Deddeh Ballah BA, Presenter: Nothing to Disclose

Melissa Mizesko, Abstract Co-Author: Nothing to Disclose

Xiaowei Zhu, Abstract Co-Author: Nothing to Disclose

J. Christopher Edgar PhD, Abstract Co-Author: Nothing to Disclose

Anne Marie Cahill MBBCh, Abstract Co-Author: Nothing to Disclose

To assess the usefulness and clinical efficacy of low dose C-arm CT for visualization of needle placement in the TMJ in children.

Between July 2007 and March 2011, 70 children with juvenile idiopathic arthritis (56F, 14M mean age 13.04 years) underwent 142 TMJ steroid injections (54 bilateral, 34 unilateral) in 88 encounters using a novel low dose C-arm CT protocol for needle localization. 115 images were reviewed for needle conspicuity and location of which 53 were bilateral, totaling 167 needle positions for assessment. Needle conspicuity was rated either as poor, adequate or excellent by two reader consensus and needle position within the TMJ was rated adequate or inadequate.

167/167 needle visualized on imaging were rated as excellent conspicuity. 132/167 (70%) needle locations were adequate. 34/54 (63%) bilateral injection encounters required only one C-arm CT image. 35/167 needles were inadequately positioned in 21 patient encounters. Of those, 30/35 were in joints with chronic disease. 8 needles in 7 encounters had steroid injection with persistent inadequate needle position with 3/7 improved, 2/7 no follow-up, 1/7 did not improve. 27/88 encounters involved multiple C-arm rotation. 23/27 encounters had multiple rotations available for review. 14/23 were performed because of poor needle positioning, 6/23 were elective multiple rotations due to bilateral injections and 3/7 were motion degraded studies. Overall, 58/88 encounters had adequate follow-up while 19/88 were referred from an outside hospital, 9/88 lacked follow-up at the time of this study, and 2/88 were lost to follow-up. Of the 58 encounters with follow-up, 33/58 encounters were symptomatic before treatment. 28/33 had resolution or improvement of symptoms, which included pain, subjective clicking and locking. Of the 5/33 without improvement, needle location was deemed adequate in 4/5, inadequate in 1/5.  

Low dose C-arm CT provides CT-guided imaging for TMJ injection at 50% of conventional CT and can be performed in the IR suite.

The inherent contrast between bone, needle, and soft tissue enables significant dose reduction to 50% of low dose conventional CT while providing diagnostically adequate images.

Ballah, D, Mizesko, M, Zhu, X, Edgar, J, Cahill, A, The Use of Low-Dose C-Arm CT in Temporomandibular Joint Injection (TMJ) in Interventional Radiology  .  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034419.html