Diagnostic efficacy and characteristic feature of MRI in pulmonary hamartoma: comparison with CT, specimen MRI, and pathology.
OBJECTIVE
To determine the diagnostic efficacy of magnetic resonance imaging (MRI) in pulmonary hamartoma and observe the significant MRI features, other than fat or characteristic calcification revealed by computed tomography (CT).


METHODS
Six hamartomas were included and surgically resected, and we prospectively studied MRI in cases showing suggestive findings of hamartoma or indeterminate nodule on CT. We analyzed the tumor on CT and MRI (available enhancement study in 4) focusing on cleftlike structure in comparison with specimen MRI (n = 3) and histopathologic findings: presence, shape, and distribution of the cleftlike structure and signal intensity and enhancement of the cleftlike structure and main portion.


RESULTS
Computed tomography revealed suggestive findings of pulmonary hamartoma (fat or popcorn calcification) in only 3. All MRI revealed cleftlike structures particularly evident on T2-weighted images with same detectability as its specimen MRI: peripheral linear or curvilinear inclusions with sometimes intratumoral cleftlike space (n = 3), variable signal intensity, and frequent enhancement (3 in 4) pathologically correlated with the variable mesenchymal tissue components and amount arrayed along respiratory epithelial cells lining the cleft and richer vascularity than main portion of pulmonary hamartoma.


CONCLUSIONS
Magnetic resonance imaging study is a useful diagnostic tool, when a discrete pulmonary nodule demonstrates neither fat nor calcification on CT, for detecting the quite typical cleftlike structure in a pulmonary hamartoma and could provide diagnostic confidence.
Park
Kae Young
KY
Department of Diagnostic Radiology, Yonsei University College of Medicine, Yongdong Severance Hospital, Seoul, South Korea.
Kim
Sang Jin
SJ
Noh
Tae Woong
TW
Cho
Sang Ho
SH
Lee
Doo Yun
DY
Paik
Hyo Chae
HC
Ryu
Young Hoon
YH
D000328:Adult; D002114:Calcinosis / Q000000981:diagnostic imaging*; D005260:Female; D006222:Hamartoma / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008171:Lung Diseases / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*