Table 1.

Q measurements on candidate ¹⁷O coils with various apertures and tuning components. The coil length was fixed at 27 cm, with apertures to emulate a single coil in a 4 (90°) or 8 channel (45°) array. The coil with 90° aperture and 2 distributed capacitors represents the baseline (row 1), while the others show compromised performance primarily due to increased capacitor loss (row 2) or reduced coil-to-sample coupling (row 3). This information motivated the implemented design (row 4), in which the aperture provided sufficient coil-to-sample coupling, while loss due to ¹H blocking circuits was considered a necessary penalty to enable 1H body coil excitation.

Aperture	Number of Distributed capacitors	Unloaded Q Qun	Loaded Q Ql	Ratio Qun/Ql
90°	2	420	190	2.21
90°	4	320	180	1.78
45°	2	285	170	1.68
90°	1 first-order and 2 second-order blocking circuits	320	180	1.78