Comprehensive Computed Tomography Research Articles

Computed Tomography Scan Correlation of Position of Appendix with Present Literature

Abstract Background The appendix exhibits varied anatomical orientations, which significantly influence the diagnosis and treatment of appendicitis. Existing literature predominantly relies on cadaveric studies to delineate common appendix positions, lacking comprehensive computed tomography (CT)-based investigations on a large scale. Thus, our study endeavors to delineate the prevailing position of the appendix on CT scans and ascertain its concordance with existing literature, thereby augmenting our understanding of this anatomical entity. This cross-sectional study was conducted in a tertiary care hospital setting. Materials and Methods A total of 1,068 patients aged 18 years and older, undergoing abdominal CT scans at the hospital between July 2020 and July 2021, were enrolled in the study, with exclusion criteria applied to conditions that could distort anatomical features. The position of the appendix was meticulously documented for each patient, alongside measurements including diameter, wall thickness, and origin. Data collection utilized a predefined Microsoft Excel sheet. Subsequently, numerical and relative frequencies were computed for appendiceal positions and origins. Additionally, diameter and wall thickness were assessed, and pertinent parameters were derived. Results The relative frequencies of various potential appendiceal positions observed in our study were as follows: subcecal: 6.6%; paracecal: 1.2%; pelvic: 21.9%; postileal: 32.9%; preileal: 6.7%; retrocecal: 28.5%; subhepatic: 2.2%. Conclusion In contrast to traditional assumptions, our findings reveal that the most prevalent positions of the appendix are postileal, retrocecal, and pelvic, challenging historical beliefs.

A multichannel analysis of imbalanced computed tomography data for lung cancer classification

Lung cancer holds the highest fatality rate among cancers, emphasizing the importance of early detection. Computer algorithms have gained prominence across various domains, including lung cancer diagnosis. These algorithms assist specialists, especially in medical imaging, yet current efforts lack comprehensive CT data analysis; especially in handling imbalanced datasets and fully exploiting spatial information. The lack of spatial analysis hinders the ability to identify subtle variations in texture and structure that are crucial for detecting lung cancer early and accurately. Therefore, this study uses a multichannel analysis of computed tomography (CT) images and deep learning-based ensemble learning (MC-ECNN) to find lung cancer even when the data is not balanced. Firstly, the data imbalance issue is tackled through the synthetic minority oversampling technique (SOMTE); afterwards, a multi-channel analysis of the data is performed to explore a distinct set of abstract features. Lastly, a deep ensemble learning method is used to classify the extracted distinct abstract feature set into the appropriate classes. The proposed method uses the discrete Fast Fourier transform (DFFT) and discrete cosine transform (DCT), along with the actual CT scans, for the multi-channel analysis of the data in different domains. The proposed model yielded 99.60% test accuracy on unseen data, which is at least 3% better than the other state-of-the-art studies considered for the comparison. In addition to the classification accuracy, the efficacy of the proposed model has also been justified through precision, recall, F1-score, support value, and misclassification rate.

BOA: A CT-Based Body and Organ Analysis for Radiologists at the Point of Care.

