Role of Elastograpgy in Cancer Detection

8/9/2019 Role of Elastograpgy in Cancer Detection

1/9


2/9

12 Journal of Diagnostic Medical Sonography 30(1)

Discussion

Advantages

Ultrasound is a noninvasive, widely available, cost-effec-

tive method of diagnostic imaging with no risk of radia-

tion exposure, adverse reaction to contrast, or other

contraindications such as previous surgeries or impaired

renal function common to other methods such as mag-

netic resonance imaging (MRI) and computed tomogra-

phy (CT). In cancer detection, RTE has been reported to

differentiate benign from malignant breast lesions with

sensitivities of 78% to 100% and specificities of 21% to

98%.6 In conjunction with other imaging techniques,

RTE can potentially improve the radiologists ability to

accurately characterize malignant lesions and distinguish

fibrotic tissue from cancerous growths. This capability

has the potential to reduce unnecessary biopsies of char-

acteristically benign masses, lowering costs and improv-

ing throughput and overall patient management.5,6

Limitations

A particular limitation of RTE in cancer assessment is spe-

cific to the histologic cell type of the cancer being evalu-

ated. RTE measures the stiffness of tumors based on the

assumption that malignancies will possess a greater cell

density; however, atypical cancers such as ductal cancers,

medullary cancers, mucinous cancers, and papillary can-

cers do not follow the principles of this assumption and

may therefore be underreported by RTE assessment

alone.

2

Similarly, adjacent inflammatory tissues canreduce the sensitivity of RTE in cancer detection, as is

seen in the presence of pancreatitis.8,9Other factors that

increase interobserver variance, and thus reduce reported

accuracy, include the type of cancer and the size of the

lesion. These two factors affect the elasticity of the lesion

and can influence interpretation.2,10These limitations have

the potential to increase false-negative results.

Ultrasound is an inherently operator-dependent modal-

ity, and variance in interobserver agreement can result

from inconsistent technique, level of experience, the avail-

able technology, and subjective interpretation of dis-

ease.2,11,12

RTE is still in the development stages, and there

is little consistency in the scoring system relative to tissuecharacteristics indicative of malignancy. Independent scor-

ing systems have been used in many trials assessing RTE

accuracy, but this lack of standardization reduces the reli-

ability of published results. A great deal of literature cen-

tering on body mass index (BMI) as a substantial limitation

suggests that increased body habitus perpetuates variance

in RTE ultrasound. However, technological advancement

in probe development is anticipated to significantly help

overcome this persistent issue in RTE application.13

Literature Review

Variance

Variance in RTE results largely from a lack of protocol

and standards for the application, measurement, scoring,

and interpretation in this developing technique. The

resulting disagreement between operators, observers, and

interpreters can be misconstrued as evidence against the

reliability of elastography, and this continues to be a chal-

lenging limitation of RTE. A clinical trial conducted to

measure the variance in elasticity images was conducted

to determine what factors have the greatest influence on

quality. The results reported that image quality was inad-

equate in 21 cases (6.7%), low in 134 cases (42.9%), and

high in 157 cases (50.3%).14

According to this study,

higher image quality was reported in conjunction with

smaller lesion size, shallower lesion depth, decreased

breast thickness at the location of the tumor, and benign

pathologic findings. The greatest impact on quality wasinversely proportional to the thickness of the breast at the

location of the target lesion where increasing thickness

resulted in decreased quality. Other variables measured

included age, BMI, mammographic density, and distance

from the nipple; none of these factors had any appreciable

impact on image quality. The reported sensitivity in dif-

ferentiating benign from malignant masses between

higher quality and lower quality images was 87.0% and

56.8%, respectively.

