Modification of the hand-held Vscan ultrasound and verification of its performance for transvaginal applications

Evaluating the accuracy and reliability of non-piezo portable ultrasound devices in postpartum care

INTRODUCTION

The early diagnosis of hemorrhage via postpartum ultrasound is crucial to initiate therapy and, thus, prevent maternal death. In these critical situations rapid availability and simple transport of ultrasound devices is vital, paving the way for a  new generation of portable handheld ultrasound devices (PUD) consisting of transducers and tablets or smart phones. However, evidence to confirm the diagnostic accuracy of these new devices is still scarce.

METHODS

The accuracy and reliability of these new devices in relation to established standard ultrasound devices is analyses in this pilot study by comparing diagnoses and by applying statistical analysis via Bland-Altman plots, intraclass correlation coefficients (ICC), and Pearson correlation coefficients (PCC). One hundred patients of a university hospital were included in this study.

RESULTS

In all cases, the same diagnosis was made regardless of the applied ultrasound device, confirming high accuracy. There was a high correlation (PCC 0.951) and excellent agreement (ICC 0.974) in the assessment of the cavum, while the assessment of the diameters of the uterus showed only a good correlation and a good agreement. Subgroup analysis for maternal weight, mode of delivery and day after delivery was performed  CONCLUSION: The same diagnosis independent of the used devices and excellent results of the cavum assessment promote the use of PUDs in a clinical setting. The slightly lower accuracy in the measurement of the uterus may be caused by the PUD's small acoustic window, reflecting one of its weaknesses. Therefore, the patient may benefit from the short time to diagnosis and the unbound location of examination, either in the delivery room, on the ward, or at home.

Portable ultrasound technologies for estimating gestational age in pregnant women: a scoping review and analysis of commercially available models

OBJECTIVES

To identify all available studies assessing the use of portable ultrasound devices for pregnant women, with the specific aim of finding evidence for devices used to determine gestational age and their validity when compared with conventional ultrasound machines. We also wanted to determine what portable ultrasound models are commercially available for obstetric use.

DESIGN

Systematic scoping review.

PRIMARY AND SECONDARY OUTCOME MEASURES

Extracted variables included study design, population, method of ultrasound measurement, devices used and whether studies formally validated accuracy against conventional ultrasound.

RESULTS

We searched four databases-Medline, Embase, CINAHL and Maternal and Infant Care. In total 56 studies from 34 countries were identified; most were observational studies. Across all studies, 27 different portable ultrasound models (from 17 manufacturers) were evaluated. Twenty-one studies assessed use of portable ultrasound for evaluating fetal characteristics or estimating gestational age, and 10 of these were formal validation studies. In total, six portable devices have been validated for gestational age estimation against a conventional ultrasound comparator. The web searches identified 102 portable devices (21 manufacturers). These were a mix of handheld devices that connected to a phone or computer, or laptop-style portable ultrasound devices. Prices ranged from US$1190 to US$30 000 and weight ranged from 0.9 kg to 13.0 kg.

CONCLUSION

While the number of commercially available portable ultrasound devices continues to grow, there remains a lack of peer-reviewed, quality evidence demonstrating their accuracy and validity when compared with conventional ultrasound machines. This review identified some models that may be useful in gestational age estimation in low-resource settings, but more research is required to help implement the technology at scale.

TRIAL REGISTRATION NUMBER

Registered via Open Science Framework (DOI: 10.17605/OSF.IO/U8KXP).

Assessment of peripheral muscle thickness and architecture in healthy volunteers using hand-held ultrasound devices; a comparison study with standard ultrasound

BACKGROUND

Pocket-sized ultrasound devices are increasingly used in a variety of clinical situations, and perform well against standard ultrasound machines. We sought to investigate if a pocket-sized ultrasound device can assess muscle thickness and architecture in healthy volunteers.

METHODS

Healthy male volunteers (n = 21) across a range of ages were recruited to the study. Laying supine, ultrasound images were taken from the right anterior and lateral thigh. Thickness of the rectus femoris (RFMT), vastus intermedius (VIMT), and the two combined (anterior thigh, AMT) were measured, along with thickness of vastus lateralis (VLMT), pennation angle (VLPA) and derived fascicle length (VLFL). These scans were performed initially using a pocket-sized ultrasound (VScan) and then using a standard device (Telemed Echoblaster 128).