The study aimed to develop the open-source body and organ analysis (BOA), a comprehensive computed tomography (CT) image segmentation algorithm with a focus on workflow integration. The BOA combines 2 segmentation algorithms: body composition analysis (BCA) and TotalSegmentator. The BCA was trained with the nnU-Net framework using a dataset including 300 CT examinations. The CTs were manually annotated with 11 semantic body regions: subcutaneous tissue, muscle, bone, abdominal cavity, thoracic cavity, glands, mediastinum, pericardium, breast implant, brain, and spinal cord. The models were trained using 5-fold cross-validation, and at inference time, an ensemble was used. Afterward, the segmentation efficiency was evaluated on a separate test set comprising 60 CT scans. In a postprocessing step, a tissue segmentation (muscle, subcutaneous adipose tissue, visceral adipose tissue, intermuscular adipose tissue, epicardial adipose tissue, and paracardial adipose tissue) is created by subclassifying the body regions. The BOA combines this algorithm and the open-source segmentation software TotalSegmentator to have an all-in-one comprehensive selection of segmentations. In addition, it integrates into clinical workflows as a DICOM node-triggered service using the open-source Orthanc research PACS (Picture Archiving and Communication System) server to make the automated segmentation algorithms available to clinicians. The BCA model's performance was evaluated using the Sørensen-Dice score. Finally, the segmentations from the 3 different tools (BCA, TotalSegmentator, and BOA) were compared by assessing the overall percentage of the segmented human body on a separate cohort of 150 whole-body CT scans. The results showed that the BCA outperformed the previous publication, achieving a higher Sørensen-Dice score for the previously existing classes, including subcutaneous tissue (0.971 vs 0.962), muscle (0.959 vs 0.933), abdominal cavity (0.983 vs 0.973), thoracic cavity (0.982 vs 0.965), bone (0.961 vs 0.942), and an overall good segmentation efficiency for newly introduced classes: brain (0.985), breast implant (0.943), glands (0.766), mediastinum (0.880), pericardium (0.964), and spinal cord (0.896). All in all, it achieved a 0.935 average Sørensen-Dice score, which is comparable to the one of the TotalSegmentator (0.94). The TotalSegmentator had a mean voxel body coverage of 31% ± 6%, whereas BCA had a coverage of 75% ± 6% and BOA achieved 93% ± 2%. The open-source BOA merges different segmentation algorithms with a focus on workflow integration through DICOM node integration, offering a comprehensive body segmentation in CT images with a high coverage of the body volume.

Constrictive pericarditis with massive pericardial effusion.

A 27-year-old man was admitted to our hospital for the investigation of pericardial effusion (PE) and ascites. Despite the accumulation of excessive pericardial fluid, vital signs of cardiac tamponade were not observed. He had no prior medical history except for a blunt chest trauma 10 years earlier. Echocardiography showed a tiny heart in extraordinarily retained massive PE (panel A, Supplementary data online, Video S1). Computed tomography (CT) revealed a distended overfilling pericardial cavity that remarkably compressed his heart and lung (panels B and C). Magnetic resonance imaging showed a thickened pericardium and a respiratory septal bounce phenomenon (see Supplementary data online, Video S2). Heart catheterization followed by a pericardial drainage of gigantic 6500 mL amount of exudative fluid suggested constrictive property of diastolic square root sign in left and right ventricular simultaneous pressure tracings (panel D). He was diagnosed with effusive–constrictive pericarditis. Despite the removal of pericardial fluid and the treatment with anti-inflammatory medications, the underlying pericardial constricted property continued to cause symptoms. He underwent a surgical removal of the thickened pericardium uneventfully (panel E). Further analysis of the volume of the thoracic cavity utilizing a comprehensive 3D-rendered CT revealed a significantly greater pre-operative volume of 9569 mL compared with the post-operative volume of 5903 mL (panel F, Supplementary data online, Video S3). This is the first report to suggest that the compensative and elastic ability of both the thoracic and pericardial cavities plays a role in protecting hemodynamics in effusive–constrictive pericarditis.

Development of the sphenoid sinus from newborn to age 18: A computed tomography imaging analysis

The sphenoid sinus (SS) is an important anatomical formation in terms of its location and relationship with important neurovascular structures. It is essential to evaluate the pneumatization and dimensions of the SS with Computed Tomography (CT) in the preoperative period of transsphenoidal interventions to be performed on tumors located in this region. The aim of this study was to evaluate the correlation of the volume and dimensions of the SS measured with CT with age in the period from birth to 18 years of age. In this retrospective study, a total of 360 brain, paranasal sinus, temporal bone and maxillofacial CT scans of individuals from birth to 18 years of age were evaluated. The cohort was divided into 18 groups with 20 (10 female, 10 male) patients in each age group. The height, width, length and volume values of the SS were measured on CT and their correlations with age and the differences between genders were evaluated statistically. It has been determined that the increases in the size and volume of the SS accelerate especially between 1 and 2 years of age and begins to reach adult dimensions after 12 years of age. Height and length of the sphenoid sinus showed a high correlation coefficient (r=0.717 and r=0.731 respectively) with age, while its width and volume showed a moderate correlation coefficient (r=0.662 and 0.543 respectively). There was no statistically significant difference between the genders in terms of SS height, width, length and volume. SS dimensions and volume showed a logaritmic growth pattern from birth to 18 years. The results of this study may help to better understand the normal development of SS in children and may serve as a reference for more comprehensive CT studies. In addition, it can help surgeons to evaluate the developmental characteristics of SS in surgical interventions for SS in children.

