Carl Chartrand-Lefebvre

Effect of the Learning Process on Procedure Times and Radiation Exposure for CT Fluoroscopy-guided Percutaneous Biopsy Procedures

PURPOSEnTo assess if the learning process associated with computed tomography fluoroscopy (CTF) technology influences procedure and fluoroscopy times for percutaneous biopsy procedures.nnnMATERIALS AND METHODSnProspective analysis of the initial 250 consecutive patients who underwent percutaneous biopsy with use of a CT scanner equipped with rapid image reconstruction and fluoroscopic capabilities in a 24-month period. All procedures were performed with both continuous and spot fluoroscopic technique, with typical radiation parameters of 50 mA, 120 kV, and a 10-mm-slice thickness. The procedures were all performed by a single experienced interventional radiologist to limit the variables of physician expertise, interventional materials used, and biopsy approach. The subject group was divided into five equal consecutive groups of 50 patients. In each subgroup, the authors recorded mean lesion size, success, and complication rates, as well as mean procedure and fluoroscopy times.nnnRESULTSnThe five subgroups were similar patient populations as documented by the absence of statistically significant differences when comparing mean lesion size, procedure success, and complication rates (P > .05; ANOVA test). A statistically significant decrease in mean fluoroscopy (groups 1-5: 50.26 vs 45.24 vs 33.86 vs 32.68 vs 25.8 sec/patient) and mean procedure times (groups 1-5: 30.08 vs 27.9 vs 26.34 vs 25.6 vs 21.6 min/patient) was recorded between the patient subgroups (P < .0001; ANOVA test).nnnCONCLUSIONnThe learning process associated with CTF technology impacts procedure parameters by decreasing both mean procedure and fluoroscopy times, thereby increasing patient turnover and decreasing radiation exposure to the patient and the operator.

Coronary artery noninvasive imaging in adult Kawasaki disease

Coronary artery aneurysms, stenoses, and thromboses are significant complications of Kawasaki disease (KD). While appearing in childhood, coronary complications are often left unrecognized until early and mid-adulthood. Along with the increasing capacity of noninvasive coronary artery imaging modalities, especially computed tomography and magnetic resonance, radiologists are more likely to face the diagnosis of KD in adults. This article will review the clinical aspects of KD for radiologists and will compare coronary imaging modalities in the diagnosis of KD.

Chest tube drainage under radiological guidance for pleural effusion and pneumothorax in a tertiary care university teaching hospital: Review of 51 cases

BACKGROUNDnChest tube drainage under radiological guidance has been used with increasing frequency as a treatment option for pleural effusions and pneumothoraxes.nnnOBJECTIVEnTo evaluate the safety and usefulness of pleural drainage under radiological guidance for pleural effusion and pneumothorax in a tertiary care university teaching hospital.nnnMETHODSnA retrospective study of cases of chest tube placement under radiological guidance over a 12-month period in a university hospital.nnnRESULTSnFifty-one percutaneous pigtail catheter drainage cases were reviewed (30 patients). Forty-six (90%) chest tubes were inserted as a first-line treatment. The overall success rate of radiological drainage was 88%. Specific success rates were 92%, 85% and 91% for loculated pleural effusion, pneumothorax and empyema, respectively. The complications were few and minor.nnnCONCLUSIONSnPigtail catheter insertion under radiological guidance is a useful procedure for the treatment of sterile pleural effusion, empyema and pneumothorax. This technique can be used as a first-line procedure in the majority of cases.

Pandemic Influenza A (H1N1) 2009: Chest Radiographic Findings from 147 Proven Cases in the Montreal Area

