Contrast-enhanced Multidetector Computed Tomography Images Research Articles

Evaluation of the performance of and interobserver agreement on postoperative baseline CT findings in the identification of locoregional recurrence in patients with pancreatic ductal adenocarcinoma.

To evaluate interobserver agreement on the findings of baseline contrast-enhanced multidetector computed tomography (CE-MDCT) performed at the postoperative third month in patients who underwent surgery due to ductal adenocarcinoma of the pancreatic head and investigate the value of these findings in predicting locoregional recurrence. The baseline CE-MDCT images of 198 patients who underwent the Whipple procedure due to pancreatic head tumors were evaluated independently by three radiologists at the postoperative third month. The radiologists were asked to note suspicious findings in terms of locoregional recurrence, including postoperative fat stranding, the presence of perivascular contrast-enhanced solid tissue, short diameter of solid tissue if present, the shape of solid tissue (convex/concave), presence of peritoneal implants, diameter (mm) of pancreatic duct dilatation if present, the presence of lymph nodes larger than 5 mm, portal vein stenosis (≥50 and <50%), the presence of ascites, and the presence of distant metastases, as specified by the Society of Abdominal Radiology in October 2022. The agreement between the radiologists and the value of these parameters in predicting locoregional recurrence were investigated. Among the CE-MDCT findings evaluated, the radiologists had a moderate-to-high level of agreement concerning the presence of perivascular contrast-enhanced solid tissue. However, there was a poor interobserver agreement on the shape of solid tissue. A very high level of agreement was found among the radiologists in the evaluation of pancreatic duct dilatation, peritoneal implants, ascites, and the presence of distant metastases. According to the univariate analysis, the rates of portal vein stenosis had a 1.419 -fold effect [odds ratio (OR)=1.419, [95% confidence interval (CI)= 0.548-3.679, p=0.041], lymph node presence had a 2.337 -fold effect [odds ratio (OR)=2.337, [95% confidence interval (CI)= 1.165-4.686, p=0.015], perivascular contrast-enhanced solid tissue had 2.241 -fold effect [odds ratio (OR)=2.241, [95% confidence interval (CI)= 1.072-4.684, p=0.005]. In the multivariate analysis, perivascular contrast-enhanced solid tissue had 2.241 -fold effect [odds ratio (OR)=2.519, [95% confidence interval (CI)= 1.132-5.605, p=0.024]. In the postoperative baseline CE-MDCT examination, the presence of solid tissue, lymph node presence, and portal vein stenosis in the surgical bed are among the findings that may indicate early locoregional recurrence in patients with pancreatic ductal adenocarcinoma.

Detecting isolated superior mesenteric artery dissection with computed tomography

Aim: Isolated superior mesenteric artery (SMA) dissection without associated aortic dissection is a rare entity. The aim of the study is to evaluate its incidence, and multidetector computed tomography (MDCT) and computed tomography angiography (CTA) findings, as well as show the clinical importance of this condition, which should be diagnosed and treated urgently. Methods: Images of all patients who underwent contrast enhanced CTA or MDCT scan from July 2017 to July 2020 at our radiology department were examined retrospectively. A total of 600 CTA and 14000 contrast enhanced MDCT scans (14600 CT) were evaluated. Only the cases with isolated SMA dissections without aortic involvement, who had arterial phases on contrast enhanced MDCT images, were included. Aortic dissection cases with SMA involvement, and non-contrast MDCT images were excluded. Age, gender, symptoms, presence of thrombosis or bowel ischemia were noted. Average extension of dissection and distance from origin were measured. Results: Ten patients (7 M, 3 F), aged between 48-66 years (mean: 57 years), had isolated SMA dissection. The mean distance of dissection from origin and mean extension were 1.9 cm and 3.4 cm, respectively. Patients were treated with conservative anticoagulation therapy. Follow-up CTA or MDCT showed normal SMA without evidence of dissection in 5 patients, decreased extension and length of dissection in 3 patients and no significant difference in 2 patients. Conclusion: Isolated SMA dissection is a rare but important cause of abdominal pain. Early diagnosis allows correct treatment. CT is a useful noninvasive method for diagnosis and anticoagulation therapy is successful.

