Thyroid nodule characterization using Spectral Detector Computed Tomography (SDCT) in comparison to ultrasound.

OBJECTIVE: To characterize thyroid nodules seen on Spectral Detector computed tomography (SDCT) in respect to their Thyroid Imaging Reporting and Data System (TI-RADS) category on Ultrasound (US). METHODS: We included patients that underwent US examination for the evaluation of thyroid nodules and contrast-enhanced SDCT examination of the neck/thorax, between the years 2018-2020. The SDCT and US were performed within 6 months of each other. Only patients with a visible thyroid nodule on SDCT were included. Attenuation measurements of the nodules in Hounsfield units (HU) were performed on the conventional CT images, virtual non-contrast (VNC) images and virtual monoenergetic images of 40 keV and 100 keV. The Iodine concentration, spectral slope and enhancement estimation results of the nodules were measured. We compared the spectral results between two groups of nodules, according to the US report: TI-RADS 2-3 and TI-RADS 4-5 groups. RESULTS: Thirty-eight nodules were included in the study, 22 nodules in the TI-RADS 2-3 group and 16 in the TI-RADS 4-5 group. The nodules of the TI-RADS 4-5 group had significantly higher Iodine concentration measurement, 4.6 ± 1.8 mg/ml, compared to 2.3 ± 1.2 mg/ml in the TI-RADS 2-3 group; significantly higher estimated enhancement, 3.9 ± 1.5, compared to 2.2 ± 0.7; and significantly higher calculated spectral slope, 5.6 ± 2.2 compared to 2.9 ± 1.5 (p < 0.001). CONCLUSION: Spectral results of SDCT may assist in differentiating intermediate-high risk (TI-RADS 4-5) from low risk (TI-RADS 2-3) thyroid nodules. ADVANCES IN KNOWLEDGE: SDCT offers additional information for the characterization of thyroid nodules.

Real-Life Diagnostic Performance of the Hypersensitivity Pneumonitis Guidelines: A Multicenter Cohort Study.

Hypersensitivity pneumonitis (HP) is a heterogeneous interstitial lung disease (ILD) that may be difficult to confidently diagnose. Recently, the 2020 ATS/JRS/ALAT HP diagnostic guidelines were published, yet data validating their performance in real-life settings are scarce. We aimed to assess the diagnostic performance of the HP guidelines compared to the gold-standard multidisciplinary discussion (MDD). For this purpose, we included consecutive ILD patients that underwent diagnostic bronchoscopy between 2017 and 2020 in three large medical centers. Four diagnostic factors (antigen exposure history, chest computed tomography pattern, bronchoalveolar lavage lymphocyte count, and histology results) were used to assign guidelines-based HP diagnostic confidence levels for each patient. A sensitivity analysis was performed, with MDD diagnosis as the reference standard. Overall, 213 ILD patients were included, 45 (21%) with an MDD diagnosis of HP. The guidelines' moderate (≥70%) confidence threshold produced optimal performance with 73% sensitivity for HP, 89% specificity, and a J-index of 0.62. The area under the receiver operating characteristic curve (AUC) for a correct guidelines-based diagnosis was 0.86. The guidelines had better performance for non-fibrotic than fibrotic HP (AUC 0.92 vs. 0.82). All diagnostic factors, except bronchoalveolar lavage lymphocyte count, were independent predictors for MDD diagnosis of HP in a multivariate analysis. In conclusion, the HP guidelines exhibited a good diagnostic performance compared to MDD diagnosis in real-life setting.

The Added Value of Bronchoalveolar Lavage for Pulmonary Tuberculosis Diagnosis in High-Risk Hospitalized Patients with Negative Sputum Samples.

Hospitalized patients with a high suspicion of pulmonary tuberculosis (HS-PTB) are isolated until a definite diagnosis can be determined. If doubt remains after negative sputum samples, bronchoscopy with bronchoalveolar lavage (BAL) is often sought. Still, evidence of the added value of BAL in this patient population is scarce. To address this issue, we included consecutive HS-PTB patients with negative sputum samples who underwent BAL between 2017 and 2018. Chest X-rays (CXR) and CT scans were evaluated by a chest radiologist blind to the final diagnosis. Independent predictors for PTB were assessed by multivariate regression, using all positive PTB patients between 2017 and 2019 (by sputum or BAL) as a control group (n = 41). Overall, 42 HS-PTB patients were included (mean age 51 ± 9, 36% female). BAL was a viable diagnostic for PTB in three (7%) cases and for other clinically relevant pathogens in six (14%). Independent predictors for PTB were ≥2 sub-acute symptoms (adjusted OR 3.18, 95% CI 1.04-9.8), CXR upper-lobe consolidation (AOR 8.70, 95% CI 2.5-29), and centrilobular nodules in chest CT (AOR 3.96, 95% CI 1.20-13.0, p = 0.02). In conclusion, bronchoscopy with BAL in hospitalized patients with HS-PTB had a 7% added diagnostic value after negative sputum samples. Our findings highlight specific predictors for PTB diagnosis that could be used in future controlled studies to personalize the diagnostic evaluation.

High Prevalence of Right Ventricular/Left Ventricular Ratio ≥1 Among Patients Undergoing Computed Tomography Pulmonary Angiography.

AIM: Increased ratio between the right and left ventricular (RV/LV) diameters ≥1 is considered an important imaging marker for risk stratification among patients diagnosed with acute pulmonary embolism (PE). Our goal was to assess the prevalence of RV/LV≥1 among consecutive patients undergoing computed tomography pulmonary angiography, and to compare the prevalence of RV/LV≥1 between patients with and without PE. METHODS: Retrospective analysis of consecutive patients who underwent computed tomography pulmonary angiography due to clinical suspicion of PE between January 1, 2014 and December 31, 2014. The axial RV/LV diameters were measured. The prevalence of RV/LV ≥1 was compared between patients with and without PE and among PE patients, between those with central versus peripheral PE. RESULTS: The final cohort included 862 patients. A total of 142 (16.5%) had PE. RV/LV ≥1 was found in 553 (64.1%) of all patients, of them in 453 (63%) patients without PE and in 100 (70.4%) patients with PE (P=0.117). On multivariate analysis, PE was not significantly associated with RV/LV ≥1 (odds ratio [OR]: 1.4; 95% confidence interval [CI]: 0.9-2.1; P=0.102). There was no significant difference in the prevalence of RV/LV ≥1 among patients with central versus peripheral PE distribution (79.5% vs. 67%, P=0.101). Older age (OR: 1.03; 95% CI: 1.02-1.04; P<0.001) and male gender (OR: 1.51; 95% CI: 1.11-2.03; P=0.008), among all patients, were significantly associated with RV/LV diameter ≥1. CONCLUSION: As RV/LV ≥1 is highly prevalent (64.1%), without a significant difference between those with and without PE, an RV/LV ≥1 might not represent the cardiac response to the acute PE event, but rather the patient's baseline condition.