Clinical and Imaging Features of COVID-19-Associated Pulmonary Aspergillosis.

BACKGROUND: COVID-19 superinfection by Aspergillus (COVID-19-associated aspergillosis, CAPA) is increasingly observed due to increased awareness and use of corticosteroids. The aim of this study is to compare clinical and imaging features between COVID-19 patients with and without associated pulmonary aspergillosis. MATERIAL AND METHODS: In this case-control study, hospitalized patients between March 2020 and March 2021 were evaluated. Two observers independently compared 105 chest CTs of 52 COVID-19 patients without pulmonary aspergillosis to 40 chest CTs of 13 CAPA patients. The following features were evaluated: lung involvement, predominant main pattern (ground glass opacity, crazy paving, consolidation) and additional lung and chest findings. Chronological changes in the abnormal extent upon CT and chronological changes in the main patterns were compared with mixed models. Patient-wise comparisons of additional features and demographic and clinical data were performed using Student's t-test, Chi-squared test, Fisher's exact tests and Wilcoxon rank-sum tests. RESULTS: Compared to COVID-19 patients without pulmonary aspergillosis, CAPA patients were older (mean age (±SD): 70.3 (±7.8) versus 63.5 (±9.5) years (p = 0.01). The time-dependent evolution rates for consolidation (p = 0.02) and ground glass (p = 0.006) differed. In early COVID-19 disease, consolidation was associated with CAPA, whereas ground glass was less common. Chronological changes in the abnormal extent upon CT did not differ (p = 0.29). Regardless of the time point, bronchial wall thickening was observed more frequently in CAPA patients (p = 0.03). CONCLUSIONS: CAPA patients showed a tendency for consolidation in early COVID-19 disease. Bronchial wall thickening and higher patient age were associated with CAPA. The overall lung involvement was similar between both groups.

Prognostic Value of Negative Coronary CT Angiography in Severely Obese Patients Prior to Bariatric Surgery: a Follow-Up After 6 Years.

BACKGROUND: This study aims to determine the long-term prognostic value of coronary CT angiography (CCTA) prior to bariatric surgery in severely obese patients with a body mass index (BMI) ≥35 kg/m2. MATERIAL AND METHODS: Seventy consecutive patients undergoing cardiac CT for coronary assessment prior to bariatric surgery were prospectively included. Images were analysed for the presence of coronary calcification and for non-obstructive (<50%) or obstructive (>50% stenosis) coronary artery disease (CAD). A median clinical follow-up of 6.1 years in 54 patients was obtained for major adverse cardiovascular events (MACEs), defined as death, non-fatal myocardial infarction or coronary revascularisation. Weight loss and BMI decrease following bariatric surgery were recorded. RESULTS: The median BMI prior to surgery was 46.9 kg/m2. The median percentage of excess BMI loss after surgery was 75%. CT showed coronary calcification in 26 (48%) patients, whereas 28 (52%) patients had no calcification. CCTA revealed normal coronaries in 47 (87%) and non-obstructive CAD in 7 (13%) patients. No obstructive CAD was found. All patients successfully underwent bariatric surgery, and no MACE occurred neither perioperatively nor in the follow-up period. The negative predictive value of CCTA was 100% (95% confidence interval of 90.1-100.0%). CONCLUSIONS: In severely obese patients, the absence of obstructive CAD in cardiac CT prior to bariatric surgery with subsequently marked weight reduction has strong long-term prognostic implications for ruling out major adverse cardiac events in the postoperative period.

Ultralow dose CT for pulmonary nodule detection with chest x-ray equivalent dose - a prospective intra-individual comparative study.

