Incidental findings of lumbar spine MRI at Bangkok Metropolitan Administration General Hospital

Abstract

Background : Low back pain is one of the most common symptoms. Magnetic resonance imaging (MRI) is the most sensitive and useful investigation in detecting and delineating spinal disease. An incidental lesion is an asymptomatic lesion found while examining a patient for an unrelated reason.

Objective : To determine frequency and majority of incidental findings in patients undergoing MRI of lumbar spine.

Method : Five hundred and ninety-seven lumbar spine MRIs in 24 months were reviewed.

Results : Incidental findings were found in forty-seven cases (7.8%). There were perineural (Tarlov) cysts 17 cases (36.2%), vertebral hemangiomas 14 cases (29.8%), renal cysts 7 cases (14.9%), uterine leiomyomas 5 cases (10.6%) and synovial cysts 3 cases (6.4%). Epidural lipomatosis, horseshoe kidney, dermoid cyst and cystic ovarian tumor, were found one of each case (2.1%). Of these 47 patients, 44 patients (93.6%) had one finding and 3 patients (6.4%) had two findings. There is no difference between genders and age groups in term of incidence of perineural cysts, vertebral hemangiomas, renal cysts and synovial cysts and no difference in age with frequency of uterine leiomyomas.

Conclusion : The incidental lesions can be seen in MRI of lumbar spine in about 8%. The major findings show no significant difference between genders and age groups. Although most incidental lesions are asymptomatic, some may be causes of low back pain and hence surgery may be required. Notification and careful interpretation of incidental findings on MRI of lumbar spine are necessary.