This study was the first of its kind in that it fills the gap in the scientific data created by the absence of any investigation making a direct comparison between 2D-sonograhpic and true urine volumes. While most hospitals in the developed world now prefer to measure urine volumes with portable bladder scanners and 3D ultrasound devices, none of these technology are widely available in Bangladesh and other developing countries. Nonetheless, hundreds to thousands of ultrasound examinations involving the measurement of maximum cystometric capacity (MCC) and postvoid residue (PVR) of urinary bladder are done with 2D stationary ultrasound every day. Despite our clinical experience that these measurements are quite accurate and reliable, it was deemed essential to establish scientific evidence in its favour.
This observational study was done in the Dept of Radiology & Imaging at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, during the period July – December 2014. 384 adult patients who came to BSMMU for ultrasound examinations were enrolled in this study and their true urine volumes were compared against that calculated using 2D B-mode ultrasound. The findings were analysed using two statistical approaches – correlation coefficient and limits of agreement. Calculation of the correlation coefficient was done so that the findings of this study could be compared with other relevant studies, most of which have used the correlation coefficient to assess the accuracy of the ultrasound equipment (3D or portable). However, Bland & Altman’s limits of agreement method is the standard statistical approach to assess agreement between two methods of clinical measurement, as determined by The Statistician, The Lancet and others.
Findings of this study show that bladder urine volumes measured by 2D B-mode ultrasound had high correlation (r = 0.96, 95% CI 0.955 – 0.969, P < 0.0001) and agreement (96.35%, LoA : -7.84 ± 53.05 mL) with true urine volumes. Sonographic urine volumes were accurate in both males and females, of all adult age groups and at all volume ranges including <100 mL.
Table of Contents
Chapter One : Introduction
1.1 Background
1.2 Rationale of the study
1.3 Hypothesis
1.4 Objectives
1.5 Review of Literature
Chapter Two : Materials and Methods
2.1 Study design
2.2 Study place
2.3 Study period
2.4 Study population
2.5 Sampling technique
2.6 Sample size
2.7 Selection criteria
2.7.1 Inclusion criteria
2.7.2 Exclusion criteria
2.8 Operational definitions
2.9 Equipment used
2.10 Data gathering instruments
2.11 Main outcome variables
2.12 Procedure
2.13 Statistical analyses
2.14 Statistical significance levels
2.15 Quality assurance strategies
2.16 Ethical measures
2.17 Study plan flow chart
2.18 Time table
Chapter Three : Results
Chapter Four : Discussion
Conclusion
Research Objectives and Topics
The primary objective of this study is to evaluate the accuracy of urine volume calculations performed by conventional stationary 2D B-mode ultrasonography in adult patients, comparing these sonographic measurements against the true volume of voided urine.
- Comparison of stationary 2D ultrasound with true urine volumes
- Evaluation of sonographic measurement accuracy across gender and age groups
- Assessment of measurement reliability at different volume ranges
- Correlation analysis using Pearson’s coefficient and Bland & Altman’s limits of agreement
- Validation of 2D ultrasound as an accessible diagnostic tool in developing countries
Excerpt from the Book
1.1 Background
Since its inception, ultrasonographic imaging has made significant contribution by obtaining important diagnostic information from patients in a rapid and noninvasive manner and has benefited from considerable improvements in image quality and visualization clarity. With the rapid advance in the field of imaging technology, ultrasound is now able to offer superior image quality, faster data acquisition, analysis and display, thus providing maximum diagnostic information.
Measurements are an important aspect of ultrasound examinations. Measurements of different organs, parts of organs, tumours, as well as the developing foetus are routine components of ultrasound studies. Linear distance measurements are considered to be sufficiently accurate and reliable. Volumetric measurements, however, are more complex as they often involve irregularly shaped organs such as the urinary or gall bladder or the ovaries (1). Nonetheless, volume measurement is important because it is necessary for the diagnosis, treatment planning and prognosis in many clinical situations and ultrasound is an easy, affordable and widely available way to do so. The most commonly used formula for this calculation is the ellipsoid formula, i.e. length × width × depth × π/6 (2,3). Since π = 3.142, π/6 = 0.52 and so volume = length × width × depth × 0.52.
Every day, hundreds of ultrasound examinations are done all around developing countries like Bangladesh involving the measurement of maximum cystometric capacity (MCC) and postvoid residue (PVR) of urinary bladder. While it is our clinical experience that these measurements are quite accurate and reliable, there has been no scientific study to establish this fact.
Chapter Summaries
Chapter One : Introduction: Provides the context of ultrasonographic imaging and the specific need for validating stationary 2D ultrasound for urine volume measurement in developing countries.
Chapter Two : Materials and Methods: Details the study design, participant selection, equipment specifications, and the statistical methodologies used to assess accuracy.
Chapter Three : Results: Presents the statistical findings, demonstrating a high correlation and agreement between sonographic calculations and true urine volumes across various demographic and volume categories.
Chapter Four : Discussion: Interprets the findings in the context of existing literature, highlighting the validity of 2D B-mode ultrasound as a reliable clinical tool.
Keywords
2D B-mode ultrasound, Urine volume, Maximum cystometric capacity, Postvoid residue, Bladder volume calculation, Ellipsoid formula, Diagnostic accuracy, Pearson’s correlation, Bland-Altman analysis, Radiology, BSMMU, Bangladesh, Urodynamics, Urinary bladder, Clinical imaging.
Frequently Asked Questions
What is the core focus of this research?
The research examines the accuracy of conventional stationary 2D B-mode ultrasound in measuring bladder urine volumes, providing scientific validation for a widely available tool in developing nations.
What are the primary themes covered?
Key themes include the comparison of sonographic measurements against voided volumes, the impact of demographic variables, and the statistical validation of the ellipsoid formula in clinical practice.
What is the main objective of the study?
The main objective is to determine whether 2D B-mode ultrasound is a sufficiently accurate and reliable tool for routine bladder volume measurement in adult patients.
Which scientific methods were employed?
The study used an observational cross-sectional design, employing Pearson’s correlation coefficient and Bland & Altman’s limits of agreement to compare sonographic results with measured voided urine.
What is addressed in the main body?
The main body covers the literature review, methodology (including participant selection and equipment usage), detailed results with statistical breakdowns, and a comprehensive discussion of findings.
Which keywords best describe this study?
Key terms include stationary 2D ultrasound, urine volume, bladder capacity, diagnostic accuracy, and Bland-Altman analysis.
Why were patients with existing Postvoid Residue (PVR) excluded from the study?
Exclusion was necessary to maintain simplicity in this initial study, focusing purely on the accuracy of 2D ultrasound in healthy bladders before testing it in patients with urological or neurological complications.
How does the accuracy of this study compare to portable bladder scanners?
The study suggests that 2D B-mode ultrasound offers an accuracy comparable to, or in some instances better than, more specialized portable bladder scanners, especially given its wider availability.
- Quote paper
- Muhammad Shoyab (Author), 2014, Determining the Accuracy of Urine Volume Calculations made by Stationary 2D B-Mode Ultrasonography, Munich, GRIN Verlag, https://www.grin.com/document/289001
