Follow-up recommendation rates with abdominopelvic photon counting CT: comparison with conventional dual-energy and...

To retrospectively compare the follow-up imaging recommendation rate in patients who underwent an abdominopelvic PCCT, dual-source dual-energy CT (DECT), or single-energy CT (SECT).

A retrospective PACS search identified all outpatient contrast-enhanced abdominal PCCT, DECT, and SECT from 4/11/2022-10/14/2024. PCCT and DECT examinations without virtual noncontrast and iodine map images in PACS were excluded. All radiology reports were reviewed for follow-up imaging recommendations and reason. Follow-up imaging recommendation rates were compared across all three scanner groups and pairwise between each scanner type. The projected cost savings related to avoided follow-up recommendations with PCCT compared with SECT was calculated using the average Medicare reimbursement for each potential follow-up examination.

16,065 examinations (median(IQR) age: 66(54-76) years; 8,433 females (52%)) including 8,246 PCCT, 3,988 DECT, and 3,831 SECT were included. Follow-up imaging was recommended in 8.1% (671/8,246) of PCCT, 8.7% (347/3,988) of DECT, and 13% (517/3,831) of SECT (p < .001). MRI was recommended in 5.2% (430/8,246) of PCCT, 4.2% (166/3,988) of DECT, and 6.4% (245/3,831) of SECT (p < .001). CT was recommended in 2.0% (168/8,246) of PCCT, 3.9% (155/3,988) of DECT, and 5% (193/3,831) of SECT (p < .001). Ultrasound was recommended in 1.4% (114/8,246) of PCCT, 1.2% (48/3,988) of DECT, and 2.7% (104/3,831) of SECT (p < .001). The total estimated cost savings of avoided subsequent imaging examinations with abdominopelvic PCCT compared with SECT was $32,904 for MRI, $71,085 for CT, and $10,888 for ultrasound, with $114,877 overall projected savings.

There were significantly reduced follow-up imaging recommendations after abdominopelvic PCCT and DECT than SECT, with projected cost savings.