Real-time elastography in the detection of prostate cancer in patients with raised PSA level

Case report: Prostatic malakoplakia: a rare disease that has a profile mimicking prostate cancer

Prostatic malakoplakia (PMP) is a rare inflammatory disease, and misdiagnosis on imaging is a major reason for unnecessary punctures; however, information on imaging is even rarer. Five patients with PMP between May 2022 and February 2023 were enrolled in this study to summarize the imaging manifestations. All patients underwent ultrasound (US)-guided prostate biopsy and were confirmed by pathology, and the presence of prostate cancer was also excluded by pathology. The five patients, with a median age of 71 years (range = 58-74 years), had a median total prostate-specific antigen (T-PSA) of 10.40 ng/mL (range = 1.74-63.42 ng/mL). In two patients, chest computed tomography showed pulmonary infections. All patients underwent magnetic resonance imaging (MRI). Of these patients, four had a Prostate Imaging-Reporting and Data System (PIRADS) score of 5, while one had a score of 4. The lesions were mostly distributed in the peripheral zone of the prostate and appeared as a high signal on T1-weighted imaging (T1WI) and a low signal on T2-weighted imaging (T2WI). In the US examination, four patients had abnormal prostate morphology, with an unsmooth envelope and non-uniform parenchymal echogenicity. Four patients had increased prostate volume. US showed a hypoechoic nodule with non-uniform internal echogenicity, and an abundant internal blood flow signal was detected by color Doppler US. PSA, MRI, and US were not specific for PMP in our study, but we found that a history of co-infection may be helpful in an accurate diagnosis and to avoid unnecessary biopsy.

Endoscopic Ultrasound (EUS) Guided Elastography

Endoscopic ultrasound (EUS) is an essential technique for the management of several diseases. Over the years, new technologies have been developed to improve and overcome certain limitations related to EUS-guided tissue acquisition. Among these new methods, EUS-guided elastography, which is a real-time method for the evaluation of tissue stiffness, has arisen as one of the most widely recognized and available. At present, there are available two different systems to perform an elastographic evaluation: strain elastography and shear wave elastography. Strain elastography is based on the knowledge that certain diseases lead to a change in tissue hardness while shear wave elastography monitored shear-wave propagation and measures its velocity. EUS-guided elastography has shown in several studies high accuracy in differentiating benign from malignant lesions from many different locations, mostly in the pancreas and lymph nodes. Therefore, nowadays, there are well-established indications for this technology, mainly for supporting the management of pancreatic diseases (diagnosis of chronic pancreatitis and differential diagnosis of solid pancreatic tumors) and characterization of different diseases. However, there are more data on new potential indications for the near future. In this review, we will present the theoretical bases of this technology and we will discuss the scientific evidence to support its use.

The expanding role of endoscopic ultrasound elastography

Endoscopic ultrasound (EUS) is an invaluable tool for assessing various GI diseases. However, using just the conventional B-mode EUS imaging may not be sufficient to accurately delineate the lesion's character. Using the principle of stress-induced tissue strain, EUS elastography (EUS-E) can help in the real-time sonographic assessment of the level of tissue stiffness or hardness of any organ of interest during a routine EUS procedure. Thus, EUS-E can better characterize the lesion's nature and highlight the more suspicious areas within an individual lesion. The most commonly studied lesions with EUS-E are the pancreatic lesions, namely, chronic pancreatitis, pancreatic cancer, and lymph nodes. However, EUS-E is gradually expanding its use for lesion characterization of the liver, bile duct, adrenals, gastrointestinal tract, and even therapy response. Moreover, the use of EUS-E along with other image enhancement techniques such as harmonic EUS and contrast-enhanced EUS can improve the accuracy of the diagnosis. However, several technical aspects need to be standardized before EUS-E can be truly used as a tool for "virtual biopsy". This review focuses on the various technical aspects of the use of EUS-E, it is established and expanding indications and an extensive outline of the various studies on EUS-E. We also discuss the current pitfalls and future trends in EUS-E.

Ultrasound Elastography in Ocular and Periocular Tissues: A Review

Ultrasound elastography has become available in everyday practice, allowing direct measurement of tissue elasticity with important and expanding clinical applications. Several studies that have evaluated pathological and non-pathological tissues have demonstrated that ultrasound elastography can actually improve the diagnostic accuracy of the underlying disease process by detecting differences in their elasticity. Ocular and periocular tissues can also be characterized by their elastic properties. In this context, a comprehensive review of literature on ultrasound elastography as well as its current applications in Ophthalmology is presented.