A study that reviewed previous cases in which RTE

was used to measure liver tissue stiffness as it relates to

fibrosis found a rate of measurement failures, or nondi-

agnostic quality, of 3.1%, and an additional 15.8% of

reported results were determined to be unreliable.15The

authors highlighted the strong correlation of failure/

unreliability with variables such as increasing age (>52

years), increased BMI (>30 kg/m2), coexisting type 2

diabetes, and operator inexperience. A similar study

reflected comparable measurements of failure and unre-

liability at 5.3% and 16%, respectively, as did studies in

France and China, reporting failure rates of approxi-

mately 5%. The implication of these studies points to

obesity as a primary factor in unreliable or failed results

in RTE. Despite the limitations noted in such studies,

the variance depicted threatens reliability of RTE inclinical applications. Contrary to these findings, a study

by Sftoiu et al16

of interobserver variability in the effi-

cacy of elastography in differentiating focal masses in

patients with chronic pancreatitis reported correlations

between 0.86 and 0.94, with good reliability in repro-

duction of images between observers. The sensitivity

was 93.4%, specificity 66.0%, positive predictive value

92.5%, negative predictive value 68.9%, and overall

accuracy 85.4%.16


3/9

Mapes-Gonnella 13

Pancreas

Chronic pancreatitis and pancreatic cancer are often

coexistent, and the detection of focal abnormalities in the

presence of inflammation is challenging. The diagnosis

and plan of care for both pancreatic inflammation and

malignancy, however, are largely dictated by imaging

results.8 RTE is a safe and effective technique that has

been reported to be instrumental in accurately diagnosing

chronic pancreatitis and pancreatic cancer8,17(Figure 1).

When compared with results of other imaging modalities,

results of RTE assessment and biopsy of pancreatic

masses have achieved a sensitivity of 85% to 90% and a

specificity of virtually 100% in the absence of chronic orpseudo-tumoral pancreatitis. Considering that 20% to

35% of patients with pancreatic lesions have coexistent

pancreatitis and that in this condition RTE typically has a

lower sensitivity (approximately 75%), caution must be

used when using this technique for diagnosis. A trial to

determine the accuracy of RTE in differentiating between

normal pancreas, chronic pancreatitis, and pancreatic

cancer reported a sensitivity of 91.4%, specificity 88.9%,

and accuracy of 90.6%.8,9A subgroup analysis within this

study differentiating pancreatic cancer from pseudo-

tumoral pancreatitis reflected good sensitivity at 93.8%

and overall accuracy of 86%, but with low specificity ofonly 63.6%.

Another trial measuring RTE sensitivity and specific-

ity in differentiating benign from malignant pancreatic

lesions compared with conventional sonography showed

a sensitivity and specificity for elastography of 92.3%

and 80.0%, respectively, compared with 92.3% and

68.9%, respectively, for conventional B-mode images.18

A trial conducted by Larino-Noia et al19evaluating RTE

accuracy in characterizing solid pancreatic masses

included RTE assessment of the mass compared with

adjacent tissue as reference areas. The results were con-firmed by histopathologic examination of the gross

specimen. Endoscopic ultrasound (EUS) elastography

had a sensitivity and specificity of strain ratio for detect-

ing pancreatic malignancies of 100% and 92.9%,

respectively.19

Liver

Hepatocellular carcinoma (HCC) is the third most com-

mon cause of cancer-related mortality worldwide, with

the majority (80%) developing in patients with advanced

liver cirrhosis or fibrosis, making it the greatest risk fac-

tor for HCC development.20Fibrotic changes in the liverhave a strong correlation with later development of HCC,

which may be treated by ablative therapies20(Figure 2).

Elastography has been used to localize hepatic masses to

improve the accuracy of biopsies and to determine the

response of malignancies to therapy21(Figure 3). Tissue

response to ablation therapy has been researched to deter-

mine whether RTE can detect changes in the biomechani-

cal properties of the tumor compared with surrounding

tissues. In one such study, elastography demonstrated the

ablated region as a well-circumscribed area of increased

stiffness compared with nonablated surrounding tissue.

These findings correlated well with contrast-enhanced

CT images as well as with the gross specimen following

resection.22

Prostate

Results of RTE evaluation of the prostate gland for cancer

have been equivocal regarding its diagnostic value

(Figure 4). Despite a clinical trial reporting 76% diagnos-

tic accuracy of endorectal elastography for prostate can-

cer detection,23 other studies found significantly lower

Figure 1. Elastography image side by side with conventionalB-mode image of a pancreatic carcinoma, demonstrating theincreased stiffness (blue) of the tumor.

