UMIN-ICDS Clinical Trial
| Unique ID issued by UMIN | UMIN000063451 |
|---|---|
| Receipt number | R000072626 |
| Scientific Title | An adjustable-delay dual-bolus contrast injection protocol for triple rule-out CT angiography: a prospective comparison with a continuous injection protocol |
| Date of disclosure of the study information | 2026/10/29 |
| Last modified on | 2026/10/29 10:56:50 |
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Basic information
Public title
Comparison of a two-bolus and a continuous contrast injection method for triple rule-out chest CT
Acronym
Contrast injection methods for chest pain CT
Scientific Title
An adjustable-delay dual-bolus contrast injection protocol for triple rule-out CT angiography: a prospective comparison with a continuous injection protocol
Scientific Title:Acronym
TRO dual-bolus study
Region
| Japan |
Condition
Condition
Patients requiring triple rule-out CT for suspected acute aortic, coronary, or pulmonary vascular disease
Classification by specialty
| Cardiology | Radiology | Cardiovascular surgery |
Classification by malignancy
Others
Genomic information
NO
Objectives
Narrative objectives1
To compare CT attenuation in the cardiac, pulmonary arterial, aortic, and delayed phases between an adjustable-delay dual-bolus injection protocol and a conventional continuous injection protocol for triple rule-out CT
Basic objectives2
Others
Basic objectives -Others
Comparison of contrast enhancement (CT attenuation)
Trial characteristics_1
Exploratory
Trial characteristics_2
Pragmatic
Developmental phase
Not applicable
Assessment
Primary outcomes
CT attenuation (HU) at 13 sites in three phases, compared between protocols; measured once at the examination by three independent observers
Key secondary outcomes
Base
Study type
Interventional
Study design
Basic design
Parallel
Randomization
Randomized
Randomization unit
Individual
Blinding
Open -but assessor(s) are blinded
Control
Active
Stratification
NO
Dynamic allocation
NO
Institution consideration
Institution is not considered as adjustment factor.
Blocking
NO
Concealment
Pseudo-randomization
Intervention
No. of arms
2
Purpose of intervention
Diagnosis
Type of intervention
| Medicine | Other |
Interventions/Control_1
Novel protocol: two 12-s boluses at 21 mgI/kg/s (iopamidol 370 mgI/mL) separated by a saline flush and an adjustable inter-bolus delay, with separately timed cardiac, pulmonary arterial, and aortic acquisitions
Interventions/Control_2
Conventional protocol: continuous injection of 70 mL at 4 mL/s followed by 30 mL at 2 mL/s and 30 mL saline (iopamidol 300 mgI/mL below 60 kg or 370 mgI/mL at 60 kg or above), with a combined helical acquisition immediately after the cardiac scan
Interventions/Control_3
Interventions/Control_4
Interventions/Control_5
Interventions/Control_6
Interventions/Control_7
Interventions/Control_8
Interventions/Control_9
Interventions/Control_10
Eligibility
Age-lower limit
| Not applicable |
Age-upper limit
| Not applicable |
Gender
Male and Female
Key inclusion criteria
Patients for whom the cardiovascular surgery service judged triple rule-out CT necessary
Key exclusion criteria
Patients in whom a single target diagnosis was evident at presentation
Target sample size
100
Research contact person
Name of lead principal investigator
| 1st name | Fumiyoshi |
| Middle name | |
| Last name | Hakamata |
Organization
Kawasaki Saiwai Hospital
Division name
Department of Radiology
Zip code
212-0014
Address
31-27 Omiya-cho, Saiwai-ku, Kawasaki, Kanagawa 212-0014, Japan
TEL
044-544-4611
f-hakamata@saiwaihp.jp
Public contact
Name of contact person
| 1st name | Kazufumi |
| Middle name | |
| Last name | Ishida |
Organization
Kawasaki Saiwai Hospital
Division name
Department of Radiology
Zip code
212-0014
Address
31-27 Omiya-cho, Saiwai-ku, Kawasaki, Kanagawa 212-0014, Japan
TEL
044-544-4611
Homepage URL
saiwai.ishida@gmail.com
Sponsor or person
Institute
Department of Radiology, Kawasaki Saiwai Hospital
Institute
Department
Personal name
Funding Source
Organization
None
Organization
Division
Category of Funding Organization
Self funding
Nationality of Funding Organization
Japan
Other related organizations
Co-sponsor
Name of secondary funder(s)
IRB Contact (For public release)
Organization
Ethics Committee, Kawasaki Saiwai Hospital (Secretariat: Hospital Safety Management Department)
Address
31-27 Omiya-cho, Saiwai-ku, Kawasaki, Kanagawa 212-0014, Japan
Tel
044-544-4611
byouinanzen@saiwaihp.jp
Secondary IDs
Secondary IDs
NO
Study ID_1
Org. issuing International ID_1
Study ID_2
Org. issuing International ID_2
IND to MHLW
Institutions
Institutions
川崎幸病院（神奈川県）
Other administrative information
Date of disclosure of the study information
| 2026 | Year | 10 | Month | 29 | Day |
Related information
URL releasing protocol
Publication of results
Partially published
Result
URL related to results and publications
Number of participants that the trial has enrolled
99
Results
Dual-bolus vs conventional: PA attenuation 467+/-82 vs 330+/-85 HU (difference 137, 95% CI 104-170); PA<300 HU 2% vs 36%; SVC 122 vs 523 HU; PA/aortic DLP 680 vs 973 mGy.cm (30% lower); all p<0.001. Aortic root >=300 HU: 94% vs 92%. Left coronary attenuation: 255 vs 295 HU (p=0.005). The PA difference increased with weight; lower coronary attenuation was mainly seen in lighter patients.