Large airway-obstructing retropharyngeal lipoma in an asymptomatic patient: a case report

BackgroundLipomas are common benign mesenchymal tumors that appear in the head and neck region in approximately 25% of cases where they are noted. Lipomas of the airway region are exceedingly rare, accounting for less than 1% of airway obstruction tumors. Correlation of radiographic findings from cone beam computed tomography (CBCT), multi-detector computed tomography (MDCT), and magnetic resonance imaging (MRI) of a rare retropharyngeal lipoma has not been previously reported. CBCT studies acquired for implant and/or other diagnostic purposes may be the first line of detection as an incidental finding.Case presentationA 66-year-old female presented for a pre-implant CBCT with no history of other complaints or signs/symptoms. CBCT imaging depicts a large, well-defined, low-attenuation/soft tissue density lesion with an undulating appearance extending from the posterior left pharyngeal wall and occluding two-thirds of the airway from C2 to C4. The lesion extends laterally into the left parapharyngeal space and inferiorly beyond the field of view of the study. Evidence of faint internal septations was noted. The patient was immediately referred for an ENT consult. Laryngoscopy, MRI, and contrast-enhanced MDCT imaging were conducted to determine the full extent and nature of the lesion, as well as to potentially plan for biopsy and/or surgical resection. Removal of the lesion was successful, and histopathologic evaluation confirmed lipoma. Periodic follow-up was recommended to monitor for possible recurrence.DiscussionThe slower growth pattern of some benign lesions may obscure any symptoms as changes the patient may normally notice take place over an extended period. Furthermore, soft tissue lesions and especially those in the posterior midline, such as in this case, may not be easily visible on routine panoramic imaging or clinical exam, allowing for substantially large growth before detection. While the soft tissue contrast of the CBCT volume is poor, enough information was present to establish an initial differential diagnosis and the need for more advanced imaging modalities. With the growing popularity and adoption of CBCT in maxillofacial imaging, a thorough understanding of the appearance of hard and soft tissue lesions, as well as a strong understanding of the baseline appearance of normal anatomy, is important to ensure no incidental pathoses go undiagnosed.

Diagnostic imaging of gastrointestinal neuroendocrine tumours (GI-NETs): relationship between MDCT features and 2010 WHO classification.

We aimed to present our series of gastrointestinal neuroendocrine tumours (GI-NETs) in order to illustrate and highlight the associated contrast-enhanced multi-detector computed tomography (MDCT) features. We also attempted to identify a relationship between MDCT imaging and the 2010 World Health Organization (WHO) classification system. We selected all patients with pathologically proven GI-NETs diagnosed between January 2010 and August 2017. Only patients undergone contrast-enhanced MDCT imaging in the immediate preoperative period were included in our study. Later, two expert radiologists retrospectively assessed MDCT intestinal and extra-intestinal signs. We also analysed the relationship between MDCT imaging and the 2010 WHO classification. A total of 20 patients (13 males, 7 females, age range 37-89years, mean age 69.9years) were included in our study. The majority of GI-NETs (85%) occurred in the small bowel and mainly in the terminal ileum. Forty-five percentage of our GI-NETs were diagnosed after an access to emergency medical service for obstruction symptoms or gastrointestinal bleeding. Regarding intestinal signs, 15/20 patients showed an intraluminal nodular mass and 5/20 a wall thickening. Extra-intestinal signs were present in 75% of cases. Desmoplastic reaction and lymph nodes metastases were significantly correlated with higher grade of GI-NETs. The majority of GI-NETs appears as intraluminal mass often associated with extra-intestinal signs. We found a significantly correlation between higher grade of GI-NETs and extra-intestinal signs. MDCT imaging may be useful in predicting the pathological classification of GI-NETs.

