Magnetic resonance imaging of the knee with ultrashort TE pulse sequences

BACKGROUND: We wished to assess the feasibility of imaging the knee with ultrashort TE (UTE) pulse sequences. SUBJECTS AND METHODS: Five volunteers and 16 patients were studied with UTE (TE=0.08 ms) sequences including later echoes. Conventional fat-suppressed images and difference images were also produced by subtracting a later echo from the first. Gadodiamide enhancement was used. RESULTS: High signal was obtained in tendons, ligaments, menisci and periosteum. Normal contrast enhancement was seen in these structures. Deep and superficial layers were seen in the articular cartilage. Cartilage defects were identified. The red zone could be differentiated from the white zone of the meniscus. Meniscal tears and degeneration were observed with low signal on subtraction images. Enhancement was seen within the anterior and posterior cruciate ligaments and associated scar tissue. CONCLUSION: Ultrashort TE imaging provides new options to visualize anatomy, manipulate conspicuity, observe contrast enhancement and demonstrate disease of the knee.