IN-VIVO H-1-NMR MICROIMAGING WITH RESPIRATORY TRIGGERING FOR MONITORING ADOPTIVE IMMUNOTHERAPY OF METASTATIC MOUSE LYMPHOMA

The metastatic ESb-MP murine lymphoma in DBA/2 mice has been used as a model for investigating metastatic disease and its cure by adoptive i mmunotherapy (ADI) as monitored by in vivo multislice spin-echo H-1 NM R microimaging at 7 T. Isoflurane inhalation anesthesia facilitated lo ng measurement sessions, and respiratory gating with a fiber-optic sen sor greatly reduced motional artifacts. With T-2 weighting (TR = 2 s, TE = 30 ms) mean signal-to-noise ratios of 30 and 15 for kidney and li ver, respectively, were achieved in 20 min (100-mu m pixels, 1-mm slic es, 25-mm field of view). Without the use of contrast agents, metastas es with diameters greater than or equal to 0.3 mm in the imaged plane could be detected as hyperintense lesions in kidney (contrast ratio ca . 1.4) and liver (contrast ratio ca. 2) with a confidence level of >98 %. For the first time the complete eradication of late-stage macroscop ic metastases by ADI could be demonstrated noninvasively by MRI.