Incidence and predictors of vascular access site complications following transfemoral transcatheter aortic valve implantation

Introduction and ObjectivesVascular access site complications in transfemoral (TF) transcatheter aortic valve implantation (TAVI) are associated with increased morbidity and mortality; however, their incidence and predictors are conflicting between studies. This study sought to assess the incidence and predictors of vascular access site complications in patients undergoing TF TAVI. MethodsA total of 140 patients undergoing TF TAVI were included in the study. Minimum iliofemoral diameter and iliofemoral calcium score (CS) were estimated from contrast-enhanced multidetector computed tomography imaging, using different thresholds according to aortic luminal attenuation. To assess the impact of the learning effect, the first 50% of TF TAVI procedures were compared to the remainder. ResultsFifty-one patients presented access site complications (7.1% major, 29.3% minor), most of which were local bleeding or hematoma (11.4%), pseudoaneurysm (7.9%) or closure device failure (5.0%). In a multivariate logistic regression analysis that included sheath-to-iliofemoral artery ratio (SIFAR) (the ratio between the sheath outer diameter and minimum iliofemoral diameter), iliofemoral CS and center experience, SIFAR was the sole independent predictor of access site complications (hazard ratio 14.5, confidence interval [CI] 95% 1.75–120.12, p=0.013). The SIFAR threshold with the highest sum of sensitivity (71.4%) and specificity (53.4%) for access site complications was 0.92 (area under the curve 0.66, 95% CI 0.56–0.75, p=0.002). ConclusionsVascular access site complications are frequent in patients undergoing TF TAVI. SIFAR was the only independent predictor of access site complications and therefore should be systematically assessed during pre-procedural imaging study.

Intrathoracic Fat Measurements Using Multidetector Computed Tomography (MDCT): Feasibility and Reproducibility.

Intrathoracic fat volume, more specifically, epicardial fat volume, is an emerging imaging biomarker of adverse cardiovascular events. The purpose of this work is to show the feasibility and reproducibility of intrathoracic fat volume measurement applied to contrast-enhanced multidetector computed tomography images. A retrospective cohort study of 62 subjects free of cardiovascular disease (55% females, age = 49 ± 11 years) conducted from 2008 to 2011 formed the study group. Intrathoracic fat volume was defined as all fat voxels measuring −50 to −250 Hounsfield Unit within the intrathoracic cavity from the level of the pulmonary artery bifurcation to the heart apex. The intrathoracic fat was separated into epicardial and extrapericardial fat by tracing the pericardium. The measurements were obtained by 2 readers and compared for interrater reproducibility. The fat volume measurements for the study group were 141 ± 72 cm3 for intrathoracic fat, 58 ± 27 cm3 for epicardial fat, and 84 ± 50 cm3 for extrapericardial fat. There was no statistically significant difference in intrathoracic fat volume measurements between the 2 readers, with correlation coefficients of 0.88 (P = .55) for intrathoracic fat volume and −0.12 (P = .33) for epicardial fat volume. Voxel-based measurement of intrathoracic fat, including the separation into epicardial and extrapericardial fat, is feasible and highly reproducible from multidetector computed tomography scans.

Incidence and predictors of vascular access site complications following transfemoral transcatheter aortic valve implantation

