Published on March 14, 2014
Note: This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues, use the RadioGraphics Reprints form at the end of this article. 2007EDUCATION EXHIBIT Daniel T. Ginat, MD, MS • StamatiaV. Destounis, MD • Richard G. Barr, MD, PhD • Benjamin Castaneda, PhD2 • John G. Strang, MD Deborah J. Rubens, MD Elastography is a technique that maps relative tissue stiffness. Ultrasonographic (US) elastography (sonoelastography) is a novel modality that is the subject of active research for clinical applica- tions, primarily breast and prostate lesion imaging. Breast and pros- tate tumors generally have biomechanical properties different from those of normal tissues:Tumors are usually stiffer.This phenomenon is responsible for tissue contrast on elastograms. For the prostate gland and breast, the main image acquisition techniques are vibration sonoelastography and compression sonoelastography.The sonoelas- tographic appearances of several common breast lesions, including fibroadenomas, simple and complex cysts, ductal carcinomas, ma- lignant lymph nodes, and hematomas, are reviewed. In addition, the US elastographic appearances of the normal prostate gland, prostate carcinomas, and benign prostate hyperplasia are illustrated. Potential pitfalls in the interpretation of elastograms, including false-positive and false-negative images, are illustrated.These imaging findings are derived from ongoing research because sonoelastography is not yet ac- cepted for routine clinical use. © RSNA, 2009 • radiographics.rsna.org US Elastography of Breast and Prostate Lesions1 RadioGraphics 2009; 29:2007–2016 • Published online 10.1148/rg.297095058 • Content Codes: 1 From the Department of Imaging Sciences (D.T.G., J.G.S., D.J.R.) and the Department of Electrical and Computer Engineering (B.C.), University of Rochester Medical Center, 601 Elmwood Ave, Box 648, Rochester, NY 14642-8648; Elizabeth Wende Breast Care, Rochester, NY (S.V.D.); and Northeastern Ohio Universities College of Medicine, Rootstown, Ohio (R.G.B.). Presented as an education exhibit at the 2008 RSNA Annual Meet- ing. Received March 19, 2009; revision requested May 1 and received July 9; accepted July 14. All authors have no financial relationships to disclose. Address correspondence to D.T.G. (e-mail: firstname.lastname@example.org). 2 Grupo de Formación y Procesamiento de Imágenes Médicas, Sección Electricidad y Electrónica, Departamento de Ingeniería, Pontificia Universidad Católica del Perú, Lima, Peru. © RSNA, 2009 See last page TEACHING POINTS
2008 November-December 2009 radiographics.rsna.org Figure 3. Normal lymph node in the breast. (a) B- mode US image of a lymph node demonstrates a reni- form shape and a fatty hilum.The lymph node measures larger on the B-mode image than on the US elastogram (b). Dotted lines indicate measurements of the lesion’s long- and short-axis dimensions: 8.8 × 4.6 mm in a and 8.1 × 3.8 mm in b.The distance ratios were calculated as 8.1 ÷ 8.8 = 0.92 (for the long-axis dimension) and as 3.8 ÷ 4.6 = 0.83 (for the short-axis dimension). Figure 1. A phantom that is isoechoic on the B- mode US image (a) becomes readily apparent on the US elastogram (b) because the phantom is relatively stiffer than the surrounding material. Introduction Ultrasonographic (US) elastography (sonoelas- tography) is a noninvasive imaging technique that can be used to depict relative tissue stiffness or displacement (strain) in response to an imparted force (1,2). Stiff tissues deform less and exhibit less strain than compliant tissues in response to the same applied force.Thus, the basis of elas- tography is analogous to manual palpation (2). The application of US elastography for imaging tissues is relatively novel, first described in 1987 by Krouskop et al (3). Since its inception, sono- elastography has been used to evaluate numer- ous types of tissues, including breast, prostate, liver, blood vessels, thyroid, and musculoskeletal structures. In particular, the breast and prostate gland have been the tissues most widely and suc- cessfully imaged with US elastography. Currently, however, the routine clinical use of diagnostic sonoelastography for breast and prostate lesions awaits validation with prospective trials. Sonoelastography is based on the comparison of signals acquired before and after tissue dis- placement. Several sonoelastographic techniques have been devised, including compression strain imaging (4), vibration sonoelastography (5), acoustic radiation force generated by the ultra- sound pulse (6), and real-time shear velocity (7). Among these techniques, compression sonoelas- tography and vibration sonoelastography cur- rently have the most prominent role in breast and prostate imaging. Compression elastography involves calculating a strain profile in a direction perpendicular to the tissue surface in response to an externally applied force. Specialized software is used to calculate the relative difference in tissue movement from one frame to another and then to estimate the tissue deformation.The deformation measurements are mapped onto an elastogram, on which stiffer areas are depicted as dark and more-elastic areas are lighter, according to convention.This permits depiction of a lesion that is otherwise isoechoic on gray-scale US images (Fig 1). Imaging soft- ware for compression elastography is currently available on some commercial US machines, including those available from Hitachi Medical Systems and Siemens. Vibration elastography, on the other hand, generates tissue displacement through the use of an independent external vibration source. Rela- tive displacement is measured by using a variant of Doppler imaging that depicts differential mo- tion of tissue types.This technique provides good correlation for tissues that have a large difference in stiffness. However, the heterogeneity of breast tissue may limit the use of vibration elastography for whole-breast imaging or for lesion detection. Figure 2. Normal breast tissue. (a) B-mode US im- age of the breast shows that a lobule of normal fatty tissue (f) is hypoechoic with respect to the surrounding glandular tissue (g). (b) US elastogram shows that the fatty tissue (f) surrounded by dense breast tissue ap- pears bright because it is appreciably “softer” than the surrounding glandular tissue (g).
