• Each year, there are about 5000 patients with coronary computed tomography angiography in Bach Mai hospitalp. • Reducing the dose of g.[r]
(1)1 Reduce the dose of contrast in
t d t h 128 li f
computed tomography 128 slice of
coronary arteries in Bach Mai Hospital
Chuyen Le Van, Tien Nguyen Cong, Dung Nguyen Tuan Bach Mai Radiology center
Bach Mai Radiology center
Abstract
• Background • Methods
• Methods • Results
(2)2 Background
• Each year, there are about 5000 patients with coronary computed tomography angiography in Bach Mai hospital
•Reducing the dose of g
contrast material is always an issue that has noticed problem
• For high diagnostic values, the intra-vascular CT number is higher than 350 HU
295 HU
is higher than 350 HU
420 HU
Cademartiri F et al Radiology 2004
Lvc1
Background
Dose of contrast
Injection speed
Left ventricular
systolic Patient’s
weight
Level of
material
p
function weight
Utsunomiya D, et al Jpn J Radiol 2016 Husmann L, et al Eur Radiol 2006
contrast
Diagnostic quality
(3)(4)3
Background - Status and improvement
•Status:
the contrast dose is 60- 70 ml
ml
Fixed injection speed is 5ml/s
•Improvement:
0.96 ml x body weight (kg) = contrast dose
Contrast dose/ 12 seconds = injection speed
injection speed
•Goal of improvement:
Reduce the contrast dose
Remain stable level of contrast
Level of contrast is higher than 350 HU
Methods
Divided into groups:
Group1 used the old technique
G 2 d th i d
Group2 used the improved technique
Comparison of groups:
1 Amount of contrast material 2 Injection speed
3 Level of contrast in vascular
(5)4
Technical table of CT scan 128-detector row machine in groups
Program Scan Type KV mAs Thickness Collimation FOV Scan Interval Delay Collimation (mm) Interval Calcium Scoring
Retrospective 120 122 2.5
(0,63 x 64)
350 2.5
(mm)
7 s
Caring Predict 120 17 5.0 350 1.0s 10s
Caring Predict 120 17 5.0
(0,63 x 8)
350 1.0s 10s
Cardiac Retrospective 120 157 0,63
(0,63x64)
350 5.0
(mm)
6 s
Preliminary results
Total patients: n = 84 Old technique (n=42) Improved technique (n=42) p-value
Age (years) 60 57 0.2
Male/female 42/42
Weight (kg) 59 58 0.6
Heart beat (beat/minute) 65 65
Heart beat (beat/minute) 65 65 0.7
Injection speed (mL/s ) 5 4.6 0.004
Contrast dose (mL) 62 56 <0.001
(6)5 Level of contrast between groups
s
t (HU) p < 0.05
v
el of contra
s Le v Old technique group improved technique group
Amount of medicine, injection speed between groups
e
(mL)
(mL/s)
p < 001 p < 01
u nt of medicin e ction speed (
p < 0.001 p < 0.01
(7)6 Conclusion
1 Reduce the dose of contrast to suit different patients
different patients
2 Change the injection speed
3 Level of intra-vascular contrast is more
stable among different patients
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