Introduction and ObjectivesVascular access site complications in transfemoral (TF) transcatheter aortic valve implantation (TAVI) are associated with increased morbidity and mortality; however, their incidence and predictors are conflicting between studies. This study sought to assess the incidence and predictors of vascular access site complications in patients undergoing TF TAVI. MethodsA total of 140 patients undergoing TF TAVI were included in the study. Minimum iliofemoral diameter and iliofemoral calcium score (CS) were estimated from contrast-enhanced multidetector computed tomography imaging, using different thresholds according to aortic luminal attenuation. To assess the impact of the learning effect, the first 50% of TF TAVI procedures were compared to the remainder. ResultsFifty-one patients presented access site complications (7.1% major, 29.3% minor), most of which were local bleeding or hematoma (11.4%), pseudoaneurysm (7.9%) or closure device failure (5.0%). In a multivariate logistic regression analysis that included sheath-to-iliofemoral artery ratio (SIFAR) (the ratio between the sheath outer diameter and minimum iliofemoral diameter), iliofemoral CS and center experience, SIFAR was the sole independent predictor of access site complications (hazard ratio 14.5, confidence interval [CI] 95% 1.75–120.12, p=0.013). The SIFAR threshold with the highest sum of sensitivity (71.4%) and specificity (53.4%) for access site complications was 0.92 (area under the curve 0.66, 95% CI 0.56–0.75, p=0.002). ConclusionsVascular access site complications are frequent in patients undergoing TF TAVI. SIFAR was the only independent predictor of access site complications and therefore should be systematically assessed during pre-procedural imaging study.

The association of left atrial low-voltage regions on electroanatomic mapping with low attenuation regions on cardiac computed tomography perfusion imaging in patients with atrial fibrillation.

Previous studies have shown that contrast-enhanced multidetector computed tomography (CE-MDCT) could identify ventricular fibrosis after myocardial infarction. However, whether CE-MDCT can characterize atrial low-voltage regions remains unknown. The purpose of this study was to examine the association of CE-MDCT image attenuation with left atrial (LA) low bipolar voltage regions in patients undergoing repeat ablation for atrial fibrillation recurrence. We enrolled 20 patients undergoing repeat ablation for atrial fibrillation recurrence. All patients underwent preprocedural 3-dimensional CE-MDCT of the LA, followed by voltage mapping (>100 points) of the LA during the ablation procedure. Epicardial and endocardial contours were manually drawn around LA myocardium on multiplanar CE-MDCT axial images. Segmented 3-dimensional images of the LA myocardium were reconstructed. Electroanatomic map points were retrospectively registered to the corresponding CE-MDCT images. A total of 2028 electroanatomic map points obtained in sinus rhythm from the LA endocardium were registered to the segmented LA wall CE-MDCT images. In a linear mixed model, each unit increase in the local image attenuation ratio was associated with 25.2% increase in log bipolar voltage (P = .046) after adjusting for age, sex, body mass index, and LA volume, as well as clustering of data by patient and LA regions. We demonstrate that the image attenuation ratio derived from CE-MDCT is associated with LA bipolar voltage. The potential ability to image fibrosis via CE-MDCT may provide a useful alternative in patients with contraindications to magnetic resonance imaging.

A fatal condition in the thoracic aorta

A fatal condition in the thoracic aorta

Ablation margin assessment of liver tumors with intravenous contrast-enhanced C-arm computed tomography

To evaluate the feasibility of intravenous contrast-enhanced C-arm computed tomography (CT) for assessing ablative areas and margins of liver tumors. Twelve patients (5 men, 7 women; mean age, 69.5 years) who had liver tumors (8 hepatocellular carcinomas, 4 metastatic liver tumors; mean size, 16.3 mm; size range, 8-20 mm) and who underwent percutaneous radiofrequency ablations (RFAs) with a flat-detector C-arm system were retrospectively reviewed. Intravenously enhanced C-arm CT and multidetector computed tomography (MDCT) images were obtained at the end of the RFA sessions and 3-7 d after RFA to evaluate the ablative areas and margins. The ablated areas and margins were measured using axial plane images acquired by both imaging techniques, with prior contrast-enhanced MDCT images as the reference. The sensitivity, specificity, and positive and negative predictive values of C-arm CT for detecting insufficient ablative margins (< 5 mm) were calculated. Statistical differences in the ablative areas and margins evaluated with both imaging techniques were compared using a paired t-test. All RFA procedures were technically successful. Of 48 total ablative margins, 19 (39.6%) and 20 (41.6%) margins were found to be insufficient with C-arm CT and MDCT, respectively. Moreover, there were no significant differences between these 2 imaging techniques in the detection of these insufficient ablative margins. The sensitivity, specificity, and positive and negative predictive values for detecting insufficient margins by C-arm CT were 90.0%, 96.4%, 94.7% and 93.1%, respectively. The mean estimated ablative areas calculated from C-arm CT (462.5 ± 202.1 mm(2)) and from MDCT (441.2 ± 212.5 mm(2)) were not significantly different. The mean ablative margins evaluated by C-arm CT (6.4 ± 2.2 mm) and by MDCT (6.0 ± 2.4 mm) were also not significantly different. The efficacy of intravenous contrast-enhanced C-arm CT in assessing the ablative areas and margins after RFA of liver tumors is nearly equivalent to that of MDCT.