Ultrasound elastography in characterization of prostatic lesions: correlation with histopathological findings

OBJECTIVE

Ultrasound elastography is increasingly used in the diagnosis of prostate cancer, however results are heterogeneous. We correlate in a large sample-size prospective study the accuracy of elastography, aiming to settle an accurate cut-off point for diagnosis and possibility of use as a screening tool.

METHODS

Prospective study that included 120 patients with mean age 59.5 ± 9.8 years, showing enlarged prostate by clinical examination with prostate-specific antigen >4 ng ml-1.The study was done using high frequency high resolution endorectal probe with real time tissue elastography.Grayscale ultrasound examination was done first with Doppler followed by elastography color-coded map and strain ratio measurement. Then, transrectal ultrasound-guided core biopsy was done from suspicious areas detected by elastography (totally or partly stiff by color-coded map or with relative increased strain ratio), besides standard six-quadrant core biopsy samples.

RESULTS

There was statistically significant difference (p < 0.001) regarding strain ratio in benign and malignant lesions. Strain ratio showed significant proportionate correlation with prostate-specific antigen level and Gleason pathological score, while no significant correlation noted with the age or the prostatic volume. A strain ratio with a cut-off value of 1.9 showed a sensitivity of 100%, specificity 93.8%, positive predictive value of 79.3%, negative predictive value 100 and 95% accuracy in differentiating between malignant and benign lesions.

CONCLUSION

Strain ratio improves the detection of prostatic cancer with high sensitivity (100%) and high negative predictive value (100%).

ADVANCES IN KNOWLEDGE

Different prostatic lesions are mostly similar in grayscale ultrasound.Imaging plays an important role in differentiation of prostatic nodules.Ultrasound elastography may play an important role in distinguishing benign from malignant nodules.

Evaluation of Tubal Pregnancy After Treatment With Methotrexate by Ultrasound Elastography

OBJECTIVES

The purpose of this study was to evaluate the application of ultrasound elastography in the assessment of methotrexate (MTX) treatment for tubal pregnancy and the association with the elasticity score and human chorionic gonadotropin (hCG) concentration.

METHODS

A total of 73 cases of unruptured tubal pregnancy were diagnosed and treated systemically with MTX. The sonographic characters of conventional transvaginal sonography and elastography and serum hCG concentrations before and after MTX therapy were retrospectively reviewed and analyzed.

RESULTS

The mean elasticity score was statistically significantly lower for the ectopic tubal masses of the success group (mean ± SD, 2.58 ± 0.68) than for the failure group (3.33 ± 0.47) on day 7 (P < .001) and similar on day 0. The median elasticity score for the success group on day 7 was 3, and for the failure group, it was 4. When elasticity scores of 3 and 2 were used for the criterion of successful MTX treatment, the elastography had 94.5% sensitivity, 61.1% specificity, 88.1% positive predictive value, and 78.6% negative predictive value. Elastography of the ectopic masses and subsequent hCG concentration at 1 week after the MTX injection in the success group had a strong relationship.

CONCLUSIONS

Our results suggest that transvaginal elastography was a useful tool in the evaluation of tubal pregnancy after pharmacologic management.

New Imaging Techniques: Endoscopic Ultrasound-Guided Elastography

Endoscopic ultrasound (EUS) is a major imaging method in the management of several diseases of the gastrointestinal tract and surrounding structures. Elastography is a novel technique providing additional information to standard B-mode imaging on the tissue stiffness. Elastography can be performed under EUS guidance. This method has proven to be an accurate and additional tool in the evaluation of pancreatic diseases and lymph nodes analysis. Possible uses include the study of liver lesions, subepithelial masses, and many more. This article reviews current knowledge and future perspectives.

Transrectal real-time tissue elastography targeted biopsy coupled with peak strain index improves the detection of clinically important prostate cancer

The focus of the present study was to evaluate transrectal real-time tissue elastography (RTE)-targeted two-core biopsy coupled with peak strain index for the detection of prostate cancer (PCa) and to compare this method with 10-core systematic biopsy. A total of 141 patients were enrolled for evaluation. The diagnostic value of peak strain index was assessed using a receiver operating characteristic curve. The cancer detection rates of the two approaches and corresponding positive cores and Gleason score were compared. The cancer detection rate per core in the RTE-targeted biopsy (44%) was higher compared with that in systematic biopsy (30%). The peak strain index value of PCa was higher compared with that of the benign lesion. PCa was detected with the highest sensitivity (87.5%) and specificity (85.5%) using the threshold value of a peak strain index of ≥5.97 with an area under the curve value of 0.95. When the Gleason score was ≥7, RTE-targeted biopsy coupled with peak strain index detected 95.6% of PCa cases, but 84.4% were detected using systematic biopsy. Peak strain index as a quantitative parameter may improve the differentiation of PCa from benign lesions in the prostate peripheral zone. Transrectal RTE-targeted biopsy coupled with peak strain index may enhance the detection of clinically significant PCa, particularly when combined with systematic biopsy.