RG ■ Volume 29 • Number 7 Ginat et al 2009 Elastographic imaging of the prostate gland can be performed with manual compression strain imaging (two-dimensional) or with external vi- bration with Doppler imaging, which permits two- and three-dimensional imaging. In the following sections, examples of breast compression sonoelastography and prostate vi- bration sonoelastography performed on patients on an experimental basis are illustrated.The salient features of commonly encountered breast and prostate lesions on conventional B-mode US images and compression elastograms are com- pared in the Table. Breast US Elastography Compression elastography may have a role for further evaluating abnormal findings on con- ventional breast US images and differentiating benign from malignant breast lesions.Thus, the eventual goal of incorporating US compression elastography into routine practice would be to re- duce the biopsy rate of benign lesions. The two most important elastographic char- acteristics in evaluating breast lesions are size and stiffness criteria.The size criterion denotes the difference in the measurement of the longest diameter on the corresponding B-mode im- age and the elastogram. Structures that are less compressible than surrounding tissues measure larger on the elastogram than they do on the cor- responding B-mode image, resulting in a size dis- cordance.Therefore, cancers will be larger on the elastogram than on the conventional US image. Alternatively, this characteristic can be expressed as a ratio, such that a ratio of elastogram–to–B- mode lesion diameters that is greater than or equal to one is suggestive of malignancy (8,9). This phenomenon is attributed to the desmo- plastic reaction incited by many malignant breast neoplasms (10). Normal Breast Tissue Biomechanical testing has shown normal fibro- glandular breast tissue to be markedly stiffer than normal fatty breast tissue by as much as two orders of magnitude (11).Therefore, at elastogra- phy, fatty tissue will appear bright with respect to the adjacent glandular tissue, and normal fibrous parenchyma appears darker (Fig 2). Normal lymph nodes are reniform in shape and contain a hyperechoic fatty hilum on B-mode US images. At elastography, these features trans- late into relative softness of the lymph node, with a slightly lower elastogram-to-B-mode size ratio (Fig 3). Comparison of Breast and Prostate Lesion Imaging Characteristics at Conventional B-mode US and US Elastography Modality and Imaging Features Type of Lesion Conventional B-mode US US Elastography Breast Invasive ductal carcinoma Hypoechoic spiculated or microlobular branching mass that is taller than wide Increased stiffness, lesion larger than on B-mode image Cyst Round/oval anechoic lesion with enhanced through transmission Bull’s-eye appearance with posterior bright enhancement Fibroadenoma Oval well-circumscribed homogeneous hyperechoic area, wider than tall Area of greater stiffness typically smaller than lesion boundaries seen on B-mode image Hematoma Variable appearance ranging from anechoic to septate cystic Variable: similar appearance to cysts, may be stiff and measure less than on B-mode image Malignant lymph node Rounded and enlarged lesion with loss of fatty hilum Low strain and larger than on B-mode image Prostate Prostate cancer Variable echogenicity but most often hypo- echoic, typically located in periphery of gland Lower strain than normal prostate tissue and benign prostatic hyperplasia (dark) Benign prostatic hyperplasia Variable appearance but most commonly heterogeneous hypoechoic area in transi- tional zone Lower strain than normal prostate tissue (dark) but features can sometimes overlap with those of prostate cancer Teaching Point
2010 November-December 2009 radiographics.rsna.org Figure 6. Fibrocystic change. (a) B-mode US im- age demonstrates an irregular heterogeneous lesion in a patient who presented with a palpable mass in the right breast. (b) On the US elastogram, the lesion ap- pears soft and smaller than on the B-mode image.The findings from a subsequent biopsy showed fibrocystic change and periductal inflammation. Dotted lines indi- cate measured lesion diameters: 1 = 7.16 mm; 2 = 5.55 mm; 3 = 5.02 mm; and 4 = 4.29 mm. Distance ratio was calculated as 5.02 ÷ 7.16 = 0.70. Figure 4. Simple cyst. (a) B-mode US image of the breast shows a classic cyst (arrowheads). (b) US elas- togram demonstrates a bull’s-eye configuration within the lesion (arrowheads), which contains bright compress- ible