Figure 2. Elastography image side by side with conventionalB-mode image of a liver with diffuse fibrotic changes, showingthe diffuse nature of the areas of increased stiffness (blue).


4/9


reliability of this modality in prostate cancer evaluation.

In a study by Magnoni et al24

examining the sensitivity of

RTE in characterizing malignant prostate masses when

compared with histological samples obtained via tran-

srectal biopsies, only 1 of 102 patients was determined to

be true positive for prostate cancer, and 6 cases demon-

strated false negatives. A clinical trial to evaluate malig-

nant prostate tissue response to high-intensity focused

ultrasound by elastographic imaging demonstrated a

marked underestimation of residual tumor volume when

compared with MRI.25

The trial did note that technical

limitations such as bandwidth and frame rate affected

the diagnostic quality of elastographic ultrasound

images. Both studies concluded that the limited accu-

racy, sensitivity, and specificity do not justify the routine

application of real-time elastography in prostate cancer

detection.

Breast

Breast cancer tissue is less elastic than normal breast tis-

sue; this increased hardness, or stiffness, is the property

that allows some breast cancers to be palpated as well as

characterized by comparative elasticity through RTE

assessment26(Figure 5). The principle of elastography is

that tissue compression produces strain (displacement)

within the tissue and that the strain is smaller in hardertissue than in softer tissue. Therefore, by measuring the

tissue strain induced by compression, we can estimate tis-

sue hardness, which may be useful in diagnosing breast

cancer. A study conducted by Ueno et al26

evaluated the

diagnostic value of RTE by examining 111 nodules and

applied varying scoring system standards for characteriza-

tion in determining its diagnostic accuracy. Elastography

achieved a sensitivity, specificity, and accuracy of 86.5%,

89.8%, and 88.3%, respectively. Applying a different set

of threshold values yielded a sensitivity, specificity, and

accuracy of 71.2%, 96.6%, and 84.7%, respectively. A

separate study using the same scoring system as Ueno et al

demonstrated RTE sensitivity and specificity of 79% and

89%, respectively.2,10A study using a scoring system dif-

ferent from the preceding studies that included 874 breast

lesions found a high specificity in benign lesions with a

negative predictive value of 98% related to the entire

group of lesions and 100% in lesions less than 5 mm.27An

imaging comparison trial conducted by Ou et al28

centered

on differentiating benign from malignant breast lesions in

dense breasts. Imaging modalities included B-mode ultra-

sound, RTE, and mammography, and the study concluded

Figure 4. Real-time elastography image side by side withconventional B-mode image showing a small lesion withincreased stiffness (blue) on the right side of a prostate. Thelesion was later confirmed to be prostate cancer.

Figure 5. Elastography image side by side with conventionalB-mode image of a fibroadenoma of the breast. The differencein stiffness between the lesion and the surrounding breasttissue is clearly contrasted in the elastography image.

Figure 3. Real-time elastography image side by sidewith conventional B-mode image in a patient withcholangiocarcinoma acquired during an endoscopic,ultrasound-guided, fine-needle aspiration. The increasedstiffness of the tumor (blue) can be seen clearly in theelastography image.


5/9

Mapes-Gonnella 15

that RTE demonstrated the highest specificity (95.7%)

and the lowest false-positive rate (4.3%). When compared

with B-mode ultrasound, RTE diagnostic accuracy was

higher at 88.2% vs 72.6%. Positive predictive values

(PPVs) also exceeded B-mode at 87.1% vs 52.5%, respec-

tively. Despite these results, sensitivity, negative predic-

tive value, and false-negative rate were comparable to the

other two methods. Increased false-negative rates in RTE

were seen with invasive ductal carcinomas and those

malignancies with a large area of central necrosis28

(Figure 6). A combination of RTE and B-mode ultrasound

had an improved sensitivity (89.7%), accuracy (93.9%),

false-negative rate (9.2%), specificity (95.7%), and posi-tive predictive value (89.7%).