WFUMB Guidelines and Recommendations on the Clinical Use of Ultrasound Elastography: Part 5. Prostate

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has produced guidelines for the use of elastography techniques, including basic science, breast, liver and thyroid elastography. Here we present elastography in prostate diseases. For each available technique, procedure, reproducibility, results and limitations are analyzed and recommendations are given. Finally, recommendations are given based on the level of evidence of the published literature and on the WFUMB expert group's consensus. This document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of prostate diseases.

Transrectal Elastographic Biopsy and Contrast-Enhanced Transrectal Biopsy May Offer Improvements Over the Current Transrectal Systemic Biopsy Technique

Prostate cancer is a common cause of cancer-related death of men in the United States. The purpose of this review is to compare the validity of transrectal ultrasound–guided systemic biopsy with contrast-enhanced transrectal ultrasound–guided systemic biopsy and transrectal elastography–guided systemic biopsy for the detection of prostate cancer. Adding contrast-enhanced or transrectal elastography core targeting to transrectal ultrasound–guided biopsy is a feasible approach to increase detection rates of higher-grade prostate cancers. Because contrast-enhanced imaging of the prostate is not approved for use in the United States, elastography is the most effective sonographic solution to improve prostate cancer detection with current screening techniques.

Comparison of meta-analyses among elastosonography (ES) and positron emission tomography/computed tomography (PET/CT) imaging techniques in the application of prostate cancer diagnosis

The early diagnosis of prostate cancer (PCa) appears to be of vital significance for the provision of appropriate treatment programs. Even though several sophisticated imaging techniques such as positron emission tomography/computed tomography (PET/CT) and elastosonography (ES) have already been developed for PCa diagnosis, the diagnostic accuracy of these imaging techniques is still controversial to some extent. Therefore, a comprehensive meta-analysis in this study was performed to compare the accuracy of various diagnostic imaging methods for PCa, including 11C-choline PET/CT, 11C-acetate PET/CT, 18F-fluorocholine PET/CT, 18F-fluoroglucose PET/CT, transrectal real-time elastosonography (TRTE), and shear-wave elastosonography (SWE). The eligible studies were identified through systematical searching for the literature in electronic databases including PubMed, Cochrane, and Web of Science. On the basis of the fixed-effects model, the pooled sensitivity (SEN), specificity (SPE), and area under the receiver operating characteristics curve (AUC) were calculated to estimate the diagnostic accuracy of 11C-choline PET/CT, 11C-acetate PET/CT, 18F-fluorocholine (FCH) PET/CT, 18F-fluoroglucose (FDG) PET/CT, TRTE, and SWE. All the statistical analyses were conducted with R language Software. The present meta-analysis incorporating a total of 82 studies demonstrated that the pooled sensitivity of the six imaging techniques were sorted as follows: SWE > 18F-FCH PET/CT > 11C-choline PET/CT > TRTE > 11C-acetate PET/CT > 18F-FDG PET/CT; the pooled specificity were also compared: SWE > 18F-FCH PET/CT > 11C-choline PET/CT > TRTE > 18F-FDG PET/CT > 11C-acetate PET/CT; finally, the pooled diagnostic accuracy of the six imaging techniques based on AUC were ranked as below: SWE > 18F-FCH PET/CT > 11C-choline PET/CT > TRTE > 11C-acetate PET/CT > 18F-FDG PET/CT. SWE and 18F-FCH PET/CT imaging could offer more assistance in the early diagnosis of PCa than any other studied imaging techniques. However, the diagnostic ranking of the six imaging techniques might not be applicable to the clinical phase due to the shortage of stratified analysis.

Diagnostic Value of Different Systematic Prostate Biopsy Methods in the Detection of Prostate Cancer with Ultrasonographic Hypoechoic Lesions--A Comparative Study

OBJECTIVE

To assess if a less extended biopsy in the transperineal approach is sufficient for detection of prostate cancer (PC) in patients with hypoechoic lesions.

METHODS

This was a prospective study of 167 consecutive patients with prostate hypoechoic lesion and who underwent transperineal ultrasound (TPUS)-guided 12-core and hypoechoic lesion core biopsy between January 2012 and February 2013.

RESULTS

PC was detected in 64.1% (107/167) of patients. The PC detection rate of the 12-core prostate biopsy scheme was the highest, but when including the hypoechoic lesion core, there was no difference between the 6- and 12-core schemes (all p > 0.05), irrespective of prostate volume or prostate-specific antigen levels (all p > 0.05).

