Study reference

Study characteristics

Patient characteristics ²

Intervention (I)

Comparison / control (C) ³

Follow-up

Outcome measures and effect size ⁴

Comments

Godt, 2018

Type of study: observational study

Setting and country: retrospective study, Norway.

Funding and conflicts of interest: The author(s) declare no potential conflicts of interest with

respect to the research, authorship, and/or publication. This research received no specific grant from any funding

agency in the public, commercial or not-for-profit sectors.

Inclusion criteria:  patients aged>16 years who

underwent triple-split-bolus-CT (TS-CT) of the thorax and abdomen and who had portal venous-CT (PV-CT) of the abdomen within six weeks after the TS-CT.

Exclusion criteria: Severely injured

patients who underwent a dual phase CT with arterial and PV phase due to suspected active bleeding were not part of our study population.

N total at baseline:

35 patients

Important prognostic factors²:

Median age of 41 years (range 18-84).

Sex: 8 women, 27 men.

Median injury severity score was 19 (range 4-55).

31 patients (88.6%) were examined due to blunt trauma injury and four patients (11.4%) due to penetrating injury.

Groups comparable at baseline? Same group who underwent the intervention and comparison.

Describe intervention (treatment/procedure/test):

Triple-split-bolus-CT (TS-CT)

The TS-CT examination was performed as one scan

of the thorax and abdomen after a non-enhanced scan

of head and cervical spine. We administered three intravenous contrast boluses (total 175mL contrast) with

saline chases at different points of time for enhancement of the urinary tract, the abdominal organs, and the large arterial vessels.  The first bolus consisted

of 20mL intravenous contrast medium followed

by a 30-mL saline chase, both at a flow rate of 3 mL/s.

At least 5 min after, the second bolus of 100mL contrast media was injected at a flow rate of 5 mL/s, followed by a 45-mL saline chase (flow rate 6 mL/s).

After a delay of 32 s, the third bolus of 55mL contrast

medium was administered followed by a 55-mL

saline chase, both injected at a rate of 5 mL/s.

Hereafter, the CT scan was initiated by manual bolus

tracking with the region of interest (ROI) in the descending

aorta.

Describe  control (treatment/procedure/test):

Portal-venous CT (PV-CT)

The PV-CT had a fixed delay of 85 s. A contrast dose

of 2mL contrast/kg body weight was administered

followed by a 50-mL saline chase, both at a flow rate of

4 mL/s. Contrast dose applied in the PV-CT group was 149mL (mean).

Length of follow-up:

Not reported.

Loss-to-follow-up:

None.

Incomplete outcome data:

None.

Outcome measures and effect size (include 95%CI and p-value if available):

There were 24 (ten hepatic, nine splenic, five renal)

organ injuries visible in the TS-CT group and 18 (eight

hepatic, seven splenic,

one pancreatic, two renal) organ injuries visible in the PV-CT group, according to consensus.

False negatives:

One pancreatic and one liver

injury were not visible in the TS-CT =2/26 = 7.7%

Three liver injuries, three renal injuries, and two splenic injuries were no longer visible on the PV-CT.

= 8/26 = 30.7%

Diagnostic image quality: no significant difference in image quality between the two protocols were reported.

Complications: not reported.

This study was not performed in children.

Two radiologists with more than ten years of experience in trauma imaging evaluated the images independently for injuries of liver, spleen, pancreas, and kidneys according to the Organ Injury Scale.

Time between the two tests: Median interval between TS-CT and PV-CT was five days

(range 0–42 days).

There was no significant

difference between the two protocols regarding image quality.

Hakim, 2016

Type of study: observational study

Setting and country: retrospective, UK

Funding and conflicts of interest: not reported.

Inclusion criteria: patients with major trauma. Only patients arriving between 9.00 and 17.00 on weekdays.

Exclusion criteria:

Abandoned studies and those with significant metal or arm streak artefact were excluded from analysis.

N total at baseline:

Intervention: 40 (2 groups of 20)

Control: 20

Important prognostic factors²:

In total, 46 males, 14 females, aged 43.8 (SD 21.5)

For example

age ± SD:

I - B: 47.9

I – C:  38

C: 42.9

58% of the 60 studies demonstrated traumatic injury (similar in each group).

Groups comparable at baseline?

Describe intervention (treatment/procedure/test):

Two biphasic injection protocols

Group B, biphasic protocol: an i.v. injection of 65-ml contrast 21 medium was commenced at a rate of 1.5 ml s ; after completion at 43 s, a second 65-ml contrast bolus was started at a rate of

s21 3.5 ml. A single spiral acquisition or “Combi-scan” was made “at approximately 60 s.

Group C, modified biphasic protocol: the two contrast boluses were commenced at the same times as in Group B, but there was a further 9-s delay before acquiring images (total delay 70 s).

Describe  control (treatment/procedure/test):

Conventional arterial and portal venous (PV) phase multidetector CT.

Group A, conventional protocol: an i.v. injection of 90-ml s2 contrast medium was given at a rate of 3.5 ml

1. Two spiral acquisitions were made—the first at 30 s to obtain an arterial phase study and the second at 70 s to obtain a PV phase study.