material (thin arrow), and a bright spot behind the cyst (thick arrow). this entity is benign and may be considered a normal variant, the differential diagnosis at imag- ing includes atypical ductal hyperplasia, lobular neoplasia, and ductal carcinoma in situ, thereby requiring biopsy. At sonoelastography, however, the benign cystic nature of fibrocystic change is often apparent (Fig 6). Fibroadenoma Fibroadenomas are benign tumors that represent the most common type of solid breast mass. At Simple Cysts, Complex Cysts, and Fibrocystic Change Simple cysts represent the most common type of breast mass. Simple cysts are benign entities that result from fluid accumulation within the terminal ducts.These lesions usually are recognized easily on conventional US images and are characterized as anechoic round or oval well-circumscribed le- sions with enhanced through transmission and an imperceptible posterior wall. However, these le- sions often demonstrate variable elastographic ap- pearances (12).The typical manifestation of a sim- ple cyst at elastography is a “target” or “bull’s-eye” appearance, in which central bright compressible material is surrounded by a dark concentric rim (Fig 4).This appearance, as well as the additional bright area often observed deep to the cyst, is at- tributable to artifact (13). The presence of internal debris or septa char- acterizes complex cysts. As a result, complex cysts can mimic the appearance of solid lesions at B-mode US (14). Lesions containing thick walls or septa or an appreciable solid component are usually subjected to biopsy (15). US elastography can help elucidate the cystic nature of lesions with confounding appearances at B-mode US (Fig 5).Thus, elastography is useful for charac- terizing complex cysts with greater confidence, which can help avoid an unnecessary core biopsy in some instances. Fibrocystic change represents a commonly en- countered spectrum of nonsimple cysts. Although Figure 5. Complex cyst mimicking a solid lesion at US. (a) B-mode US image demonstrates a round hypoechoic breast lesion without associated through transmission. (b) US elastogram shows that the le- sion that appeared “solid” on the B-mode image is a cyst.The findings from fine-needle aspiration helped confirm that the lesion was a complicated cyst, and the lesion was completely aspirated. Teaching Point
RG ■ Volume 29 • Number 7 Ginat et al 2011 Figure 9. Invasive ductal carcinoma.The breast le- sion measures smaller on the B-mode US image (a) than on the US elastogram (b) in the transverse plane. The lesion is too large to measure accurately in the anteroposterior plane; dotted lines indicate measure- ments of the lesion diameter: 21.9 × 34.2 mm in a and 24.9 × 29.6 mm in b. In addition, the lesion is stiffer than the surrounding tissues.The findings from a US- guided core biopsy revealed invasive ductal carcinoma. Figure 8. False-positive finding of malignancy on a US elastogram of the left breast.The fibroadenoma measures smaller on the B-mode US image (a) than on the elastogram (b). Dotted lines indicate measured lesion diameters: 1 = 6.19 mm; 2 = 14.93 mm; 3 = 7.36 mm; and 4 = 19.74 mm. Distance ratio was cal- culated as 19.74 ÷ 14.93 = 1.32. Figure 7. Fibroadenoma. (a) B-mode US image of the left breast shows a lobulated hypoechoic lesion that is taller than wide, with posterior acoustic shadowing. (b) US elastogram, however, shows the lesion to be smaller than on the B-mode image.The findings from biopsy revealed a fibroadenoma. elastographic findings tend to occur in fibroad- enomas that are larger than 2 cm and contain calcifications (17). Invasive Ductal Carcinoma Invasive ductal carcinoma is the most common malignant neoplasm of the breast. At mammogra- phy, invasive ductal carcinoma typically manifests as a dense spiculated irregular mass associated with microcalcifications, particularly pleomor- phic microcalcifications, and indistinct margins that reflect the infiltrative behavior of the tumor. Similarly, characteristic US features of invasive ductal carcinoma include a hypoechoic spiculated or microlobular branching mass that is taller than wide, with angular margins and a hyperechoic halo. Skin thickening, lymphadenopathy, edema, and ligament retraction are secondary indicators of malignancy that can also be identified at US examination. Invasive ductal carcinoma is generally much stiffer than any of the other breast tissues and be- nign tumors such as fibroadenomas (18,19). As a result, invasive ductal carcinoma typically