Review on ultrasound measurement of bladder or detrusor wall thickness in women: techniques, diagnostic utility, and use in clinical trials

Purpose

To provide a narrative review of literature evaluating ultrasound techniques for the measurement of bladder wall hypertrophy in women as an alternative to invasive urodynamic assessment for the diagnosis of lower urinary tract symptoms (LUTS).

Methods

A literature review was performed using PubMed and all paper journals of congress abstracts searching for articles on ultrasound measurement of bladder wall thickness (BWT) or detrusor wall thickness (DWT) published between January 1990 and May 2012. Each study was classified with a level of evidence using the Oxford Centre for Evidence-based Medicine classification (2009).

Results

Ultrasound measurement of bladder wall hypertrophy is not standardised, and techniques vary widely according to anatomical approach, ultrasound frequency and other factors. This review compared transvaginal, translabial/transperineal and suprapubic approaches for ultrasound BWT/DWT measurement. BWT/DWT measurements correlated well with urodynamic diagnoses of detrusor overactivity (DO) using all three ultrasound techniques. BWT values were consistently higher in women with DO than in women with stress incontinence, although threshold values for the differential diagnosis of DO varied between clinical studies (5.0–6.5 mm using transvaginal ultrasound). Few data were available on the use of translabial or suprapubic ultrasound in women. Inter- and intraobserver variability was higher with transperineal and suprapubic ultrasound, and these techniques appear less reliable than transvaginal ultrasound. Studies suggest that BWT is reduced in response to antimuscarinic therapy in women with overactive bladder or DO.

Conclusions

Data from clinical trials suggest that transvaginal ultrasound measurement of BWT is a reliable method of diagnosing DO in women with LUTS, and BWT decreases during antimuscarinic therapy.     

Measuring ulnar variance: A comparison of techniques

This study compared three commonly used methods of measuring ulnar variance. The comparison included the project- a-line technique (A), the method of concentric circles (B), and the method of perpendiculars (C). Specific features studied were variations in results generated by each technique as well as the interobserver and intraobserver reliability for each technique. The only significant difference among techniques was between techniques A and B (p = 0.0224), where mean A values were more positive than mean B values. Observers were found to differ significantly (p = 0.0092) independent of technique. All methods studied were highly reliable, although the method of perpendiculars was most reliable for both interobserver (reliability = 0.9801) and intraobserver (reliability = 0.9719) reliability. This study shows that the clinician may choose whichever technique he prefers when measuring ulnar variance.     

Reliability analysis for radiographic measurement of limb length discrepancy: full-length standing anteroposterior radiograph versus scanogram

Patients with limb length discrepancy (LLD) often have associated angular deformities requiring a standing full-length radiograph of the lower limb in addition to a scanogram. The purpose of our study was to determine the intraobserver and interobserver reliability of measuring LLD with both techniques, using computed radiography. The LLD was measured on 70 supine scanograms and standing anteroposterior radiographs of the lower extremity by 5 blinded observers on 2 separate occasions. Intraclass correlation coefficient (ICC) and mean absolute difference (in millimeters) was calculated to assess intraobserver and interobserver reliability and found to be excellent for both radiographic techniques. Intraobserver ICC and mean absolute difference was 0.975 to 0.995 and 1.5 to 2.6 mm for scanogram and 0.939 to 0.996 and 1.5 to 4.6 mm for the standing radiograph, respectively. Repeated measurements for both radiographic studies were within 5 mm of the first measurement greater than 90% and within 10 mm greater than 95% of times. Interobserver ICC and mean absolute difference was 0.979 and 2.6 mm for scanogram and 0.968 and 3.0 mm for the standing radiograph. The reliability was excellent irrespective of age, sex, and underlying diagnosis other than Blount disease, which had good reliability. A standing anteroposterior radiograph of the lower extremity should be the imaging modality of choice when evaluating patients with limb length inequality who may have angular deformities because it allows a comprehensive evaluation of the extremity and is as reliable as a scanogram for measuring LLD. This approach may decrease the radiation exposure and financial burden involved in assessing patients with unequal limb lengths.     

超声与MRI诊断血管前置

目的探讨产前超声与MRI诊断血管前置的临床价值。方法回顾分析6例血管前置的产前超声与MRI表现。结果 6例中,4例接受经腹及经会阴超声检查,2例接受经腹及经阴道超声检查,其后接受MR检查,并一致诊断为血管前置,术后均得到证实。结论超声及MRI均能良好地显示宫颈内口处血管前置;结合彩色多普勒及经会阴、经阴道超声检查,可大幅提高诊断率。     

Reliability of Determining and Measuring Acromial Enthesophytes

Background

Although the reliability of determining acromial morphology has been examined, to date, there has not been an analysis of interobserver and intraobserver reliability on determining the presence and measuring the size of an acromial enthesophyte.

