Two-dimensional ultrasound (US) imaging has been successfully used in clinical applications as a low-cost, portable and non-invasive image modality for more than three decades. Recent advances in ...computer science and technology illustrate the promise of the 3-D US modality as a medical imaging technique that is comparable to other prevalent modalities and that overcomes certain drawbacks of 2-D US. This systematic review covers freehand 3-D US imaging between 1970 and 2017, highlighting the current trends in research fields, the research methods, the main limitations, the leading researchers, standard assessment criteria and clinical applications. Freehand 3-D US systems are more prevalent in the academic environment, whereas in clinical applications and industrial research, most studies have focused on 3-D US transducers and improvement of hardware performance. This topic is still an interesting active area for researchers, and there remain many unsolved problems to be addressed.
Objective
To investigate the value of the sonographic identification of deep infiltrating endometriosis (DIE) in women presenting with complaints suggestive of DIE. Sonography findings were ...correlated with subsequent surgical exploration, and histologic verification.
Methods
A retrospective observational case series was investigated to document the ability of the use of sonography to accurately detect the presence of deep infiltrating endometriosis. The clinical observations were performed consistent with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations for observational studies. Recognizing the real‐world office setting for this may introduce the importance of the practical clinical aspects of diagnostic procedures in general.
Results
Three‐dimensional transvaginal sonography was able to accurately identify deep invasive endometriosis in 92% of the 100 women subjectively complaining of the associated symptoms of endometriosis, who underwent sonography, surgical exploration, and pathologic analysis. Additional sonographic evidence of pelvic pathology was found during the course of this investigation, perhaps complementing other means for diagnosing endometriosis.
Conclusion
Three‐dimensional transvaginal sonography is a diagnostic tool that can effectively identify deep infiltrating endometriosis, which may otherwise go undetected and untreated. These findings should encourage the use of sonography for the detection of this subtype of endometriosis.
Synopsis
A series of cases is described of sonographically detected deep infiltrating endometriosis with three‐dimensional transvaginal sonography, which were all surgically explored and histologically examined.
Background
Synovitis is one of the defining characteristics of osteoarthritis (OA) in the carpometacarpal (CMC1) joint of the thumb. Quantitative characterization of synovial volume is important for ...furthering our understanding of CMC1 OA disease progression, treatment response, and monitoring strategies. In previous studies, three‐dimensional ultrasound (3‐D US) has demonstrated the feasibility of being a point‐of‐care system for monitoring knee OA. However, 3‐D US has not been tested on the smaller joints of the hand, which presents unique physiological and imaging challenges.
Purpose
To develop and validate a novel application of 3‐D US to monitor soft‐tissue characteristics of OA in a CMC1 OA patient population compared to the current gold standard, magnetic resonance imaging (MRI).
Methods
A motorized submerged transducer moving assembly was designed for this device specifically for imaging the joints of the hands and wrist. The device used a linear 3‐D scanning approach, where a 14L5 2‐D transducer was translated over the region of interest. Two imaging phantoms were used to test the linear and volumetric measurement accuracy of the 3‐D US device. To evaluate the accuracy of the reconstructed 3‐D US geometry, a multilayer monofilament string‐grid phantom (10 mm square grid) was scanned. To validate the volumetric measurement capabilities of the system, a simulated synovial tissue phantom with an embedded synovial effusion was fabricated and imaged. Ten CMC1 OA patients were imaged by our 3‐D US and a 3.0 T MRI system to compare synovial volumes. The synovial volumes were manually segmented by two raters on the 2D slices of the 3D US reconstruction and MR images, to assess the accuracy and precision of the device for determining synovial tissue volumes. The Standard Error of Measurement and Minimal Detectable Change was used to assess the precision and sensitivity of the volume measurements. Paired sample t‐tests were used to assess statistical significance. Additionally, rater reliability was assessed using Intra‐Class Correlation (ICC) coefficients.
Results
The largest percent difference observed between the known physical volume of synovial extrusion in the phantom and the volume measured by our 3D US was 1.1% (p‐value = 0.03). The mean volume difference between the 3‐D US and the gold standard MRI was 1.78% (p‐value = 0.48). The 3‐D US synovial tissue volume measurements had a Standard Error Measurement (SEm) of 11.21 mm3 and a Minimal Detectible Change (MDC) of 31.06 mm3, while the MRI synovial tissue volume measurements had an SEM of 16.82 mm3 and an MDC of 46.63 mm3. Excellent inter‐ and intra‐rater reliability (ICCs = 0.94–0.99) observed across all imaging modalities and raters.
Conclusion
Our results indicate the feasibility of applying 3‐D US technology to provide accurate and precise CMC1 synovial tissue volume measurements, similar to MRI volume measurements. Lower MDC and SEm values for 3‐D US volume measurements indicate that it is a precise measurement tool to assess synovial volume and that it is sensitive to variation between volume segmentations. The application of this imaging technique to monitor OA pathogenesis and treatment response over time at the patient's bedside should be thoroughly investigated in future studies.