Anatomy of Cerebral Arteries with Clinical Aspects in Patients with Ischemic Stroke

Computed tomography (CT) angiography is the main method for the initial evaluation of cerebral circulation in acute stroke. A comprehensive CT examination that includes a review of the three-dimensional and maximum-intensity projection images of the main intra and extracranial arteries allows the identification of most abnormalities and normal variants. Anatomical knowledge of the presence of any normal variants, such as fenestration, duplications, and persistent fetal arteries, plays a crucial role in the diagnosis and therapeutic management of acute stroke. However, the opposite is also true. In fact, sometimes it is the clinical picture that allows weighing how relevant or not the alteration found is. Therefore, in this review, a concise representation of the clinical picture attributable to a given arterial vessel will be included.

Evaluation of cardiovascular morphology and associated anomalies in patients with crossed pulmonary arteries on multidetector computed tomography angiography.

The present study sought to study morphology and associated cardiovascular anomalies in patients with crossed pulmonary arteries on multidetector computed tomography (CT) angiography. We retrospectively evaluated all CT angiography studies performed at a tertiary medical center from January2014 to December2021 to identify patients with crossed pulmonary arteries. The associated cardiovascular anomalies as identified on CT angiography were evaluated. Out of 4773 patients who had undergone CT angiography for evaluation of congenital heart diseases, we identified 24 (0.5%) patients (18 males; mean age: 7.7 years) with crossed pulmonary arteries. Tetralogy of Fallot was associated in seven (29.17%) patients, double outlet right ventricle in one (4.17%) patient, and common arterial trunk in four (16.67%) patients. An aortopulmonary window was seen in three (12.5%) patients while atrial septal defect and ventricular septal defect were seen in two (8.33%) and 16 (66.67%) patients, respectively. Aortic arch anomalies were present in 16 (66.67%) patients including interrupted aortic arch and coarctation of aorta with hypoplastic aortic arch seen in two (8.33%) patients each. A double aortic arch with an atretic left arch was seen in one (4.17%) patient. Coronary artery anomalies were seen in three (12.5%) patients. Crossed pulmonary arteries are a rare anomaly and their presence suggests the coexistence of a variety of cardiovascular anomalies, including aortic arch anomalies and outflow tract malformations. Comprehensive CT angiography-based evaluation of cardiovascular morphology is imperative in the presence of crossed pulmonary arteries to facilitate presurgical planning.

Imaging characteristics and associations of left atrioventricular valve atresia and patent aortic root with lateralized atrial chambers on multidetector CT.

To study the imaging characteristics and the associations of left atrioventricular valve atresia with patent aortic root and lateralized atrial chambers on multidetector computed tomography (CT) angiography. We retrospectively evaluated all the CT angiography studies performed for the evaluation of various congenital heart diseases at our center from January 2014 to December 2021. Cases with left atrioventricular valve atresia and patent aortic root with lateralized atrial chambers were identified. The types of cardiovascular involvement as identifiable on CT angiography were studied and compiled. A total of 38 patients with left atrioventricular valve atresia and patent aortic root were included (median age: 5 months, males: 31). A total of 89.5% had usual atrial arrangement and 10.5% had mirror imagery of atria. Normal drainage of right and left superior caval veins and inferior caval vein into systemic venous atrium was seen in 77.8%, 61.5%, and 86.6%, respectively. Anomalous pulmonary venous drainage was seen in 3 (7.9%) patients. Atrial and ventricular septal defects were the most common associations. Imperforate left atrioventricular membrane was seen in 9 (23.7%) patients and absent left atrioventricular connection in 27 (71.1%). Discordant right atrioventricular connection was seen in 5 (13.1%) patients. While a double outlet right ventricle (76.3%) was the most common ventriculoarterial connection, discordant ventriculo-arterial connection (transposition) in 4 (10.5%). Most patients had good sized pulmonary arteries. Patent arterial duct and right aortic arch were seen in 29% and 21%, respectively. Aberrant right subclavian artery was the most common arch vessel anomaly. Coronary anomalies were seen in 7 patients (19%); single coronary artery being the most common. Majority of the patients with left atrioventricular valve atresia and patent aortic root with lateralized atrial chambers have usual atrial arrangement, normal right atrioventricular connections and a double outlet configuration of the right ventricle. Absent left atrioventricular connection is a more common than imperforate left atrioventricular valve membrane. Atrial and ventricular septal defects are the most common associations. Comprehensive CT based evaluation of vascular and nonvascular thoracic structures is imperative before surgery or interventions in patients with mitral atresia.

