The Automated Breast Volume Scanner (ABVS): Initial Experiences in Lesion Detection Compared with Conventional Handheld B-Mode Ultrasound: a Pilot Study of 50 Cases
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International Journal of Women’s Health Dovepress open access to scientific and medical research Open Access Full Text Article ORIGINAL RESEARCH The Automated Breast Volume Scanner (ABVS): initial experiences in lesion detection compared with conventional handheld B-mode ultrasound: a pilot study of 50 cases Sebastian Wojcinski1 Abstract: The idea of an automated whole breast ultrasound was developed three decades ago. Andre Farrokh1 We present our initial experiences with the latest technical advance in this technique, the automated 2 Ursula Hille breast volume scanner (ABVS) ACUSON S2000TM. Volume data sets were collected from 50 3 Jakub Wiskirchen patients and a database containing 23 women with no detectable lesions in conventional ultrasound Samuel Gyapong1 (BI-RADS®-US 1), 13 women with clearly benign lesions (BI-RADS®-US 2), and 14 women with Amr A Soliman1,4 known breast cancer (BI-RADS®-US 5) was created. An independent examiner evaluated the ABVS Friedrich Degenhardt1 data on a separate workstation without any prior knowledge of the patients’ histories. The diagnostic Peter Hillemanns2 accuracy for the experimental ABVS was 66.0% (95% confidence interval [CI]: 52.9–79.1). The 1 Department of OB/GYN, Franziskus independent examiner detected all breast cancers in the volume data resulting in a calculated sensi- Hospital, Bielefeld, Germany; 2Department of OB/GYN, Hannover Medical School, tivity of 100% in the described setting (95% CI: 73.2%–100%). After the ABVS examination, there 3 Hannover, Germany; Department of were a high number of requests for second-look ultrasounds in 47% (95% CI: 30.9–63.5) of the Radiology, Franziskus Hospital, Bielefeld, Germany; 4Department of OB/GYN, Faculty healthy women (with either a clearly benign lesion or no breast lesions at all in conventional handheld of Medicine, University of Alexandria, ultrasound). Therefore, the specificity remained at 52.8% (95% CI: 35.7–69.2). When comparing Alexandria, Egypt the concordance of the ABVS with the gold standard (conventional handheld ultrasound), Cohen’s Kappa value as an estimation of the inter-rater reliability was κ = 0.37, indicating fair agreement. Video abstract In conclusion, the ABVS must still be regarded as an experimental technique for breast ultrasound, which definitely needs to undergo further evaluation studies. Keywords: breast cancer, automated breast ultrasound, automated breast volume scanner, ABVS Introduction Breast ultrasound is a commonly accepted and reliable diagnostic method for women with clinically or radiologically suspicious breast lesions.1 Although it is not estab- lished as a routine part of screening programs, bilateral whole breast ultrasound has even demonstrated diagnostic advantages in screening asymptomatic women.2–6 Breast Point your SmartPhone at the code above. If you have a 7,8 QR code reader the video abstract will appear. Or use: ultrasound has been performed for more than 50 years. Conventional handheld http://dvpr.es/wojcinski ultrasound (HHUS) is the gold standard for performing the examination. Obviously, sonography is an examiner-dependent method and the examiner has to be present at Correspondence: Sebastian Wojcinski the time of image acquisition. Franziskus Hospital, Department The concept of automated breast ultrasound dates back to the 1970s when the first of OB/GYN, Kisker Str 27, 33615 9 Bielefeld, Germany applicable systems were reported by Maturo et al. In the current report we present our Tel +49 521 589 1501 initial experiences with the latest technical advance in automated breast ultrasound, Fax +49 521 589 1504 TM Email [email protected] the Automated Breast Volume Scanner (ACUSON S2000 ABVS; Siemens Medical submit your manuscript | www.dovepress.com International Journal of Women’s Health 2011:3 337–346 337 Dovepress © 2011 Wojcinski et al, publisher and licensee Dove Medical Press Ltd. This is an Open Access article http://dx.doi.org/10.2147/IJWH.S23918 which permits unrestricted noncommercial use, provided the original work is properly cited. Wojcinski et al Dovepress Solutions, Inc, Mountain View, CA). This system can be Thus, we created a database containing 50 patients exhib- operated by an assistant medical technician or radiographer. iting BI-RADS®-US 1, 2, and 5 findings in conventional The ABVS acquires a whole series of consecutive B-mode examinations. In our cohort the age ranged from 32 to 72 pictures and reconstructs 3D data sets of the entire breast years (median 52 years). According to the BI-RADS®-US volume. These data can be sent to a separate workstation to categorization, 46% (n = 23) of our cases were assigned as be independently analyzed by a specialist. BI-RADS®-US 1, 26% (n = 13) had BI-RADS®-US 2 lesions, We evaluated whether or not breast lesions, previously and 28% (n = 14) of the cases had BI-RADS®-US 5 lesions. detected by means of conventional ultrasound, could also be All cases of BI-RADS®-US 5 