Standing Position Ultrasonography: Imaging Efficacy in Detecting Liver Diaphragmatic Dome Blind Area Lesions
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.
調査の概要
詳細な説明
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:
- Liver dome lesions (≤3 cm) confirmed by CT/MRI (plain + enhanced) within 6 months (for multiple lesions, include the one closest to the diaphragm);
- Superior border of lesion ≤1 cm from the diaphragm;
- Lesion size ≤3 cm.
Exclusion Criteria:
- Inability to cooperate with three-position ultrasound examination;
- Subcutaneous emphysema affecting ultrasound;
- Chilaiditi syndrome (interposition of colon).
Equipment & Methods
Equipment:
GE LOGIQ-E9 ultrasound system with C1-6-D low-frequency convex probe.
Procedure:
- Patients fasted for 2-3 hours and rested for 10-20 minutes before examination.
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:
- 2 = Fully visible: Clear lesion without gas/bone shadowing; complete margins; measurable size.
- 1 = Partially visible: Suboptimal visualization; obscured by gas/bone; incomplete margins; unmeasurable size.
- 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:
- 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.
- 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.
- 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.
研究の種類
入学 (実際)
連絡先と場所
研究場所
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Jilin
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Changchun、Jilin、中国、130000
- The First Hospital of Jilin University
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参加基準
適格基準
就学可能な年齢
- 子
- 大人
- 高齢者
健康ボランティアの受け入れ
サンプリング方法
調査対象母集団
説明
Inclusion Criteria:
- Liver dome lesions (≤3 cm) confirmed by CT/MRI (plain + enhanced) within 6 months (for multiple lesions, include the one closest to the diaphragm);
- Superior border of lesion ≤1 cm from the diaphragm;
- Lesion size ≤3 cm.
Exclusion Criteria:
- Inability to cooperate with three-position ultrasound examination;
- Subcutaneous emphysema affecting ultrasound;
- Chilaiditi syndrome (interposition of colon).
研究計画
研究はどのように設計されていますか？
デザインの詳細
コホートと介入
グループ/コホート |
|---|
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Three scanning positions
Inclusion Criteria:
Exclusion Criteria:
Equipment: GE LOGIQ-E9 ultrasound system with C1-6-D low-frequency convex probe. Procedure:
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. |
この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
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Evaluation of Image Display Effects Under Three Body Positions
時間枠：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
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協力者と研究者
研究記録日
主要日程の研究
研究開始 (実際)
一次修了 (実際)
研究の完了 (実際)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (実際)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
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