Application of streak metal artifact reduction technique in cone-beam computed tomography guided percutaneous transthoracic needle biopsy

Table 1 Artifact evaluation on cone-beam computed tomography with original reconstruction and streak metal artifact reduction technique reconstruction with full volume of interest

Artifact type	Original	SMART-Full			χ²	P value
		N	Y	Total
Radial	N	51	1	52
	Y	19	2	21
	Total	70	3	73	14.45	< 0.001
Streak	N	69	0	69
	Y	4	0	4
	Total	73	0	73	2.25	< 0.001
Thickening	N	42	6	48
	Y	14	11	25
	Total	56	17	73	2.450	0.118
Dark streak	N	2	0	2
	Y	45	26	71
	Total	47	26	73	43.022	< 0.001

CBCT: Cone-beam computed tomography; SMART-Full: Streak metal artifacts reduction technique with a full volume of interest; SMART-Small: Streak metal artifacts reduction technique with a small volume of interest containing only the coaxial needle; N: No; Y: Yes.

Table 2 Artifact evaluation of cone-beam computed tomography images with iterative streak metal artifact reduction technique reconstruction using full volume of interest and small volume of interest

Artifact type	SMART-Full	SMART-Small			χ²	P value
		N	Y	Total
Radial	N	6	44	50
	Y	0	23	23
	Total	6	67	73	42.023	< 0.001
Streak	N	61	8	69
	Y	0	4	4
	Total	61	12	73	6.125	0.008
Thickening	N	51	5	56
	Y	2	15	17
	Total	53	20	73	0.571	0.453
Dark streak	N	36	11	47
	Y	0	26	26
	Total	36	37	73	9.091	< 0.001

CBCT: Cone-beam computed tomography; SMART-Full: Streak metal artifacts reduction technique with a full volume of interest; SMART-Small: Streak metal artifacts reduction technique with a small volume of interest containing only the coaxial needle; N: No; Y: Yes.

Table 3 Paired sample t-test results of original cone-beam computed tomography and streak metal artifacts reduction technique with a full volume of interest reconstructed cone-beam computed tomography (n = 73), mean ± SD

Variables	Original	SMART-Full	Mean difference	t (df)	P value	Cohen’s d
Puncture needle diameter	2.05 ± 0.59	2.16 ± 0.52	-0.12	-4.48 (72)	< 0.001	-0.53
ROI minimum density	-926.12 ± 206.22	-788.34 ± 299.63	-137.78	-5.93 (72)	< 0.001	-0.69
ROI maximum density	18.88 ± 287.83	2.52 ± 260.45	16.36	0.82 (72)	0.414	0.1
ROI average density	-483.77 ± 269.29	-426.76 ± 302.13	-57.01	-5.40 (72)	< 0.001	-0.63

CBCT: Cone-beam computed tomography; SMART-Full: Streak metal artifacts reduction technique with a full volume of interest; SMART-Small: Streak metal artifacts reduction technique with a small volume of interest containing only the coaxial needle; ROI: Region of interest; t (df): t-statistic with degrees of freedom.