Figure 1
Radiographically occult fracture of the right proximal femur in an 86-year-old female patient admitted to the emergency department after low-energy trauma. (a) Radiographs of the right hip and pelvis performed the day of the trauma did not demonstrate any fracture. The patient was included in a research study and imaged at both MRI and CT that same day. MRI of the pelvis demonstrated a poorly defined medullary area in the right greater trochanter (arrow) with decreased signal intensity on the (b) spin-echo T1-weighted sequence and (c) fat-only T2-weighted Dixon images and increased signal intensity on the (d) Short Tau Inversion Recovery (STIR) sequence and (e) water-only T2-weighted Dixon images. A central linear low signal intensity area on the fluid-sensitive images was suggestive of a trabecular fracture (arrowhead), but no cortical interruption was seen. (f) Bone kernel multiplanar reconstructions (MPR) and (g) Maximum Intensity Projection (MIP) reconstructions of the pelvic CT demonstrated the cortical bone interruption (arrow) that was not visible at MRI. (h) Soft tissue kernel MPR also demonstrated the “bone marrow edema” of the right greater trochanter (arrow).