Contrast-enhanced Thoracic CT Research Articles

A CT-based novel model to predict pathological complete response of locally advanced esophageal squamous cell carcinoma to neoadjuvant PD-1 blockade in combination with chemotherapy

PurposeTo develop a novel CT-based model to predict pathological complete response (pCR) of locally advanced esophageal squamous cell carcinoma (ESCC) to neoadjuvant PD-1 blockade in combination with chemotherapy. Methods117 consecutive patients with locally advanced ESCC were stratified into training cohort (n = 82) and validation cohort (n = 35). All patients underwent non-contrast and contrast-enhanced thoracic and upper abdominal CT before neoadjuvant PD-1 blockade in combination with chemotherapy (CTpre), and after two cycles of the therapy before esophagectomy (CTpost), respectively. Univariate analyses and binary logistic regression analyses of ESCC quantitative and qualitative CT features were performed to determine independent predictors of pCR. Prediction performance of the model developed with independent predictors from training cohort was evaluated by receiver operating characteristic (ROC) analysis, and validated by Kappa test in validation cohort. ResultsIn training cohort, the difference in CT attenuation between tumor and background normal esophageal wall obtained from CTpre (ΔTNpre), tumoral increased CT attenuation after contrast-enhanced scan from CTpost images (ΔTpost) and gross tumor volume (GTV) from CTpre were independent predictors of pCR (odds ratio = 1.128 (95% confidence interval (CI): 0.997–1.277), 1.113 (95%CI: 0.965–1.239) and 1.133 (95%CI: 1.043–1.231), respectively, all P-values < 0.05). Logistic regression model equation (0.121 × ΔTNpre + 0.107 × ΔTpost + 0.125 × GTV − 9.856) to predict pCR showed the best performance with an area under the ROC of 0.876, compared with each independent predictor. The good performance was confirmed by the Kappa test (K-value = 0.796) in validation cohort. ConclusionsThis novel model can be reliable to predict pCR to neoadjuvant PD-1 blockade in combination with chemotherapy in locally advanced ESCC.

Association between thoracic and third lumbar CT-derived muscle mass and density in Caucasian patients without chronic disease: a proof-of-concept study

BackgroundComputed tomography (CT) is increasingly used in the clinical workup, and existing scan contains unused body composition data, potentially useful in a clinical setting. However, there is no healthy reference for contrast-enhanced thoracic CT-derived muscle measures. Therefore, we aimed at investigating whether there is a correlation between each of the thoracic and third lumbar vertebra level (L3) skeletal muscle area (SMA), skeletal muscle index (SMI), and skeletal muscle density (SMD) at contrast-enhanced CT in patients without chronic disease.MethodsA proof-of-concept retrospective observational study was based on Caucasian patients without chronic disease, who received CT for trauma between 2012 and 2014. Muscle measures were assessed using a semiautomated threshold-based software by two raters independently. Pearson’s correlation between each thoracic level and third lumbar and intraclass correlation between two raters and test–retest with SMA as proxy parameters were used.ResultsTwenty-one patients (11 males, 10 females; median age 29 years) were included. The second thoracic vertebra (T2) had the highest median of cumulated SMA (males 314.7 cm2, females 118.5 cm2) and SMI (97.8 cm2/m2 and 70.4 cm2/m2, respectively). The strongest SMA correlation was observed between T5 and L3 (r = 0.970), the SMI between T11 and L3 (r = 0.938), and the SMD between the T10 and L3 (r = 0.890).ConclusionsThis study suggests that any of the thoracic levels can be valid to assess skeletal muscle mass. However, the T5 may be most favourable for measuring SMA, the T11 for SMI, and T10 for SMD when using contrast-enhanced thoracic CT.Relevance statementIn COPD patients, a CT-derived thoracic muscle mass assessment may help identify who would benefit from focused pulmonary rehabilitation: thoracic contrast-enhanced CT conducted as part of the standard clinical workup can be used for this evaluation.Key points• Any thoracic level can be used to assess thoracic muscle mass.• Thoracic level 5 is strongly associated with the 3rd lumbar muscle area.• A strong correlation between the thoracic level 11 and the 3rd lumbar muscle index.• Thoracic level 10 is strongly associated with the 3rd lumbar muscle density.Graphical