is ap- preciably darker than normal tissues or benign le- sions and is substantially larger on the elastogram than on B-mode US images (Fig 9).The area of mammography, these lesions classically are seen as lobulated circumscribed masses with coarse calcifications in a “popcorn” configuration. US images typically demonstrate fibroadenomas as well-circumscribed hypoechoic masses that are wider than tall, such that the long axis is paral- lel to the skin. Occasionally, fibroadenomas can have confounding features at B-mode US, such as dimensions that are taller than wide. In such instances, sonoelastography can help elucidate the benign nature of the lesion (Fig 7). Indeed, as many as 73% of fibroadenomas could be dif- ferentiated from malignant tumors on the basis of elastographic size and brightness criteria (16). However, fibroadenomas sometimes have elas- tographic size or stiffness features that are more typical of malignancy (Fig 8). Such false-positive Teaching Point
2012 November-December 2009 radiographics.rsna.org Figure 12. Hematoma. (a) B-mode US image of the breast demonstrates a superficial heterogeneous mass. (b) US elastogram shows that the lesion is stiff but measures smaller than on the B-mode image. Dotted lines indicate measurements of the lesion diameter: 11.0 × 5.3 mm in a and 10.2 × 4.2 mm in b.The dis- tance ratios were calculated as 10.2 ÷ 11.0 = 0.93 (for the long-axis dimension) and as 4.2 ÷ 5.3 = 0.79 (for the short-axis dimension). At physical examination, skin discoloration was noted in the corresponding area, a finding consistent with a hematoma. Figure 11. Lymph node with metastatic involve- ment. (a) B-mode US image demonstrates a lymph node that appears benign on the basis of its reniform shape and echogenicity. Dotted line indicates a lesion diameter of 20.4 mm. (b) Corresponding US elasto- gram, however, shows a stiff area that turned out to be a metastatic focus (arrows). Dotted line indicates a lesion diameter of 24.0 mm. Figure 10. Potential pitfall: false-negative findings on the US elastogram in a biopsy-proved case of invasive ductal carcinoma of the breast. (a) B-mode US image shows a hypoechoic lesion that is wider than tall but has microlobulations. (b) US elastogram shows that the lesion does not appear particularly stiff, and the boundaries are difficult to discern. Dotted lines indicate measurements of the lesion diameter: 26.3 × 19.8 mm in a and 25.6 × 19.5 mm in b. In retrospect, the vertical elastographic measurement should have included the dark rim (arrows) as well. metastases tend to appear stiffer and dispropor- tionately larger at elastography (Fig 11). Hematoma Breast hematomas may be iatrogenic or a result of trauma. US appearance of these lesions varies with time, beginning as hyperechoic fluid col- lections that progress to hypoechoic lesions and then to septate cystic structures that eventually regress. At mammography, hematomas may ap- pear as irregular masses of increased density. Al- though clinical history and results of physical ex- amination are often helpful in confirming the di- agnosis, further work-up is sometimes warranted. Elastography can help confirm benign nature of hematomas by demonstrating low stiffness and a low elastogram–to–B-mode size ratio (Fig 12). increased stiffness that is often apparent with in- vasive ductal carcinoma on the elastograms may indicate tumor extension not apparent at B-mode imaging. In addition, some cancers that are seen as areas of shadowing on US images appear as discrete masses on elastograms (20). Although uncommon, invasive ductal carci- noma can have the appearance of a benign well- circumscribed round mass on B-mode US im- ages. Similarly, tumor necrosis can manifest as anechoic areas with acoustic enhancement that can mimic cysts. False-negative elastograms can also occur and are characterized by high strain, erroneous measurements, and other technical errors (Fig 10). Lesions that have only one dis- cordant feature between the B-mode US image and the elastogram may be considered indeter- minate on the elastogram. Overall, US elastog- raphy is reported to have a sensitivity greater than 95% and a specificity of about 85% for differentiating between benign and malignant breast lesions (8,10). Metastatic Lymph Node Involvement At B-mode US, malignant lymph nodes clas- sically exhibit rounded enlargement with ef- facement of the normal fatty hilum.The use of Doppler US can improve the diagnostic accuracy for metastatic involvement by demonstrating increased vascularity (18). Similar to other ma- lignant breast lesions, lymph nodes that contain