Balloon-Expandable Valve Geometry After Transcatheter Aortic Valve Replacement in Low-Risk Patients With Bicuspid Versus Tricuspid Aortic Stenosis

BackgroundProspective bicuspid low-risk transcatheter aortic valve replacement (TAVR) registries' data demonstrated encouraging short-term results. Detailed data on transcatheter heart valve (THV) geometry after deployment using contemporary devices are lacking. This study sought to examine valve geometry after TAVR in patients with bicuspid aortic stenosis (AS). MethodsThe study population was patients from the LRT (Low Risk TAVR) trial who underwent TAVR using the SAPIEN 3 THV for bicuspid and tricuspid AS. THV geometry measured on 30-day computed tomography (CT) included valve height, angle, depth, and eccentricity. Additionally, THV hemodynamics and outcomes post-TAVR were compared among patients with bicuspid and tricuspid AS. ResultsA total of 107 patients from the LRT trial using the SAPIEN 3 THV were included in our analysis. On 30-day CT, the valve height ratio (1.07 vs. 1.07; p = 0.348), depths (right [5.6 mm vs. 6.2 mm; p = 0.223], left [5.3 mm vs. 4.4 mm; p = 0.082] and non [4.8 mm vs. 4.5 mm; p = 0.589] coronary cusps), eccentricities (1.08 vs. 1.07; p = 0.9550), and angles (except the right [3.9 degrees vs. 6.3 degrees; p = 0.003] and left [3.6 degrees vs. 6.0 degrees; p = 0.007]) were similar between bicuspid and tricuspid patients. Hemodynamics, stroke, and mortality were similar at 1 year. ConclusionDespite challenging bicuspid anatomy of the aortic valve, our comprehensive CT analysis supports similar THV geometry between patients with bicuspid and tricuspid AS undergoing TAVR using the SAPIEN 3 THV in low-risk patients. This translated to excellent short-term clinical outcomes and THV hemodynamics in both aortic valve morphologies. Trial registryNCT02628899, https://clinicaltrials.gov/ct2/show/NCT02628899.

Value of CT Imaging in the Differentiation of Gastric Leiomyoma From Gastric Stromal Tumor.

To discuss significant computed tomography (CT) findings that differentiate gastric leiomyomas (GLs) from small gastric stromal tumors (GSTs). One hundred sixty cases with pathologically proven GLs (n = 50) and GSTs (n = 110) with comprehensive CT images were enrolled in this retrospective study. Computed tomography findings (ie, size, location, contour, growth pattern, enhancement degree, necrosis, ulceration, calcification, and lymph nodes) were analyzed through the χ2 or Fisher exact test, independent T test, and multivariate (logistic regression) analysis. Sensitivity and specificity were also calculated. Features of cardia location, endophytic growth, homogeneous gradual enhancement, absent of necrosis, long diameter less than 24 mm, short diameter less than 20 mm, unenhanced CT value larger than 35.2 Hounsfield units (HU), portal venous phase CT value larger than 67.4 HU, and enhancement degree of arterial and venous phase less than 16.2 HU and 32.4 HU were found to be statistically significant between GLs and small GSTs (P < .05). On multivariate analysis, cardia location, endophytic growth, and homogeneous gradual enhancement were independent predictive factors for GLs and small GSTs. These 10 CT criteria are very helpful to differentiate GLs from small GSTs. Especially cardia location, endophytic growth, and homogeneous gradual enhancement are of high value in differential diagnosis.

Computed tomography-derived left atrial volume index, sex, and age to predict the presence and the extent of left atrial low-voltage zones in patients with atrial fibrillation: The ZAQ score.