A Rare Case of Recurrent Hematuria from Right Kidney: Radiologic Diagnosis and Treatment

We report the case of a young woman admitted because of several and recurring episodes of macroscopic hematuria beginned after her first pregnancy. Contrast-enhanced multidetector computed tomography images showed dilated ovarian veins due to a typical pelvic varicocele. We supposed to be a right ovarian vein syndrome, a rare clinical situation characterized by an anomalous compression of the lumbar ureter by the ectasic ovarian vein; this condition may cause a chronic inflammatory stimulus above the urothelial mucosa with a following hematuria. All symptoms were solved by an endovascular treatment through the sclero-embolisation of the pelvic varicocele. After eighteen months the patient didn't present hematuria anymore and she no longer complained about her right side lumbar pain.

Comparison of combined oral and iv contrast-enhanced versus single iv contrast-enhanced mdct for the detection of acute appendicitis

The aim of our study was to compare the diagnostic ability of oral added intravenous (IV) contrast-enhanced multidetector computed tomography (MDCT) versus only IV contrast-enhanced MDCT in diagnosing of acute appendicitis. MDCT images of 200 patients were evaluated prospectively in this study. Patients were randomized into one of two groups: Group 1 (Gp1) patients underwent 16-MDCT performed with oral and IV contrast-enhanced and Group 2 (Gp2) subjects underwent 16-MDCT with only IV contrast-enhanced protocol. Final decision was based on histopathologic operative data and follow-up of patients. In Gp1, Reader1 had 96.9% and 98.5% and Reader2 had 84% and 94.7% sensitivity and specificity values respectively. For Gp2, the values for Reader1 were 81% and 94%. For Reader2 in Gp2, the values were 76% and 91%. We achieved higher sensitivity and specificity values with combined contrast administration versus only IV contrast-enhanced MDCT imaging. However, there was no statistically significant differences between two readers in the AUC values of each group for the detection of acute appendicitis. It is statistically concluded that oral contrast do not contribute to the a better accuracy. So in the routine practice, oral contrast has not to be recommended.

Multidetector Computed Tomography Myocardial Perfusion Imaging During Adenosine Stress

The purpose of this study is to validate the accuracy of multidetector computed tomography (MDCT) to measure differences in regional myocardial perfusion during adenosine stress in a canine model of left anterior descending (LAD) artery stenosis, during first-pass, contrast-enhanced helical MDCT. Myocardial perfusion imaging by MDCT may have significant implications in the diagnosis and treatment of coronary artery disease. Eight dogs were prepared with a LAD stenosis, and contrast-enhanced MDCT imaging was performed 5 min into adenosine infusion (0.14 to 0.21 mg/kg/min). Images were analyzed using a semiautomated approach to define the regional signal density (SD) ratio (myocardial SD/left ventricular blood pool SD) in stenosed and remote territories, and then compared with microsphere myocardial blood flow (MBF) measurements. Mean MBF in stenosed versus remote territories was 1.37 +/- 0.46 ml/g/min and 1.29 +/- 0.48 ml/g/min at baseline (p = NS) and 2.54 +/- 0.93 ml/g/min and 8.94 +/- 5.74 ml/g/min during adenosine infusion, respectively (p < 0.05). Myocardial SD was 92.3 +/- 39.5 HU in stenosed versus 180.4 +/- 41.9 HU in remote territories (p < 0.001). There was a significant linear association of the SD ratio with MBF in the stenosed territory (R = 0.98, p = 0.001) and between regional myocardial SD ratio and MBF <8 ml/g/min, slope = 0.035, SE = 0.007, p < 0.0001. Overall, there was a significant non-linear relationship over the range of flows studied (LR chi-square [2 degrees of freedom] = 31.8, p < 0.0001). Adenosine-augmented MDCT myocardial perfusion imaging provides semiquantitative measurements of myocardial perfusion during first-pass MDCT imaging in a canine model of LAD stenosis.

