Standing Position Ultrasonography: Imaging Efficacy in Detecting Liver Diaphragmatic Dome Blind Area Lesions

May 5, 2026 updated by: Dezhi Zhang, The First Hospital of Jilin University

Study on the Imaging Efficacy of Standing Position Ultrasonography in Detecting Lesions Within the Blind Area Near the Diaphragmatic Dome of the Liver

Objective: To compare the detection efficacy of standing, supine, and left lateral decubitus ultrasonographic scanning for space-occupying lesions ≤3cm in the liver dome "blind area" and assess the feasibility of standing position as a routine scanning posture, providing a theoretical basis for optimizing liver ultrasound protocols.

Methods: Prospectively enrolled patients (CT/MRI-confirmed liver dome lesions) admitted to our Hepatobiliary-Pancreatic Department (Feb 2024-Feb 2025). Three sonographers, blinded to other positions' results, performed scans in standing, supine, and left lateral positions. Fleiss' kappa assessed inter-sonographer agreement. An image quality scoring system (0=not visible; 1=partially visible; 2=fully visible) was used by two blinded radiologists. Baseline data (sex, age, BMI), lesion location, size, type, and liver parenchymal status (normal, fatty liver, liver damage [diffuse disease/cirrhosis]) were recorded. Wilcoxon test compared display scores. Subgroup analyses evaluated confounding factors. A Generalized Estimating Equations (GEE) model controlled repeated-measures bias, reporting ORs.

Study Overview

Status

Completed

Conditions

Detailed Description

Patient Collection:

Enroll patients hospitalized in our Hepatobiliary-Pancreatic Department between February 2024 and February 2025 with subphrenic liver lesions confirmed by CT or MRI. These patients underwent ultrasound examinations. Collect and record demographic data (sex, age, height, weight, BMI) and lesion characteristics (size, location, type, liver background).

Inclusion & Exclusion Criteria

Inclusion Criteria:

  1. Liver dome lesions (≤3 cm) confirmed by CT/MRI (plain + enhanced) within 6 months (for multiple lesions, include the one closest to the diaphragm);
  2. Superior border of lesion ≤1 cm from the diaphragm;
  3. Lesion size ≤3 cm.

Exclusion Criteria:

  1. Inability to cooperate with three-position ultrasound examination;
  2. Subcutaneous emphysema affecting ultrasound;
  3. Chilaiditi syndrome (interposition of colon).

Equipment & Methods

Equipment:

GE LOGIQ-E9 ultrasound system with C1-6-D low-frequency convex probe.

Procedure:

  1. Patients fasted for 2-3 hours and rested for 10-20 minutes before examination.

  2. Three scanning positions (Fig 2.1):

    • Supine: Arms raised above head, fully exposing intercostal/subcostal areas; back parallel to bed.

      • Left Lateral Decubitus: Arms raised, fully exposed intercostal/subcostal areas; side-facing away from examiner; back perpendicular to bed.

        • Standing: Arms raised, fully exposed intercostal/subcostal areas; upright with body axis vertical to floor.

Ultrasound Image Acquisition:

Three sonographers (>3 years' experience) randomly selected one position per patient. Scanning included intercostal/subcostal approaches. Patients cooperated with breathing/positioning. If a lesion was detected, the clearest image was saved; if not, no image was captured. Sonographers were blinded to lesion presence and prior CT/MRI results. Each sonographer left the room after scanning their assigned position.

Image Quality Evaluation:

Evaluation:

Two blinded radiologists (>3 years' experience) independently scored lesion visibility. Discrepancies were resolved by re-evaluation and consensus. Evaluators were blinded to patient position.

Scoring System:

  1. 2 = Fully visible: Clear lesion without gas/bone shadowing; complete margins; measurable size.
  2. 1 = Partially visible: Suboptimal visualization; obscured by gas/bone; incomplete margins; unmeasurable size.
  3. 0 = Not visible: Undetectable.

Sonographer Consistency Test:

20 randomly selected patients were re-scanned by all three sonographers across all positions. Each sonographer recorded lesion detectability per position.

Bias Control:

Selection Bias: Consecutive enrollment of eligible patients. Sonographer Bias: Blinded scanning; no prior knowledge of CT/MRI/history; Fleiss' kappa for inter-operator consistency.

Reader Bias: Independent blinded scoring with consensus for discrepancies.

Quality Control:

Strict adherence to protocol; trained/certified personnel; standardized data collection/entry/analysis; complete records; predefined statistical methods; unbiased reporting.

