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 is beneficial after initial negative radiographs to prevent delayed diagnosis. MRI has excellent sensitivity, and it allows for definitive diagnosis. MRI typically demonstrates linear T1 and T2 hypointense signal, representing fracture lines, and T1 hypointense and T2 hyperintense signal in the surrounding bone marrow, representing associated edema. MRI demonstrates stress abnormalities as early as bone scintigraphy but with more specificity [25-28]. US Area of Interest There is increasing evidence of the usefulness of US in the early diagnosis of stress fractures of the distal extremities [44,45] and may allow for visualization of posterior sacral fractures. However, definitive diagnosis of suspected hip or pelvic fractures should not be delayed by choosing US as the second-line study following negative or indeterminate radiographs, considering that additional imaging may be required following a negative or US indeterminate examination. Variant 5: Adult. Suspect subchondral stress fracture at an extremity joint. Radiographs negative or indeterminate. Next imaging study. Area of Interest: pelvis, ankle, elbow, femur, foot, forearm, hand, hip, humerus, knee, leg tib/fib, shoulder, or wrist. Bone Scan Whole Body with SPECT or SPECT/CT Area of Interest Normal bone scintigraphy generally excludes a diagnosis of stress fracture, and the patient can return to normal activity. Tc-99m-methyl diphosphonate is a marker of bone perfusion and bone turnover [68]. Relative uptake is dependent on both the perfusion of a region of bone as well as the area of the mineralization front of bone (eg, osteoid).
Stress Fatigue Insufficiency Fracture Including Sacrum Excluding Other Vertebrae PCAs. 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 is beneficial after initial negative radiographs to prevent delayed diagnosis. MRI has excellent sensitivity, and it allows for definitive diagnosis. MRI typically demonstrates linear T1 and T2 hypointense signal, representing fracture lines, and T1 hypointense and T2 hyperintense signal in the surrounding bone marrow, representing associated edema. MRI demonstrates stress abnormalities as early as bone scintigraphy but with more specificity [25-28]. US Area of Interest There is increasing evidence of the usefulness of US in the early diagnosis of stress fractures of the distal extremities [44,45] and may allow for visualization of posterior sacral fractures. However, definitive diagnosis of suspected hip or pelvic fractures should not be delayed by choosing US as the second-line study following negative or indeterminate radiographs, considering that additional imaging may be required following a negative or US indeterminate examination. Variant 5: Adult. Suspect subchondral stress fracture at an extremity joint. Radiographs negative or indeterminate. Next imaging study. Area of Interest: pelvis, ankle, elbow, femur, foot, forearm, hand, hip, humerus, knee, leg tib/fib, shoulder, or wrist. Bone Scan Whole Body with SPECT or SPECT/CT Area of Interest Normal bone scintigraphy generally excludes a diagnosis of stress fracture, and the patient can return to normal activity. Tc-99m-methyl diphosphonate is a marker of bone perfusion and bone turnover [68]. Relative uptake is dependent on both the perfusion of a region of bone as well as the area of the mineralization front of bone (eg, osteoid).