Guilherme Watte

Magnetic resonance imaging of pulmonary nodules: accuracy in a granulomatous disease–endemic region

AbstractObjectiveTo estimate the diagnostic accuracy of signal intensity of the lesion-to-spinal cord ratio (LSR) and apparent diffusion coefficient (ADC) in diffusion-weighted (DW) magnetic resonance imaging of pulmonary nodules suspicious for lung cancer in granulomatous lung disease-endemic regions.MethodsForty-nine patients with indeterminate solitary pulmonary nodules detected by chest computed tomography and histopathologically confirmed diagnoses were included in the study. DW images were analysed semiquantitatively by focusing regions of interest on the lesion and spinal cord at the same level (for LSR calculation). ADCs were estimated from ratios of the two image signal intensities. Ratios of T1 and T2 signal intensity between nodules and muscle were calculated for comparison.ResultsMean ADCs ± standard deviations for lung cancer and benign lesions were 0.9 ± 0.2 and 1.3 ± 0.2 × 10-3 mm2/s, respectively. Mean LSRs were 1.4 ± 0.3 for lung cancer and 1 ± 0.1 for benign lesions. ADCs and LSRs differed significantly between malignant and benign lesions (P < 0.001). Mean T2 signal intensity ratios also differed significantly between benign and malignant lesions (0.8 ± 0.2 vs. 1.6 ± 0.2; P < 0.05).ConclusionsDWI can help to differentiate malignant from benign lesions according to ADC and the LSR with good accuracy.Key Points• DW imaging can help differentiate malignant from benign pulmonary nodules. • ADC and LSR signal intensities had only small overlap between malignant and benign pulmonary nodules. • Mean T2 signal intensity ratios differed significantly between benign and malignant lesions.

Functional improvement in patients with idiopathic pulmonary fibrosis undergoing single lung transplantation.

Abstract Objective: To evaluate the changes in lung function in the first year after single lung transplantation in patients with idiopathic pulmonary fibrosis (IPF). Methods: We retrospectively evaluated patients with IPF who underwent single lung transplantation between January of 2006 and December of 2012, reviewing the changes in the lung function occurring during the first year after the procedure. Results: Of the 218 patients undergoing lung transplantation during the study period, 79 (36.2%) had IPF. Of those 79 patients, 24 (30%) died, and 11 (14%) did not undergo spirometry at the end of the first year. Of the 44 patients included in the study, 29 (66%) were men. The mean age of the patients was 57 years. Before transplantation, mean FVC, FEV1, and FEV1/FVC ratio were 1.78 L (50% of predicted), 1.48 L (52% of predicted), and 83%, respectively. In the first month after transplantation, there was a mean increase of 12% in FVC (400 mL) and FEV1 (350 mL). In the third month after transplantation, there were additional increases, of 5% (170 mL) in FVC and 1% (50 mL) in FEV1. At the end of the first year, the functional improvement persisted, with a mean gain of 19% (620 mL) in FVC and 16% (430 mL) in FEV1. Conclusions: Single lung transplantation in IPF patients who survive for at least one year provides significant and progressive benefits in lung function during the first year. This procedure is an important therapeutic alternative in the management of IPF.

Interobserver agreement between radiologists and radiology residents and emergency physicians in the detection of PE using CTPA

OBJECTIVE To assess interobserver agreement between thoracic radiologists, radiology residents, and emergency physicians in diagnosing pulmonary embolism (PE). MATERIALS AND METHODS Emergency physicians, radiology residents, and thoracic radiologists evaluated 123 computed tomography pulmonary angiography images. Interobserver agreement was analysed using kappa statistics. RESULTS Very good agreements were observed between thoracic radiologists and radiology residents (0.81 and 0.82). Fair and moderate agreements (0.39 and 0.42) were demonstrated between emergency physicians and thoracic radiologists. CONCLUSIONS Important differences in interobserver agreement were found, with emergency physicians tending to overdiagnose PE.

