Age / Sex : 54 / F

Chief complaint: Rt. Upper extremity radiculopathy

What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(답안은 한 개만 보내주시기 바랍니다)

Courtesy: 이준우 (Joon Woo Lee), 분당 서울대학교 병원 (Seoul National University Bundang Hospital)

Artifactual high signal due to low flow in the Lt. jugular vein (MRI Pitfalls)

Discussion

Findings:

1)     MR (1, 2)

-       MRI axial T2WI in the cervical region, Lt. side internal jugular vein show high signal (arrowed) where as Rt. Side internal jugular vein show normal T2 flow void. Additionally there is Rt. Side neural foraminal stenosis at C5/6 level correlated with patient’s symptom.

2)     CT

-       Pre-operative CT angiography show lack of contrast filling in Lt. side internal jugular vein

Differential Diagnosis: none

Diagnosis: Artifactual high signal due to low flow in the Lt. jugular vein (MRI Pitfalls)

Discussion: This is a common finding in MRI cervical region spine on axial T2WI and can be passed off as normal. It is important to consider the anatomy of the jugular vein here, which is not symmetric. Internal jugular veins join subclavian veins before draining in to the SVC via innominate veins. SVC being on Rt. Side, Rt. Innominate vein is short. The Lt. innominate vein, which is nearly twice as long as the Rt. Side, must cross the midline to join SVC which is on Rt. Side of the midline. So due to slow flow or sometimes reversed flow in the Lt. jugular vein which occur secondary to compression of this Lt. innominate vein by the aorta as the vein passes under the sternum, there is artifactual high signal in the Lt. jugular vein. It is clinically important that many clinicians mistake this finding for thrombosis and perform the additional Doppler sonography.

References:

 Practical MR Physics and case file of MR artifacts and pitfalls, Alexander C. Mamourian, MD.