were histologically confirmed detected and correctly classified by an independent examiner after the study setting was completed. who used only ABVS data. To the best of our knowledge, this The mean tumor size for the malignant lesions was is one of the first descriptive studies dealing with the clinical 23.4 mm (range 13 to 55). application of the ABVS system. After anonymization, the ABVS database was then available for evaluation by an independent second examiner. Materials and methods We compared the performance of the ABVS (experimental General design and creation method) to the HHUS (gold standard). of the patient database Our study was conducted at the Breast Cancer Center of Technical background of the ABVS Franziskus Hospital in Bielefeld, Germany, between March The ACUSON S2000TM ABVS is an ultrasound system that 2010 and May 2010. The responsible ethical committee did automatically surveys and acquires full-field volumes of the not require additional approval for this noninterventional breast (Figure 1). study design. All examinations were performed using the For automated scanning, we used the integrated Siemens Siemens ACUSON S2000TM ultrasound system (Siemens 14L5BV linear transducer (14 MHz, 15.4 cm) with 768 Medical Solutions, Inc, Mountain View, CA). piezoelectric elements. These images have a depth of up to The study cohort was recruited from patients who 6 cm. In the process of automated scanning, the transducer attended the outpatient service of our breast cancer center. covers a distance of 16.8 cm, acquiring 318 high-resolution The patients were referred to our clinic due to specific diag- slices for post-processing. Therefore, the maximum volume nostic queries such as palpable breast lesions, breast pain, is 1552.3 cm³ and the slice thickness is about 0.5 mm. suspicious mammograms, and intensified screening in high- In order to optimize the ABVS results there is a wide range risk populations. All patients received conventional HHUS as of known imaging modes including tissue harmonic imaging the standard diagnostic method and subsequent examinations (THI) and Advanced SieClearTM spatial compounding and whenever necessary. For each patient, the B-mode ultrasound Dynamic TCETM (tissue contrast enhancement) technology, pictures were categorized according to the Breast Imaging Reporting and Data System criteria of the American College of Radiology (ACR BI-RADS®-US).10 Patients with a final categorization of BI-RADS®-US 1, 2, and 5 in the conventional ultrasound examination were regarded as being suitable for our study. We excluded patients with BI-RADS®-US 0, 3 and 4 lesions as the focus of our study was on the bare detection of clearly benign and clearly malignant lesions and not on the evaluation of questionable lesions. Patients with a history of breast surgery, bra cup sizes greater than D, inflammatory conditions of the breast, and skin disorders were also excluded. Patients who met the inclusion criteria and who agreed to be enrolled in our study signed an informed consent form and subsequently received the additional ABVS Figure 1 Installation of the ACUSON S2000TM ABVS ultrasound system. On the left-hand side is the ACUSON S2000TM machine, on the right-hand side is the examination. 14L5BV volume transducer attached to a mechanical arm. 338 submit your manuscript | www.dovepress.com International Journal of Women’s Health 2011:3 Dovepress Dovepress The automated breast volume scanner as well as new processing algorithms for nipple shadow and reverberation artifacts that are automatically applied when using the ABVS. The Reverberation Removal Algorithm processes the 3D data and determines whether tissue contact is present and where it is not. The data corresponding to the area with no tissue contact are removed. This is intended to suppress the reverberation artifacts from the noncontact areas. The adaptive Nipple Shadow Reduction Tool analyzes data on a case-by-case basis and is thought to enhance the structures in the retro-areolar area and to improve the visualization of this important region. Finally, a Gain Collection Algorithm analyzes the 3D data and adjusts for the brightness variation Figure 3 Coronal view of the volume data at a depth of 10.4 mm from the skin line. The yellow spot indicates the position of the nipple. artifacts caused by transducer channel-to-channel variations. After acquisition, the data are automatically sent from the ultrasound system to a breast ultrasound review workstation, the other imaging modalities when available (mammography, which provides comprehensive analysis and manipulation of magnetic resonance imaging [MRI]). the 3D data: the workstation presents images through multi- For HHUS we used the integrated Siemens 18L6 HD planar reconstruction (MPR, Figure 2). All volume data sets linear transducer (5.5–18 MHz, 5.6 cm). The patient was can also be viewed in multiple orientations, including the in the supine position with the ipsilateral hand raised standard transverse, sagittal, coronal, radial, and anti-radial above the head. All examinations were performed with planes, as well as any other user-defined plane (Figure 3).