Objective To describe chest radiographic findings in patients with isolated and complicated acute novel influenza A (H1N1) virus infection. Methods Retrospective study of 147 patients (64 men, mean age 41) with reverse-transcriptase polymerase chain reaction confirmed acute influenza A (H1N1) infection, who also had a chest radiograph <72 hours of viral specimen collection. Radiographs were analysed for acute findings. A correlation with bacterial cultures results was performed. The unpaired 2-sample equal-variance Student t test was applied to continuous variables and the Pearson χ2 test of association to discrete variables. Results In 71% of cases, chest radiograph was normal. The presence of acute imaging findings was associated with older age (P < .05), increased number of comorbidities (most commonly, chronic obstructive pulmonary disease, diabetes, asthma) (P < .05), higher rate of hospitalization (P < .05) and intensive care unit admission, and increased mortality. Predominant acute radiographic finding in isolated influenza A (H1N1) was alveolar opacity (88%), either unifocal or multifocal, most often in the lower lobes. In the subgroup of patients with positive imaging findings and for whom nonviral microbiologic data was available, 62% had superimposed bacterial or fungal infection. Conclusion In the majority of patients with acute influenza A (H1N1) infection, the chest radiograph is normal. Acute imaging findings are associated with older age, an increased number of comorbidities, and a higher rate of complications and mortality. The predominant radiographic finding of isolated primary influenza A (H1N1) infection is alveolar opacity. Superimposed bacterial infection is frequent and must be excluded in patients with abnormal imaging.

Accuracy and rate of coronary artery segment visualization with CT angiography for the non-invasive detection of coronary artery stenoses

ObjectivesTo evaluate CT coronary angiography (CTA) when compared with catheter coronary angiography (CCA), for the detection of coronary artery stenoses and rate of optimal coronary artery segment visualization.MethodRetrospective, two-center study enrolling 26 patients who underwent CCA and ECG-gated 16-detector CTA (slice thickness 0.6xa0mm; rotation 500xa0ms).Results and conclusion283 segments were available for postprocessing. Sensitivity, specificity, and positive predictive value were, respectively, 80, 100, and 100%, for detecting more than 50% luminal stenoses, when optimally visualized segments were considered, in comparison to CCA. Negative predictive value was excellent (98%). Rate of non-optimally visualized coronary segments was 26%. Most clinical benefits of coronary CT angiography should probably be obtained when it is performed to exclude significant stenoses on selected populations of patients with a low pre-test probability of severe coronary artery disease, and under optimal conditions of controlled heart rate and minimal presence of calcium.

Pulmonary arteriovenous malformation (PAVM) reperfusion after percutaneous embolization: Sensitivity and specificity of non-enhanced CT

PURPOSEnTo evaluate the sensitivity and specificity of non-enhanced chest CT to detect reperfusion after pulmonary arteriovenous malformation (PAVM) embolization.nnnMATERIALS AND METHODSnThe Institutional Review Board approved this retrospective HIPAA-compliant study and waived the need for patient consent. All consecutive patients who underwent PAVM embolization between January 2000 and April 2011 were included. Complex PAVMs and patients without available pre- and/or post-embolization CT were excluded. PAVM artery, aneurysm and vein diameters were measured on non-enhanced chest CT before and after PAVM embolization. Pulmonary angiography (PA) was the reference standard to assess PAVM reperfusion. Reperfusion detection was analyzed with receiver operating characteristic (ROC) curves according to percentage of diameter reduction cut-off. Inter-observer concordance was ascertained with intra-class correlation coefficients (ICCs).nnnRESULTSnOut of 68 patients with PAVM embolizations, 42 (62%) had 108 PAVMs that met inclusion/exclusion criteria. Areas under the ROC curves for PAVM reperfusion detection were 0.84, 0.87, and 0.78, respectively, for PAVM artery, aneurysm and vein (p>0.05). Sensitivity varied between 51% and 56%, and specificity between 86% and 98% for the <30% diameter reduction cut-off. Sensitivity was between 98% and 100%, and specificity, between 20% and 47% for the <70% diameter reduction cut-off. ICCs for inter-observer concordance were 0.58, 0.88 and 0.68 for percentage reduction of PAVM artery, aneurysm and vein, respectively.nnnCONCLUSIONnPAVM diameter reduction cut-offs of <30% and <70%, to detect PAVM reperfusion on non-enhanced CT reported in the literature, would respectively result in low sensitivity and specificity.