Length of follow-up:

Not reported.

Loss-to-follow-up:

NA

Incomplete outcome data:

NA

Outcome measures and effect size (include 95%CI and p-value if available):

False negatives: No

injuries were considered

“missed” on the review of follow-up studies, subsequent clinical dialogue or discharge summaries.

Diagnostic image quality: all studies were considered to be of satisfactory diagnostic quality (score ≥3). The conventional protocol, considered the ‘gold standard’ produced the best quality images. When comparing the single bolus with the biphasic protocols, a statistically significant higher ratio of studies were of excellent (score 5) rather than good (score 4) diagnostic quality. However, when comparing the number of studies which were good or excellent (score 4 or 5) across each group, there was no significant difference.

Complications: not reported.

Beenen, 2015

Type of study: observational study

Setting and country: prospective, NL

Funding and conflicts of interest: not reported

Inclusion criteria: All consecutive polytrauma patients who were admitted during day time were eligible.

Exclusion criteria:  age <18 years, known pregnancy, patients referred from other hospitals or any

patient judged too unstable to undergo scanning and requiring resuscitation or immediate

operation.

N total at baseline:

Intervention: 10 (group C)

Control: 10 (group A)

Important prognostic factors²:

For example

age ± SD:

I: 60.5 (21.1)

C: 52.6 (23.2)

Sex:

I: 8/2

C: 6/4

Groups comparable at baseline? Redelijk

Describe intervention (treatment/procedure/test):

Group C. Split Bolus. Equal to Group A, but with split bolus technique: non-contrast enhanced CT of the brain and cervical spine, followed by repositioning of the arms alongside the head and scanning the torso with a fixed delay split bolus: at 60 sec before start of the CT 80 ml intravenous contrast medium at a rate of 4 ml/s and saline chase, followed at 20 seconds before start of the CT by 40 ml contrast medium at a rate of 5 ml/s and saline chase.

Describe  control (treatment/procedure/test):

Group A. Conventional total-body trauma CT. Non-contrast enhanced CT brain and cervical spine with arms alongside the patient, after which arms were elevated and positioned alongside

the head followed by CT of chest / abdomen/ pelvis after administration of 100 ml intravenous contrast medium at a rate of 4 ml/s in the venous phase, started after 60 seconds.

Length of follow-up:

All patients were followed during the complete hospital stay.

Loss-to-follow-up:

NA

Incomplete outcome data:

NA

Outcome measures and effect size (include 95%CI and p-value if available):

False negatives: not reported.

Diagnostic image quality: reported an nearly excellent (score 5) overall quality in the split bolus group and good (score 4) overall quality in the group that received the conventional protocol. In particular, the image quality of the abdominal aorta was higher in the group that received the split bolus protocol in comparison with the conventional protocol (good (4.17) versus. satisfactory (3.27), p = 0.014).

Complications: not reported.

Group B. One volume contrast CT. Non-contrast enhanced CT of the brain, followed by a

contrast enhanced volume-CT from skull base until the pubic symphysis, 4 ml/s with fixed delay of 30 seconds and arms alongside the body. Cervical spine was included into this torso scan, with the upper abdomen generally scanned in a late arterial phase.

Overall quality was rated nearly excellent (4.75) in the split bolus Group C, good (4.1) in the conventional Group A, and more than satisfactory in the one volume Group B (3.38).

Leung, 2015

Type of study: observational study

Setting and country: retrospective, UK

Funding and conflicts of interest: not reported.

Inclusion criteria: all trauma patients over the age of 18 who underwent pan-CT.

Exclusion criteria: young age.

N total at baseline:

Intervention: 78

Control: 73

Important prognostic factors²:

age ± SD:

I: mean age 47.1 years

C: mean age 44.3 years

Sex:

I: 58 men

C: 58 men

Groups comparable at baseline? yes

Describe intervention (treatment/procedure/test):

Split bolus protocol

In the split-bolus protocol,

only a plain scan of the head was performed, as the

cervical spine acquisition was acquired with the thorax, abdomen, and pelvis.

The split-bolus protocol was performed from the Circle

of Willis to the pubic symphysis using a contrast medium injection of 65 ml at 2 ml/s (for solid-organ enhancement) followed by an 85 ml bolus at 3.5 ml/s after a 10 seconds delay (arterial enhancement), then a 30 ml saline flush at

3.5 ml/s. The total injection time for this protocol was 77

seconds. The single-pass acquisition was started 77 seconds after initiation of contrast medium injection.

Describe  control (treatment/procedure/test):

Dual-phase protocol

In the traditional protocol, a plain scan of the head and

cervical spine were performed first.

The conventional trauma protocol included two phases; a bolus-tracking arterial phase acquisition from lung apices to

the pubic symphysis triggered at 100 HU in the descending aorta, followed by a manually triggered venous phase from

the diaphragm to the pubic symphysis acquired 50 seconds after completion of the arterial acquisition. In this protocol, an injection of 100 ml contrast material at a rate of 4 ml/s was given with a saline flush of 50 ml at a rate of 4 ml/s.

Length of follow-up:

Not reported.