Pulmonary vein isolation is the cornerstone of catheter ablation in patients with atrial fibrillation (AF). However, with advanced left atrial (LA) structural changes, additional targeted catheter ablation of low-voltage zones (LVZs) has produced favorable results. Therefore, with the advent of single-shot techniques, it would be helpful to predict the presence of LVZs before an ablation procedure. We hypothesized that computed tomography (CT)-derived left atrial volume index (LAVI), in combination with other objective parameters, could be used to develop a score able to predict the presence of LVZs. In a large cohort of patients undergoing their first AF ablations, comprehensive echocardiographic evaluations and cardiac CT were performed. During the electrophysiological studies, LA geometry and electroanatomic voltage maps were created. LVZs were defined as areas ≥1 cm2 with bipolar peak-to-peak voltage amplitudes ≤0.5 mV. In a derivation cohort of 374 patients, predictors of LVZs were identified by regression analysis and used to build the Zentralklinik Bad Berka and University of L'Aquila (ZAQ) score (age ≥65 years; female sex; and CT-LAVI ≥57 mL/m2 ). The ZAQ score of 2 points accurately identified the presence and the extent of LVZs (area under the curve [AUC], 0.809; 95% confidence interval [CI], 0.758-0.861; P < .001 and 3 [interquartile range, IQR, 1.5-4.5] vs 7 cm2 [IQR 4-9]; P = .001). In a validation cohort of 103 patients, the predictive value of the score was confirmed (AUC, 0.793; 95% CI, 0.709-0.878; P < .001 and 4 [IQR, 2-7] vs 11.5 cm2 [IQR, 8-16.5]; P = .001). The ZAQ score identifies LVZs and may be useful for planning the ablation strategy ahead of time.

CT texture analysis for the prediction of KRAS mutation status in colorectal cancer via a machine learning approach

PurposeThis study aimed to investigate whether a machine learning-based computed tomography (CT) texture analysis could predict the mutation status of V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) in colorectal cancer. MethodThis retrospective study comprised 40 patients with pathologically confirmed colorectal cancer who underwent KRAS mutation testing, contrast-enhancement CT, and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) before treatment. Of the 40 patients, 20 had mutated KRAS genes, whereas 20 had wild-type KRAS genes. Fourteen CT texture parameters were extracted from portal venous phase CT images of primary tumors, and the maximum standard uptake values (SUVmax) on 18F-FDG PET images were recorded. Univariate logistic regression was used to develop predictive models for each CT texture parameter and SUVmax, and a machine learning method (multivariate support vector machine) was used to develop a comprehensive set of CT texture parameters. The area under the receiver operating characteristic (ROC) curve (AUC) of each model was calculated using five-fold cross validation. In addition, the performance of the machine learning method with the CT texture parameters was compared with that of SUVmax. ResultsIn the univariate analyses, the AUC of each CT texture parameter ranged from 0.4 to 0.7, while the AUC of the SUVmax was 0.58. Comparatively, the multivariate support vector machine with comprehensive CT texture parameters yielded an AUC of 0.82, indicating a superior prediction performance when compared to the SUVmax. ConclusionsA machine learning-based CT texture analysis was superior to the SUVmax for predicting the KRAS mutation status of a colorectal cancer.

Obesity and calcification of the ligaments of the spine: a comprehensive CT analysis of the entire spine in a random trauma population

Background ContextObesity, which is currently surging to epidemic levels within the United States, has been linked to hyperostotic conditions like diffuse idiopathic skeletal hyperostosis (DISH) and ossification of the posterior longitudinal ligament (OPLL). Excess adipose tissue and insulin-resistance may cause a systemic increase in serum levels of proinflammatory cytokines and these signals can affect bone metabolism. Spinal ligaments and discs may have receptors for these signaling molecules. Anecdotal observations at this institution suggested that there is a clinically important subset of younger patients with obesity and multilevel stenosis in the presence of unusual calcification of the spinal ligaments that is distinct from DISH. PurposeTo determine if there is an association between truncal obesity and calcifications of the spine in nonelderly adults. Study Design/SettingThis is a retrospective analysis of 214 sequential trauma patients between the ages of 29 and 50. Patients’ age, sex, truncal obesity, history of hypertension, and diabetes were assessed for association with ligamentous calcification of the spine. Patient SampleSequential trauma patients were chosen from our institution's trauma database between 2006 and 2007. MethodsFull spine computed tomography (CT) imaging was examined for bone formation in the region of the anterior longitudinal ligament (ALL) and annulus, posterior longitudinal ligament (PLL) and annulus, and the ligamentum flavum (LF). Visceral and subcutaneous abdominal fat were also evaluated. The authors report no study funding sources or conflicts of interest. Outcome MeasuresCalcification of the ALL, PLL, and LF were assigned a score at each level and then combined for a total calcification score (TCS) for the entire spine. Obesity was estimated using a truncal body mass index (TBMI) by using a previously validated CT derived truncal total adiposity volume (TAV). ResultsALL calcification was associated with age, male gender, hypertension, and increased adiposity. PLL calcification was significantly associated with age and hypertension. LF calcification was only associated with increased obesity. ConclusionsIn our analysis of nonelderly patients, LF calcification was independently associated with truncal obesity. This implies obesity plays a greater role in calcification than could be accounted for by simply age-related degeneration or gender.