CONCLUSIONS

A more limited biopsy scheme could be sufficient for the detection of PC if the hypoechoic lesion is sampled.

New endoscopic ultrasound techniques for digestive tract diseases: A comprehensive review

Endoscopic ultrasound (EUS) is one of the most important modalities for the diagnosis of digestive tract diseases. EUS has been evolving ever since it was introduced. New techniques such as elastography and contrast enhancement have emerged, increasing the accuracy, sensitivity and specificity of EUS for the diagnosis of digestive tract diseases including pancreatic masses and lymphadenopathy. EUS-elastography evaluates tissue elasticity and therefore, can be used to differentiate various lesions. Contrast-enhanced EUS can distinguish benign from malignant pancreatic lesions and lymphadenopathy using the intravenous injection of contrast agents. This review discusses the principles and types of these new techniques, as well as their clinical applications and limitations.

Elastography in clinical practice

Elastography is a new technique that evaluates tissue stiffness. There are two elastography methods, strain and shear wave elastography. Both techniques are being used to evaluate a wide range of applications in medical imaging. Elastography of breast masses and prostates have been shown to have high accuracy for characterizing masses and can significantly decrease the need for biopsies. Shear wave elastography has been shown to be able to detect and grade liver fibrosis and may decrease the need for liver biopsy. Evaluation of other organs is still preliminary. This article reviews the principles of elastography and its potential clinical applications.

Skin imaging in systemic sclerosis

Fibrotic involvement of the skin is a cardinal feature of systemic sclerosis (SSc). The extent of skin involvement is associated with internal organ involvement, coinciding with more severe disease course and poor prognosis. A palpation-based semi-quantitative score, the modified Rodnan skin score, is widely used for the assessment of skin involvement, but it is entailed by significant limitations. More objective approaches to measure skin involvement employing imaging have been explored continuously in the past decades and are currently advancing. Here, we review the use of different imaging techniques for the assessment of skin involvement in patients with SSc, focusing mainly on ultrasound, magnetic resonance imaging, and optical coherence tomography.

Real-time elastography in the diagnosis of patients suspected of having prostate cancer: a meta-analysis

The goal of the study described here was to assess the performance of real-time elastography (RTE) in the detection of prostate cancers using a meta-analysis. A literature search of PubMed, Medline, Embase and the Cochrane Library was conducted. Published studies that evaluated the diagnostic performance of RTE in the diagnosis of prostate cancer and using the histopathology of the radical prostatectomy specimen as a reference standard were included. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and area under the curve were calculated to examine the accuracy of RTE. A total of seven studies that included 508 patients were analyzed. The pooled sensitivity and specificity for the diagnosis of prostate cancer by RTE were 0.72 (95% confidence interval: 0.70-0.74) and 0.76 (0.74-0.78), respectively. The summary diagnostic odds ratio was 12.59 (7.26-21.84), and the area under the curve was 0.841 (Q* = 0.773). In conclusion, RTE imaging has high accuracy in the detection of prostate cancers using the histopathology of the radical prostatectomy specimen as the reference standard and may reduce the number of core biopsies in the future.

Doppler spectral waveform parameters at neurovascular bundle vessels in patients with prostate biopsy

INTRODUCTION AND OBJECTIVES

There is a need to improve prescreening determination of prostate cancer to better select patients who need biopsy. Such a strategy properly implemented, will decrease the number of negative biopsies for prostate cancer and in turn better balance the risks and morbidity for patients recommended for biopsy. The aim of study is to investigate Doppler spectral waveform parameters of neurovascular bundle (NVB) vessels and determine differences between benign and malignant pathologies.

PATIENTS AND METHODS

We performed a prospective analysis involving 292 patients who received prostate biopsy for elevated prostate-specific antigen (PSA) values or abnormal digital rectal examination, as well as 174 patients with symptomatic benign prostatic hyperplasia. Doppler spectral waveform (DSW) parameters (peak-systolic velocity [PSV], end-diastolic velocity [EDV], and resistive index [RI]) were measured at bilateral NVB vessels through Doppler transrectal ultrasound at the right lateral decubitus position, compared, and analyzed among patients with benign versus malignant histology for each side.

RESULTS

Overall, both PSV and EDV at malignant sides were significantly higher than those at benign sides, as well as lower RI (all p-values <0.05, unpaired t-test). In subgroup analysis with 93 patients of serum PSA between 10 and 20 ng/mL and 56 patients with one-side malignancy, higher EDV and lower RI were significantly associated with malignancies (all p<0.05). The values of PSV and EDV rather than RI might be influenced by the patients' position and RI by the prostate volume.