Diagnostic challenges in primary cardiac lymphoma, the opportunity of 18F-FDG PET/CT integrated with contrast-enhanced CT

BackgroundThe purpose of this study was to retrospectively evaluate the value of 18F-FDG PET/CT integrated with contrast-enhanced CT (CECT) in the differential diagnosis of primary cardiac lymphomas (PCLs) and primary cardiac angiosarcomas (PCAs). MethodsClinical and imaging data of patients with PCLs and PCAs were collected. All patients underwent preoperative 18F-FDG PET/CT and thoracic CECT. The enhancement pattern and tumor morphology were analyzed using CECT images. The intensity- and volume-based PET parameters of cardiac lesions were analyzed. The performance characteristics of all parameters were assessed. ResultsNine patients with PCL and eight patients with PCA were analyzed. There were significant differences in SUVmax (t = 3.790, P = .002), SUVmean (t = 4.273, P = .001), metabolic tumor volume (U = 13.00, P = .027), tumor-to-liver ratio (U = 10.00, P = .011), and total lesion glycolysis (U = 4.0, P = .001) between PCLs and PC18As. There were significant differences in the enhancement pattern of tumors (P = .002) and tumor morphology (P = .015). The combination of F-FDG PET/CT and CECT improved the diagnostic accuracy, and the combination cutoff (SUVmean > 5.17) could reach 100%, but the difference was not statistically significant (P > .05). ConclusionThe intensity- and volume-based PET parameters of PCL were significantly higher than those of PCA. The enhancement pattern and tumor morphology were also different. According to these characteristics, the two most common types of primary cardiac malignancies can be differentiated.

Artificial intelligence can detect left ventricular dilatation on contrast-enhanced thoracic computer tomography relative to cardiac magnetic resonance imaging.

To assess the diagnostic accuracy of an automated algorithm to detect left ventricular (LV) dilatation on non-ECG gated CT, using cardiac magnetic resonance (CMR) as reference standard. Consecutive patients with contrast-enhanced CT thorax and CMR within 31 days (2016-2020) were analysed (n = 84). LV dilatation was defined against age-, sex- and body surface area-specific values for CMR. CTs underwent automated artificial intelligence(AI)-derived analysis that segmented ventricular chambers, presenting maximal LV diameter and volume. Area under the receiver operator curve (AUC-ROC) analysis identified CT thresholds with ≥90% sensitivity and highest specificity and ≥90% specificity with highest sensitivity. Youden's Index was used to identify thresholds with optimised sensitivity and specificity. Automated diameter analysis was feasible in 92% of cases (77/84; 45 men, age 61 ± 14 years, mean CT to CMR interval 10 ± 8 days). Relative to CMR as a reference standard, 45% had LV dilatation. In males, an automated LV diameter measurement of ≥55.5 mm was ≥90% specific for CMR-defined LV dilatation (positive predictive value (PPV) 85.7%, negative predictive value (NPV) 61.2%, accuracy 68.9%). In females, an LV diameter of ≥49.7 mm was ≥90% specific for CMR-defined LV dilatation (PPV 66.7%, NPV 73.1%, accuracy 71.9%). AI CT volumetry data did not significantly improve AUC performance. Fully automated AI-derived analysis LV dilatation on routine unselected non-gated contrast-enhanced CT thorax studies is feasible. We have defined thresholds for the detection of LV dilatation on CT relative to CMR, which could be used to routinely screen for dilated cardiomyopathy at the time of CT. We show, for the first time, that a fully-automated AI-derived analysis of maximal LV chamber axial diameter on non-ECG-gated thoracic CT is feasible in unselected real-world cases and that the derived measures can predict LV dilatation relative to cardiac magnetic resonance imaging, the non-invasive reference standard for determining cardiac chamber size. We have derived sex-specific cut-off values to screen for LV dilatation on routine contrast-enhanced thoracic CT. Future work should validate these thresholds and determine if technology can alter clinical outcomes in a cost-effective manner.

