Extravasated contrast volumetric assessment on computed tomography angiography in gastrointestinal bleeding: A useful predictor of positive angiographic findings

Table 1 Computed tomography angiography acquisition protocol

CTA acquisition protocol (128 MDCT-GE medical system)
KVp	100-120 kVp
mAs	200-700 (smart mA)
Collimation	80 mm
Rotation time	0.28 s
Pitch	0.992
FOV	Large body
Acquisition thickness	2.5 mm
Reconstruction thickness	0.625 mm
Contrast medium volume	1.2-1.5 mL/kg
Contrast medium infusion rate	≥ 4 mL/s
IDR	1.4-1.8

CTA: Computed tomography angiography; IDR: Iodine delivery rate; FOV: Field of view; MDCT: Multi-detector row spiral computed tomography.

Table 2 Demographic, etiological, laboratory, and clinical data of study population, n (%)

Characteristic	Value
Demographic	n (range)
Patients (n)	35
Age (yr)	67 (19-92)
Male/female	22/13
Weight (kg)	86 (67-118)
Height (cm)	175 (155-188)
BMI (kg/m2)	25.7 (17-33.5)
Etiological
Bleeding site
Upper GI tract	15 (42.9)
Lower GI tract	20 (57.1)
Bleeding cause
Peptic ulcer	8 (22.8)
Diverticular disease	10 (28.5)
Gastritis or duodenitis	3 (8.5)
Angiodysplasia	3 (8.5)
Pancreatitis	2 (5.7)
Spontaneous	4 (11.4)
Iatrogenic	5 (14.2)
Vascular territory
Gastroduodenal artery	5 (14.2)
Left gastric artery	3 (8.5)
Short gastric artery	1 (2.8)
Pancreaticoduodenal artery	4 (11.4)
Superior mesenteric artery (terminal branches)	1 (2.8)
Right colic artery (distal branches)	2 (5.7)
Ileo-colic artery	3 (8.5)
Marginal artery	2 (5.7)
Jejunal artery	2 (5.7)
Ileal artery	3 (8.5)
Inferior mesenteric artery (terminal branches)	6 (17.1)
Sigmoid artery (terminal branches)	2 (5.7)
Inferior epigastric artery	1 (2.8)
Laboratory
Pre-CTA haemoglobin (g/dL), median (interquartile range)	7.5 (4-13)
Clinical
Hematemesis	9 (25.7)
Coffee ground emesis	4 (11.4)
Melena	5 (14.2)
Haematochezia	14 (40)
Haemodynamic instability	3 (8.5)

BMI: Body mass index; GI: Gastrointestinal; CTA: Computed tomography angiography.

Table 3 Arterial and venous volumes, bleeding rate, and time interval between computed tomography angiography and catheter angiography of general population

Parameter	General population
Time interval between CTA and DSA, median (interquartile range) (h)	4 (2-9)
Bleeding arterial volume, median (interquartile range) (mL)	0.46 (0.21-0.76)
Bleeding venous volume, median (interquartile range) (mL)	1.83 (0.66-2.83)
Bleed rate, median (interquartile range) (mL/min)	2.04 (0.05-3.09)

CTA: Computed tomography angiography; DSA: Digital subtraction angiography.

Table 4 Parameters evaluated in computed tomography angiography-angiography concordance group and in computed tomography angiography-angiography non-concordance group, n (%)

Parameter	Concordance group (n = 19)	Non-concordance group (n = 16)	P value, Chi-square test	P value, Mann-Whitney U test
Patients	19 (54.2)	16 (45.7)
Age (yr)	73.3 (± 18.0)	62.8 (± 17.3)		0.05
Male/female (ratio)	11/8	10/6	NS
Haemoglobin, median (interquartile range) (g/dL)	7.2 (6-8.2)	8 (7.5-8.3)		NS
Upper bleeding	9 (47.4)	6 (37.5)	NS
Lower bleeding	10 (52.6)	10 (62.5)	NS
Time interval between CTA and DSA, median (interquartile range) (h)	3 (2-5)	6.5 (2.7-20)		0.02
Bleeding arterial volume, median (interquartile range) (mL)	0.55 (0.25-0.80)	0.33 (0.18-0.66)		NS
Bleeding venous volume, median (interquartile range) (mL)	2.06 (1.67-4.66)	0.9 (0.27-2.15)		0.02
Bleed rate, median (interquartile range) (mL/min)	2.18 (1.30-5.01)	0.19 (0.02-2.21)		0.02

CTA: Computed tomography angiography; DSA: Digital subtraction angiography; NS: Not significant.

Table 5 Inter-reader agreement of volumetric analyses of arterial and venous phases

Variable	Reader A	Reader B	Average difference (95%CI)	DS of average difference	95% upper agreement limit (95%CI)	95% lower agreement limit (95%CI)
Volume in the arterial phase	0.70 ± 0.83	0.75 ± 1.01	-0.05 (-0.23 to 0.13)	± 0.52	0.98 (0.73–1.36)	-1.98 (-1.46 to -0.83)
Volume in the venous phase	2.50 ± 2.70	3.05 ± 3.88	-0.56 (-1.54 to 0.42)	± 2.85	5.03 (3.67 to 7.09)	-6.15 (-8.20 to -0.79)

DS: Digital subtraction.