Three-Dimensional Computed Tomographic Characterization of Normal Anatomic Morphology and Variations of the Distal Tibiofibular Syndesmosis

Malreduction of distal tibiofibular syndesmosis (DTFS) leads to poor functional outcomes after ankle fracture surgery. Difficulty achieving anatomic alignment of the syndesmosis is due to variable morphology of the fibular incisura of the tibia and a paucity of literature regarding its morphologic characteristics. We surveyed 775 consecutive ankle computed tomography (CT) scans performed from June 2008 to December 2011, and 203 (26.2%) were included for evaluation. Two observers performed quantitative measurements and qualitative evaluated fibular incisura morphology. Tang ratios for fibular rotation, anterior and posterior tibiofibular distances, fibular incisura depth, and subjective morphologies on CT were assessed using conventional multiplanar reconstruction (MPR) and maximum intensity projections (MIPs). On conventional CT, the mean Tang ratio was 0.97 ± 0.06; the mean anterior tibiofibular distance was 2.17 ± 0.87 mm; the mean posterior tibiofibular distance was 3.52 ± 0.94 mm; and the mean depth of fibular incisura was 3.29 ± 1.19 mm. Five morphologic variations of the fibular incisura were identified: crescentic, trapezoid, flat, chevron, and widow's peak. The most common fibular incisura morphology was crescentic (61.3%), followed by trapezoid shape (25.1%); the least common morphology was flat (3.1%). Interobserver variability with intraclass correlation coefficient (ICC) was slightly higher for all quantitative measures on MPR (ICC = 0.72 to .81) versus MIP (ICC = 0.64 to 0.75). ICC for incisura shape and depth assessments was poor on both modalities (0.13 to 0.38). This comprehensive CT study reports on quantitative and qualitative descriptive measures to evaluate fibular incisura morphologies and fibular orientation. It also defines the frequency of DTFS measures and the interobserver performance on 2 CT evaluation methods.

COMPUTED TOMOGRAPHY AS A COMPONENT OF PREOPERATIVE PLANNING FOR METAL TRANSITIONAL SPINE FIXATION IN THE CORRECTION OF SCOLIOTIC DEFORMITIES BY HYBRID CONSTRUCTS

Objective:to assess whether computed tomography (CT) data can be used for metal transitional spine fixation in patients with thoracic and thoracolumbar scoliosis at the stage of surgical intervention planning.Material and methods.Thirty-nine patients with grades 3 and 4 (according to V.D. Chaklin) or type I–III (according to the classification proposed by L. Lenke) thoracic and thoracolumbar idiopathic scoliosis were examined. All the patients underwent a comprehensive radiographic and CT examinations. The radiomorphometric features of the spine were used to plan surgical interventions.Results.The protocol was clarified for preoperative scoliosis examination using CT data on cervicothoracic and thoracolumbar vertebrae. A personalized approach to planning an operation on the basis of CT examination permits one to eliminate destabilization of the supporting elements of the corrective system at the most. Reducing the risk of postoperative losses of correction contributes to the use of multi-rod constructs.Conclusion.CT that enables a comprehensive assessment of existing pathology and clarification of the nature of impending surgery should be carried out in patients with thoracic and thoracolumbar idiopathic scoliosis at the stage of preoperative planning for metal transitional spine fixation.

Tissue is more important than time: insights into acute ischemic stroke from modern brain imaging.