Magnetic Resonance Imaging of Pulmonary Embolism: Diagnostic Accuracy of Unenhanced MR and Influence in Mortality Rates

ObjectivesWe evaluated the diagnostic value for pulmonary embolism (PE) of the True fast imaging with steady-state precession (TrueFISP) MRI, a method that allows the visualization of pulmonary vasculature without breath holding or intravenous contrast.MethodsThis is a prospective investigation including 93 patients with suspected PE. All patients underwent TrueFISP MRI after undergoing CT pulmonary angiography (CTPA). Two independent readers evaluated each MR study, and consensus was obtained. CTPA results were analysed by a third independent reviewer and these results served as the reference standard. A fourth radiologist was responsible for evaluating if lesions found on MRI for both analysis were the same and if these were the correspondent lesions on the CTPA. Sensitivity, specificity, predictive values and accuracy were calculated. Evidence for death from PE within the 1-year follow-up was also assessed.ResultsTwo patients could not undergo the real-time MRI and were excluded from the study. PE prevalence was 22%. During the 1-year follow-up period, eight patients died, whereas PE was responsible for 12.5% of cases. Between patients who developed PE, only 5% died due to this condition. There were no differences between MR and CT embolism detection in these subjects. MR sequences had a sensitivity of 85%, specificity was 98.6% and accuracy was 95.6%. Agreement between readers was high (κ= 0.87).ConclusionsCompared with contrast-enhanced CT, unenhanced MR sequences demonstrate good accuracy and no differences in the mortality rates in 1 year were detected.

Use of MDCT to Assess the Results of Bronchial Thermoplasty

OBJECTIVE The purpose of this study was to evaluate the use of MDCT to assess response to bronchial thermoplasty treatment for severe persistent asthma. MATERIALS AND METHODS MDCT data from 26 patients with severe persistent asthma who underwent imaging before and after bronchial thermoplasty were analyzed retrospectively. Changes in the following parameters were assessed: total lung volume, mean lung density, airway wall thickness, CT air trapping index (attenuation < -856 HU), and expiratory-inspiratory ratio of mean lung density (E/I index). Asthma Quality of Life Questionnaire score changes were also assessed. RESULTS Median total lung volumes before and after bronchial thermoplasty were 2668 mL (range, 2226-3096 mL) and 2399 mL (range, 1964-2802 mL; p = 0.08), respectively. Patients also showed a pattern of obstruction improvement in air trapping values (median before thermoplasty, 14.25%; median after thermoplasty, 3.65%; p < 0.001] and in mean lung density values ± SD (before thermoplasty, -702 ± 72 HU; after thermoplasty, -655 ± 66 HU; p < 0.01). Median airway wall thickness also decreased after bronchial thermoplasty (before thermoplasty, 1.5 mm; after thermoplasty, 1.1 mm; p < 0.05). There was a mean Asthma Quality of Life Questionnaire overall score change of 1.00 ± 1.35 (p < 0.001), indicating asthma clinical improvement. CONCLUSION Our study showed improvement in CT measurements after bronchial thermoplasty, along with Asthma Quality of Life Questionnaire score changes. Thus, MDCT could be useful for imaging evaluation of patients undergoing this treatment.

Silicosis prevalence and risk factors in semi‐precious stone mining in Brazil

BACKGROUND Underground mining generates large amounts of dust and exposes workers to silica. This study aims to determine the prevalence and predictor factors for the development of silicosis among semi-precious-stone mineworkers in southern Brazil working in a self-administered cooperative. METHODS In a cross-sectional study of 348 current workers and retirees, demographic data, medical, and occupational history were collected through an interview performed by a nurse and medical record review. Risk factor associations were studied by Poisson multivariate regression. RESULTS The overall prevalence of silicosis was 37%, while in current miners it was 28%. Several risk factors for silicosis were identified in the univariate analysis. Inadequate ventilation in the underground galleries combined with dry drilling, duration of silica exposure, and (inversely) education remained significant in the multivariate analysis (P < 0.05). CONCLUSION This study is unusual in studying semi-precious stone mineworkers in a self-administered worker cooperative with limited resources. The prevalence of silicosis was very high. A number of recommendations are made-including technical support for worker cooperatives, surveillance of silica exposure and silicosis, exposure reduction measures, and benefits allowing impaired miners to leave the industry.

Effects of blood glucose level on 18F fluorodeoxyglucose (18F-FDG) uptake for PET/CT in normal organs: an analysis on 5623 patients

Our purpose was to evaluate the effect of glycemia on 18F-FDG uptake in normal organs of interest. The influences of other confounding factors, such as body mass index (BMI), diabetes, age, and sex, on the relationships between glycemia and organ-specific standardized uptake values (SUVs) were also investigated. We retrospectively identified 5623 consecutive patients who had undergone clinical PET/CT for oncological indications. Patients were stratified into groups based on glucose levels, measured immediately before 18F-FDG injection. Differences in mean SUVmax values among glycemic ranges were clinically significant only when >10% variation was observed. The brain was the only organ that presented a significant inverse relationship between SUVmax and glycemia (p < 0.001), even after controlling for diabetic status. No such difference was observed for the liver or lung. After adjustment for sex, age, and BMI, the association of glycemia with SUVmax was significant for the brain and liver, but not for the lung. In conclusion, the brain was the only organ analyzed showing a clinically significant relationship to glycemia after adjustment for potentially confounding variables. The lung was least affected by the variables in our model, and may serve as an alternative background tissue to the liver.

