This is Barry Belosis, one of the musculoskeletal radiology fellows at Stanford University. 25-year-old male weightlifter presents with right anterior hip pain, concern for stress fracture. The patient in this case presented with this MRI coronal T2 FATSAT imaging showing edema or increased signal in the right femoral neck with a band of sclerosis medially compatible with stress fracture. Mild edema signal is also noted in the left femoral neck, but without hypo-intense or dark line, likely representing stress reaction. In patients with suspected hip stress fracture, radiograph is the initial imaging modality of choice. As in this 45-year-old female with left hip pain, although radiograph is insensitive and can be normal in most cases, this patient shows a band of sclerosis in the left femoral neck compared to the normal side on the right, which you don't see a sclerotic band. This is concerning for stress fracture. This patient underwent MRI showing edema along the left femoral neck with a band of sclerosis or this hypo-intense band within the edema consistent with stress fracture. In our coronal T1-weighted imaging, we can see this hypo-intensity correlating to the edema seen in the T2 FATSAT imaging and again the hypo-intense band medially. In some cases, such as in this 22-year-old female, the left hip demonstrates no sclerosis and is normal. Two months later in this follow-up imaging, we can see a band of sclerosis consistent with stress fracture. This is in a different patient. In patients with suspected femoral acetabular impingement, again, radiograph is the imaging modality of choice as it can demonstrate bony abnormality. This 20-year-old male with right hip pain demonstrates bony protuberance in the superior aspect of the right femoral head-neck junction, which is also seen on the contralateral left hip. This finding is typically seen in the case of CAM-type femoral acetabular impingement. If there is concern for labral pathology, MR-rheography can be performed for further evaluation. On the left-hand side, we can see a normal labrum showing a triangular hypo-intense band without signal abnormality within it. On the right-hand side, in our T1-facet imaging, we can see there is increased signal in the subtons of the labrum consistent with a labral tear. When evaluating the labrum, we look at all the sequences and all the planes. To look at the superior labrum, it is best depicted in our coronal imaging, showing this triangular hypo-intense band. And in our axial imaging, we best see the anterior and posterior labrum in our T2-weighted fat-suppressed imaging, whereas the anterior superior labrum is best seen on our sagittal imaging, such as this proton density fat-suppressed images. This is an example on an abnormal labrum. Here on our T1-weighted imaging, we can see a bony protuberance at the femoral head-neck junction with dissociated hyper-intensity within the labrum, correlating to this hyper-intensity or bright signal on our T1-weighted fat-suppressed imaging, consistent with an anterior labral tear. On our coronal T1 fat-suppressed imaging, we can again see the superior labrum with some fluid traversing the substance, consistent with labral tear.

2nd Edition, CASE 21

2nd Edition

Hip

stress fracture

femoral neck

MRI

labral tears

imaging techniques