Solitary pulmonary nodules: MR evaluation of enhancement patterns with contrast-enhanced dynamic snapshot gradient-echo imaging.
OBJECTIVE
To evaluate the enhancement patterns of solitary pulmonary nodules (SPNs) with dynamic contrast-material-enhanced magnetic resonance (MR) imaging to differentiate between benign and malignant SPNs.


METHODS
Twenty-eight patients with SPNs 30 mm or smaller in diameter were examined with pre- and postcontrast, electrocardiographically gated, T1-weighted spin-echo (SE) sequences and a snapshot gradient-echo (GRE) sequence after bolus injection of a paramagnetic contrast agent. For all SPNs (20 malignant, eight benign), the percentage increase in signal intensity (%SI) on the postcontrast T1-weighted SE images and the enhancement curves (%SI/sec) for the snapshot GRE measurements were established from regions of interest.


RESULTS
Malignant nodules showed a higher increase of signal intensity during the first transit of the bolus of contrast material on the dynamic snapshot GRE images (malignant: median, 18.1 %SI/sec; range, 6.7-95.2 %SI/sec; benign: median, 2.3 %SI/sec; range, 0.1-8.1 %SI/sec) (P < .0001). Static T1-weighted SE measurements did not allow differentiation between malignant (median, 53.4 %SI; range 12.5-110.0 %SI) and benign (median, 33 %SI; range, 0.8-85.5 %SI) (P > .2) nodules on the basis of the degree of contrast enhancement.


CONCLUSIONS
Dynamic contrast-enhanced MR measurements of tumor enhancement can provide additional information about the nature of SPNs.
Gückel
C
C
Department of Radiology, University Hospital of Basle, Switzerland.
Schnabel
K
K
Deimling
M
M
Steinbrich
W
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D006801:Humans; D008168:Lung / Q000473:pathology*; D008175:Lung Neoplasms / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis*
D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate; D005682:Gadolinium