Effects of blood glucose level on 18F-FDG uptake for PET/CT in normal organs: A systematic review

Purpose To perform a systematic review of the effect of blood glucose levels on 2-Deoxy-2-[18F]fluoro-D-glucose (18F-FDG) uptake in normal organs. Methods We searched the MEDLINE, EMBASE and Cochrane databases through 22 April 2017 to identify all relevant studies using the keywords “PET/CT” (positron emission tomography/computed tomography), “standardized uptake value” (SUV), “glycemia,” and “normal.” Analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Maximum and mean SUVs and glycemia were the main parameters analyzed. To objectively measure the magnitude of the association between glycemia and 18F-FDG uptake in different organs, we calculated the effect size (ES) and the coefficient of determination (R2) whenever possible. Results The literature search yielded 225 results, and 14 articles met the inclusion criteria; studies included a total of 2714 (range, 51–557) participants. The brain SUV was related significantly and inversely to glycemia (ES = 1.26; R2 0.16–0.58). Although the liver and mediastinal blood pool were significantly affected by glycemia, the magnitudes of these associations were small (ES = 0.24–0.59, R2 = 0.01–0.08) and negligible (R2 = 0.02), respectively. Lung, bone marrow, tumor, spleen, fat, bowel, and stomach 18F-FDG uptakes were not influenced by glycemia. Individual factors other than glycemia can also affect 18F-FDG uptake in different organs, and body mass index appears to be the most important of these factors. Conclusion The impact of glycemia on SUVs in most organs is either negligible or too small to be clinically significant. The brain SUV was the only value largely affected by glycemia.

Multidetector Computed Tomography Findings in Pulmonary Hamartomas: A New Fat Detection Threshold.

Purpose: The aim of the study was to determine the accuracy of multidetector computed tomography in the evaluation of histologically confirmed pulmonary hamartomas (PHs), with a special focus on fat detection. Materials and Methods: Data from 55 patients who had received a histologically confirmed diagnosis of PH and had undergone 64-slice thoracic MDCT were retrospectively evaluated. Results: PHs manifested predominantly as peripheral pulmonary nodules with lobulated margins. The average lesion diameter was 1.51 cm (SD 0.6 cm). Histologic analyses identified fat content in 43/55 (78.2%) surgical specimens. The accuracy, sensitivity, and specificity of fat detection at a density threshold of −40 HU were 83.7%, 100%, and 87.2%, respectively. A threshold of −33 HU yielded better results (95.3%, 100%, and 96.3%, respectively). Popcorn-like calcifications were found in only 12/55 (21.8%) PHs and were the only imaging feature suggestive of PH in 7.2% of cases. Most (66%) lesions with popcorn-like calcifications also contained fat. Conclusions: The adoption of a new threshold for fat content (<−33 HU) can lead to further improvements in the overall ability to detect PHs by CT.

Psychiatric hospitalizations in the Rio Grande do Sul State (Brazil) from 2000 to 2011

OBJECTIVE To examine the variation in the rates of psychiatric hospitalization and the mean hospital stay time in the public health system in the state of Rio Grande do Sul, in the south of Brazil, from 2000 to 2011. METHODS This was an ecological study. Data were collected from DATASUS. The rates were obtained from diagnosis of admissions due to psychoactive substance use and to other causes, stratified by the gender of the patients. The data were analyzed using Poisson regression and Spearman correlation coefficient. RESULTS Increasing hospitalization rates were observed for women with disorders due to substance use (p < 0.001) and other causes (p < 0.001), and among men with disorders due to the use of alcohol or other drugs (p < 0.001). This elevation of the rates remained statistically significant and inversely correlated to the length of hospital stay (p < 0.001). DISCUSSION In a period of expansion of the local care networks for mental health, an increase in the occupancy of psychiatric beds in the state was noticed, with shorter length of stay and greater diversity of gender and causes of hospitalization.