Results date posted
| 2026 | Year | 10 | Month | 29 | Day |
Results Delayed
| Delay expected |
Results Delay Reason
Preparation of a manuscript for an international journal is ongoing after completion of the study; the manuscript has not yet been published.
Date of the first journal publication of results
Baseline Characteristics
One hundred examinations in 99 patients. Dual-bolus/conventional groups: male:female 38:12/36:14 (p = 0.65), age 74.2 +/- 12.1/69.5 +/- 13.8 years (p = 0.075), and body weight 59.0 +/- 10.8/64.8 +/- 15.8 kg (p = 0.037). Body weight was higher in the conventional group; body-weight-adjusted analyses were added for the report.
Participant flow
One hundred examinations in 99 patients were allocated by alternation in order of examination date (dual-bolus 50, conventional 50); one patient was examined twice, once with each protocol. Enrollment was limited to shifts when a technologist trained in both protocols was on duty, so enrollment was not consecutive; at other times patients were scanned with the dual-bolus protocol, then in routine use, and were not enrolled. No examination was excluded. One conventional-protocol patient received iomeprol 350 mgI/mL because of a history of reaction to iodinated contrast.
Adverse events
Outcome measures
No missing measurements at any of the 13 sites.
Plan to share IPD
No
IPD sharing Plan description
There is no plan to share individual participant data.
Progress
Recruitment status
Completed
Date of protocol fixation
| 2015 | Year | 05 | Month | 01 | Day |
Date of IRB
| 2015 | Year | 04 | Month | 24 | Day |
Anticipated trial start date
| 2015 | Year | 06 | Month | 23 | Day |
Last follow-up date
| 2015 | Year | 10 | Month | 29 | Day |
Date of closure to data entry
| 2016 | Year | 01 | Month | 05 | Day |
Date trial data considered complete
| 2026 | Year | 10 | Month | 24 | Day |
Date analysis concluded
| 2026 | Year | 10 | Month | 24 | Day |
Other
Other related information
This study was a prospective comparison completed in 2015, and this record is a late registration made after completion. Allocation was by alternation in order of examination date (quasi-randomized), not by random numbers. Both injection protocols compared were already in routine clinical use at our institution, and at the time the investigators did not recognize the study as one requiring prospective registration in a public registry; it was therefore not registered in advance. The 2015 protocol specified between-protocol comparison of CT attenuation at 13 sites. The protocol date given is that of the revised application reflecting the committee's conditions, which coincides with the conditional approval notice; according to the examination records, enrollment ran from June 23 to October 29, 2015. Contrast dose, DLP, and patient characteristics were recorded at each examination. For the 2026 report, pulmonary arterial attenuation, superior vena cava and right ventricular attenuation, and pulmonary arterial and aortic acquisition DLP were designated as primary endpoints and a body-weight analysis was added; these were defined after data collection, using the 2015 records. The data-lock and analysis dates are those on which the data were verified against the hospital examination records and reanalyzed in 2026. Interim results from the first 80 patients were presented at the 43rd Autumn Scientific Congress of the Japanese Society of Radiological Technology (2015) and at ECR 2016.
Management information
Registered date
| 2026 | Year | 10 | Month | 29 | Day |
Last modified on
| 2026 | Year | 10 | Month | 29 | Day |
Link to view the page
Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000072626