Loss-to-follow-up:

Not reported.

Incomplete outcome data:

Not reported.

Outcome measures and effect size (include 95%CI and p-value if available):

False negatives: not reported.

Complications: not reported.

One disadvantage of the split-bolus protocol is the higher

contrast medium dose required; however, given the young age of this population, the renal effects of iodinated contrast medium is of less concern.

Yaniv, 2013

Type of study: observational study

Setting and country: retrospective, Israel

Funding and conflicts of interest: not reported.

Inclusion criteria: all CT examinations of consecutive multi trauma patients were included.

Exclusion criteria: Exclusion criteria included patient’s age below 18 years, inability of raising the patient’s arms,

And the patient having been transferred from another hospital.

N total at baseline:

Intervention: 40 

Control: 42

Important prognostic factors²:

age ± SD:

I: mean age 47.3  years (range 18-88)

C: mean age 38.1 years (range 18-87)

Groups comparable at baseline? yes

Describe intervention (treatment/procedure/test):

In both the conventional and revised protocols an

unenhanced examination of the head and neck and upper abdomen starting at the lower chest and ending at the caudal tip of the liver was performed first.

Revised protocol

This was followed by a single-phase craniocaudal

spiral acquisition of the chest abdomen and pelvis, which started at the middle of the seventh cervical

vertebra and ended at the proximal femurs. The

triphasic injection protocol consisted of an injection of

80 ml contrast material at a rate of 3 ml/s (iomeprol, 350 mg iodine/ml, Iomeron 350, Braco), a delay of 13 s, another 50 ml contrast medium injected at a rate of 4 ml/s, followed finally by 30 ml saline at the same rate. The scan started 75 s

after initiation of the first injection. The total volume of contrast medium was increased in this protocol when divided into two injections in order to obtain good vascular enhancement.

Conventional protocol

The conventional trauma protocol included two phases: chest angiography starting at the middle of the seventh cervical vertebrae and ending at the caudal level of the kidneys, and porto-venous abdomen and pelvis scanning starting just

above the diaphragm and ending at the proximal femurs. In this protocol, an injection of 90 ml contrast material (iomeprol, 350 mg iodine/ml, Iomeron 350, Barco, Milano Italy) at a rate of 4 ml/s was followed by another injection of 30 ml saline at a rate of 4 ml/s (Table 1). The chest angiographic CT acquisition started by bolus-tracking, and it was followed by a scan of the abdomen. This latter scan started 70 s after the beginning of the first injection with a section

thickness of 3 mm and an increment of 3 mm.

Describe  control (treatment/procedure/test):

The control group consisted of patients who went CT angiography of the abdomen for reasons other than trauma.

The abdominal angiographic protocol of the control

group included an unenhanced examination of the abdomen and a single angiographic acquisition of the abdomen and pelvis starting at the dome of the diaphragm and ending at the proximal femurs. This group was included in the study in order to compare the abdominal intravascular

attenuation values in an arterial phase scan with those in the conventional and revised protocol. This protocol consisted of an injection of 90 ml contrast material at a rate of 4 ml/s followed by an injection of 30 ml saline at the same

rate. Scanning was initiated by bolus tracking. The section thickness was 2 mm and the increment was 1 mm.

Length of follow-up:

Not reported.

Loss-to-follow-up:

Not reported.

Incomplete outcome data:

Not reported.

Outcome measures and effect size (include 95%CI and p-value if available):

False negatives: not reported.

Diagnostic image quality: Overall, a significantly higher score was given to the revised protocol compared to the conventional protocol by both reviewers (2.95 versus. 2.46 and 2.59 versus. 2.08).

Conventional: 18.2 +/- 8.2 (chest, abdomen and pelvis)

Revised protocol: 12.4 +/- 4.4 mSv (chest abdomen and pelvis)

Complications: not reported.

Study reference

(first author, year of publication)

Bias due to a non-representative or ill-defined sample of patients?¹

(unlikely/likely/unclear)

Bias due to insufficiently long, or incomplete follow-up, or differences in follow-up between treatment groups?²

(unlikely/likely/unclear)

Bias due to ill-defined or inadequately measured outcome ?³

(unlikely/likely/unclear)

Bias due to inadequate adjustment for all  important prognostic factors?⁴

(unlikely/likely/unclear)

Godt, 2018

Likely

“The authors accepted a selection bias due to the fact that all patients included had the indication for a PV-CT”.

Unlikely

Likely

The range in time interval between the two tests is 0-42 days. A delay of 42 days may result in a higher number of false negatives for PV-CT.

Unlikely

Hakim, 2016

Unlikely

Consecutive patients were included and excluded patients were justified.

Unlikely

Unlikely

Unlikely

Beenen, 2015

Unlikely

Consecutive patients were included.

Unlikely

Unlikely

Unlikely

Leung, 2015

Unlikely

Selection bias was not significant as

the choice of imaging protocol was made based on which consultant radiologist was on-call rather than patient factors.

Unlikely

Unlikely

Unlikely

Yaniv, 2013

Unlikely

Consecutive patients were included.

Unlikely

Unlikely

Unlikely