Table 1.

Advantages and disadvantages of diagnostic modalities in acute gastrointestinal (GI) bleeding

	Endoscopy	Radionuclide imaging	Catheter angiography	MDCT
Advantages	Highly sensitive and specific in upper GI bleeding Can treat GI bleeding if detected Can sample tissue if suspected malignancy	Can detect low rates of bleeding Can detect arterial or venous bleeding Non-invasive	Can treat GI bleeding if detected High spatial resolution Small vessels can be selectively injected	Readily available Rapid acquisition Precise anatomic localization
Disadvantages	May not be universally available Cannot visualize the majority of the small bowel Limited visualization of bleeding with active haemorrhage	Often cannot precisely localize the site of bleeding Time consuming May not be available in the acute setting	Requires a high rate of bleeding for detection of extravasation Invasive and time consuming Radiation dose	May be less sensitive than radionuclide imaging Radiation dose Requires i.v. contrast

MDCT, multidetector CT.