Lisette van Dam

Detection of UEDVT by MR-NCTI 5 85 RESULTS Patients A total of 218 consecutive patients with clinically suspected UEDVT were screened, of whom 148 patients (68%) were excluded for various reasons as per predefined exclusion criteria ( Figure 2 ). Among the 148 patients excluded, 22 patients (15%) could not be included because of the presence of an implantable device not compatible with MRI (e.g. pacemaker). A total of 70 patients provided written informed consent. MR-NCTI images were adequate for interpretation in 89% of the cases: eight patients were excluded from the main analysis due to MR imaging artefact issues rendering image quality insufficient for final diagnosis. In one patient MRI could not be performed due to claustrophobia, whilst another patient experienced acute clinical deterioration during scanning. Hence, 60 patients could be included, of whom 30 patients had a confirmed UEDVT and 30 patients had UEDVT ruled out. All patients were subjected to MRDTI, but due to logistical reasons, 3D TSE-SPAIR sequence could not be performed in 8 (13%). The baseline characteristics of the 60 study patients are shown in Table 3 . In two patients (3.3%) UEDVT was excluded based on an unlikely clinical probability according the Constans rule in combination with a normal D-dimer result and these patients had no VTE at follow-up. UEDVT was ruled out based on diagnostic imaging in 28 patients and none of these patients were diagnosed with VTE during follow-up ( Figure 2 ). The diagnosis was based on (repeat) ultrasonography in 43 patients (72%) and (CT)venography in 15 patients (25%). In 12 patients (20%) (CT)venography was performed because of an inconclusive CUS or negative CUS but high clinical suspicion. Of these 12 patients, 3 patients had a negative (repeat) CUS for UEDVT of whom 2 patients were diagnosed with UEDVT based on (CT)venography and in one patient UEDVT was also excluded based on (CT)venography. In 9 patients (repeat) CUS was positive for UEDVT, but the diagnosis was uncertain and were thus referred for (CT)venography. UEDVT was excluded based on (CT)venography in one patient and also positive for UEDVT in 8 patients.