Magnetic resonance imaging and 67Ga scan versus computed tomography in the staging and in the monitoring of mediastinal malignant lymphoma: a prospective pilot study.
OBJECTIVE
To assess the potential value of magnetic resonance imaging (MRI) combined with 67Ga single-photon emission computed tomography (SPECT) versus computed tomography (CT) in the staging and in the monitoring of mediastinal malignant lymphoma.


METHODS
Twenty-three patients, referred to our institute for the evaluation of lymphoma, underwent CT, 67Ga scan, and MRI between April 1993 and February 1996 at sequential intervals. The tests studied (MRI, 67Ga, and CT) were performed according to the following schedule: 1) before start of therapy; 2) after four courses of chemotherapy; and 3) 2, 6, 12, and 18 months after the end of treatment.


RESULTS
All patients studied at the time of diagnosis had abnormal gallium accumulation in the mediastinum as well as pathologic CT and pathologic signal intensity at MRI. Six months after the end of treatment full consistency was found between the results of MRI and SPECT, whereas during treatment and 2 months after the end of therapy MRI and 67Ga scan were not in agreement in nine patients. In the 23 patients in follow-up, in CT there were nine false-positive and three false-negative findings; in SPECT three false negatives; in MRI one false positive and one false negative.


CONCLUSIONS
MRI can give morphologic information similar to CT, even superior due to multiplanarity and with major precision in the distinction between fibrosis and active disease. MRI is thus an alternative to CT. The association with SPECT allows a great diagnostic accuracy in the positive and negative predictive value.
Bendini
M
M
Institute of Diagnostic Radiology, University of Udine, Italy.
Zuiani
C
C
Bazzocchi
M
M
Dalpiaz
G
G
Zaja
F
F
Englaro
E
E
D000293:Adolescent; D000328:Adult; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005710:Gallium Radioisotopes; D006689:Hodgkin Disease / Q000175:diagnosis / Q000000981:diagnostic imaging; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008479:Mediastinal Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods* / Q000706:statistics & numerical data; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data
D005710:Gallium Radioisotopes