Frequency and Predictors of Pulmonary Arterial Stump Thrombosis following Pneumonectomy or Lobectomy

Objectives: Pulmonary artery stump thrombosis (PAST) following pneumonectomies/lobectomies is rare; its clinical importance is unknown. The objectives of this study were to analyze the prevalence and risk factors of PAST and the clinical significance in patients with pneumonectomy/lobectomy. Methods: All adult cases who underwent pneumonectomy/lobectomy in our hospital for any reason and who underwent control contrast-enhanced thoracic CT during the follow-up period were included in the study. Demographic and clinical features of the patients, data on surgery, and the features of thrombi were recorded. Results: During the 4-year study period, a total of 454 patients underwent pneumonectomy/lobectomy (93 pneumonectomy and 361 lobectomy). Among the patients, 202 patients (50 pneumonectomy and 152 lobectomy) with at least one follow-up thorax CT were included in the analyses. PAST was detected in 9 (4.5%) of 202 patients and mostly seen in patients with pneumonectomy (lobectomy: 2.6% vs. pneumonectomy: 10%, p = 0.043) and in patients whose pulmonary artery was ligated by using stapler (suture ligation 1% vs. stapler: 7.4%, p = 0.034). Pulmonary artery stump was also longer in patients with PAST (8.48 ± 11.22 mm vs. 23.55 ± 11.22 mm, p < 0.001). Univariate logistic regression analysis showed that pneumonectomy and longer pulmonary artery stump length were found to be significantly associated with PAST (p = 0.041 and p = 0.001, respectively). Conclusions: PAST was detected in 4.5% of our subjects undergoing lobectomy/pneumonectomy. PAST was found to be significantly higher in subjects who underwent pneumonectomy, those with longer pulmonary artery stump, and those with pulmonary artery stump ligated by using stapler.

The direct costs of coronary CT angiography relative to contrast-enhanced thoracic CT: Time-driven activity-based costing

BackgroundCoronary CT angiography (CCTA) and contrast-enhanced thoracic CT (CECT) are distinctly different diagnostic procedures that involve intravenous contrast-enhanced CT of the chest. The technical component of these procedures is reimbursed at the same rate by the Centers for Medicare and Medicaid Services (CMS). This study tests the hypothesis that the direct costs of performing these exams are significantly different. MethodsDirect costs for both procedures were measured using a time-driven activity-based costing (TDABC) model. The exams were segmented into four phases: preparation, scanning, post-scan monitoring, and image processing. Room occupancy and direct labor times were collected for scans of 54 patients (28 CCTA and 26 CECT studies), in seven medical facilities within the USA and used to impute labor and equipment cost. Contrast material costs were measured directly. Cost differences between the exams were analyzed for significance and variability. ResultsMean CCTA duration was 3.2 times longer than CECT (121 and 37 ​min, respectively. p ​< ​0.01). Mean CCTA direct costs were 3.4 times those of CECT ($189.52 and $55.28, respectively, p ​< ​0.01). Both labor and capital equipment costs for CCTA were significantly more expensive (6.5 and 1.8-fold greater, respectively, p ​< ​0.001). Segmented by procedural phase, CCTA was both longer and more expensive for each (p ​< ​0.01). Mean direct costs for CCTA exceeded the standard CMS technical reimbursement of $182.25 without accounting for indirect or overhead costs. ConclusionThe direct cost of performing CCTA is significantly higher than CECT, and thus reimbursement schedules that treat these procedures similarly undervalue the resources required to perform CCTA and possibly decrease access to the procedure.

Combined PET/CT with thoracic contrast-enhanced CT in assessment of primary cardiac tumors in adult patients

