Adrenal venous sampling in primary hyperaldosteronism: correlation of hormone indices and collimated C-arm CT findings

Purpose To evaluate the feasibility and effect of an approach to adrenal venous sampling (AVS) analysis by combining established selective cortisol and aldosterone indices with the acquisition of a collimated C-arm CT(CACT Coll ). Methods Overall, 107 consecutive patients (45f,62 m; 54 ± 10 years) undergoing 111 AVS procedures without hormonal stimulation from 7/13 to 2/20 in a single institution were retrospectively analysed. Hormone levels were measured in sequential samples of the suspected adrenal veins and right iliac vein, and selectivity indices (SI) computed. Stand-alone SI Cortisol and/or SI Aldosterone ≥ 2.0 as well as SI Cortisol and/or SI Aldosterone ≥ 1.1 combined with positive right-sided CACT Coll of the adrenals ( n = 80; opacified right adrenal vein) were defined as a successful AVS procedure. Radiation exposure of CACT was measured via dose area product (DAP) and weighed against an age-/weight-matched cohort ( n = 66). Results Preliminary success rates (SI Cortisol and/or SI Aldosterone ≥ 2.0) were 99.1% (left) and 72.1% (right). These could be significantly increased to a 90.1% success rate on the right, by combining an adjusted SI of 1.1 with a positive CACT Coll proving the correct sampling position. Sensitivity for stand-alone collimated CACT (CACT Coll ) was 0.93, with 74/80 acquired CACT Coll confirming selective cannulation by adrenal vein enhancement. Mean DAP Coll_CACT measured 2414 ± 958 μGyxm 2 , while mean DAP Full-FOV_CACT in the matched cohort measured 8766 ± 1956 μGyxm 2 (p < 0.001). Conclusion Collimated CACT in AVS procedures is feasible and leads to a significant increase in success rates of (right-sided) selective cannulation and may in combination with adapted hormone indices, offer a successful alternative to previously published AVS analysis algorithms with lower radiation exposure compared to a full-FOV CACT.