Table 1.

Diagnostic modalities for DVT.

Modality	Description	Advantages	Limitations	Ref
D-dimer test	Analysis of degradation product levels of fibrin blood clot	Simple; direct combinational algorithm	Inaccurate; depends on patient condition	10, 12–14
Venography	Contrast agent with an external transducer; observation of preventive blood flow	Widely used; improved potential especially with combination methods; high accuracy	Invasive; high costs; risks – allergy, renal dysfunction, morbidity; inaccurate in low limb thrombosis; accessing difficulty in obesity, edema, cellulitis	15 – 17
IP	Electrical impedance detects blood volume changes due to cobstruction in flow	More sensitive compared to Venography	Not specific; false positive results due to variation in position, pregnancy, tumor; fails to detect calf thrombus	15, 16
CT	Contrast medium based technique	Potentially detects concurrent DVT as stand-alone technique	Rarely used due to intravenous administration of contrast medium	17
MRI	Enhanced contrast agents instead of gaseous substances; requires specific targeted nanomarkers	High spatial resolution and structural definition; can distinguish old and new clots	Molecular marker concentration dependent sensitivity, most expensive technique	15, 17–19
VS	Radioactive contrast agent (99mTc)-labeled peptides for thrombus targeting	High sensitivity; improved visualization	Toxicity due to radioactive materials; time consuming	15, 16, 20–23
Ultrasound	B-mode/doppler, compression, color duplex, and combined ultrasound	High spatial and temporal resolution; no pain	Rare use in new thrombi detection within post thrombotic limb	24 – 29