A new modified MR dual precision positioning of thin-slice oblique sagittal fat suppression proton density weighted imaging: its diagnostic accuracy in anterior cruciate ligament injury

Figures

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  Figure 1. Scanning method for the new modified DPP-TSO-SAG-FS-PDWI sequence. The left knee of a 26-year-old man was displayed on (a–c). ACL on the new modified DPP-TSO-Sag-FS-PDWI sequence (c) were performed along its anatomic direction on axial and coronal PDWI (as yellow line marked on (a and b)). Its complete structure was shown in the yellow range (arrow on (c)) with low signal intensity.

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  Figure 2. Normal ACL presence on MRI and arthroscopy of a 14-years-old female teenager. The ACL was shown on sagittal T1WI (a), coronal T2WI (b), Sagittal PDWI (c), coronal PDWI (d), and axial PDWI (e). It was tilted from the tibial to the condyle and the attachment was inserted from the condyle to the notch with low signal intensity (arrows). The ligament could be displayed completely on one level of the new modified DPP-TSO-Sag-FS-PDWI (arrow on (f)). The normal appearance of ACL was proved on arthroscopy (arrow on (g)).

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  Figure 3. Grade I injury of ACL presence on MRI and arthroscopy of a 34-years-old woman. The shape and signal intensity of the ACL (arrows) was similar to the normal ligament on sagittal T1WI (a), coronal T2WI (b), Sagittal PDWI (c), coronal PDWI (d), and axial PDWI (e) with effusion of knee joint on PDWI. The ligament was tortuous as “S-shaped” and localized edema with increased signal intensity in the tibial part on the new modified DPP-TSO-Sag-FS-PDWI (arrow on (f)). Arthroscopy showed the ligament was loose with a hematoma in the anterior tibial part of the ligament (arrow on (g)).

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  Figure 4. Grade II injury presence on MRI and arthroscopy of a 35-years-old man. The remaining structure of ACL was shown on sagittal and coronal T1WI (arrows on (a and b)). The ligament lost continuity and turned thinner, and its shape was distorted with a high signal on sagittal PDWI (arrow on (c)) and coronal PDWI (arrow on (d)). The signal of ACL increased and surrounded by the fluid on axial PDWI (arrow on (e)). It could be shown on the new modified DPP-TSO-Sag-FS-PDWI (f) that most of the ACL was swollen with the increased signal. A tear was seen at the posterior femoral part of the ACL, surrounded by fluid, and the free edge was reflexed (arrow), which was corresponded to the arthroscopic image. Arthroscopy showed that most remaining part of the ACL was still attached to the origin site and a small portion of the fibrous was tearing down in the middle of ACL (arrow on (g)).

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  Figure 5. Grade III injury presence on MRI and arthroscopy of a 23-years-old woman. The absence of ligament integrity and continuity were shown on sagittal, and coronal T1WI (arrows on (a and b)). Remaining filamentous ACL with surrounding liquid (arrows) still could be seen on sagittal PDWI (c), coronal PDWI (d), and axial PDWI (e), which would cause misdiagnosis. The ligament was completely separated into two parts and the two damaged ends with their intermediate filled fluids (arrow) were displayed on the new modified DPP-TSO-Sag-FS-PDWI (f). Arthroscopy found the ligament was divided into two parts without continuity and completely separated, one of the damaged edges faced up (arrow on (g)).