Accuracy of MRI on Diagnosis of Solitary Pulmonary Nodule

Solitary pulmonary nodule (SPN) is defined as a discrete, well margined opacity up to 3cm in diameter that is surrounded by normal lung tissue and is not associated with any other abnormality in the lung or nearby lymph nodes. CT scan is the modality of choice for detection of SPN. Lack of ionizing radiation and high spatial resolution are the main benefits of MRI, nevertheless the usefulness of this imaging modality on diagnosis of lung nodules has not been well established. Aim of this study was to determine the accuracy of MRI on diagnosis of SPNs that their presence have been confirmed by CT scan.
Subjects and A total of 32 patients, confirmed for SPN according to CT scan findings and 11 patient with normal CT scan were included in this prospective study were allocated as case and control groups respectively. Sensitivity, specificity and positive and negative predictive values of MRI were determinated. Site and size of pulmonary nodules as well as different MRI sequences were the investigated parameters.
Statistical analysis showed the least diagnostic sensitivity for T1w sequences (27%). T2w images and Fat-sat slices had 55% and 36% sensitivity respectively. Specificity of 97% for T1w images, 90% for T2w slices and 90% in Fat-sat sequences were the other results.
Although specificity of different sequences of MRI was ≥90% , low sensitivity and breath holding technique precludes its routine usage for the suspected patients with SPN and early detection of pulmonary nodules in high risk patients.