Background18F-FDG PET/CT is a key molecular imaging modality to noninvasively assess and differentiate benign and malignant cardiac tumors. However, few benign cardiac tumors can be characterized by increased 18F-FDG uptake, which makes differential diagnosis difficult. This study sought to retrospectively evaluate whether combined 18F-FDG PET/CT with thoracic contrast-enhanced CT (CECT) helps in assessing primary cardiac tumors in adult patients, compared with CECT or PET/CT alone.MethodsForty-six consecutive patients who were diagnosed as primary cardiac tumors were enrolled. All patients underwent 18F-FDG PET/CT followed by thoracic CECT before biopsy or surgery. Visual qualitative interpretation and quantitative analysis were performed, and diagnostic performance was evaluated.ResultsMore than half (16/29) of benign tumors exhibited with mild 18F-FDG uptake. There were significant differences in 18F-FDG uptake and the degree of absolute enhancement between benign and malignant tumors (P < 0.001). The combination of two modalities improved the specificity from 79 to 93%, the positive predictive value from 73 to 89%, and the accuracy of diagnosis from 85 to 93%. There were significant differences between PET/CT alone or thoracic CECT alone and combined modalities (P = 0.034 and P = 0.026, respectively). The combination with the optimal SUVmax cutoff value generated 94% sensitivity, 100% specificity, 97% negative predictive values, 100% positive predictive values, and 98% accuracy rates.ConclusionsCombining 18F-FDG PET/C with thoracic CECT significantly improved specificity and accuracy compared to CECT or PET/CT alone in detecting tumors. This combination of diagnostic imaging is effective in differentiating malignant from benign masses.

Adjuvant volumetric modulated arc therapy compared to 3D conformal radiation therapy for newly diagnosed soft tissue sarcoma of the extremities: outcome and toxicity evaluation

To assess the impact of adjuvant volumetric modulated arc therapy (VMAT) compared with three-dimensional conformal radiation therapy (3DCRT) in terms of toxicity and local control (LC) in patients with soft tissue sarcoma of the extremities. From 2004 to 2016, 109 patients were treated, initially using 3DCRT and subsequently with VMAT. Clinical outcome was evaluated by contrast-enhanced MRI, thoracic and abdominal CT 3 months after treatments and then every 6 months. Toxicity was evaluated with Common Terminology Criteria for Adverse Events scale v. 4.3. Patients presented Stage III soft tissue sarcoma disease (77%), localized tumor (95%) at the lower extremity (87%), adipocytic histotype (46%). Surgical resection was performed in all patients, followed by adjuvant 3DCRT in 38, and VMAT in 71. The median total dose was 66 Gy/33 fractions (range 60-70 Gy;25-35 fractions). More successful bone sparing was recorded using VMAT (p < 0.001). Median follow-up was 61 months, 93 and 58 months for 3DCRT and VMAT group, respectively. The 2- and 5 year LC were 95.3±2.1%, and 87.4±3.4% for the whole cohort, 92.0±4.5%, 82.9±6.4% for 3DCRT, 97.1±2.0%, 89.6±4.1% for VMAT (p = 0.150). On univariate and multivariate analysis the factors recorded as conditioning LC were the status of the surgical resection margins (p = 0.028) and the total dose delivered (p = 0.013). The availability of modern radiotherapy technique permit a better conformity on the target with maximum sparing of normal tissue and acceptable side-effects. VMAT is a safe and feasible treatment with limited rate of toxicity, compared to 3DCRT. Results on LC of VMAT are encouraging. Soft tissue sarcoma of the extremities can benefit from the use of VMAT, with a reduction of the high dose to bones to avoid radiation osteonecrosis. An adequate total dose of at least 66 Gy and a radical surgical margin allow a good local control.

Can texture features improve the differentiation of infiltrative lung adenocarcinoma appearing as ground glass nodules in contrast-enhanced CT?

