Israel Medical Association Journal

Background: Coronavirus disease-2019 (COVID-19) chest computed tomography (CT) involves ground-glass opacity (GGO) and denser consolidations, which are crucial for diagnosis.

Objectives: To determine optimal window settings for characterization and detection of GGO and dense consolidation on CT imaging in COVID-19 patients using a Simplex-based approach.

Methods: The study included 54 conventional CTs of COVID patients in two phases. First, CT images of 14 patients with GGO and 4 with dense consolidation were included. Seven radiologists evaluated representative images in different windows of varied width and center. They were graded for adequacy of characterization and detection. A Simplex algorithm was used to iteratively determine the optimal window settings. Surface response maps expressing the relationship between window settings and overall reader grades were constructed. Next, the reviewers compared manufacturer recommendations to the new optimal windows found on CT images of 40 patients.

Results: Overall, 12 different window settings were evaluated over a total of 1176 reads. Optimal characterization and detection of pure GGO was seen with a center of 630 HU and width 1460 HU, producing higher grades for both detection and characterization than the manufacturer window settings (P = 0.005). Optimal windowing for dense consolidation was like manufacturer measures (-585 HU and 1800 HU). In phase 2, an overwhelming preference of 78% favoring the optimal window compared to conventional settings was found.

Conclusions: GGO lung opacities characteristic for COVID-19 can be best seen using a lower CT windowing width than the manufacturer's recommendations, unlike denser consolidations, possibly due to differences in underlying pathophysiology.

Background: Lung disease in patients with famHiat dys-autonomia is caused mainly by recurrent aspiration of gastric contents, food and liquids swallowed incorrectly.

Objective: To describe chest computed tomography findings in patients with familial dyautonomia.

Methods: A retrospective analysis of chest CT findings was performed for 34 FD patients (15 females, 19 males) with a mean age of 18± 12.8 years.

Results: The CT revealed bronchial wall thickening (in 94% of the patients), atelectasis (in 73%), ground glass opacities (in 53%), focal hyperinflation (in 44%), fibrosis (in 29%) and bronchiectasis (in 26%). The extrapulmonary abnormalities were scoliosis (79%) and esophageal dilatation (35%). Silent fractures were noted in two vertebral bodies and one rib.

Conclusions: Pulmonary changes were consistent with chronic inflammation in the bronchi and interstitial tissues. Ground  glass opacities and fibrosis support the theory that these changes could be due to gastric aspiration. Bronchiectasis is less frequent. Esophageal dilatation with fluid overflow adds to aspiration. Fractures can be asymptomaflc and are often missed.
 

Objectives: To present a variety of radiologic findings on high resolution computerized tomography in eight sequential patients with COP[1], together with clinical and pathologic correlation.

Methods: Sequential HRCT[2] examinations of eight patients (four males) aged 53–80 years (mean 65.5 years) with pathologically proven COP were retrospectively analyzed by a consensus of two experienced chest radiologists for the existence and distribution of airspace consolidation, ground-glass opacities, nodular thickening along bronchovascular bundles, small (<1 cm) and large (>1 cm) nodules. The distribution of radiologic findings was classified as unilateral or bilateral, located in the upper, lower or middle lobe, and central or peripheral. Also recorded was the presence or absence of mediastinal lymphadenopathy and pleural effusion. Correlation with clinical symptoms was analyzed.

Results: All eight patients had bilateral airspace consolidations: in two cases consolidations were limited to central fields, in four they were peripheral, and in the remaining two cases they were both central and peripheral. Small nodules were noted in six cases and large nodules in three. Ground-glass opacities were found in four cases. All patients had enlarged lymph nodes (1–1.5 cm) in the mediastinum. Radiologic abnormalities resolved or improved after steroid treatment in all patients.

Conclusions: HRCT findings of bilateral multiple heterogenic lung infiltrates and nodules associated with mild mediastinal lymphadenopathy in a patient with non-specific clinical symptoms are suggestive of COP; in such cases, lung biopsy is indicated. Radiologic resolution of abnormalities correlates well with clinical improvement under adequate steroid treatment.

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[1] COP = cryptogenic organizing pneumonia

[2] HRCT = high resolution computerized tomography