Questions/Purposes

The hypothesis of this study was that there will be poor intraobserver and interobserver reliability in the (1) determination of the presence of an acromial enthesophyte, (2) determination of the size of an acromial enthesophyte, and (3) determination of acromial morphology.

Patients and Methods

Fifteen fellowship-trained orthopedic shoulder surgeons reviewed the radiographs of 15 patients at two different intervals. Measurement of acromial enthesophytes was performed using two techniques: (1) enthesophyte length and (2) enthesophyte–humeral distance. Acromial morphology was also determined. Interobserver and intraobserver agreement was determined using intraclass correlation and kappa statistical methods.

Results

The interobserver reliability was fair to moderate and the intraobserver reliability moderate for determining the presence of an acromial enthesophyte. The measurement of the enthesophyte length showed poor interobserver and intraobserver reliability. The measurement of the enthesophyte–humeral distance showed poor interobserver reliability and moderate intraobserver reliability. The interobserver and intraobserver reliability in determining acromial morphology was found to be moderate and good, respectively.

Conclusions

There is fair to moderate reliability among fellowship-trained shoulder surgeons in determining the presence of an acromial enthesophyte. However, there is poor reliability among observers in measuring the size of the enthesophyte. This study suggests that the enthesophyte–humeral distance may be more reliable than the enthesophyte length when measuring the size of the enthesophyte.     

Measurement variance in limb length discrepancy: clinical and radiographic assessment of interobserver and intraobserver variability

The purpose of this study was to assess interobserver and intraobserver variability in the assessment of clinical and radiographic measurement of lower limb length discrepancy. Clinical measurements included direct measurement with a tape measure from anterior superior iliac spine (ASIS) to lateral malleolus and ASIS to medial malleolus as well as block measurement. Slit scanogram radiographic measurement was also evaluated. All three clinical measurements had excellent reliability, but the relatively large mean differences and the large 95% confidence intervals for clinical measurements limit the usefulness of these techniques. Slit scanogram measurement was the most reliable measurement technique. The intraobserver variance of direct slit scanogram measurement included intraclass correlation coefficient of 0.99, mean difference of 0.1 cm, and 95% confidence interval of 0.4 cm. Results were not influenced by patient age or body mass index. Slit scanogram measurement is the preferred method for assessment of limb length discrepancy. The direct slit scanogram measurement described in the text follows the mechanical axis line of the leg in the "at ease" standing position described by Paley. Direct measurement using a measuring tape on a full-length slit scanogram is more reliable than indirect measurement using horizontal lines drawn to a radiolucent ruler that is positioned by a technician, since direct measurement avoids errors due to nonparallel positioning of the limb relative to the ruler, and direct measurement also avoids errors due to non-horizontal lines drawn from standard bony landmarks to the ruler. The ideal radiographic measurement technique would have high reliability and accuracy and would minimize or eliminate radiation.     

Comparison between manual and computer-assisted measurements of hallux valgus parameters

BACKGROUND: The aim of this study was to determine if there are intraobserver and interobserver differences in reliability when measuring hallux valgus angles (HVA), 1-2 intermetatarsal angles (IMA), and distal metatarsal articular angles (DMAA) manually compared to computer-assisted means. Our hypothesis was that the measurements taken by computer-assisted methods of these three forefoot angles would be superior in consistency and accuracy compared to manual measurements. METHODS: Four examiners studied 20 weightbearing anteroposterior radiographs of patients with hallux valgus. Manual measurements were taken on photographic prints using a goniometer and a fine point pen. Computer-assisted measurements were taken on digitized images using computer software. Three sets of measurements by both of these methods were taken 1 week apart. RESULTS: There was no statistically significant difference between digital and manual measurements for any of the three angles measured (p .05). However, the reliability of measurements within a range of 5 degrees for both methods was 70.6% for HVA, 84% for 1-2 IMA, and 59% for DMAA. CONCLUSION: There were no significant differences in interobserver and intraobserver reliability in measuring 1-2 IMA and HVA, regardless of the method of measurement; however, there was a significant difference in interobserver reliability when measuring the DMAA either on computer or manually (p = <.05).     