RESULTS

In all six variables, there was no significant difference between the two sets of measurements. Intra-class correlation co-efficients (ICC) for VLMT, VLPA, and AMT were all excellent (0.93, 0.89, 0.90 respectively) with the derived value of VLFL having an ICC of 0.84. All ICC values were statistically significant. Regression analysis demonstrated no evidence of proportional bias in any of the measured or derived variables.

CONCLUSION

A pocket-sized ultrasound device gives similar measurements of lower limb muscle thickness and architecture as a standard device in healthy volunteers.

Hand-Held Ultrasound Devices Compared with High-End Ultrasound Systems: A Systematic Review

The aim of this study was to review the scientific literature available on the comparison of hand-held ultrasound devices with high-end systems for abdominal and pleural applications. PubMed, Embase, Web of Science and Cochrane were searched following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Original research describing hand-held ultrasound devices compared with high-end systems was included and assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2. The search was limited to articles published since 1 January 2012. A total of 2486 articles were found and screened by title and abstract. A total of 16 articles were chosen for final review. All of the included articles showed good overall agreement between hand-held and high-end ultrasound systems. Strong correlations were found when evaluating ascites, hydronephrosis, pleural cavities, in detection of abdominal aortic aneurysms and for use with obstetric and gynaecological patients. Other articles found good agreement for cholelithiasis and for determining the best site for paracentesis. QUADAS-2 analysis suggested few risks of bias and almost no concerns regarding applicability. For distinct clinical questions, hand-held devices may be a valuable supplement to physical examination. However, evidence is inadequate, and more research is needed on the abdominal and pleural use of hand-held ultrasound with more standardised comparisons, using only blinded reviewers.

A urologic stethoscope? Urologist performed sonography using a pocket-size ultrasound device in the point-of-care setting

PURPOSE

Ultrasound is commonly used in urology. Technical advances with reduced size and cost led to diffusion of small ultrasound devices to many clinical settings. Even so, most ultrasound studies are performed by non-urologists. We aimed to evaluate the utility of a pocket-size ultrasound device (Vscan™ GE Healthcare) and the quality of urologist performed study.

METHODS

Three consecutive studies were performed: (1) a urologist using the pocket ultrasound, (2) a sonographist using the pocket ultrasound, and (3) a sonographist using a standard ultrasound device. Thirty-six patients were evaluated with a basic urologic ultrasound study. An excepted deviation between studies was preset for numeric parameters and t test performed. Ordinal parameters were analyzed using Cohen's kappa coefficient.

RESULTS

Kidney length, renal pelvis length, renal cyst diameter, post-void residual and prostate volume (transabdominal) differences were found to be insignificant when comparing a urologist pocket ultrasound study to a sonographist standard ultrasound study (P = 0.15; P = 0.21; P = 0.81; P = 0.32; P = 0.07, respectively). Hydronpehrosis evaluation (none, mild, moderate and severe) and the presence of ureteral jet signs conferred a high inter-observer agreement when comparing the above studies using the Cohen's kappa coefficient (K = 0.63; K = 0.62, respectively).

CONCLUSIONS

Urologist performed pocket ultrasound study is valid in evaluating the upper and lower urinary tract and is practical in many clinical scenarios. The urologic stethoscope is now becoming a reality within reach.

The Application of Hand-Held Ultrasound Scanner in Teaching of Telemedicine and Rural Medicine

Stethoscope, the symbol of modern medicine has been in place for more than 150 years. However, this reliable diagnostic instrument has started showing its age with the arrival of a newer diagnostic instrument: the hand-held ultrasound.

Hand-held ultrasound is rapidly expanding in many specialties but not yet in obstetrics and gynecology. There is a paucity of literature on the application of hand-held ultrasound in obstetrics and gynecology, in contrast to a large volume of literature published by other specialties. Several studies demonstrated that medical students and residents can improve the accuracy of their physical examinations with the use of hand-held ultrasound. Similarly, physical examinations performed by hospitalists with hand-carried ultrasound are more accurate than those performed without the instrument. Advances in technology have contributed to the improvement of image quality and portability. As a result, these devices become increasingly available in many clinical settings such as point of care, telemedicine and rural medicine. The quality of ultrasound images of the hand-held scanner is inferior to those of standard laptop ultrasound. However, the hand-held ultrasound requires much less time for setup.

Although there have been recommendations for training guidelines for operators of hand-held ultrasound, standards for optimal training to achieve level of competency have not been determined.

How to cite this article

Wright J, Noriega O, Ho H. The Application of Hand-Held Ultrasound Scanner in Teaching of Telemedicine and Rural Medicine. Donald School J Ultrasound Obstet Gynecol 2014;8(1):87-91.