Keywords:
Education and training, Education, CT, MR, Digital radiography, Musculoskeletal system
Authors:
P. C. Mohan, M. T. Mohamed Shah; Singapore/SG
DOI:
10.1594/essr2018/P-0127
Background
The incidence of sacral and pelvic ISFs is increasing due to rapidly aging populations.
ISFs are a significant cause of functional disability in the elderly [1].
They are a result of normal stresses on abnormal bone which are largely a result of osteoporosis.
Patients may present with chronic lower back,
pelvic or groin pain with (usually minor) or without trauma [2,3].
Other risk factors include prior radiotherapy to the pelvis (e.g.
for sacral chordomas or cervical cancer),
prolonged corticosteroid therapy, chronic medical conditions such as rheumatoid arthritis and renal failure,
multiple myeloma,
hyperparathyroidism and Paget's disease,
and prior surgery (e.g.
lumbosacral fusion or hip arthroplasty) [4,5].
Therefore,
diagnosis of ISFs may be challenging or delayed,
partly from the non-specific nature of the presenting complaints and from detection failure or difficulty on initial radiographic evaluation [6]. In this pictorial essay,
we briefly review the bony anatomy of the sacrum and pelvis,
review the features of ISFs on various imaging modalities and their complications,
review potential pitfalls in imaging interpretation and discuss cases to highlight some of the pearls and potential pitfalls.