Fetal brain MRI: neurometrics, typical diagnoses, and resolving common dilemmas.

This review presents a practical approach to imaging the fetal brain by MRI. Herein, we demonstrate how to measure brain structures and fluid spaces, and discuss the importance of comparing measurements to normative biometric references at a corresponding gestational age. We present some common imaging dilemmas of the technical aspects of fetal MRI with regard to typical regions of abnormality including the cerebrum, the ventricular system, and the posterior fossa, and discuss how to resolve them.

CT Morphologic Characteristics and Variant Patterns of Interstitial Pulmonary Fibrosis in Systemic Lupus Erythematosus.

PURPOSE: To assess CT features of pulmonary fibrosis in patients with systemic lupus erythematosus (SLE) and to assess the presence of several distinctive patterns of fibrosis associated with connective tissue disease. MATERIALS AND METHODS: A cross-sectional retrospective analysis was performed. An institutional clinical database was queried for the years of 2005-2015 to identify CT examination reports of patients with SLE and fibrotic lung disease, which yielded 50 patients (median age, 49 years; age range, 22-71 years; 46 women). CT examination reports were scored by two subspecialty thoracic radiologists using a standard multilevel semiquantitative system. Readers noted the presence or absence of several recently described CT signs of variant patterns of fibrosis in connective tissue disease (the "anterior upper lobe," "straight-edge," and "exuberant honeycombing" signs), as well as two other morphologic characteristics (an "island-like" appearance of areas of well-defined fibrosis with angular margins surrounded by normal lung and confluent regions of lucent lung destruction). RESULTS: The most common CT patterns were characterized as either fibrotic nonspecific interstitial pneumonia (38%, 19 of 50) or variant fibrosis (44%, 22 of 50). CT signs of variant fibrosis were identified by both readers in up to 62% of patients, with good κ agreement (0.44-0.64); the island-like sign (62%) and anterior upper lobe sign (52%) were most commonly observed. Pulmonary function test results showed correlations with several imaging findings but did not show correlations with CT signs of variant fibrosis. CONCLUSION: When present, pulmonary fibrosis in SLE often has a distinctive appearance and may also manifest as several variant fibrotic patterns.Keywords: CT, Lung© RSNA, 2021See also the commentary by White in this issue.

Higher Coronary Plaque Burden in Psoriatic Arthritis Is Independent of Metabolic Syndrome and Associated With Underlying Disease Severity.

OBJECTIVE: To examine the effect of metabolic syndrome and psoriatic disease-related variables on coronary plaque burden in psoriatic arthritis (PsA) patients. METHODS: Fifty PsA patients without symptoms of coronary artery disease (CAD) (25 with metabolic syndrome and 25 without metabolic syndrome) and 50 age- and sex-matched controls underwent 64-slice coronary computed tomography angiography. Plaque localization, segment involvement score (SIS), segment stenosis score (SSS), and total plaque volume (TPV) were calculated. Plaques were classified as calcified, mixed, or noncalcified. Kruskal-Wallis test, rank correlations, and linear regression analyses were used to study the relationship between PsA, metabolic syndrome, and plaque burden. RESULTS: Plaques were found in 76% of PsA patients versus 44% of controls (P = 0.001), and a higher proportion of patients with PsA had affected coronary vessels (P = 0.007). SIS, SSS, and TPV were greater in PsA patients than controls (P = 0.003, P = 0.001, and P ≤ 0.001, respectively). More PsA patients had mixed plaques, and mixed plaque volume was higher than in controls (P < 0.001). PsA patients with metabolic syndrome and those without metabolic syndrome had similar plaque burdens and types. SIS, SSS, and TPV did not show significant relationships with features of metabolic syndrome, but did significantly correlate with disease activity measures. TPV was associated with a diagnosis of PsA (B = 0.865, P = 0.008), but not with metabolic syndrome. Age, highest C-reactive protein level, highest swollen joint count, disease duration, and plasma glucose level were independent predictors of higher plaque burden in PsA. CONCLUSION: PsA is associated with accelerated coronary plaque formation, particularly mixed plaques, independent of metabolic disease. Psoriatic disease activity and severity may predict coronary plaque burden better than traditional risk factors.

Pulmonary fibrosis: tissue characterization using late-enhanced MRI compared with unenhanced anatomic high-resolution CT.

PURPOSE: We aimed to prospectively evaluate anatomic chest computed tomography (CT) with tissue characterization late gadolinium-enhanced magnetic resonance imaging (MRI) in the evaluation of pulmonary fibrosis (PF). METHODS: Twenty patients with idiopathic pulmonary fibrosis (IPF) and twelve control patients underwent late-enhanced MRI and high-resolution CT. Tissue characterization of PF was depicted using a segmented inversion-recovery turbo low-angle shot MRI sequence. Pulmonary arterial blood pool nulling was achieved by nulling main pulmonary artery signal. Images were read in random order by a blinded reader for presence and extent of overall PF (reticulation and honeycombing) at five anatomic levels. Overall extent of IPF was estimated to the nearest 5% as well as an evaluation of the ratios of IPF made up of reticulation and honeycombing. Overall grade of severity was dependent on the extent of reticulation and honeycombing. RESULTS: No control patient exhibited contrast enhancement on lung late-enhanced MRI. All IPF patients were identified with late-enhanced MRI. Mean signal intensity of the late-enhanced fibrotic lung was 31.8±10.6 vs. 10.5±1.6 for normal lung regions, P < 0.001, resulting in a percent elevation in signal intensity from PF of 204.8%±90.6 compared with the signal intensity of normal lung. The mean contrast-to-noise ratio was 22.8±10.7. Late-enhanced MRI correlated significantly with chest CT for the extent of PF (R=0.78, P = 0.001) but not for reticulation, honeycombing, or coarseness of reticulation or honeycombing. CONCLUSION: Tissue characterization of IPF is possible using inversion recovery sequence thoracic MRI.

Imaging in cystic fibrosis and non-cystic fibrosis bronchiectasis.

Bronchiectasis is defined as a permanent and progressive dilation of the airways, typically as a result of inflammation, infection, and subsequent repair. It typically presents with chronic cough, suppurative sputum production, and airway dilation. High-resolution computed tomography (HRCT) is now well established as the primary imaging tool for its investigation. Cystic fibrosis (CF) remains the most common autosomal recessive inherited disorder worldwide and its pulmonary hallmark is bronchiectasis. Although CF and non-CF bronchiectasis are different clinical entities, they are typically imaged using HRCT and share many imaging aspects, and also some differences. Several important recent CT technology developments have improved the detection and characterization of bronchiectasis and its complications. Many CT aspects of radiation exposure have also undergone important enhancements in recent years resulting in significant dose reductions. This is particularly relevant in a pulmonary disease such as bronchiectasis, which often undergoes serial HRCT surveillance in contemporary practice. Several new CT clinical applications in bronchiectasis have been recently advanced, and CT is now being increasingly incorporated into investigative algorithms to assess bronchiectasis treatment effects. In this review, we assess the latest imaging features of CF and non-CF bronchiectasis, discuss radiation dose reducing methods and technology of the latest scanners, describe recent CT clinical applications, and explore the use of CT as a treatment surrogate in CF and non-CF bronchiectasis.