Bladder-wall-thickness ultrasound scan in the investigation of LUTS in women: challenges and limitations

Bladder-wall-thickness (BWT) ultrasound assessment in lower urinary tract conditions has been studied extensively for the last 30 years. There is some evidence that it may have diagnostic utility in detrusor overactivity (DO). The cutoff value for BWT for diagnosing DO is still a matter of debate, with different studies using different values. Transvaginal scanning is the most accurate route of measuring BWT, with excellent interobserver variation and reproducibility. There is still ongoing evaluation of bladder ultrasound and its place in the investigation of overactive bladder symptoms.     

Assessment of talar flattening in adult idiopathic clubfoot

BACKGROUND: The radius/length (R/L) ratio was developed to evaluate the convexity of the talar dome in idiopathic clubfoot. However, the index has not been tested for its reliability and reproducibility. METHODS: The R/L ratio was determined by three independent observers on the radiographs of 21 adult patients with idiopathic clubfoot and 30 adult subjects with normal feet. The reproducibility and the reliability of the R/L ratio were calculated. RESULTS: For the normal feet the reproducibility and the reliability of the R/L ratio was high (correlation coefficient > 0.87). For the patients with clubfoot, the reliability and reproducibility depended on the severity of talar flattening. For a radius of less than 45 mm the mean intraobserver correlation coefficient was 0.74 (range 0.54 to 0.83) and the mean interobserver correlation coefficient was 0.58 (range 0.49 to 0.75). For a radius of more than 45 mm no statistically significant intraobserver and interobserver correlations were found. CONCLUSION: The current results indicate that the R/L ratio of talar flattening is reliable and reproducible for mild talar deformity but not for severe flattening (radius of more than 45 mm).     

Measurement variations in scoliotic angle, vertebral rotation, vertebral body height, and intervertebral disc space height

Thirty consecutive posteroanterior and lateral radiographs of patients with adolescent idiopathic scoliosis with a mean Cobb angle of 24.4 degrees were read. In measuring the scoliotic angle, the interobserver error (SD) was 2.8 degrees and the intraobserver, 1.8 degrees. Rotation of the apical vertebra was estimated by measuring the translation of the pedicle on posteroanterior radiographs. For vertebral rotation, the interobserver measurement error (SD) was 3.4 and the intraobserver, 1.8%. The height of the apical vertebral body and the intervertebral disc space next inferior to it were measured on lateral radiographs as the anterior angles of the diagonals of the respective body or disc space. In measuring the vertebral body height, the interobserver error (SD) was 3.2 and the intraobserver, 2.6 degrees, and in measuring the intervertebral disc space height, the interobserver error was 2.4 and the intraobserver, 1.8 degrees. The angles can be transformed to a corresponding height/length ratio by a simple trigonometrical formula.     

Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools

The objective of this study is to determine the intraobserver and interobserver reliability of end vertebra definition and Cobb angle measurement using printed and digital radiographs of 48 patients with scoliosis. The Cobb angle and the end vertebra were assessed by six observers in 48 patients with scoliosis using printed and digital radiographs. Definition of end vertebra and measurement of the Cobb angle was repeated three times with a 3 week interval. Intraclass correlation coefficients (ICC) were used to determine the interobserver and intraobserver reliabilities. 95% prediction limits for the errors in measurements are provided. For the Cobb angle a mean ICC of 0.97 was determined for intra- and interobserver reliability measurement of the printed radiographs. For the electronic radiographs a mean ICC value of 0.93 was determined for interobserver reliability and a mean ICC value of 0.96 for intraobserver reliability. Intraobserver ICC for definition of end vertebrae was 0.8 for both methods. Interobserver ICC was 0.83 for the manual and 0.74 in the digital method. One pitfall in angle measurement implies the Cobb method itself which measures in two dimensions. Until we develop a proper tri-dimensional measuring system an error is introduced. For the Cobb angle measurement the definition of end vertebrae introduces the main source of error. Digital radiography does not improve the measurement accuracy.     