Measurement of cardiac ventricular volumes using multidetector row computed tomography: comparison of two- and three-dimensional methods

This study compared a three-dimensional volumetric threshold-based method to a two-dimensional Simpson's rule based short-axis multiplanar method for measuring right (RV) and left ventricular (LV) volumes, stroke volumes, and ejection fraction using electrocardiography-gated multidetector computed tomography (MDCT) data sets. End-diastolic volume (EDV) and end-systolic volume (ESV) of RV and LV were measured independently and blindly by two observers from contrast-enhanced MDCT images using commercial software in 18 patients. For RV and LV the three-dimensionally calculated EDV and ESV values were smaller than those provided by two-dimensional short axis (10%, 5%, 15% and 26% differences respectively). Agreement between the two methods was found for LV (EDV/ESV: r=0.974/0.910, ICC=0.905/0.890) but not for RV (r=0.882/0.930, ICC=0.663/0.544). Measurement errors were significant only for EDV of LV using the two-dimensional method. Similar reproducibility was found for LV measurements, but the three-dimensional method provided greater reproducibility for RV measurements than the two-dimensional. The threshold value supported three-dimensional method provides reproducible cardiac ventricular volume measurements, comparable to those obtained using the short-axis Simpson based method.

Characterization of Acute and Chronic Myocardial Infarcts by Multidetector Computed Tomography

We evaluated whether contrast-enhanced multidetector computed tomography (CE-MDCT) might characterize myocardial infarct (MI) with patterns similar to those obtained by contrast-enhanced magnetic resonance (CE-MR) and studied the underlying mechanisms. In vivo infarct characterization by CE-MDCT was shown to be feasible between 4 and 20 minutes after contrast injection in 7 pigs with MI. Subsequently, in 16 patients with acute MI and 21 patients with chronic MI, contrast patterns by CE-MDCT were related to CE-MR. Eighteen patients had hypoenhanced regions on early CE-MDCT images at the time of coronary imaging, and 34 patients had hyperenhanced regions on images acquired 10 minutes later. On a segmental basis, there was moderately good concordance of early hypoenhanced regions (92%, kappa=0.54, P<0.001) and late hyperenhanced regions (82%, kappa=0.61, P<0.001) between CE-MDCT and CE-MR. Absolute sizes of early hypoenhanced (6+/-16 versus 7+/-16 g, P=0.25) and late hyperenhanced (36+/-34 versus 31+/-40 g, P=0.14) regions were similar on CE-MDCT and CE-MR and were highly correlated (r=0.93, P<0.001 and r=0.89, P<0.001 respectively). In 8 retrogradely perfused infarcted rabbit hearts, contrast kinetics of iomeprol were similar to gadodiamide, ie, slow wash in (8.7+/-6.7 versus 1.2+/-0.3 minutes, P<0.001) in infarct core and slow washout (20+/-12 versus 2.5+/-0.5 minutes, P<0.001) in both infarct core and rim compared with the remote region. Because iodated contrast agents have similar kinetics in infarcted and noninfarcted myocardium as gadolinium DPTA, CE-MDCT can characterize acute and chronic MI with contrast patterns similar to CE-MR. CE-MDCT may thus provide important information on infarct size and viability at the time of noninvasive coronary imaging.