ObjectivesTo investigate the validity and efficacy of comparing texture features from contrast-enhanced images with non-enhanced images in identifying infiltrative lung adenocarcinoma represented as ground glass nodules (GGN). Materials and methodsA retrospective cohort study was conducted with patients presenting with lung adenocarcinoma and treated at a single centre between January 2015 to December 2017. All patients underwent standard and contrast-enhanced thoracic CT scans with 0.5 mm collimation and 1 mm slice reconstruction thickness before surgery. A total of 34 lung adenocarcinoma patients (representing 34 lesions) were analysed; including 21 instances of invasive adenocarcinoma (IAC) lesions, 4 instances of adenocarcinoma in situ (AIS) lesions, and 9 minimally invasive adenocarcinoma (MIA) lesions. After radiologists manually segmented the lesions, texture features were quantitatively extracted using Artificial Intelligence Kit (AK) software. Then, multivariate logistic regression analysis based on standard and contrast-enhanced CT texture features was employed to analyse the invasiveness of lung adenocarcinoma lesions appearing as GGNs. A receiver operating characteristic (ROC) curve analysis was used to evaluate the performance of those models. ResultsA total of 21 quantitative texture features were extracted using the AK software. After dimensionality reduction, 5 and 3 features extracted from thin-section unenhanced and contrast-enhanced CT, respectively, were used to establish the model. The area under the ROC curve (AUC) values for unenhanced CT and enhanced CT features were 0.890 and 0.868, respectively. There was no significant difference (P = 0.190) in the AUC between models based on non-enhanced and contrast-enhanced CT texture features. ConclusionCompared with unenhanced CT, texture features extracted from contrast-enhanced CT provided no benefit in improving the differential diagnosis of infiltrative lung adenocarcinoma from non-infiltrative malignancies appearing as GGNs.

Early and delayed phases of contrast-enhanced CT for evaluating patients with malignant pleural effusion. Results of pairwise comparison by multiple observers

To compare images from early and delayed phases of contrast-enhanced thoracic CT for assessing pleural thickening or nodules in a series of patients with malignant pleural effusions. Blinded images from 36 patients with malignant pleural effusions showing pleural lesions in both early (35 s delayed) and delayed (70 s delayed) phases of thoracic and abdominal contrast-enhanced CT scan were retrospectively assessed by six observers. First, images were individually scored in a six-point scale grading the quality of visualization of pleural findings such as pleural thickening or nodules. This was followed by a paired analysis, where the readers had to choose the one showing the highest quality between two images presented together corresponding to both phases of the same patient showing the same pleural lesion. When possible, contrast attenuation of the abnormal pleura was measured. Statistical analysis was performed by using paired t-test and χ 2. Mean attenuation of pleural lesions was significantly higher in the delayed phase (76.0 ± 25.1 vs 57.5 ± 20.7, p < 0.001). Mean score and score of individual images was statistically significant better for the delayed phase for all observers. In the paired analysis, all the readers preferred the delayed phase over the early phase in 77.8 to 91.7% of the cases. Delayed phase of contrast-enhanced CT is preferable to early phase for evaluating pleural findings. Advances in knowledge: Pleural attenuation is greater for the delayed phase compared with the early phase of contrast-enhanced chest CT. In the pairwise comparison, all the observers prefer the delayed phase over the early phase for pleural evaluation.

Best Protocol for Combined Contrast-Enhanced Thoracic and Abdominal CT for Lung Cancer: A Single-Institution Randomized Crossover Clinical Trial.

The purpose of this study was to evaluate the superiority of either of two protocols for combined contrast-enhanced thoracic and abdominal CT of patients with lung cancer by comparing contrast enhancement, contrast-related artifacts, image quality, and radiation dose. In this randomized controlled crossover clinical trial, 77 patients who underwent 203 CT examinations were enrolled. All patients underwent at least two examinations performed with both protocols. Protocol A consisted of two acquisitions: one 35-second delayed CT acquisition for the chest followed by a 70-second delayed abdominal acquisition. Protocol B was a single 60-second delayed acquisition covering the chest and the abdomen. Attenuation and noise of the aorta, pulmonary artery, and liver were measured. Contrast-related artifacts, mediastinal lymph node visualization, liver enhancement, and noise were visually scored. Dose-length product was recorded. Statistical analysis was performed by t and chi-square tests and kappa statistics. Contrast-related artifacts were more severe at all evaluated levels, and visualization of lymph node regions was statistically significantly worse with protocol A. There were no differences in enhancement or noise score of the liver. Tumor delineation and pleural findings were better evaluated with delayed phase images. Dose-length product was significantly higher with protocol A (645.0 vs 521.5 mGy · cm; p < 0.0001). A single 60-second delayed acquisition for thoracic and abdominal contrast-enhanced CT is associated with less contrast artifact and affords better visualization of lymph nodes at a lower radiation dose while acceptable vascular and hepatic contrast enhancement is maintained.