Three dimensional (3D) power ultrasound sources with 20 kHz frequency and 14∼22 μm amplitudes were introduced into the solidification process of AZ91 magnesium alloy, and the acoustic spectra versus ...temperature were synchronously examined. The measured sound pressure monotonically increased with the rise of both ultrasound dimension and amplitude, whereas the transient cavitation intensity firstly increased to its maximum under 3D ultrasound sources at 18 μm amplitude and then unexpectedly declined if further raising the amplitude to 22 μm. The grain size of primary α-Mg phase which was refined down to 16% of that under static solidification mainly depended on the transient cavitation intensity, indicating that the transient cavitation enhanced the nucleation rate by over two orders of magnitudes and dominated the grain refinement. The dislocation density within α-Mg phase increased owing to the intense vibration under semi-solid state. A more homogeneous distribution of divorced eutectic β-Mg14Al12 phase and a smaller amount of β precipitation were induced due to the grain refinement and suppressed segregation for primary α-Mg phase. The microstructural evolution improved the mechanical properties for AZ91 alloy, where its elongation rate and tensile strength were enhanced by the factors of 2.4 and 1.7, respectively. It is demonstrated that applying 3D ultrasound sources provides an effective approach to modulate solidified microstructures and enhance mechanical performances for magnesium alloy.
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Introduction/Aims
Ultrasound imaging of muscle tissue conventionally results in two‐dimensional sampling of tissue. For heterogeneously affected muscles, a sampling error using two‐dimensional (2D) ...ultrasound can therefore be expected. In this study, we aimed to quantify and extend ultrasound imaging findings in neuromuscular disorders by using three‐dimensional quantitative muscle ultrasound (3D QMUS).
Methods
Patients with facioscapulohumeral dystrophy (n = 31) and myotonic dystrophy type 1 (n = 16) were included in this study. After physical examination, including Medical Research Council (MRC) scores, the tibialis anterior muscle was scanned with automated ultrasound. QMUS parameters were calculated over 15 cm of the length of the tibialis anterior muscle and were compared with a healthy reference data set.
Results
With 3D QMUS local deviations from the healthy reference could be detected. Significant Pearson correlations (P < .01) between MRC score and QMUS parameters in male patients (n = 23) included the mean echo intensity (EI) (0.684), the standard deviation of EI (0.737), and the residual attenuation (0.841). In 91% of all patients, mean EI deviated by more than 1 standard deviation from the healthy reference. In general, the proportion of muscle tissue with a Z score >1 was about 50%.
Discussion
In addition to mean EI, multiple QMUS parameters reported in this study are potential biomarkers for pathology. Besides a moderate correlation of mean EI with muscle weakness, two other parameters showed strong correlations: standard deviation of EI and residual attenuation. Local detection of abnormalities makes 3D QMUS a promising method that can be used in research and potentially for clinical evaluation.
Retroperitoneal cysts (RPCs) are rare types of cyst in the retroperitoneal space that are frequently misdiagnosed as gynecological tumors. This case report details, an epidermoid RPC, identified ...through 2D ultrasound, with attempts to visualize its rendered images using 3D ultrasound. A 39‐year‐old female patient was admitted to the hospital following the detection of a pelvic mass during a routine physical examination. Initially, the lesion was suspected to be an ovarian tumor, but subsequent ultrasound investigations suggested an epidermoid RPC. This diagnosis was later confirmed by pelvic magnetic resonance imaging. The definitive diagnosis was made following laparoscopic exploration and pathological examination. This case is shared to analyze the ultrasound characteristics of epidermoid RPCs.
(A) The transvaginal ultrasound revealed a single mass (white arrow) located behind the cervix and vagina. (B) A thin strip of blood flow signal was seen around the mass.
Background
Fetal macrosomia is associated with an increased risk of adverse maternal and neonatal outcomes.
Objectives
To compare the accuracy of antenatal two‐dimensional (2D) ultrasound, ...three‐dimensional (3D) ultrasound, and magnetic resonance imaging (MRI) in predicting fetal macrosomia at birth.
Search strategy
Medline (1966–2013), Embase, the Cochrane Library and Web of Knowledge.
Selection criteria
Cohort or diagnostic accuracy studies of women with a singleton pregnancy, who had third‐trimester imaging to predict macrosomia (>4000 g, >4500 g or >90th or >95th centile).
Data collection and analysis
Two reviewers screened studies, performed data extraction and assessed methodological quality. The bivariate model was used to obtain summary sensitivities, specificities and likelihood ratios.
Main results
Fifty‐eight studies (34 367 pregnant women) were included. Most were poorly reported. Only one study assessed 3D ultrasound volumetry. For predicting birthweight >4000 g or >90th centile, the summary sensitivity for 2D ultrasound (Hadlock) estimated fetal weight (EFW) >90th centile or >4000 g (29 studies) was 0.56 (95% CI 0.49–0.61), 2D ultrasound abdominal circumference (AC) >35 cm (four studies) was 0.80 (95% confidence interval 95% CI 0.69–0.87) and MRI EFW (three studies) was 0.93 (95% CI 0.76–0.98). The summary specificities were 0.92 (95% CI 0.90–0.94), 0.86 (95% CI 0.74–0.93) and 0.95 (95% CI 0.92–0.97), respectively.
Conclusion
There is insufficient evidence to conclude that MRI EFW is more sensitive than 2D ultrasound AC (which is more sensitive than 2D EFW); although it was more specific. Further primary research is required before recommending MRI EFW for use in clinical practice.
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Systematic review of antenatal imaging to predict macrosomia. MRI EFW is more sensitive than ultrasound EFW.
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Systematic review of antenatal imaging to predict macrosomia. MRI EFW is more sensitive than ultrasound EFW.
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