Highlights of the development in ultrasound during the last 70 years: A historical review.

This review looks at highlights of the development in ultrasound, ranging from interventional ultrasound and Doppler to the newest techniques like contrast-enhanced ultrasound and elastography, and gives reference to some of the valuable articles in Acta Radiologica. Ultrasound equipment is now available in any size and for any purpose, ranging from handheld devices to high-end devices, and the scientific societies include ultrasound professionals of all disciplines publishing guidelines and recommendations. Interventional ultrasound is expanding the field of use of ultrasound-guided interventions into nearly all specialties of medicine, from ultrasound guidance in minimally invasive robotic procedures to simple ultrasound-guided punctures performed by general practitioners. Each medical specialty is urged to define minimum requirements for equipment, education, training, and maintenance of skills, also for medical students. The clinical application of contrast-enhanced ultrasound and elastography is a topic often seen in current research settings.

The efficacy of using computer-aided detection (CAD) for detection of breast cancer in mammography screening: a systematic review.

BACKGROUND: Early detection of breast cancer (BC) is crucial in lowering the mortality. PURPOSE: To present an overview of studies concerning computer-aided detection (CAD) in screening mammography for early detection of BC and compare diagnostic accuracy and recall rates (RR) of single reading (SR) with SR + CAD and double reading (DR) with SR + CAD. MATERIAL AND METHODS: PRISMA guidelines were used as a review protocol. Articles on clinical trials concerning CAD for detection of BC in a screening population were included. The literature search resulted in 1522 records. A total of 1491 records were excluded by abstract and 18 were excluded by full text reading. A total of 13 articles were included. RESULTS: All but two studies from the SR vs. SR + CAD group showed an increased sensitivity and/or cancer detection rate (CDR) when adding CAD. The DR vs. SR + CAD group showed no significant differences in sensitivity and CDR. Adding CAD to SR increased the RR and decreased the specificity in all but one study. For the DR vs. SR + CAD group only one study reported a significant difference in RR. CONCLUSION: All but two studies showed an increase in RR, sensitivity and CDR when adding CAD to SR. Compared to DR no statistically significant differences in sensitivity or CDR were reported. Additional studies based on organized population-based screening programs, with longer follow-up time, high-volume readers, and digital mammography are needed to evaluate the efficacy of CAD.

A comparative study of strain and shear-wave elastography in an elasticity phantom.

OBJECTIVE. The purpose of this study was to assess the diagnostic accuracy of strain and shear-wave elastography for determining targets of varying stiffness in a phantom. The effect of target diameter on elastographic assessments and the effect of depth on shear-wave velocity were also investigated. MATERIALS AND METHODS. We examined 20 targets of varying diameters (2.5-16.7 mm) and stiffnesses (8, 14, 45, and 80 kPa) with a 4-9-MHz linear-array transducer. Targets were evaluated 10 times with three different methods-shear-wave elastography, strain ratio, and strain histogram analysis-yielding 600 evaluations. AUCs were calculated for data divided between different stiffnesses. A 1.5-6-MHz curved-array transducer was used to assess the effect of depth (3.5 vs 6 cm) on shear-wave elastography in 80 scans. Mixed model analysis was performed to assess the effect of target diameter and depth. RESULTS. Strain ratio and strain histogram AUCs were higher than the shear-wave velocity AUC (p < 0.001) in data divided as 80 versus 45, 14, and 8 kPa. In data divided as 80 and 45 versus 14 and 8 kPa, the methods were equal (p = 0.959 and p = 1.000, respectively). Strain ratios were superior (p = 0.030), whereas strain histograms were not significantly better (p = 0.083) than shear-wave elastography in data divided as 80, 45, and 14 versus 8 kPa. Target diameter had an effect on all three methods (p = 0.001). Depth had an effect on shear-wave velocity (p = 0.001). CONCLUSION. The ability to discern different target stiffnesses varies between shear-wave and strain elastography. Target diameter affected all methods. Shear-wave elastography is affected by target depth.

Strain Elastography Ultrasound: An Overview with Emphasis on Breast Cancer Diagnosis.

Strain elastography (SE), which estimates tissue strain, is an adjunct to the conventional ultrasound B-mode examination. We present a short introduction to SE and its clinical use. Furthermore, we present an overview of the 10 largest studies performed on the diagnostic accuracy of SE in breast cancer diagnostics. Eight of 10 studies presented data for both SE and B-mode imaging. Seven studies showed better specificity and accuracy for SE than for B-mode imaging in breast cancer diagnosis. Four studies showed an increase in specificity and accuracy when combining B-mode imaging with SE. The ways of combining B-mode imaging with SE in the diagnosis of breast cancer differed between the five studies. We believe that further studies are needed to establish an optimal algorithm for the combination of B-mode ultrasound and SE in breast cancer.