MR MICROSCOPY OF THE RAT LUNG USING PROJECTION RECONSTRUCTION

Projection reconstruction has been implemented with self refocused selection pulses on a small bore, 2.0 T MR microscope, to allow imaging of lung parenchyma. Scan synchronous ventilation and cardiac gating have been integrated with the sequence to minimize motion artifacts. A systematic survey of the pulse sequence parameters has been undertaken in conjunction with the biological gating parameters to optimize resolution and signal-to-noise (SNR). The resulting projection images with effective echo time of <300 musec allow definition of lung parenchyma with an SNR improvement of approximately 15 x over a more conventional 2DFT short echo gradient sequence.