Effects of bladder volume on transabdominal ultrasound measurements of intravesical prostatic protrusion and volume

BACKGROUND: A filled bladder acts as an acoustic window for transabdominal ultrasound measurements of intravesical prostatic protrusion and volume. The aim of this study is to evaluate the effects of bladder volume on transabdominal ultrasound measurements of these parameters. METHODS: Twenty-two patients undergoing transurethral resection of the prostate (TURP) were studied. Under general anesthesia just before TURP, a transrectal ultrasound measurement of prostate volume was obtained. The bladder was then filled in a stepwise manner with 100, 200, 300, 400 and 500 mL. At each volume, the intravesical prostatic protrusion and prostatic volume were measured transabdominally using ultrasound. RESULTS: There was an obvious trend of decreasing mean transabdominal intravesical prostatic protrusions with increasing bladder volume. The mean transabdominal intravesical prostatic protrusion at bladder volumes 100, 200, 300, 400 and 500 mL was 9.1, 8.8, 7.4, 5.8 and 4.6 mm, respectively. The bladder volume at which maximum prostatic protrusion occurred was between 100 and 200 mL. The mean transabdominal prostate volume at the five increasing bladder volumes was 50.6, 48.7, 49.2, 47.9 and 41.4 mL, and these were correlated to transrectal prostate volume, particularly when the bladder volume was less than 400 mL. CONCLUSIONS: Transabdominal ultrasound measurement of prostatic protrusion is dependent on bladder volume. Transabdominal ultrasound measurement of prostatic volume correlates well with the transrectal measurement of the same parameter when the bladder volume is less than 400 mL.     

Bensahel et al. and International Clubfoot Study Group evaluation of treated clubfoot: assessment of interobserver and intraobserver reliability

In order to assess interobserver and intraobserver reliability of an evaluation system of the International Clubfoot Study Group, 30 children treated for unilateral clubfoot and their radiographs were examined by three different observers. The mean intraobserver kappa value was found to be 0.62. The mean interobserver kappa value was 0.73. These kappa values correlated with a substantial degree of agreement. Interobserver reliability for all subgroup evaluations (morphologic, functional and radiological) and total scores was 90% or over. This also indicates a good interobserver reliability. In conclusion, the Bensahel et al. and International Clubfoot Study Group outcome evaluation system may be used reliably for the assessment of outcome of the treatment of clubfoot.     

Intraobserver and interobserver reliabilty of measures of kyphosis in thoracolumbar fractures

Background contextConsensus documents have recently been developed enumerating the radiographic parameters thought to be most valid in the clinical evaluation of patients with thoracolumbar fractures.PurposeThe objective of this study was to assess the measurement reliability of plain X-rays, computed tomography (CT), and magnetic resonance imaging (MRI) and their inter-modality agreement, as the three imaging modalities are often clinically interchangeable. This process is an essential reliability evaluation of the measurement parameters being proposed.Study designThis study evaluated the interobserver and intraobserver reliability of plain radiographs, CT, and MRI measurements of sagittal kyphosis in thoracolumbar fractures.Patient sampleSuitable plain X-ray, CT, and MRI radiographic imaging of ten cases of thoracolumbar fracture were examined.MethodsSuitable plain X-ray, CT, and MRI radiographic imaging of ten cases of thoracolumbar fracture were examined by ten independent spine surgery fellowship-trained observers.Outcome measuresCobb angle measurement, Gardner segmental deformity angle, and anterior body compression percentage were measured.ResultsRegardless of the imaging modality or the parameter being measured, the intraobserver reliability is always better than the interobserver. Plain radiography has better overall, interobserver and intraobserver reliability, followed by CT and then MRI. Reliability is very high in general, with the highest reliability for intraobserver reliability of the linear measures on plain radiographs. The inter-modality agreement is highest for plain X-ray and CT.ConclusionsThis study demonstrates that Cobb angle measurement, Gardner segmental deformity angle, and anterior body compression percentage are reliable measures of thoracolumbar fracture kyphosis with very high interobserver and intraobserver reliability and very high inter-modality agreement of plain X-ray with CT.     

Not all spondylolisthesis grading instruments are reliable

Spondylolisthesis is the slippage of one vertebral body on an adjacent level, and occurs commonly at the lumbosacral junction in children. Many radiographic measurement instruments have been described to predict progression and need for intervention. We evaluated the reliability of eight common grading instruments. Four raters reviewed 30 lateral radiographs of the lumbar spine in patients with spondylolisthesis. Each rater measured each film twice, and had mean individual correlation coefficients of at least 0.76 (range, 0.76-0.91). Only three measurements had interobserver correlations greater than 0.75 (slip percentage, Meyerding's grade, and sacral inclination), which corresponded to excellent reliability. For intraobserver reliability, six measurements had correlations greater than 0.75 (all except kyphosis angle and lumbar index), indicating excellent agreement. Slip percent, Meyerding's grade, and sacral inclination had excellent interobserver agreement and intraobserver agreement.     

