Table 2.

Patients with venous thromboembolism after initially normal proximal venous ultrasound

Age (years), sex	Risk factors	D-dimer at time of initial US (μg/mL)	D-dimer at time of VTE diagnosis (μg/mL)	Symptoms at time of VTE diagnosis	Time from initially normal US to VTE diagnosis (days)	Subsequent PE study	Results of repeated proximal US at time of VTE diagnosis
88, M	History of DVT and PE	NP	3.88	Dyspnea and hypoxia	3	PE on V/Q	DVT
44, F	History of PE after IVC filter placement, Factor V Leiden mutation, elevated homocysteine level	NP	NP	Dyspnea	7	PE on V/Q	NP
64, F	Obesity, metastatic small-bowel carcinoid tumor, hospitalization for treatment of epidural abscess and osteomyelitis after decompression surgery	NP	3.73	Hypoxia and tachycardia	9	PE on CTA	NP
70, M	Prostate cancer	NP	NP	Lower extremity pain and swelling	9	NP	DVT
84, M	Type 2 diabetes	NP	NP	Lower extremity erythema, pain, and swelling	21	NP	DVT
66, F	Immobilization because of cuboid fracture	NP	1.63	Chest pain	28	PE on CTA	NP
61, M	History of DVT and PE	NP	1.67	Chest pain	32	PE on CTA	DVT
63, F	History of DVT, hospitalization for treatment of acute diverticulitis	NP	2.12	Dyspnea and chest pain	35	PE on CTA	No DVT
53, F	Metastatic breast cancer, recent lengthy plane ride	2.29	NP	Dyspnea and chest pain	49	PE on CTA	No DVT
94, F	History of DVT and PE	NP	NP	Lower extremity erythema, pain, and swelling	49	NP	DVT
68, M	Metastatic squamous cell of head and neck with recent robotic radiosurgery for pelvic node metastasis	NP	NP	Lower extremity swelling	60	NP	DVT

CTA = computed tomography angiography; DVT = deep venous thrombosis; F = female; IVC = inferior vena cava; M = male; NP = not performed; PE = pulmonary embolism; US = ultrasound, V/Q = ventilation-perfusion scan; VTE = venous thromboembolism.