Magnetic resonance imaging of pulmonary nodules: accuracy in a granulomatous disease–endemic region

• Published in: European radiology Vol. 26; no. 9; pp. 2915 - 2920
• Main Authors: Henz Concatto, Natália, Watte, Guilherme, Marchiori, Edson, Irion, Klaus, Felicetti, José Carlos, Camargo, José Jesus, Hochhegger, Bruno
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-09-2016; Springer Nature B.V
• Subjects: Accuracy; Aged; Biopsy; Diagnosis, Differential; Diagnostic Radiology; Diffusion Magnetic Resonance Imaging - methods; Endemic Diseases; Female; Granuloma; Hospitals; Humans; Imaging; Internal Medicine; Interventional Radiology; Lung cancer; Lung diseases; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - pathology; Magnetic Resonance; Magnetic resonance imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Multiple Pulmonary Nodules - diagnostic imaging; Multiple Pulmonary Nodules - pathology; Neuroradiology; Radiology; Ratios; Reproducibility of Results; Sensitivity and Specificity; Solitary Pulmonary Nodule - diagnostic imaging; Solitary Pulmonary Nodule - pathology; Spinal cord; Spinal Cord Diseases; Thoracic surgery; Tomography; Tomography, X-Ray Computed; Tumors; Ultrasound; Brazil; Differentiation of malignant from benign lesions; Granulomatous disease-endemic region; Magnetic resonance imaging; Pulmonary nodules; Diffusion weighted
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-015-4125-1

Objective
To estimate the diagnostic accuracy of signal intensity of the lesion-to-spinal cord ratio (LSR) and apparent diffusion coefficient (ADC) in diffusion-weighted (DW) magnetic resonance imaging of pulmonary nodules suspicious for lung cancer in granulomatous lung disease-endemic regions.
Methods
Forty-nine patients with indeterminate solitary pulmonary nodules detected by chest computed tomography and histopathologically confirmed diagnoses were included in the study. DW images were analysed semiquantitatively by focusing regions of interest on the lesion and spinal cord at the same level (for LSR calculation). ADCs were estimated from ratios of the two image signal intensities. Ratios of T1 and T2 signal intensity between nodules and muscle were calculated for comparison.
Results
Mean ADCs ± standard deviations for lung cancer and benign lesions were 0.9 ± 0.2 and 1.3 ± 0.2 × 10
-3
mm
2
/s, respectively. Mean LSRs were 1.4 ± 0.3 for lung cancer and 1 ± 0.1 for benign lesions. ADCs and LSRs differed significantly between malignant and benign lesions (
P
 < 0.001). Mean T2 signal intensity ratios also differed significantly between benign and malignant lesions (0.8 ± 0.2 vs. 1.6 ± 0.2;
P
 < 0.05).
Conclusions
DWI can help to differentiate malignant from benign lesions according to ADC and the LSR with good accuracy.
Key Points
•
DW imaging can help differentiate malignant from benign pulmonary nodules.
•
ADC and LSR signal intensities had only small overlap between malignant and benign pulmonary nodules.
•
Mean T2 signal intensity ratios differed significantly between benign and malignant lesions.