Although superior to radiography, it is less sensitive than nuclear scintigraphy or MRI [23]. The benefit of CT seems to lie in its specificity, ranging from 88% to 98% in a recent meta-analysis regarding accuracy of imaging modalities for lower extremity stress fractures, and thus may confirm a finding suspected to represent stress fracture on MRI [24]. CT may also be useful in cases where MRI results are equivocal. MRI Area of Interest Without and With IV Contrast There is no relevant literature to support the use of MRI area of interest without and with IV contrast because it does not provide added information over noncontrast imaging with regard to stress injury. MRI Area of Interest Without IV Contrast MRI demonstrates stress abnormalities as early as bone scintigraphy and with as much sensitivity [25-28]. In the absence of an actual stress fracture, stress reaction, or muscle/tendon injuries can be identified using fluid-sensitive sequences. Thus, MRI may be considerably more specific than scintigraphy [22,23]. The recent literature supports MRI as the procedure of choice for early diagnosis of both fatigue and insufficiency types of stress fractures, outperforming all other modalities [15,22,23,29-39]. Fluid-sensitive sequences are the favored initial sequence for MRI screening [40]. Short tau inversion recovery (STIR) and T1-weighted images demonstrate a fracture line surrounded by edema. MRI of an osseous stress injury contains prognostic as well as diagnostic information [41,42]. Radiography Area of Interest Radiographs are insensitive for stress fracture in the early stages of injury and in elderly patients with underlying osteoporosis. However, if symptoms have been present for at least 10 to 14 days, radiographs can achieve sensitivity of 30% to 70%, making them an effective screening tool [43]. If the findings on radiographs are conclusive for stress fracture, often no further imaging needs to be performed.
Stress Fatigue Insufficiency Fracture Including Sacrum Excluding Other Vertebrae PCAs. Although superior to radiography, it is less sensitive than nuclear scintigraphy or MRI [23]. The benefit of CT seems to lie in its specificity, ranging from 88% to 98% in a recent meta-analysis regarding accuracy of imaging modalities for lower extremity stress fractures, and thus may confirm a finding suspected to represent stress fracture on MRI [24]. CT may also be useful in cases where MRI results are equivocal. MRI Area of Interest Without and With IV Contrast There is no relevant literature to support the use of MRI area of interest without and with IV contrast because it does not provide added information over noncontrast imaging with regard to stress injury. MRI Area of Interest Without IV Contrast MRI demonstrates stress abnormalities as early as bone scintigraphy and with as much sensitivity [25-28]. In the absence of an actual stress fracture, stress reaction, or muscle/tendon injuries can be identified using fluid-sensitive sequences. Thus, MRI may be considerably more specific than scintigraphy [22,23]. The recent literature supports MRI as the procedure of choice for early diagnosis of both fatigue and insufficiency types of stress fractures, outperforming all other modalities [15,22,23,29-39]. Fluid-sensitive sequences are the favored initial sequence for MRI screening [40]. Short tau inversion recovery (STIR) and T1-weighted images demonstrate a fracture line surrounded by edema. MRI of an osseous stress injury contains prognostic as well as diagnostic information [41,42]. Radiography Area of Interest Radiographs are insensitive for stress fracture in the early stages of injury and in elderly patients with underlying osteoporosis. However, if symptoms have been present for at least 10 to 14 days, radiographs can achieve sensitivity of 30% to 70%, making them an effective screening tool [43]. If the findings on radiographs are conclusive for stress fracture, often no further imaging needs to be performed.