Incidental Thyroid Nodules Detected on Thoracic Contrast-Enhanced CT in the Pediatric Population: Prevalence and Outcomes.

The purpose of this study was to investigate the prevalence and outcomes of incidental thyroid nodules detected on thoracic contrast-enhanced CT (CECT) in the pediatric population. We used our hospital information system to retrospectively identify all consecutive pediatric patients (< 21 years old) with newly detected thyroid nodules reported on thoracic CECT performed between January 2006 and January 2013. The study population was categorized into two groups: patients with (group 1) and without (group 2) an available follow-up thyroid ultrasound study. Two pediatric radiologists systematically reviewed the CT studies, available follow-up thyroid ultrasound studies, and outcomes of patients meeting the inclusion criteria. For patients without an available follow-up ultrasound study (group 2), the duration of clinical follow-up was also evaluated. If a biopsy was performed, the pathologic diagnosis was correlated with the imaging findings. The study population consisted of 35 thoracic CECT studies from 35 pediatric patients (18 females, 17 males; mean age, 13 ± 6.2 [SD] years) who met the inclusion criteria. The prevalence of incidental thyroid nodules detected on thoracic CECT in our study population was 1.4% (35/2525 patients; 95% CI, 1-2%). Seventeen of the 35 (49%) patients (group 1) underwent follow-up thyroid ultrasound, six (17%) of whom ultimately underwent biopsy of the thyroid nodule for pathologic diagnosis. Among these six patients, two (33%) were found to have malignant thyroid nodules: papillary thyroid carcinoma and thyroid involvement by an underlying Burkitt lymphoma. Therefore, the prevalence of malignancy among incidentally detected thyroid nodules on thoracic CECT in pediatric patients in this study was 5.7% (2/35 patients; 95% CI, 2-18%). The remaining four of six patients (67%) had benign thyroid nodules. Eighteen of the 35 (51%) patients (group 2) had only clinical follow-up information (mean follow-up, 27.1 ± 21.1 months); no neoplasm subsequently developed from incidentally detected thyroid nodules among this subset. Thyroid nodules detected incidentally on thoracic CECT are rare in pediatric patients. However, when thyroid nodules are present, ultrasound (with or without biopsy for pathologic evaluation) is an appropriate strategy because of the rare but real possibility of an underlying thyroid malignancy in the pediatric population.

Potential for radiation dose savings in abdominal and chest CT using automatic tube voltage selection in combination with automatic tube current modulation.

The purpose of this study was to evaluate the simultaneous use of automatic tube current modulation (ATCM) and automatic tube voltage selection (ATVS) for abdominal and chest CT examinations regarding radiation dose reduction and image quality. We enrolled 617 patients who all underwent contrast-enhanced chest or abdominal CT and divided them into two groups. In group A, 317 patients who underwent CT with only ATCM and a fixed body mass index-adjusted tube voltage (120 kV or 100 kV) were enrolled. In group B, both ATCM and ATVS were used. Image attenuation and noise were measured in different anatomic regions. The mean contrast-to-noise ratio and the signal-to-noise ratio of abdomen and chest CT was higher in group B compared with group A (p < 0.0001). In total, the effective radiation doses for abdomen and chest CT examinations were significantly reduced in group B by 18% compared with group A (p < 0.0001). When only examining those who benefited from the ATVS tool, a dose reduction of 35% for chest CT and 42% for abdomen CT could be achieved (p < 0.0001 for each). The simultaneous use of ATVS and ATCM enables significant radiation dose reduction in abdominal and thoracic contrast-enhanced CT examinations compared with the use of ATCM alone.