RG ■ Volume 29 • Number 7 Ginat et al 2013 of endorectal US for prostate cancer detection is about 50% (20).The added use of Doppler imaging increases the detection rate by only 5%. In contrast, endorectal real-time elastography enables the diagnosis of prostate cancer with a re- ported accuracy of 76% (20). However, the ma- jor role of elastography is to improve the results of image-directed biopsy and therapy, compared with the use of endorectal US alone. Prostate cancers have a higher elastic modulus (stiffness) than that of surrounding normal prostate tissue (15,21). Consequently, prostate cancers will appear dark on elastograms. Often, intermediate-grade (Fig 13) and high-grade (Fig 14) malignant lesions that are subtle or even un- apparent on B-mode US images are prominent on elastograms as dark areas of low strain. Prostate US Elastography Two main types of US elastography have been applied for imaging the prostate: compression and vibration. Compression imaging is similar to that demonstrated in the breast cases already described.The subsequent examples are derived from vibration techniques, which are not yet available commercially. Prostate Cancer Endorectal US continues to be the most com- monly used imaging modality for assessing the prostate; however, it is relatively inaccurate for cancer detection. Endorectal US has a role in guiding prostate biopsies (19). Magnetic reso- nance imaging and computed tomography are mainly implemented for staging. At B-mode US, most prostate cancers are hy- poechoic, but many are isoechoic, and a few are hyperechoic. As a result, the overall sensitivity Figure 14. Prostate adenocarcinoma with Gleason score of 9/10, involv- ing two of two core samples and approximately 60% of the tissue. (a) Right parasagittal conventional US image shows that the lesion (arrow) is mildly hypoechoic. (b) Corresponding right parasagittal US elastogram better de- picts the lesion (arrow) as a dark area of low strain. (c) Photomicrograph (hematoxylin-eosin stain) of a transverse histologic section (dashed line in a and b indicates the plane of section) shows that there is good size correlation between the histologic extent of the lesion (arrow) and the lesion extent de- lineated on the elastogram. Figure 13. Prostate adenocarcinoma with Gleason score of 6/10. (a) Sag- ittal endorectal US image with the prostate gland outlined shows no discrete lesion (arrow). (b) Sagittal US elastogram shows strong vibration in the nor- mal prostate tissue and also an area of no vibration (arrow) anteriorly from the midportion of the gland to the base. (c) Photomicrograph (hematoxylin- eosin stain) of a transverse histologic section that included the correspond- ing lesion (arrow) at the base shows good correlation, with the deficit noted anteriorly on the elastogram through the selected plane of section (dashed line in a and b) in the midportion of the gland.The smaller lesion outlined in blue in c is outside the plane of the elastogram. Teaching Point
2014 November-December 2009 radiographics.rsna.org Figure 15. Sagittal three-di- mensional in vivo prostate elasto- gram (green), with tumors displayed in red, is fused with the histologic section. Overlap with tumor is dis- played in brown. Figure 16. Benign prostatic hyperplasia. (a) Transverse B-mode US image demonstrates a mildly prominent isoechoic area (arrow) in the central zone of the prostate gland. (b) Corresponding transverse elastogram shows that the area of benign prostatic hyperplasia (arrow) is more conspicuous.The le- sion demonstrates greater stiffness than the surrounding normal prostate tis- sue. (c) Photomicrograph (hematoxylin-eosin stain) shows that there is good correlation between the extent of the lesion (arrow) on the histologic section and the lesion extent on the elastogram. Figure 17. Benign prostatic hyperplasia and prostate adenocarcinoma. Sagittal B-mode US image (top left) shows no apparent lesions. US elasto- gram (top right) shows that both benign prostatic hyperplasia and prostate adenocarcinoma (white arrows) demonstrate low strain with respect to the normal prostate tissue. Bottom: Photomicrograph A (hematoxylin-eosin stain) of prostate adenocarcinoma and photomicrograph B (hematoxylin- eosin stain) of benign prostatic hyperplasia demonstrate that the distribu- tion of the lesions (outlined in blue) on the histologic samples matches well with the elastographic findings.