Destounis et al11

published results of a multicenter

study evaluating the sensitivity and specificity of RTE in

characterizing and differentiating breast lesions.

Sensitivity and specificity obtained by the various centers

participating in the study ranged between 96.7% and

100% and between 66.7% and 95.4%, respectively. The

marked variance in specificity was attributed by the

authors to differences in the examination technique. This

concern about interoperator variance was also raised by

Moon et al12as a potential limitation that undermines the

reliability of published data and overall utility.

Tumor Response

Ensuring accurate characterization, staging, and monitor-

ing of tumors and their response to therapy is a challeng-

ing but critical role of diagnostic imaging modalities

(Figure 7).

Second to malignancies of the skin, breast cancer is

the most frequent type of cancer diagnosed in women;

more than 200,000 new cases of invasive breast cancer

were diagnosed in the United States during 2012.7

Approximately 5% to 20% of these patients will present

with locally advanced breast cancer (LABC), which is

defined as stage III or inoperable disease, characterized

by tumors that are larger than 5 cm and/or involving the

skin or chest wall, with or without lymphatic involve-

ment. When compared with early stage breast cancer,LABC has a much poorer prognosis and higher rate of

recurrence (10%-20%). Only 55% of LABC patients sur-

vive to 5 years because of the high risk for metastatic

spread. Approximately 75% of LABCs show marked

response to initial chemotherapy, improving surgical out-

come. In more than 50% of cases there is only micro-

scopic tumor, or no residual tumor at all, following

surgical intervention.27

Imaging to assess for early functional changes that

indicate the extent of therapy response is critical in deter-

mining the plan of care for cancer patients. The earlier a

response can be detected, the more tailored a patientstreatment can be to improve outcome. In LABC, admin-

istration of neoadjuvant therapy is a standard protocol

prior to surgical resection to ensure disease-free margins

and lower the chance of in situ reoccurrence. Such neoad-

juvant therapy has been linked to increased survival rates

up to 70%.7,27

A recent study by Falou et al7centered on

elastographic assessment of tumor response to neoadju-

vant therapy. Nine patients demonstrated positive

response to neoadjuvant therapy by elastography evalua-

tion that was confirmed surgically, and five patients dem-

onstrated poor response to therapy by RTE. One patient

demonstrated a false-positive response to therapy due to

the invasive, mucinous nature of her specific LABC, apattern that presents with biomechanical properties of

decreased stiffness, atypical of LABC cancers.

Studies have measured tumor response to therapy in

order to determine criteria for treatment efficacy. One

such treatment that has been under development for the

past two decades is percutaneous ethanol injection (PEI),

studied for its effect on small HCCs. Ethanol has a pattern

of diffusion in tissue that creates a cytotoxic environment

resulting from protein denaturation, cellular dehydration,

and microvessel thrombosis contributing to coagulation

necrosis in local HCC cells. Studies have shown that up

to 70% of treated HCC tumors smaller than 3 cm result incomplete coagulation necrosis, and the 5-year survival

rate is between 40% and 65% for PEI-treated patients

who have concomitant hepatic cirrhosis.29To evaluate the

potential of RTE to measure tumor response to treatment,

Bai et al29

conducted RTE following PEI, using the area

of a lesion created in vivo to depict temporal formation of

the ethanol-induced response. The results demonstrated

the formation of a focal area of lower strain with well-

defined borders within 2 minutes of PEI, the maximum

area being reached at 2 minutes. The authors concluded

Figure 6. Elastography image side by side with conventionalB-mode image of an invasive ductal carcinoma of the breast.Note the difference in stiffness of this lesion (blue) comparedwith the fibroadenoma of Figure 5.


6/9


that RTE is a valuable tool for monitoring tumor response

to PEI. Their study also indicated some value in using

RTE for real-time assessment of PEI response by necrotic

formation. This will allow physicians to adjust the dose

of PEI based on RTE findings, thus improving patient

outcome and treatment efficacy and reducing recurrence

rate of inadequately treated tumors.

