjustment for conventional cardiac risk. BMI showed a significant association with significant coronary stenosis presence (P = .02).The association of BMI with significant coronary stenosis presence after adjustment for conventional cardiac risk factors (P = .03).BMI showed no significant association with CAC and coronary plaque presence (P > .05). Conclusion PFV showed a significant independent association with coronary calcification and significant coronary stenosis in patients with hypertension rather than BMI.