Ultrashort echo time MRI of the lung in children and adolescents: comparison with non-enhanced computed tomography and standard post-contrast T1w MRI sequences

Abstract

Objectives To compare the diagnostic value of ultrashort echo time (UTE) magnetic resonance imaging (MRI) for the lung versus the gold standard computed tomography (CT) and two T1-weighted MRI sequences in children. Methods Twenty-three patients with proven oncologic disease (14 male, 9 female; mean age 9.0 + / − 5.4 years) received 35 low-dose CT and MRI examinations of the lung. The MRI protocol (1.5-T) included the following post-contrast sequences: two-dimensional (2D) incoherent gradient echo (GRE; acquisition with breath-hold), 3D volume interpolated GRE (breath-hold), and 3D high-resolution radial UTE sequences (performed during free-breathing). Images were evaluated by considering image quality as well as distinct diagnosis of pulmonary nodules and parenchymal areal opacities with consideration of sizes and characterisations. Results The UTE technique showed significantly higher overall image quality, better sharpness, and fewer artefacts than both other sequences. On CT, 110 pulmonary nodules with a mean diameter of 4.9 + / − 2.9 mm were detected. UTE imaging resulted in a significantly higher detection rate compared to both other sequences (p < 0.01): 76.4% (84 of 110 nodules) for UTE versus 60.9% (67 of 110) for incoherent GRE and 62.7% (69 of 110) for volume interpolated GRE sequences. The detection of parenchymal areal opacities by the UTE technique was also significantly higher with a rate of 93.3% (42 of 45 opacities) versus 77.8% (35 of 45) for 2D GRE and 80.0% (36 of 45) for 3D GRE sequences (p < 0.05). Conclusion The UTE technique for lung MRI is favourable in children with generally high diagnostic performance compared to standard T1-weighted sequences as well as CT. Key Points • Due to the possible acquisition during free-breathing of the patients, the UTE MRI sequence for the lung is favourable in children. • The UTE technique reaches higher overall image quality, better sharpness, and lower artefacts, but not higher contrast compared to standard post-contrast T1-weighted sequences. • In comparison to the gold standard chest CT, the detection rate of small pulmonary nodules small nodules ≤ 4 mm and subtle parenchymal areal opacities is higher with the UTE imaging than standard T1-weighted sequences.

Sensitivity and specificity of magnetic resonance imaging in routine diagnosis of pulmonary lesions: a comparison with computed tomography

“…For SNs between 6 and 8 mm with malignant risk of 1–2%, (Lung-RADS score 3), T1-VIBE showed the lowest sensitivity of 80% and T2WI achieved higher sensitivity of 93.3%, which was superior to the published studies showing sensitivity of 75% for 6–8 mm nodules by T1WI ( 23 ). Recently, ultra short echo time (UTE), which is used in conjunction with the PD-weighted 3D GRE sequence, has been reported more promising and useful in pulmonary diseases assessment ( 9 , 18 , 24 ). UTE achieved the sensitivity of 83–94.4% for 6–8 mm nodules ( 15 , 25 ), which was comparable to our results.…”

Röntgenuntersuchungen des Thorax bei Kindern und Jugendlichen

“…7 . Die MRT wird zunehmend als bildgebende Alternative zur Diagnostik pulmonaler Rundherde diskutiert; ein Benefit der MRT scheint eine mögliche bessere Differenzierung zwischen benignen und malignen Rundherden im Vergleich zu anderen Modalitäten zu sein [ 34 , 35 ].

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Röntgenuntersuchungen des Thorax bei Kindern und Jugendlichen

“…7 . Die MRT wird zunehmend als bildgebende Alternative zur Diagnostik pulmonaler Rundherde diskutiert; ein Benefit der MRT scheint eine mögliche bessere Differenzierung zwischen benignen und malignen Rundherden im Vergleich zu anderen Modalitäten zu sein [ 34 , 35 ].

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