Conclusion

RTE is an emerging imaging modality that provides data

related to the biomechanical properties of tissue for charac-

terization of malignant and benign masses. Limitations of

RTE include operator dependence, increased BMI, tissue

thickness anterior to breast masses, histologic composi-tion of atypical cancers, and lack of standard scoring

methods and protocols, which hamper reliability. However,

RTE remains a cost-effective, noninvasive, and widely

available technique that poses less risk to patients compared

with other imaging modalities, making it ideal for screening

and monitoring disease processes.2RTE has established a

developing role in distinguishing benign and malignant

masses in the pancreas, and the high degree of sensitivity in

breast imaging suggests that this modality may reduce

unnecessary biopsies. In addition to screening, published

reports have reflected a strong correlation between RTE and

pathologic response of breast tumors following neoadju-

vant chemotherapy.7This correlation has been documented

in RTE determination of tumor response to ablative therapy

as well.22,29

These findings facilitate the establishment of

protocols for techniques that monitor the response of cancer

to specific therapies. RTE can be instrumental in tailoring

treatment to patients exhibiting a negative tumor response.

This ability of response monitoring has the potential to

improve patient outcome, efficacy, and cost of care, reduc-

ing recurrence rates and overall mortality in some cancers.

Overall, while RTE is a relatively new technique, research

has supported the value of this modality in multiple cancer-

related applications that promise to aid in the screening,

detection, and monitoring of malignancies and enhance-ment of cancer therapies through measured response.

Declaration of Conflicting Interests

The author declared no potential conflicts of interest with

respect to the research, authorship, and/or publication of this

article.

Funding

The author received no financial support for the research,

authorship, and/or publication of this article.

Figure 7. Representative elastography and B-mode images in patients with locally advanced breast cancer from a nonresponder(A) and a responder (B) taken at baseline prior to treatment, at week 1, at week 4, at week 8, and preoperatively.7(The colorbar on the right indicates relative stiffness; the scale bar equals 1 cm.)


7/9

Mapes-Gonnella 17

References

1. United States Food and Drug Administration. 2013.

Available from: http://www.accessdata.fda.gov/cdrh_docs/

pdf13/k131527.pdf. Accessed on June 5, 2013.

2. Bonardi M, Alessi S, Goddi A: Breast elastography: a lit-

erature review.J Ultrasound2012;15:192198.

3. Lee C, Karadayi K, Luo YKS: Real-time ultrasound elas-

tography on a multi-core DSP. University of Washington

Engineering Department, Seattle, 2011. http://www.ti.com/

lit/wp/sprabn9/sprabn9.pdf. Accessed on June 5, 2013.

4. Orenstein B: Hard decisionsultrasound elastography

seeks to help characterize breast lesions and, more recently,

throughout the body. Radiology Today 2011;12(4):26.

http://www.radiologytoday.net/archive/rt0411p26.

shtml#sthash.sgBcFdZ4.dpuf. Accessed on June 5, 2013.

5. Vinnicombe S, Planche K: Breast imaging in the new era.

Cancer Imaging2004;4(2):3950.

6. Brennan S, Dershaw D, Ginsberg M, et al: Advances in

oncologic imaging update on 5 common cancers. Ca

Cancer J Clin2012;62:364393. 7. Falou O, Sadeghi-Naini A, Prematilake S, et al: Evaluation

of neoadjuvant chemotherapy response in women with

locally advanced breast cancer using ultrasound elastogra-

phy. Transl Oncol2013;6:1724.

8. Wallace M, Gill K: EUS elastography for pancreatic mass

lesions: between image and FNA? Gastrointest Endosc

2008;68(6):10951097.

9. Vilmann P, Gorunescu F, Suaftoiu A, et al: Neural net-

work analysis of dynamic sequences of EUS elastography

used for the differential diagnosis of chronic pancreatitis

and pancreatic cancer. Gastrointest Endosc2008;68:1086

1094.

10. Martegani A, Di Cioccio B, Baldassarre S, Giuseppetti GM:

Elastosonography in the diagnosis of the nodular breastlesions: preliminary report.Radiol Med2005;110:6976.

