Table 1 gives the indications, strengths and limitations of the DCE-CT technique

When should a DCE-CT be performed?

Currently DCE-CT is a complementary imaging test that is usually performed alongside more widely accepted tests such as CT and ¹⁸F FDG PET-CT to enable further non-invasive lesion characterization. Where in the diagnostic pathway a DCE-CT should ideally be performed during the work up of a SPN is yet to be determined.

DCE-CT should be considered for patients with soft tissue SPN that are considered low to moderate risk for malignancy or following a t¹⁸F FDG PET-CT that shows indeterminate low grade tracer uptake less than the mediastinal blood pool where obtaining tissue diagnosis by biopsy would be considered high risk [1, 7].

DCE-CT is unhelpful in the characterization of pure ground glass nodules and part solid nodules with a soft tissue component that measures < 8 mm. It is also of limited accuracy in ‘flat’ nodules that may measure 8 mm in the axial dimension but only 3-4 mm in the cranio-caudal direction (Fig. 1). Polygonal shaped lesions with no central spherical/oval component where a reproducible region of interest (ROI) cannot be drawn should also be excluded (Fig. 2). As the technique involves the administration of iodinated contrast it is contraindicated in patients with known intravenous contrast allergies and renal impairment.

Strengths and weaknesses of DCE CT.

The main strengths of DCE-CT are the relatively low cost, convenience, the simplicity of image acquisition and the widespread availability of suitable CT machines capable of undertaking the protocol. The examination has a room time of 10mins and the image analysis is straightforward and can be performed on any standard commercial software in a matter of minutes.

The disadvantage of this technique is the use of ionizing radiation. With the advent of multi-detector CT previous limitations of reduced anatomic coverage of CT has improved with cranio-caudal coverage of large volumes to encompass a SPN now possible.