Reason: History of sacral chordoma with multiple lesions within the pelvis. Need MRI sacrum to evaluate extent of disease. Compare to prior imaging, which has been uploaded into PACS. History: History of surgical resection of a 15 cm sacral chordoma, now with multiple lesions with the pelvis and palpable mass in buttocks. There are postoperative changes of a partial sacrectomy extending from the level of S2 down with displacement of the rectum posteriorly, appearing similar to the prior study. Edema-type signal within the bones along the pubic symphysis is likely degenerative in etiology. The bones are otherwise within normal limits. There is a small fluid collection within the scar tissue posteriorly, perhaps slightly smaller than that seen on the prior study. Innumerable nodular masses are noted within the gluteus maximus musculature bilaterally as well as within the adjacent subcutaneous fat of the buttocks bilaterally. Additional nodular masses are situated along the posterior column of the acetabula adjacent to the obturator internus muscles, more so on the left than on the right. One of the larger masses within the left gluteus maximus muscle measures just over 6 cm in its greatest dimension on the coronal series 9, similar in size to that seen on the prior study. A second mass within the subcutaneous fat between the intergluteal cleft and the medial margin of the left gluteus maximus is approximately 2.5 x 2.3 cm, previously measuring approximately 2.0 x 1.5 x 2.3 cm. A smaller mass within the medial fibers of the right gluteus medius muscle measures approximately 1.5 x 1.0 cm, previously 1.0 x 0.8 cm.
Innumerable masses within the posterior soft tissues as described above, presumably representing spread of the patient's chordoma with some lesions having increased in size compared to the prior study.