11. Destounis S, Lackey LB, Svensson WE, et al: Evaluation of

breast lesions using sonographic elasticity imaging: a mul-

ticenter trial.J Ultrasound Med2012;31:281287.

12. Moon WK, Choi JW, Cho N, Jang M, Kim KG, Chung

SY: Differentiation of benign from malignant nonpalpable

breast masses: a comparison of computer-assisted quantifi-

cation and visual assessment of lesion stiffness with the use

of sonographic elastography.Acta Radiol2010;51(1):914.

13. Afdhal E, Cohen EN: Ultrasound-based hepatic elas-

tography: origins, limitations, and applications. J Clin

Gastroenterol2010;44(9):637645.

14. Moon W, Cho N, Kim S, Chang J: Breast mass evalua-

tion: factors influencing the quality of US elastography.

Radiology2011;259(1):5964.

15. Kemp W, Hodge A: Transient elastography: the big-

ger we are, the harder to scan. J Gastroenterol Hepatol

2011;26:300305.

16. Sftoiu A, Vilmann P, Gorunescu F, et al: Accuracy of

endoscopic ultrasound elastography used for differential

diagnosis of focal pancreatic masses: a multicenter study.

Endoscopy2011;43(7):596603.

17. Hitachi Medical Systems Europe. Real time elastography.

http://www.hitachi-medical-systems.eu/products-and-ser

vices/ultrasound/hitachi-real-time-tissue-elastography-hi-rte/

clinical-applications.html#Further-examples-5. Accessed on

June 5, 2013.18. Botelberge T, Borie E, Pesenti C, et al: Endoscopic ultra-

sound elastography for evaluation of lymph nodes and pan-

creatic masses: a multicenter study. World J Gastroenterol

2009;15(13):15871593.

19. Larino-Noia J, Abdulkader I, Forteza J, Dominguez-

Munoz J, Iglesias-Garcia J: Quantitative endoscopic

ultrasound elastography: an accurate method for the dif-

ferentiation of solid pancreatic masses. Gastroenterology

2010;139(4):11721180.

20. Gordon-Walker T, Aucott R, van Deemter M, et al:

Matrix stiffness modulates proliferation, chemotherapeutic

response, and dormancy in hepatocellular carcinoma cells.

Hepatology2011;53(4):11921205.

21. Sandulescu L, Padureanu V, Dumitrescu CI, et al: A pilotstudy of real time elastography in the differentiation of

focal liver lesions. Current Health Sciences J2012;38:14.

22. Gauthier T, Fernandez A, Xie H, et al: Ultrasound-based elas-

tography: a novel approach to assess radio frequency ablation

of liver masses performed with expandable ablation probes: a

feasibility study.J Ultrasound Med2008;27(6):935946.

23. Stamatia D, Barr R, Castaneda B, Strang J, Rubens D,

Ginat D: US elastography of breast and prostate lesions.

Radiographics2009;29:20072016.

24. Magnoni P, Giusti G, Seveso M, et al: Impact of real-time

elastography versus systematic prostate biopsy method

on cancer detection rate in men with a serum prostate-

specific antigen between 2.5 and 10 mg/mL. ISRN Oncol

2013;2013:584672.

25. Souchon R, Rouvire O, Gelet A, Chapelon JY, Curiel L:

Elastography for the follow-up of high-intensity focused

ultrasound prostate cancer treatment: initial comparison

with MRI. Ultrasound Med Biol2005;31(11):14611468.

26. Ueno E, Tohno E, Kamma H, Takahashi H, Shiina T, Itoh

A: Breast disease: clinical application of US elastography

for diagnosis.Radiology2006;239:341350.

27. Aiani L, Baldassarre S, Bulzacki A, et al: Characterization

of breast lesions with real-time sonoelastography: results

from the Italian multicenter clinical trial. SKK01-09

RSNA Nov 29, 2006. Available from: http://rsna2006.

rsna.org/rsna2006/V2006/conference/event_display.

cfm?em_id=4430351.28. Ou B, Luo BM, Feng X, et al: Comparison of ultra-

sound elastography, mammography, and sonography in

the diagnosis of solid breast lesions. J Ultrasound Med

2007;26:807815.

