MDCT in acute ischaemic left colitis: a pictorial essay

The pathogenesis of acute ischaemic colitis depends on two different forms of vascular colonic insult: occlusive injury and non-occlusive injury. Clinically, ischaemic colitis may be classified as two major forms: mild (non-gangrenous) and acute fulminant (gangrenous). The classic presentation is abdominal pain, diarrhoea and/or rectal bleeding, but it is not specific and highly variable and so the diagnosis usually depends on clinical suspicion and is supported by serologic and colonoscopic findings. Imaging methods have their role in diagnosing IC. While plain radiography and ultrasound can orient the diagnosis, CT allows to define the morphofunctional alterations discriminating the non-occlusive forms from the occlusive forms and in most cases to estimate the timing of ischaemic damage. Purpose of the review is to define the role of CT in the early identification of pathological findings and in the definition of evolution of colonic ischaemic lesions, in order to plan the correct therapeutic approach, suggesting the decision of medical or surgical treatment.