1. Fatty degeneration of coccyx Jalal Jalal Shokouhi-M.D. ISR and CIRAD president, Jaam e jam and koorosh medical centersJalal Jalal Shokouhi-M.D. ISR and CIRAD president, Jaam e jam and koorosh medical centers jalaljalalshokouhi@hotmail.comjalaljalalshokouhi@hotmail.com www.medimage.ir +989121137884www.medimage.ir Shahyar Pashae, anatomist, Bonidad daneshname negari farsiShahyar Pashae, anatomist, Bonidad daneshname negari farsi Mohammad hossein Herischi, professor of orthopedy, Baku, Republic AzerbaijanMohammad hossein Herischi, professor of orthopedy, Baku, Republic Azerbaijan Click here to email me : Jalaljalalshokouhi@hotmail.com Jalaljalalshokouhi@hotmail.com Visit my webpage by clicking here: www.medimage.ir www.medimage.ir

2. X-ray and X-ray CT show bony content of sacrum and coccyx. Alignment of coccyx is not regular in population and lateral,anterior and posterior deciations are common. Anterior deviation or inward deformity is more common. By MR-imaging we fund fatty infiltration in 5 th segment of sacrum and all segments of coccyx and this is a population variant in 97% of them. Cause could be immobility of these parts. T1 and STIR-T2 images in sagittal plane are the key for diagnosis.

3. 1.X-ray cannot show coccyx in details 2.X-ray CT can shows calcification degree of segments 3.MRI can shows fatty content of the segments or bone marrow

6. Mal-alignment of coccyx is not a pathology (is variant) painfull coccyx could be extracted even by normal imaging findings.

7. T2 sag. Fatty infiltration of S3- S4-S5 and all coccyx

8. T1 sag.

9. 97% of population in our random study in PACS show full fatty infiltration of 2 lower sacral segments and all segments of coccyx.

10. T1 and T2 sag. Of regular sacrococyx

11. What is the cause: could be immobility MRI pulses of T1 sagittal and STIR-T2 are used for net diagnosis (key for diagnosis).

12. T1 and T2 sag. Anteverted cocyx

13. Deformed coccyx

14. Peri-sacrococyx inflammation by STIR images Look at the “whale”,anterior to the rectum, an animal as biggest mammal

15. Close up view

16. http://www.spine-health.com/conditions/lower-back- pain/coccygectomy-surgery-coccydynia-tailbone-pain http://www.spine-health.com/conditions/lower-back- pain/coccygectomy-surgery-coccydynia-tailbone-pain http://www.basicspine.com/conditions-procedures/spine- conditions/coccyx.html http://www.basicspine.com/conditions-procedures/spine- conditions/coccyx.html http://morphopedics.wikidot.com/coccyx-injury http://ehealthforum.com/health/sacrum-coccyx-mri-t389625.html http://ehealthforum.com/health/chronic-coccyx-pain-for-years-mri- showed-nothing-t299414.html http://ehealthforum.com/health/chronic-coccyx-pain-for-years-mri- showed-nothing-t299414.html http://medical-dictionary.thefreedictionary.com/fatty+degeneration http://symptoms.rightdiagnosis.com/cosymptoms/coccyx- pain/degenerative-joint-changes-desc.htm http://symptoms.rightdiagnosis.com/cosymptoms/coccyx- pain/degenerative-joint-changes-desc.htm