PURPOSE: To prospectively evaluate the accuracy of ultralow radiation dose CT of the chest with tin filtration at 100 kV for pulmonary nodule detection. MATERIALS AND METHODS: 202 consecutive patients undergoing clinically indicated chest CT (standard dose, 1.8 ± 0.7 mSv) were prospectively included and additionally scanned with an ultralow dose protocol (0.13 ± 0.01 mSv). Standard dose CT was read in consensus by two board-certified radiologists to determine the presence of lung nodules and served as standard of reference (SOR). Two radiologists assessed the presence of lung nodules and their locations on ultralow dose CT. Sensitivity and specificity of the ultralow dose protocol was compared against the SOR, including subgroup analyses of different nodule sizes and types. A mixed effects logistic regression was used to test for independent predictors for sensitivity of pulmonary nodule detection. RESULTS: 425 nodules (mean diameter 3.7 ± 2.9 mm) were found on SOR. Overall sensitivity for nodule detection by ultralow dose CT was 91%. In multivariate analysis, nodule type, size and patients BMI were independent predictors for sensitivity (p < 0.001). CONCLUSIONS: Ultralow dose chest CT at 100 kV with spectral shaping enables a high sensitivity for the detection of pulmonary nodules at exposure levels comparable to plain film chest X-ray. KEYPOINTS: • 91% of all lung nodules were detected with ultralow dose CT • Sensitivity for subsolid nodule detection is lower in ultralow dose CT (77.5%) • The mean effective radiation dose in 202 patients was 0.13 mSv • Ultralow dose CT seems to be feasible for lung cancer screening.

Suction/Inspiration against resistance or standardized Mueller maneuver : a new breathing technique to improve contrast density within the pulmonary artery: a pilot CT study.

OBJECTIVE: Our aim was to prospectively investigate whether the recently introduced suction/inspiration against resistance breathing method leads to higher computed tomography (CT) contrast density in the pulmonary artery compared to standard breathing. MATERIAL AND METHODS: The present study was approved by the Medical Ethics committee and all subjects gave written informed consent. Fifteen patients, each without suspicious lung emboli, were randomly assigned to four different groups with different breathing maneuvers (suction against resistance, Valsalva, inspiration, expiration) during routine CT. Contrast enhancement in the central and peripheral sections of the pulmonary artery were measured and compared with one another. RESULTS: Peripheral enhancement during suction yielded increased mean densities of 138.14 Hounsfield units (HU) (p = 0.001), compared to Valsalva and a mean density of 67.97 HU superior to inspiration (p = 0.075). Finally, suction in comparison to expiration resulted in a mean increase of 30.51 HU (p = 0.42). Central parts of pulmonary arteries presented significantly increased enhancement values (95.74 HU) for suction versus the Valsalva technique (p = 0.020), while all other mean densities were in favour of suction (versus inspiration: p = 0.201; versus expiration: p = 0.790) without reaching significance. CONCLUSION: Suction/Inspiration against resistance is a promising technique to improve contrast density within pulmonary vessels, especially in the peripheral parts, in comparison to other breathing maneuvers. KEY POINTS: • Suction/Inspiration against resistance is promising to improve contrast density within the pulmonary artery. • Patients potentially suffering pulmonary embolism are able to follow suction/inspiration against resistance. • Contrast density after suction is superior in comparison to other breathing maneuvers.

Suction against resistance: a new breathing technique to significantly improve the blood flow ratio of the superior and inferior vena cava.

OBJECTIVES: Optimal contrast within the pulmonary artery is achieved by the maximum amount of contrast-enhanced blood flowing through the superior vena cava (SVC), while minimum amounts of non-contrasted blood should originate from the inferior vena cava (IVC). This study aims to clarify whether "suction against resistance" might optimise this ratio. METHODS: Phase-contrast pulse sequences on a 1.5T MRI magnet were used for flow quantification (mean flow (mL/s), stroke volume (Vol) in the SVC and IVC in volunteers. Different breathing manoeuvers were analysed repeatedly: free breathing; inspiration; expiration; suction against resistance, and Valsalva. To standardise breathing commands, volunteers performed suction and Valsalva manoeuvers with an MR-compatible manometer. RESULTS: Suction against resistance was associated with a significant drop of the IVC/SVC flow quotient (1.63 [range 1.3-2.0] p < 0.05 at -10 mmHg and 1.48 [1.1-1.9] p < 0.01 at -20 mmHg) corresponding to increased blood flow from SVC and diminished flow originating from the IVC. The remaining breathing commands (free breathing 2.2; inspiration 2.4; expiration 2.4; Valsalva 10 mmHg 2.3; Valsalva 20 mmHg 2.6; and Valsalva 30 mmHg 2.2) showed no differences (p > 0.05). CONCLUSIONS: Suction against resistance caused a significant drop in the IVC/SVC quotient. Theoretically, this breathing manoeuver might significantly improve the enhancement characteristics of CT angiography. KEY POINTS: Suction provokes reduction in blood flow in the inferior vena cava. Ratio between the inferior and superior vena cava blood flow diminished during suction. Manometer used during breathing standardises MR phase-contrast blood flow measurements.