Diagnostic accuracy of magnetic resonance imaging for the detection of pulmonary nodules simulated in a dedicated porcine chest phantom

Comparison of chest computed tomography and 3-T magnetic resonance imaging results in patients with common variable immunodeficiency

Background

Patients with common variable immunodeficiency (CVID) have an increased incidence of pulmonary infections and require frequent follow-up computed tomography (CT) scans.

Purpose

To evaluate the diagnostic performance of 3-T magnetic resonance imaging (MRI) in patients with CVID.

Material and Methods

In this prospective study, 3-T MRI was performed in 20 patients with CVID. The patients were imaged with CT and MRI scans on the same day. The MRI protocol included a T2-weighted HASTE sequence (TR=1400 ms, TE=95 ms, slice thickness (ST)=3 mm), T2-weighted BLADE sequence (TR=5379 ms, TE=100 ms, ST=3 mm), and 3D VIBE sequence (TR=3.9 ms, TE=1.32 ms, ST=3 mm). Mediastinal and parenchymal changes were compared. A modified Bhalla scoring system was used in the evaluation of CT and MRI scans.

Results

A total of 17 (85%) patients had parenchymal abnormalities identified by CT or MRI. Similar findings were detected with CT and MRI in the assessment of the severity of bronchiectasis ( P=0.083), bronchial wall thickening ( P=0.157), and mucus plugging ( P=0.250). Consolidations were detected with both modalities in all patients. There was excellent concordance between the two modalities in the evaluation of nodules >5 mm (nodule size 5–10 mm, P=0.317; nodule size >10 mm, P=1). However, MRI failed to detect most of the small nodules (<5 mm).

Conclusion

3-T MRI detected mediastinal and parenchymal alterations in patients with CVID and provided findings that correlated well with CT. Despite a few limitations, MRI is a well-suited radiation-free technique for patients requiring longitudinal imaging.

Imaging of GBM in the Age of Molecular Markers and MRI Guided Adaptive Radiation Therapy

Glioblastoma (GBM) continues to be one of the most lethal malignancies and is almost always fatal. In this review article, the role of radiation therapy, systemic therapy, as well as the molecular basis of classifying GBM is described. Technological advances in the treatment of GBM are outlined as well as the diagnostic imaging characteristics of this tumor. In addition, factors that affect prognosis such as differentiating progression from treatment effect is discussed. The role of MRI guided radiation therapy and how this technology may provide a mechanism to improve the care of patients with this disease are described.

Detection of lung lesions in breath-hold VIBE and free-breathing Spiral VIBE MRI compared to CT

BACKGROUND

Detection of pulmonary nodules in MRI requires fast imaging strategies without respiratory motion impairment, such as single-breath-hold Cartesian VIBE. As patients with pulmonary diseases have limited breath-hold capacities, this study investigates the clinical feasibility of non-Cartesian Spiral VIBE under free-breathing compared to CT as the gold standard.

METHODS

Prospective analysis of 27 oncological patients examined in PET/CT and PET/MR. A novel motion-robust 3D ultrashort-echo-time (UTE) MR sequence was evaluated in comparison with CT and conventional breath-hold MR. CT scans were performed under breath-hold in end-expiratory and end-inspiratory position (CT ex, CT in). MR data was acquired with non-contrast-enhanced breath-hold Cartesian VIBE followed by a free-breathing 3D UTE Spiral VIBE. Impact of respiratory motion on pulmonary evaluation was investigated by two readers in Cartesian VIBE, followed by UTE Spiral VIBE and CT ex and the reference standard of CT in. Diagnostic accuracy was calculated, and visual image quality assessed.

RESULTS

Higher detection rate and sensitivity of pulmonary nodules in free-breathing UTE Spiral VIBE in comparison with breath-hold Cartesian VIBE were found for lesions > 10 mm (UTE Spiral VIBE/VIBE/CT ex): 93%/54%/100%; Lesions 5-10 mm: 67%/25%/ 92%; Lesions < 5 mm: 11%/11%/78%. Lobe-based analysis revealed sensitivities and specificities of 64%/96%/41% and 96%/93%/100% for UTE Spiral VIBE/VIBE/CT ex.

CONCLUSION

Free-breathing UTE Spiral VIBE indicates higher sensitivity for detection of pulmonary nodules than breath-hold Cartesian VIBE and is a promising but time-consuming approach. However, sensitivity and specificity of inspiratory CT remain superior in comparison and should be preferred for detection of pulmonary lesions.