Perfusion-weighted map and perfused blood volume in comparison with CT angiography source imaging in acute ischemic stroke different sides of the same coin?

Intraprocedural blood volume measurement using C-arm CT as a predictor for treatment response of malignant liver tumours undergoing repetitive transarterial chemoembolization (TACE)

PURPOSE

To evaluate feasibility of measuring parenchymal blood volume (PBV) of malignant hepatic tumours using C-arm CT, test the changes in PBV following repeated transarterial chemoembolization (TACE) and correlate these changes with the change in tumour size in MRI.

METHODS

111 patients with liver malignancy were included. Patients underwent MRI and TACE in a 4- to 6-week interval. During intervention C-arm CT was performed. Images were post-processed to generate PBV maps. Blood volume data in C-arm CT and change in size in MRI were evaluated. The correlation between PBV and size was tested using Spearman rank test.

RESULTS

Pre-interventional PBV maps showed a mean blood volume of 84.5 ml/1000 ml ± 62.0, follow-up PBV maps after multiple TACE demonstrated 61.1 ml/1000 ml ± 57.5. The change in PBV was statistically significant (p = 0.02). Patients with initial tumour blood volume >100 ml/1000 ml dropped 7.1% in size and 47.2% in blood volume; 50-100 ml/1000 ml dropped 4.6% in size and 25.7% in blood volume; and <50 ml/1000 ml decreased 2.8% in size and increased 82.2% in blood volume.

CONCLUSION

PBV measurement of malignant liver tumours using C-arm CT is feasible. Following TACE PBV decreased significantly. Patients with low initial PBV show low local response rates and further increase in blood volume, whereas high initial tumour PBV showed better response to TACE.

KEY POINTS

Parenchymal blood volume assessment of malignant hepatic lesions using C-arm CT is feasible. The parenchymal blood volume is reduced significantly following transarterial chemoembolization. Parenchymal blood volume can monitor the response of tumours after transarterial chemoembolization. Although not significant, high initial parenchymal blood volume yields better response to TACE.

[Vascular assessment in stroke codes: role of computed tomography angiography]

Advances in imaging studies for acute ischemic stroke are largely due to the development of new efficacious treatments carried out in the acute phase. Together with computed tomography (CT) perfusion studies, CT angiography facilitates the selection of patients who are likely to benefit from appropriate early treatment. CT angiography plays an important role in the workup for acute ischemic stroke because it makes it possible to confirm vascular occlusion, assess the collateral circulation, and obtain an arterial map that is very useful for planning endovascular treatment. In this review about CT angiography, we discuss the main technical characteristics, emphasizing the usefulness of the technique in making the right diagnosis and improving treatment strategies.