Statistical Analysis:

  1. SPSS 26.0 software. Fleiss' kappa assessed inter-sonographer agreement. Normally distributed data: mean±SD; non-normal: median (IQR). Friedman test compared scores across positions; Wilcoxon signed-rank test for pairwise comparisons. Significance: P<0.05.
  2. Subgroup Analysis: Stratified by BMI (normal/underweight, overweight/obese), liver background (normal, fatty liver, liver damage [diffuse disease/cirrhosis]), lesion location (S4, S7, S8), size (0-1 cm, 1.1-2.0 cm, 2.1-3.0 cm), and type (HCC, non-HCC). Non-parametric tests repeated per subgroup.
  3. Generalized Estimating Equations (GEE): Binary logistic model (patient ID as subject variable; outcome: complete visibility) with exchangeable working correlation matrix. Covariates: position (supine as reference), location (S8 as reference), liver background, lesion type, size, and BMI. Results: OR (95% CI). Sensitivity analysis compared exchangeable, AR1, and unstructured correlation matrices.

Study Type

Observational

Enrollment (Actual)

95

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Jilin
      • Changchun, Jilin, China, 130000
        • The First Hospital of Jilin University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Enroll patients hospitalized in our Hepatobiliary-Pancreatic Department between February 2024 and February 2025 with subphrenic liver lesions confirmed by CT or MRI. These patients underwent ultrasound examinations. Collect and record demographic data (sex, age, height, weight, BMI) and lesion characteristics (size, location, type, liver background).

Description

Inclusion Criteria:

  1. Liver dome lesions (≤3 cm) confirmed by CT/MRI (plain + enhanced) within 6 months (for multiple lesions, include the one closest to the diaphragm);
  2. Superior border of lesion ≤1 cm from the diaphragm;
  3. Lesion size ≤3 cm.

Exclusion Criteria:

  1. Inability to cooperate with three-position ultrasound examination;
  2. Subcutaneous emphysema affecting ultrasound;
  3. Chilaiditi syndrome (interposition of colon).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Three scanning positions

Inclusion Criteria:

  1. Liver dome lesions (≤3 cm) confirmed by CT/MRI (plain + enhanced) within 6 months (for multiple lesions, include the one closest to the diaphragm);
  2. Superior border of lesion ≤1 cm from the diaphragm;
  3. Lesion size ≤3 cm.

Exclusion Criteria:

  1. Inability to cooperate with three-position ultrasound examination;
  2. Subcutaneous emphysema affecting ultrasound;
  3. Chilaiditi syndrome (interposition of colon).

Equipment:

GE LOGIQ-E9 ultrasound system with C1-6-D low-frequency convex probe.

Procedure:

  1. Patients fasted for 2-3 hours and rested for 10-20 minutes before examination.
  2. Three scanning positions :

Supine: Arms raised above head, fully exposing intercostal/subcostal areas; back parallel to bed.

Left Lateral Decubitus: Arms raised, fully exposed intercostal/subcostal areas; side-facing away from examiner; back perpendicular to bed.

Standing: Arms raised, fully exposed intercostal/subcostal areas; upright with body axis vertical to floor.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Evaluation of Image Display Effects Under Three Body Positions
Time Frame: The time from discovery of the space-occupying lesion to image acquisition was less than six months

Two ultrasound physicians, each with over three years of experience, independently evaluated the visibility of space-occupying lesions in the acquired images. If their initial assessments differed, they re-evaluated the images and reached a consensus through discussion. Both physicians were blinded to the patient's scanning position during evaluation.

Scoring Criteria:

A three-point scoring system was used to assess the visibility of lesions near the diaphragmatic dome (refer to Figures 2.2 and 2.3 for examples):

Score 2 (Fully Visible): The space-occupying lesion is clearly visualized without obscuration by gas or ribs. Margins are complete, and lesion size can be accurately measured.

Score 1 (Partially Visible): The space-occupying lesion is visualized suboptimally, obscured by gas or ribs. Margins are incomplete, and lesion size cannot be accurately measured.

Score 0 (Not Visible): The space-occupying lesion is completely undetectable.
The time from discovery of the space-occupying lesion to image acquisition was less than six months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

The First Hospital of Jilin University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 1, 2024

Primary Completion (Actual)

February 1, 2025

Study Completion (Actual)

July 1, 2025

Study Registration Dates

First Submitted

May 5, 2026

First Submitted That Met QC Criteria

May 5, 2026

First Posted (Actual)

May 12, 2026

Study Record Updates

Last Update Posted (Actual)

May 12, 2026

Last Update Submitted That Met QC Criteria

May 5, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024-HS-125

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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