The clinical practice of acute ischemic stroke treatment has undergone a major change over the last 5 years, as multimodal imaging becomes more accessible, and evidence mounts that individualized treatment is possible. Multimodal imaging performed before treatment provides invaluable information to treating clinicians, which includes confirmation of the diagnosis, and provides guidance on the appropriateness and the likely outcome of intravenous or endovascular treatment for individual patients (and their families). However, often health systems struggle to keep pace with science; thus, a one-size fits all protocol-driven basic imaging approach is still the norm in many stroke centers. Comprehensive multimodal computed tomography (CT) (incorporating noncontrast CT, CT angiography, and perfusion CT) provides rapid, reliable information about stroke pathophysiology that cannot be provided by more limited imaging prior to treatment. Multimodal CT identifies treatment responders for both intravenous thrombolysis and endovascular therapy. Now we are in the era of thrombectomy, the use of multimodal imaging routinely to guide treatment can no longer be avoided. In light of the ground breaking thrombectomy trial results and previous studies validating the use of multimodal imaging, there is now a strong rationale for performing comprehensive multimodal CT assessments before treatment as a standard of care for all stroke patients.

Cost effectiveness of the addition of a comprehensive CT scan to the abdomen and pelvis for the detection of cancer after unprovoked venous thromboembolism

ImportanceUnprovoked venous thromboembolism (VTE) can be the first manifestation of cancer. It is unclear if extensive screening for occult cancer including a comprehensive computed tomography (CT) scan of the abdomen/pelvis is cost-effective in this patient population. ObjectiveTo assess the health care related costs, number of missed cancer cases and health related utility values of a limited screening strategy with and without the addition of a comprehensive CT scan of the abdomen/pelvis and to identify to what extent testing should be done in these circumstances to allow early detection of occult cancers. Participants and settingCost effectiveness analysis using data that was collected alongside the SOME randomized controlled trial which compared an extensive occult cancer screening including a CT of the abdomen/pelvis to a more limited screening strategy in patients with a first unprovoked VTE, was used for the current analyses. Main outcomes and measuresAnalyses were conducted with a one-year time horizon from a Canadian health care perspective. Primary analysis was based on complete cases, with sensitivity analysis using appropriate multiple imputation methods to account for missing data. ResultsData from a total of 854 patients with a first unprovoked VTE were included in these analyses. The addition of a comprehensive CT scan was associated with higher costs ($551 CDN) with no improvement in utility values or number of missed cancers. Results were consistent when adopting multiple imputation methods. Conclusions and relevanceThe addition of a comprehensive CT scan of the abdomen/pelvis for the screening of occult cancer in patients with unprovoked VTE is not cost effective, as it is both more costly and not more effective in detecting occult cancer.

Screening for Occult Cancer in Unprovoked Venous Thromboembolism

BackgroundVenous thromboembolism may be the earliest sign of cancer. Currently, there is a great diversity in practices regarding screening for occult cancer in a person who has an unprovoked venous thromboembolism. We sought to assess the efficacy of a screening strategy for occult cancer that included comprehensive computed tomography (CT) of the abdomen and pelvis in patients who had a first unprovoked venous thromboembolism.MethodsWe conducted a multicenter, open-label, randomized, controlled trial in Canada. Patients were randomly assigned to undergo limited occult-cancer screening (basic blood testing, chest radiography, and screening for breast, cervical, and prostate cancer) or limited occult-cancer screening in combination with CT. The primary outcome measure was confirmed cancer that was missed by the screening strategy and detected by the end of the 1-year follow-up period.ResultsOf the 854 patients who underwent randomization, 33 (3.9%) had a new diagnosis of occult cancer between randomization and the 1-year follow-up: 14 of the 431 patients (3.2%) in the limited-screening group and 19 of the 423 patients (4.5%) in the limited-screening-plus-CT group (P=0.28). In the primary outcome analysis, 4 occult cancers (29%) were missed by the limited screening strategy, whereas 5 (26%) were missed by the strategy of limited screening plus CT (P=1.0). There was no significant difference between the two study groups in the mean time to a cancer diagnosis (4.2 months in the limited-screening group and 4.0 months in the limited-screening-plus-CT group, P=0.88) or in cancer-related mortality (1.4% and 0.9%, P=0.75).ConclusionsThe prevalence of occult cancer was low among patients with a first unprovoked venous thromboembolism. Routine screening with CT of the abdomen and pelvis did not provide a clinically significant benefit. (Funded by the Heart and Stroke Foundation of Canada; SOME ClinicalTrials.gov number, NCT00773448.)