Pericardial Fat Necrosis Presenting as Acute Pleuritic Chest Pain

A 58-year-old man presented to the Emergency Department with a 4-day history of acute and progressive left pleuritic chest pain. The chest pain appeared suddenly, awakening the patient in the middle of the night. There was no history of trauma or associated dyspnea. Pain was not entirely relieved by non-steroidal anti-inflammatory drugs (NSAIDS). Prior medical history was relevant for diabetes, hypertension, and dyslipidemia. There were no risk factors for pulmonary embolus. On examination, the patient was cooperative and alert. Vitals signs were normal. Physical examination revealed decreased air entry in the left lower lung. Calves were non-tender and not swollen. The initial chest X-ray study showed a rise of the left hemidiaphragm and small left pleural effusion (Figure 1). Laboratory values were normal, with negative cardiac enzyme levels and D-dimers. The electrocardiogram (ECG) showed a normal sinus rhythm with a right bundle branch block, the exact same result as an ECG done 5 years prior (Figure 2). The patient’s pain was relieved by morphine. Probability for pulmonary embolus was intermediate at ventilation-perfusion scintigraphy, which demonstrated a ventilation-perfusion mismatch in the lateral basal segment of the left lower lobe. Intravenous heparin was started. Due to the result of lung scintigraphy, a pulmonary computed tomography (CT) angiography was requested. CT angiography did not show any signs of pulmonary embolism, although distal vascular evaluation at both lung bases was limited due to respiratory artifacts.

A rare case of anomalous origin of the left main coronary artery in an adult patient

Anomalous origin of left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly that causes a left-to-right shunt via the coronary system, resulting in coronary steal. We report an unusual case of a healthy 48 years-old patient presenting with dyspnea on exertion and mild chest pain who underwent surgical correction of this rare anomaly. Multiple procedures have been proposed in adults with ALCAPA. Although re-implantation of the left main coronary artery (LMCA) to the aorta remains the most physiological correction for this anomaly, the combination of LMCA ligation and coronary artery bypass grafting provides a dual coronary flow system and is preferable when re-implantation is impossible.

Postoperative imaging after lung transplantation.

Lung transplantation (LT) is an established procedure for chronic end-stage lung diseases. Complications are frequent and diverse and are the consequence of the complex surgical technique, the severity of the initial pathology, and the deep state of posttransplantation immunosuppression. Complications following LT include primary graft dysfunction, rejection (hyperacute, acute, and chronic), infections, posttransplantation lymphoproliferative disease, pleural and airway complications, native lung complications, and recurrence of primary disease. An understanding of these complications, their temporal evolution, and the role of radiology and other diagnostic methods in their diagnosis and management will help reduce the morbidity and mortality associated with LT.

Comparison of the effect of low- and iso-osmolar contrast agents on heart rate during chest CT angiography: Results of a prospective randomized multicenter study

PURPOSEnTo prospectively compare the effect of intravenous injection of low-osmolar iopamidol with that of intravenous injection of iso-osmolar iodixanol on heart rate (HR) during nongated chest computed tomographic (CT) angiography.nnnMATERIALS AND METHODSnThis multicenter study was approved by local institutional review boards, and patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA regulations. One hundred and thirty patients (54 male; mean age, 52 years) clinically suspected of having pulmonary embolism were referred for pulmonary CT angiography and were randomly assigned to receive 80 mL of either iopamidol (370 mg of iodine per milliliter, n = 63) or iodixanol (320 mg of iodine per milliliter, n = 67) at a rate of 4 mL/sec. HR (measured in beats per minute) was monitored from 5 minutes before the start of injection to the end of imaging, and precontrast HR and maximum postcontrast HR were recorded. Student t and χ(2) tests were used for continuous and categorical variables, respectively.nnnRESULTSnPrecontrast HR in patients who received iopamidol (mean, 81 beats per minute ± 18 [standard deviation]) was similar to that in patients who received iodixanol (mean, 77 beats per minute ± 17) (P = .16). Mean postcontrast HR was 87 beats per minute ± 17 and 82 beats per minute ± 18 (P = .16) in the iopamidol and iodixanol groups, respectively. Mean increase from precontrast HR to postcontrast HR was 5 beats per minute ± 9 and 5 beats per minute ± 7 (P = .72) in the iopamidol and iodixanol groups, respectively. Thirty-five (56%) of the 63 patients who received iopamidol and 33 (49%) of the 67 patients who received iodixanol had an HR increase of fewer than 5 beats per minute, 15 (24%) and 18 (27%) patients, respectively, had an increase of 5-9 beats per minute, and four (6%) and three (4%) patients, respectively, had an increase of more than 20 beats per minute. These proportions were not significantly different between the groups (P = .51, χ(2) test).nnnCONCLUSIONnHigh-rate intravenous administration of 80 mL of iopamidol and iodixanol during pulmonary CT angiography slightly increased HR; there was no difference in HR between the contrast agent groups.