29. Bai J, Cui L, Wang J, et al: Elastographic evaluation of the

temporal formation of ethanol-induced hepatic lesions: prelim-

inary in vitro results.J Ultrasound Med2007;26:11911199.


8/9

Article: The Emerging Role of Elastography in Cancer:

Diagnostic Value in Detecting and Assessing Therapeutic

Response to Treatment

Author: Tia Mapes-Gonnella, BS, RDMS

Category: General/Abdominal Sonography

Credit: 1.0 SDMS CME Credit

Objectives: After studying the article entitled The

Emerging Role of Elastography in Cancer: Diagnostic

Value in Detecting and Assessing Therapeutic Response

to Treatment, you will be able to:

1. Describe the different types of elastography imaging

2. Determine appropriate applications for elastography

imaging

3. Describe the limitations of elastography imaging

1. Quasistatic elastography is an imaging technique

that applies stress to tissue and then measures the

resulting tissue

a. Pressure

b. Strain

c. Force

d. Velocity

2. Shear wave elastography determines tissue stiff-

ness by creating shear waves and measuring

their

a. Pressure

b. Strain

c. Displacement

d. Velocity

3. Acoustic radiation force impulse elastographyuses a short burst of focused ultrasound to cause

and then measure tissue

a. Pressure

b. Force

c. Displacement

d. Velocity

4. Typically, the most elastic tissue of those shown

below is

a. Normal tissue

b. Malignant tissue

19584 JDMXXX10.1177/8756479313519584Journal of DiagnosticMedica l SonographyJDMSCME ArticleSDMSCME Credite2013

JDMS CME Article-SDMS

CME Creditavailable to SDMS Members Only

SDMS members can earn FREE SDMS CME credit by reading this approved CME

article and successfully completing the online CME test. If you are not a current SDMS

member but would like to earn SDMS CME credit, please visit http://www.sdms.org/

members/login.asp to join SDMS.

Instructions

1. Each question has only one correct answer.

2. Go online to http://www.sdms.org/members/login.asp to score your test answers (SDMS membership num-

ber required). NO JDMS CME tests will be accepted by mail or FAX.

3. You will receive your test score results immediately*if you achieve a score of 70% or better, SDMS CME

credit will be awarded.

4. Awarded CME credits are tracked in the SDMS CME Tracker system. For more information about the SDMS

CME Tracker system, visit http://www.sdms.org/members/login.asp.

*Because the correct answers will be provided after you submit your answers, only one attempt is permitted to

successfully complete the JDMS CME article test. Please verify your answers before submission.


9/9

JDMS CME ArticleSDMS CME Credit 19

c. Fibrotic tissue

d. Inflammatory tissue

5. The type of cancer that would be most reliably

detected by elastography is

a. Papillary cancer

b. Ductalc. Medullary cancer

d. Pancreatic cancer

6. In general, the cancer type for which elastography

has been reported to show the lowest sensitivity

has been

a. Pancreatic cancer

b. Liver cancer

c. Prostate cancer

d. Breast cancer

7. When comparing elastography results, the sensi-tivity of low-quality images compared with high-

quality images is lower by approximately

a. 10%

b. 20%

c. 30%

d. 40%

8. Failure or inaccuracy of elastography to differen-

tiate benign from malignant lesions in the abdo-

men is considered primarily to be a result of

a. Patient age

b. Obesity

c. Ethnicity

d. Lesion size

9. Much of the variability in the reported accuracy

of elastography to characterize lesions is consid-

ered to be caused by

a. Lack of standardized technique, scoring, and

interpretation

b. Equipment

c. Tumor stage

d. Tumor size

10. For lesions in dense breasts, the positive predic-

tive value of real-time elastography comparedwith B-mode ultrasonography has been reported

to be higher by approximately

a. 35%

b. 25%

c. 15%

d. 5%

Documents

Role of Elastograpgy in Cancer Detection