Chronic Aspiration as a Cause for Dendriform Pulmonary Ossifications.

Teaching point: Dendriform pulmonary ossifications (DPO) are a rare form of diffuse pulmonary ossifications, in which these ossifications are organised in dendrite-like lines in the periphery of the bases of the lung, most commonly attributed to underlying interstitial lung disease (ILD), but can also be found in patients with chronic aspiration if no other CT findings of ILD are present.

Rare and potentially lethal case of a round lesion in the lung.

A pulmonary venous aneurysm (PVA) is extremely rare. A PVA can be either congenital or acquired. Possible symptoms include thoracic pain, dyspnoea, haemoptysis and palpitations but can also occur asymptomatically. Treatment can be conservative or surgical depending on growth and risk of rupture or development of mitral insufficiency, symptoms and thrombus formation. Only a few cases have been described in the literature. A recent case study and a literature review are described below.

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH): An Underrecognized Cause of Multiple Lung Nodules and Mosaic Perfusion Pattern.

Teaching Point: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is an underrecognized and misdiagnosed cause of multiple lung nodules in combination with mosaic attenuation.

Deep Learning-based Approach for Automated Assessment of Interstitial Lung Disease in Systemic Sclerosis on CT Images.

PURPOSE: To develop a deep learning algorithm for the automatic assessment of the extent of systemic sclerosis (SSc)-related interstitial lung disease (ILD) on chest CT images. MATERIALS AND METHODS: This retrospective study included 208 patients with SSc (median age, 57 years; 167 women) evaluated between January 2009 and October 2017. A multicomponent deep neural network (AtlasNet) was trained on 6888 fully annotated CT images (80% for training and 20% for validation) from 17 patients with no, mild, or severe lung disease. The model was tested on a dataset of 400 images from another 20 patients, independently partially annotated by three radiologist readers. The ILD contours from the three readers and the deep learning neural network were compared by using the Dice similarity coefficient (DSC). The correlation between disease extent obtained from the deep learning algorithm and that obtained by using pulmonary function tests (PFTs) was then evaluated in the remaining 171 patients and in an external validation dataset of 31 patients based on the analysis of all slices of the chest CT scan. The Spearman rank correlation coefficient (ρ) was calculated to evaluate the correlation between disease extent and PFT results. RESULTS: The median DSCs between the readers and the deep learning ILD contours ranged from 0.74 to 0.75, whereas the median DSCs between contours from radiologists ranged from 0.68 to 0.71. The disease extent obtained from the algorithm, by analyzing the whole CT scan, correlated with the diffusion lung capacity for carbon monoxide, total lung capacity, and forced vital capacity (ρ = -0.76, -0.70, and -0.62, respectively; P < .001 for all) in the dataset for the correlation with PFT results. The disease extents correlated with diffusion lung capacity for carbon monoxide, total lung capacity, and forced vital capacity were ρ = -0.65, -0.70, and -0.57, respectively, in the external validation dataset (P < .001 for all). CONCLUSION: The developed algorithm performed similarly to radiologists for disease-extent contouring, which correlated with pulmonary function to assess CT images from patients with SSc-related ILD.Supplemental material is available for this article.© RSNA, 2020.

Does Ipsilateral-Dependent Positioning During Percutaneous Lung Biopsy Decrease the Risk of Pneumothorax?

OBJECTIVE: The purpose of this study is to determine whether placing patients in an ipsilateral-dependent position during percutaneous CT-guided transthoracic biopsy reduces the pneumothorax rate. MATERIALS AND METHODS: Between July 2013 and August 2017, a total of 516 patients (317 men and 199 women; mean age, 66.4 years) underwent core needle biopsies performed using 17- and 18-gauge needles. The overall pneumothorax rate and the rate of pneumothorax requiring drainage catheter insertion were compared between group A (patients placed in an ipsilateral-dependent position) and group B (patients placed in a position other than the ipsilateral-dependent position), with use of a chi-square test or Fisher exact test, as appropriate. Linear regression analysis and multiple regression analysis were performed for risk factors of pneumothorax, including patient characteristics (e.g., emphysema along the needle track), lesion characteristics (e.g., size and position), and biopsy technique characteristics (e.g., needle path length, needle-pleura angle, and fissure crossing). RESULTS: For patients in group A and group B, the overall pneumothorax rate (21/94 [22.3%] and 95/422 [22.5%], respectively; p = 0.97) and the rate of pneumothorax requiring drainage catheter insertion (6/94 [6.4%] and 28/422 [6.6%], respectively; p = 0.90) were not statistically different. After multiple regression analysis, the only independent risk factors for pneumothorax and insertion of a drainage catheter were needle path length (p < 0.001 and p = 0.02, respectively), emphysema along the needle track (p = 0.01 and p < 0.001, respectively), and fissure crossing (p = 0.04 and p < 0.001, respectively). CONCLUSION: Even though the pneumothorax rate does not appear to be reduced, with the limits of a retrospective evaluation considered, other advantages of the ipsilateral decubitus position exist, including protection of the contralateral lung in patients with severe hemoptysis.

Intravoxel incoherent motion and dynamic contrast-enhanced MRI for differentiation between hepatocellular adenoma and focal nodular hyperplasia.

OBJECTIVE: To examine if intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced MRI (DCE-MRI) can be used as new and supplemental MRI techniques to differentiate hepatocellular adenomas (HCAs) from focal nodular hyperplasias (FNHs) and analyse if diffusion parameter apparent diffusion coefficient (ADC) and IVIM parameter true diffusion coefficient (D) differ in doing so. METHODS: This prospective study included 21 patients (8 HCAs and 13 FNHs) who underwent a specifically designed MRI scanning protocol, including series for analysis of IVIM (four b-values 0, 10, 150 and 800 s mm-2) and DCE-MRI. On a dedicated workstation, identical regions of interest were placed in parametric maps of Ktrans, Ve, D and ADC in each lesion for quantification. Diagnostic accuracy was assessed using receiver operating characteristics analysis. Time-intensity curves (TICs) were classified in different types. RESULTS: HCAs had significantly lower values for Ktrans (mean 1.45 vs 2.68 min-1; p = 0.029) and D (mean 1.02 × 10-3 vs 1.22 × 10-3 mm2 s-1; p = 0.033). Both parameters showed good diagnostic accuracy of 76%. TIC analysis could not differentiate between HCAs and FNHs. CONCLUSION: In this exploratory study, Ktrans and D were able to differentiate HCAs from FNHs in most cases, whereas Ve, ADC and TIC analysis were not. Advances in knowledge: Histological differences between HCAs and FNHs can be quantified on MRI using Ktrans and D.

Primary Angiosarcoma of the Central Nervous System: Case Report and Review of the Imaging Features.

Primary angiosarcoma of the central nervous system is a rare malignant tumor with only 28 reported cases so far. Imaging findings have only been reported in a few cases. We report a case of intracranial angiosarcoma in a Caucasian male and present a review of the imaging features in the recent literature. The tumor mostly presents as a well-demarcated, heterogeneous, moderately to strongly enhancing lesion with signs of intratumoral bleeding and surrounding vasogenic edema. The differential imaging features of common hemorrhagic intracranial tumors are discussed.