Exudative pleural effusions: Comparative study of image assisted Abram needle pleural biopsy and medical thoracoscopy

BackgroundPleural tissue can be harvested either by means of closed biopsies, thoracoscopy or open surgical biopsies. Access to thoracoscopy and open surgical biopsies is limited in many parts of the world and closed biopsies are therefore the preferred initial investigation (Diacon et al., 2003) [6]. Aim of the studyThis study aimed to compare the diagnostic efficiency of image-assisted ANPB with that of medical thoracoscopy in patients with exudative pleural effusion. Patients and methodsForty patients with non-diagnosed exudative pleural effusions were recruited. All had a contrast-enhanced thoracic CT scan to assess pleural thickening. Patients were randomly stratified by baseline pleural thickening, to either image-assisted Abrams’ pleural biopsy (n=20) or medical thoracoscopy biopsy (n=20). ResultsDiagnostic sensitivity of image-assisted ANPB for 20 patients (group I) was 75% (15/20), for group Ia was 60% (6/10), and for group Ib was 90% (9/10). Diagnostic sensitivity of thoracoscopy for 20 patients (group II) was 85% (17/20), for group IIa was 80% (8/10), and for group IIb was 90% (9/10). ConclusionsImage-assisted Abram-needle pleural biopsy is a primary alternative to thoracoscopy in exudative pleural effusions associated with pleural thickening.

Right atrial thrombus in cholangiocellular carcinoma: Case report and a review of the literature

Intrahepatic cholangiocarcinomas are rare, aggressive tumours. We discuss an afflicted patient who had relatively larger thrombi disseminated into the right atrium. A 63-year-old female patient with intrahepatic cholangiocarcinoma referred with complaints of swellings on her face, upper half of her body, and both arms. On contrast-enhanced thoracic CT scans and transthoracic echocardiograms of the patient an intraluminal thrombus measuring 36.3 × 25.7 mm extending to the orifice of the right atrium was seen. Thrombolytics were not successful in reducing the dimensions of the thrombus.

Cardiac tamponade related to a coronary injury by a pericardial calcification: an unusual complication

BackgroundCardiac tamponade is a rare but severe complication of pericardial effusion with a poor prognosis. Prompt diagnosis using transthoracic echocardiography allows guiding initial therapeutic management. Although etiologies are numerous, cardiac tamponade is more often due to a hemopericardium. Rarely, a coronary injury may result in such a hemopericardium with cardiac tamponade. Coronary artery aneurysm are the main etiologies but blunt, open chest trauma or complication of endovascular procedures have also been described.Case presentationA 83-year-old hypertensive man presented for dizziness and hypotension. The patient had oliguria and mottled skin. Transthoracic echocardiography disclosed a circumferential pericardial effusion with a compressed right atrium, confirmed by contrast-enhanced thoracic CT scan. A pig-tail catheter allowed to withdraw 500 mL of blood, resulting in a transient improvement of hemodynamics. Rapidly, recurrent hypotension prompted a reoperation. An active bleeding was identified at the level of the retroventricular coronary artery. The pericardium was thickened with several "sharping" calcified plaques in the vicinity of the bleeding areas. On day 2, vasopressors were stopped and the patient was successfully extubated. Final diagnosis was a spontaneous cardiac tamponade secondary to a coronary artery injury attributed to a "sharping"calcified pericardial plaque.ConclusionCardiac tamponade secondary to the development of a hemopericardium may develop as the result of a myocardial and coronary artery injury induced by a calcified pericardial plaque.

Characterization of mesothelioma and tissues present in contrast‐enhanced thoracic CT scans

The purpose of this study was to characterize the Hounsfield unit (HU) distributions of mesothelioma and other tissues present in contrast-enhanced thoracic CT scans, to compare the HU distributions of mesothelioma, muscle, and liver by scanner and reconstruction filter/kernel combination, and to assess interpatient HU distribution variability. The database consisted of 28 contrast-enhanced thoracic CT scans from different patients. For each scan, regions of interest were manually outlined within each of 13 tissues, including mesothelioma. For each tissue, the empirical percentiles in HU values were calculated along with the interpatient variability. The HU distributions of select tissues were compared across three different scanner and reconstruction filter/kernel combinations. The HU distributions of blood-containing tissues demonstrated substantial overlap, as did the HU distributions of pleural effusion, mesothelioma, muscle, and liver. The HU distribution of fat had the least overlap with the other tissues. Fat and muscle had the lowest interpatient HU variability and the narrowest HU distributions, while blood-containing tissues had the highest interpatient HU variability. A soft-tissue reconstruction filter/kernel yielded the narrowest HU distribution, and fat with artifact had the widest HU distribution. Characterization of tissues in CT scans enhances the understanding of those tissues' HU distributions. Due to their overlapping HU distributions and close spatial proximity to one another, separating pleural effusion, mesothelioma, muscle, and liver from one another is a difficult task based on HU value thresholding alone. The results illustrate the wide distributions and large variability that exist for tissues present in clinical thoracic CT scans.