Interobserver and intraobserver reliability of radiographic evidence of bone healing at osteotomy sites

Plain radiographs are commonly used to evaluate the degree of bone healing after an osteotomy and the application of an external fixator. The purpose of the study was to assess intraobserver and interobserver reliability in determining bone healing, defined as bridging callus across three of four cortices, of osteotomy sites on radiographs. Substantial intraobserver reliability and a high intraobserver percentage agreement were found. Interobserver reliability was moderate and interobserver percentage agreement was less than half for agreement between all involved orthopaedic surgeons. The lower reliability across surgeons suggests that the determination of the extent of the bone healing is subjective.     

Sonography of the bladder

Ultrasonography (US) is the method of choice for the diagnosis of bladder disease. It is superior to other imaging techniques, such as urography and cystography, in depicting certain structures and abnormalities. US examination of the bladder should include a study of the ureterovesical junction and the structures round the vesical neck. The examination technique may be transabdominal, transrectal or transvaginal, or transurethral. The bladder pathology that can be studied by US includes cystitis, calculi, clots, diverticula, trauma and tumors. The sensitivity and the specificity of the method are very high and sometimes superior to cystoscopy. Sonography can be used to explore patients with stress incontinence and those with abdominal trauma. The ureterovesical junction may be clearly examined by US and the pathology of the papilla clearly defined.     

Cervical spine injury severity score. Assessment of reliability

BACKGROUND: Systems for classifying cervical spine injury most commonly use mechanistic or morphologic terms and do not quantify the degree of stability. Along with neurologic function, stability is a major determinant of treatment and prognosis. The goal of our study was to investigate the reliability of a method of quantifying the stability of subaxial (C3-C7) cervical spine injuries. METHODS: A quantitative system was developed in which an analog score of 0 to 5 points is assigned, on the basis of fracture displacement and severity of ligamentous injury, to each of four spinal columns (anterior, posterior, right pillar, and left pillar). The total possible score thus ranges from 0 to 20 points. Fifteen examiners assigned scores after reviewing the plain radiographs and computed tomography images of thirty-four consecutive patients with cervical spine injuries. The scores were then evaluated for interobserver and intraobserver reliability with use of intraclass correlation coefficients. RESULTS: The mean intraobserver and interobserver intraclass correlation coefficients for the fifteen reviewers were 0.977 and 0.883, respectively. Association between the scores and clinical data was also excellent, as all patients who had a score of > or =7 points had surgery. Similarly, eleven of the fourteen patients with a score of > or =7 points had a neurologic deficit compared with only three of the twenty with a score of <7 points. CONCLUSIONS: The Cervical Spine Injury Severity Score had excellent intraobserver and interobserver reliability. We believe that quantifying stability on the basis of fracture morphology will allow surgeons to better characterize these injuries and ultimately lead to the development of treatment algorithms that can be tested in clinical trials.     

The reliability of quantitative analysis on digital images of the scoliotic spine

Although analysis of scoliotic deformity is still studied extensively by means of conventional roentgenograms, computer-assisted digital analysis may allow a faster, more accurate and more complete evaluation of the scoliotic spine. In this study, a new computer-assisted measurement method was evaluated. This method uses digital reconstruction images for quantitative analysis of the scoliotic spine. The aim of the current study was to determine the reliability of the computer-assisted measuring method, which was done by establishing coefficients of repeatability for a variety of measurements. Measurements were carried out by five observers on 30 frontal and 10 lateral scoliotic digital reconstruction images. Each image was measured on three separate occasions by placing anatomical vertebral landmarks and drawing lines with a computer pointing device. The computer then calculated a number of geometrical shape parameters from scale calibration, landmarks and lines. The intra- and interobserver results were subjected to an analysis of variance to assess the level of agreement, and the means and standard deviations were calculated. The coefficient of repeatability (CR) was taken to be equal to two standard deviations. The mean intraobserver CR was found to be 3.1 degrees for the Cobb angle on the frontal digital image and 3.3 degrees for the kyphosis Cobb angle on the lateral overview. The mean difference in the intraobserver CR of the Cobb angle between measurements made by placing landmarks and those made by drawing lines was not statistically significant (P>0.05). The mean intraobserver CR for the other parameters can be summarized as follows: for lateral deviation it was 0.8 mm, for axial rotation 4.0 degrees and for length of the spine 3.3 mm. The interobserver bias was negligible. It can be concluded that the reliability of our new method for quantifying geometrical variables on digital reconstruction images is better than measurements on conventional roentgenograms in previously published reports. The presented method is therefore considered to be more accurate for research of spinal deformities and more adequate for clinical management of scoliosis.