RG ■ Volume 29 • Number 7 Ginat et al 2015 Overall, US elastography has a sensitivity in the range of 68%–86%, a specificity of 72%–81%, and an accuracy of 76% for the detection of prostate cancers (19,22,23). In addition, the sensitivity is 85% and the specificity 93% for peripheral lesions (23). Sonoelastography-guided prostate biopsies yield detection rates that are nearly threefold higher than those for systematic biopsy techniques while requiring fewer core samples (24).With regard to brachytherapy, it is feasible to image radioactive brachytherapy seeds with US elastog- raphy; however, it is not yet established whether this imaging modality would be of benefit for seed implantation (25). Image processing of the elastograms, including three-dimensional volume rendering, can be per- formed to provide comprehensive lesion assess- ment (Fig 15).This type of image reconstruction can be useful for surgical planning, particularly for partial prostatectomy. Benign Prostatic Hyperplasia The appearance of benign prostatic hyperplasia at endorectal US is variable but usually consists of a heterogeneous hypoechoic area or areas in the transitional zone (26). In general, foci of benign prostatic hyperplasia have elastic moduli (stiffness) that are an order of magnitude greater than those of normal prostate tissues but are less than those of prostate carcinomas (21). As a re- sult, on elastograms, benign prostatic hyperplasia will appear darker than normal prostate tissue (Fig 16). However, the difference between benign prostatic hyperplasia and prostate carcinoma can be difficult to discern because benign prostatic hyperplasia also appears darker than the back- ground tissues. Consequently, benign prostatic hyperplasia can represent a false-positive finding for cancer (Fig 17). Conclusions Although not yet established for routine clinical use, US elastography is a promising adjunctive modality for evaluating breast and prostate le- sions, on the basis of the results of the initial laboratory and clinical investigations. Neverthe- less, validation of this modality through prospec- tive trials is warranted. Ultimately, sonoelas- tography is expected to improve the accuracy of diagnosis for breast and prostate lesions in conjunction with conventional modalities. As a result, US elastography may be used to reduce biopsy rates for breast lesions and to more ap- propriately guide biopsy of prostate lesions.The potential use of US elastography for therapeutic applications is also foreseen. For example, real- time elastography could be applied to monitor therapy with lesion ablation, such as radiofre- quency ablation and treatment with high-inten- sity focused ultrasound. References 1. 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RG Volume 29 Number November-December 2009 Ginat et al US Elastography of Breast and Prostate Lesions Daniel T. Ginat, MD, MS, et al Page 2009 The two most important elastographic characteristics in evaluating breast lesions are size and stiffness criteria. Page 2010 - which central bright compressible material is surrounded by a dark concentric rim. Page 2011 Invasive ductal carcinoma typically is appreciably darker than normal tissues or benign lesions and is substantially larger on the elastogram than on B-mode US images. Page 2013 Prostate cancers have a higher elastic modulus (stiffness) than that of surrounding normal prostate tissue (15,21). Consequently, prostate cancers will appear dark on elastograms. Page 2015 As a result, on elastograms, benign prostatic hyperplasia will appear darker than normal prostate tissue. 7 RadioGraphics 2009; 29:2007–2016 • Published online 10.1148/rg.297095058 • Content Codes:
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Although not yet established for routine clinical use, US elastography is a promising adjunctive modality for evaluating breast and prostate lesions; the ...
2008 November-December 2009 radiographics.rsna.org Figure 3. Normal lymph node in the breast. (a) B-mode US image of a lymph node demonstrates a reni-
1. Radiographics. 2009 Nov;29(7):2007-16. doi: 10.1148/rg.297095058. US elastography of breast and prostate lesions. Ginat DT, Destounis SV, Barr RG ...
Ultrasound elastography of the prostate: ... US elastography should become an ... These figures are slightly higher than those for breast cancer for ...
This is the basic principle of real-time elastography, ... About Us; BioMed Research ... and T. Hall, “Elastic moduli of breast and prostate tissues ...
Breast elastography is a new sonographic imaging technique which provides information on breast lesions in addition to conventional ...
US Elastography of Breast and Prostate Lesions1 on ResearchGate, the professional network for scientists.
Elastography is used for detection and diagnosis of breast, thyroid and prostate ... of breast lesions when shear wave elastography images are added to ...
Value of Elastography in Prostate Cancer Diagnosis ... between US image-pairs of tissue under ‘compression ... et al. Elastic moduli of breast and prostate
US elastography is currently ... Value of real-time elastography targeted biopsy for prostate cancer detection in men ... MR elastography of ...