Detection of upper extremity deep vein thrombosis by magnetic resonance non-contrast thrombus imaging.

BACKGROUND: Compression ultrasonography (CUS) is the first line imaging test for diagnosing upper extremity deep vein thrombosis (UEDVT), but often yields inconclusive test results. Contrast-venography is still considered the diagnostic standard but is an invasive technique.

AIM: We aimed to determine the diagnostic accuracy of Magnetic Resonance Non-Contrast Thrombus Imaging (MR-NCTI) for the diagnosis of UEDVT.

METHODS: In this international multicentre diagnostic study, we prospectively included patients with clinically suspected UEDVT who were managed according to a diagnostic algorithm that included a clinical decision rule (CDR), D-dimer test and diagnostic imaging. UEDVT was confirmed by CUS or (computed tomography (CT)) venography. UEDVT was excluded by 1) an unlikely CDR and normal D-dimer, 2) a normal serial CUS or 3) a normal (CT) venography. Within 48 hours after the final diagnosis was established, patients underwent MR-NCTI. MR-NCTI images were assessed post-hoc by two independent radiologists unaware of the presence or absence of UEDVT. The sensitivity, specificity and interobserver agreement of MR-NCTI for UEDVT were determined.

RESULTS: MR-NCTI demonstrated UEDVT in 28 of 30 patients with UEDVT and was normal in all 30 patients where UEDVT was ruled out, yielding a sensitivity of 93% (95%CI 78-99%) and specificity of 100% (95%CI 88-100%). The interobserver agreement of MR-NCTI had a kappa value of 0.83 (95%CI 0.69-0.97).

CONCLUSIONS: MR-NCTI is an accurate and reproducible method for diagnosing UEDVT. Clinical outcome studies should determine whether MR-NCTI can replace venography as the second-line imaging test in case of inconclusive CUS.