Tamponade with a thickened pericardium

A 24-year-old Caribbean man, with no previous medical history, presented with cough, dyspnoea, and weight loss of 6 kg over the previous month. He reported a 2-month history of night sweats without fever. Physical examination revealed breath frequency of 40 breaths per min and a tachycardia of 121 beats per min, with soft heart sounds and ankle oedema. Laboratory fi ndings showed a normal complete blood count and C-reactive protein of 107 mg/L. HIV serology was negative. Echocardiography found a tamponade with a thickened pericardium (6 mm), confi rmed by a contrast-enhanced thoracic CT scan (fi gure). Aspiration of fl uid from the pericardium yielded 2 litres of fl uid. Pericardial biopsy showed caseous necrosis. Cultures and PCR were positive for Mycobacterium tuberculosis in the pericardial fl uid. Disseminated pulmonary involvement was found on lung-windowed CT scan. The patient was given antituberculous treatment combining isoniazid, rifampicin, ethambutol, and pyrazinamide for 2 months, then isoniazid and rifampicin for the following 4 months. Corticotherapy was started at the same time as the antituberculous treatment, consisting of prednisone 1 mg/kg per day for 1 month tapered over the following 2 months. The patient remains disease-free after 26 months. Pericardial involvement is seen in up to 2% of patients with pulmonary tuberculosis. Tamponade is a frequent presentation in tuberculous pericarditis, happening in almost 90% of cases. Besides positive cultures, other important features for positive diagnosis are fever and night sweats, weight loss, serum globulin (greater than 40 g/L), and peripheral blood leukocyte count (less than 10×10 cells per L). Some investigators suggest that pericardial interferon γ, when available, is a useful diagnostic test with a better positive predictive value than pericardial adenosine deaminase. The use of corticosteroids in the treatment of tuberculous pericarditis needs further discussion. A small study has revealed that corticosteroids reduce complications in patients not infected with HIV. However, more studies in larger populations and in patients infected with HIV are warranted to better assess the role of corticosteroids in tuberculous pericarditis.

18F-FDG PET/CT in mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic country: consideration of lymph node calcification and distribution pattern to improve specificity

The aim of the study was to assess the accuracy of (18)F-fluorodeoxyglucose (FDG) PET/CT in mediastinal lymph node staging of patients with non-small-cell lung cancer (NSCLC) in a region with a high prevalence of granulomatous disease. Between March 2004 and February 2006, all patients with NSCLC underwent FDG PET/CT and contrast-enhanced thoracic CT, and subsequent surgical resection. PET/CT and contrast-enhanced CT images of 182 patients (126 men and 56 women; mean age 60.7 years) with NSCLC were acquired. Mediastinal node staging was determined using the American Joint Committee on Cancer (AJCC) staging system. Surgical and histological findings served as the reference standard. A total of 182 patients with 778 mediastinal node stations were evaluated. Sensitivity and specificity of contrast-enhanced CT were 36% and 80% on a per-patient basis and 23% and 92% on a per-node station basis. Sensitivity and specificity of PET/CT were 81% and 73% on a per-patient basis and 75% and 85% on a per-node station basis. After lymph nodes with calcification and bilateral hilar distribution were considered benign, sensitivity and specificity of PET/CT were 75% and 89% on a per-patient basis and 66% and 96% on a per-node station basis. This prospective study suggests that FDG PET/CT can more accurately stage mediastinal lymph nodes than CT. Considering lymph node calcification and distribution pattern could improve specificity at the cost of a decrease in sensitivity.

Anomalous unilateral pulmonary vein in a patient with aortic coarctation

A 34-year-old woman with previous aortic coarctation repair at the age of 5 years was referred for review. She was in good health. On clinical examination, there was no blood pressure difference between the arms, but pedal pulses were weak. A contrast-enhanced 64-slice thoracic CT scan was performed to assess the coarctation repair.