Low-Volume Contrast Medium Protocol for Comprehensive Cardiac and Aortoiliac CT Assessment in the Context of Transcatheter Aortic Valve Replacement

To investigate the diagnostic performance of a comprehensive computed tomography (CT) protocol for both cardiac and aortoiliac evaluation of patients considered for transcatheter aortic valve replacement (TAVR) using a single, low-volume contrast medium (CM) injection. Forty-four TAVR candidates were retrospectively analyzed. All underwent retrospectively electrocardiogram-gated cardiac CT followed by high-pitch CT angiography of the aortoiliac vasculature using one of two single injection protocols of 320 mgI/mL iodine CM: group A (n = 22), iodine delivery rate-based (1.28 gI/s), 60-mL CM volume, 4.0 mL/s flow rate; group B (n = 22), clinical routine protocol, 100-mL CM volume, 4.0 mL/s flow rate. Mean arterial attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Subjective image quality was assessed. Aortic root and iliofemoral dimensions could be analyzed in all cases. Patient characteristics showed no significant differences. Mean attenuation at the levels of the aortic root (285.8 ± 83.0 HU vs 327.5 ± 70.8 HU, P = .080) and the iliofemoral access route (256.8 ± 88.5 HU vs 307.5 ± 93.2 HU, P = .071), as well as SNR and CNR were nonsignificantly lower in group A compared to group B. Subjective image quality was equivalent. In multimorbid TAVR patients, the performance of a combined CT protocol using a single low-volume CM bolus is feasible with maintained image quality compared to a standard protocol.

IMPACT OF BICUSPID VERSUS TRICUSPID AORTIC VALVE PHENOTYPE ON THE RELATIONSHIP BETWEEN AORTIC VALVE CALCIFICATION MEASURED BY CT AND THE DOPPLER-ECHOCARDIOGRAPHIC PARAMETERS OF AORTIC STENOSIS SEVERITY -PROGRESSA STUDY

Up to 30% of the patients with aortic stenosis (AS) and preserved LV ejection fraction (LVEF) have a discrepancy among the echocardiographic parameters of stenosis severity, the most frequent being an aortic valve area (AVA) < 1.0 cm2 consistent with severe stenosis and mean gradient (MG) < 40 mm Hg consistent with non-severe stenosis. Measurement of aortic valve calcification (AVC) by computed tomography (CT) correlates well with echocardiographic parameters of AS severity and it has been shown to be useful to corroborate stenosis severity in patients with discordant grading at echocardiography. However, the impact of the aortic valve phenotype (i.e. bicuspid vs. tricuspid) on this relationship between AVC and hemodynamic severity of AS remains unknown. The aims of this study were to evaluate relationship and concordance between echocardiographic and CT parameters of AS severity, with respect to aortic valve phenotype. 188 patients with AS and preserved LVEF were prospectively recruited in the PROGRESSA study (Clinical Trial register: NCT01679431) and underwent a comprehensive Doppler-echocardiography and CT scan. Echocardiographic parameters of AS severity included MG, AVA and indexed AVA (AVAi). AVC was determined by the Agatston method and indexed to the LV outflow tract area (i.e. AVC density: AVCd). The stenosis was considered severe when AVCd was ≥300 AU/cm2 in women and ≥500 AU/cm2 in men as previously described. AVCd correlated well with the echocardiographic parameters of stenosis severity (r>0.53; p<0.0001) in the patients with tricuspid valve but there was no significant correlation in the patients with a bicuspid valve (r<0.14; p>0.40). Of note, 5 of the 38 patients (13%) with a bicuspid valve had very low AVCd (<4 AU/cm2) despite the presence of at least moderate AS on echocardiography confirmed by several parameters including the gradient (MG>20mmHg). Although AVC measured by CT may be useful to corroborate stenosis severity in patients with discordant echocardiographic findings, this parameter should be used with caution in patients with a bicuspid valve given that it may yield to false negative result in about 10-15% of the cases.