Non-contrast CT at comparable dose to an abdominal radiograph in patients with acute renal colic; impact of iterative reconstruction on image quality and diagnostic performance

Insights into Imaging

Table 3 Summary of the 16 calculi that were missed in 11 patients on the LD-ASIR 70 images

	Size (mm)	Location	Obstructing (y/n)	Attenuation (HU)	BMI	DLP for LD-CT	DLP for CD-CT
1	2.1	Renal-left inter pole	n	303	35.6	46.23	496.84
2	1.5	Renal-left inter pole	n	183	35.6	46.23	496.84
3	2	Renal-left inter pole	n	212	35.6	46.23	496.84
4	1.3	Renal-left inter pole	n	139	35.6	46.23	496.84
5	3.5	Renal left lower pole	n	437	29.2	33.99	474.96
6	2.3	Renal-right lower pole	n	278	47.4	32.6	917.92
7	2.4	Renal-left inter pole	n	425	22.9	33.31	158.84
8	2.5	Renal-right inter pole	n	302	19.7	30.18	171.24
9	2.4	Renal-left inter pole	n	314	26.3	29.64	310.88
10	1.9	Renal-right lowr pole	n	201	18.2	32.5	129
11	2.3	Renal-left inter pole	n	215	28.8	33.77	424.34
12	3	Renal-right lower pole	n	419	30.7	30.72	194.07
13	3.9	Renal-right upper pole	n	558	30.7	30.72	194.07
14	1.7	Renal-left lower pole	n	180	28.5	38.21	437.23
15	2	Renal-right lower pole	n	233	28.4	48.42	299.61
16	2.2	Renal-right lower pole	n	299	28.4	48.42	299.61

Relative conspicuity of missed calculi between the CD-CT 5-mm ASIR-40 and the 5-mm LD-CT images reconstructed with FBP is scored on a 0–5 point scale (0 = not seen; 1 = much worse; 3 = equal; 4 = better; 5 = excellent)