Plain English Summary
Background and study aims
X-ray images are a primary tool in investigating diseases of the hip joint. The reproducibility of this examination is especially important for diagnosis and monitoring of arthritis and following hip replacement surgery. Pelvis x-rays are routinely performed with the patient lying down, however some studies have shown that standing is more effective, demonstrating abnormalities taking into consideration the effect of load. Previous research has demonstrated that the pelvis tilts with different postures (i.e. lying, sitting, standing) and understanding these changes to the resultant x-ray image is vital. Importantly, no research has considered the radiation dose implications of changing from supine to standing technique. The aim of this study is to examine the differences in diagnostic markers and radiation dose between the different positions in three phases.
Who can participate?
Adults aged 18 and older who are referred for a pelvis or hip x-ray and are able to stand unaided.
What does the study involve?
This study includes two phases. In phase, participants have their height, weight and trunk diameter/circumference measured whilst erect and supine (laying on their back). They have the standard supine pelvis X-ray performed. For phase two, an anthropomorphic phantom will then be utilised to establish the imaging protocol to provide suitable quality images with the lowest radiation dose. The third phase of the study will then recruit more participants who have been referred for pelvis or hip x-rays and they will have their imaging performed in both lying and standing positions. The recruitment and refusal rates are used to inform future study design and confirm sample size. The data will assist in determining variation in radiation dose, anatomical measures for hip disease and anatomy between positions.
What are the possible benefits and risks of participating?
No direct benefit will be received by participants in the study. There are no anticipated risks associated with participation.
Where is the study run from?
Pinderfields Hospital (UK)
When is the study starting and how long is it expected to run for?
November 2017 to May 2018
Who is funding the study?
Society and College of Radiographers (SCoR) (UK)
Who is the main contact?
Miss Martine Harris (Scientific)
A pilot study to compare supine and erect pelvis radiographs – assessment of impact on radiation dose and diagnostic quality
This feasibility study aims to determine if patient posture (erect or supine) has an effect on soft tissue anatomy (body shape/size). We want to identify the implications of postural changes on radiation dose and image quality for X-Ray examination.
The study objectives are to:
1. Identify radiation dose and image quality metrics
2. Determine the scope of a future research study proposal, including trial procedures, imaging protocols and patient information
3. Identify the recruitment and refusal rates to such research
Yorkshire & The Humber - South Yorkshire Research Ethics Committee, 14/12/2017, ref: 17/YH/0363
Non-randomised; Interventional; Design type: Diagnosis, Imaging, Other
Primary study design
Secondary study design
Non randomised study
Patient information sheet
See additional files
Specialty: Musculoskeletal disorders, Primary sub-specialty: Other; UKCRC code/ Disease: Musculoskeletal/ Other osteopathies
In phase 1 the participants have measures undertaken in the supine and erect position but just have the standard supine pelvis X-Ray performed.
During phase 3 a new cohort of participants are recruited to have measures and an additional pelvis X-Ray taken in the erect position in addition to the standard supine pelvis X-Ray.
There is no follow-up post intervention in either phase.
Primary outcome measure
Difference in abdominal soft tissue thickness, measured by a researcher with a tape measure (in cm) in supine and erect position at baseline (incorporating phase 1 & 3 data).
Secondary outcome measures
1. Difference in abdominal circumference, measured (in cm) in supine and erect position at baseline (incorporating phase 1 & 3 data)
2. BMI will be calculated using height and weight measurements obtained at baseline (incorporating phase 1 & 3 data).
3. Difference in radiation dose between X-Rays performed in supine and erect position as measured by dose area product (DAP) at baseline (phase 3).
4. Image quality variation between supine and erect X-Rays performed at baseline will be measured using a validated psychometric scale (phase 3).
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Patients over the age of 18 who attend for x-ray of the hip or pelvis from a MYH OP clinic or their GP
2. Able to stand unaided
3. Have not had lower limb surgery in the last six months
4. Able to provide written informed consent.
1. Patients who over the age of 18 attend for x-ray of the hip or pelvis from a MYH OP or their GP
2. Not pregnant
3. Able to provide written informed consent
4. Able to stand unaided
5. Have not had recent trauma or a pelvic x-ray or pelvic radiotherapy in the preceding 6 months
Target number of participants
Planned Sample Size: 240; UK Sample Size: 240
Participant exclusion criteria
Patients who are under the age of 18, pregnant, have undergone lower limb surgery within the previous six months or are unable to provide written informed consent will be excluded from the study. A further exclusion will be related to patients who are unable to stand unaided, as the ability to weight bear would be a key component in performance of an x-ray in the erect posture.
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Society and College of Radiographers (SCoR)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journal. The intention is to publish by December 2018.
Please see additional files for protocol version 1.4.
IPD sharing statement:
The data sharing plans for the current study are unknown and will be made available at a later date.
Intention to publish date
Participant level data
To be made available at a later date
Basic results (scientific)