CONCLUSIONS

In this study, DSW parameters (mainly EDV and RI) at NVB vessels were significantly associated with prostate cancer, particularly in patients with serum PSA of 10-20 ng/mL. It should be in caution that the patients' position and prostate volume may influence the Doppler signal as demonstrated in the current study. These findings can provide more diagnostic information before prostate biopsy.

Quantitative assessment of bladder neck compliance by using transvaginal real-time elastography of women

To assess the feasibility of using ultrasound real-time elastography (RTE) to measure bladder neck compliance, we performed real-time elastography measurements by manually applying repetitive compression with the transducer on the scan position of the bladder neck. Instant elastography index (EI) and mean EI of anterior and posterior lips of the bladder neck were calculated. The EI values of anterior and posterior lips of the bladder neck were analyzed in relation to age, body surface area, body mass index, detrusor wall thickness and length, width and thickness of the bladder neck in healthy women. The intra-observer and inter-observer repeatability of measurements in different parts of the bladder neck were assessed using intra-class correlation coefficients with 95% confidence intervals and Bland-Altman analysis. There were no statistically significant differences between elastography measurements made by the same or two different observers in each area measured. There was no significant difference between anterior and posterior lip thickness of the bladder neck. The distribution of the elastography measurements indicated that the anterior lip of the bladder neck was slightly harder than the posterior lip. On the whole, from the results of the study, it was clear that EIs of the bladder neck were related to age in healthy women. Stepwise multiple regression analysis results revealed that age was the only independent factor modulating compliance of the bladder neck in healthy women. It is possible to provide a reproducible semi-quantification of real-time elastography in bladder neck compliance.

Transrectal prostate biopsy

Grayscale transrectal ultrasonographic prostate biopsy using local anesthesia remains the standard approach to the definitive diagnosis of prostate cancer. Careful patient evaluation and preparation are essential to maximize the results and minimize the complications of the biopsy procedure.

Potential role of strain elastography for detection of the extent of large-scar endometriosis

OBJECTIVES

The purpose of this study was to evaluate the clinical value of strain elastography for detection of the lesion extent of large-scar endometriosis and compare it to conventional sonography and magnetic resonance imaging (MRI).

METHODS

Eight patients suspected of having large-scar endometriosis underwent transabdominal sonography, strain elastography, and MRI. The mass was located and assessed for its size, imaging appearance, and, especially, widest boundary and vertical extent. After wide surgical excision and pathologic diagnosis, lesions in the central area shown on conventional sonography and the extended area shown on strain elastography underwent immunohistochemical examination.

RESULTS

Nodules were always deep in the subcutaneous plane, in contact with the fascia or muscle. Horizontally, the mean lesion size shown on conventional sonography was mainly consistent with the size on MRI in all cases, but it was obviously smaller on sonography than on strain elastography in 7 cases. Vertically, the lesion depth was mainly consistent with the depth on MRI in 7 cases, but it was more infiltrative on strain elastography in 6 cases. The vertical and horizontal infiltration scales of the postoperative specimens were consistent with strain elastography in all cases. All 8 patients showed strong collagen type I expression in the central area of the lesions; 6 patients showed strong collagen type I expression and the other 2 showed moderate expression in the extended area.

CONCLUSIONS

Strain elastography can elevate the diagnostic accuracy of large-scar endometriosis, the extent of which may be evaluated insufficiently by transabdominal sonography and MRI.

Update on ultrasound elastography: miscellanea. Prostate, testicle, musculo-skeletal

Nowadays ultrasound elastosonography is an established technique, although with limited clinical application, used to assess tissue stiffness, which is a parameter that in most cases is associated with malignancy. However, although a consistent number of articles have been published about several applications of elastosonography, its use in certain human body districts is still not well defined. In this paper we write on the use of elastosonography in prostate, testicle and musculo-skeletal apparatus. We report and compare the work of several authors, different type of elastosonography (shear wave, strain elastography, etc.) and instrumental data obtained in the study of both benign and malignant lesions.

Image-guided robotic interventions for prostate cancer

Robotic prostatectomy is a common surgical treatment for men with prostate cancer, with some studies estimating that 80% of prostatectomies now performed in the USA are done so robotically. Despite the technical advantages offered by robotic systems, functional and oncological outcomes of prostatectomy can still be improved further. Alternative minimally invasive treatments that have also adopted robotic platforms include brachytherapy and high-intensity focused ultrasonography (HIFU). These techniques require real-time image guidance--such as ultrasonography or MRI--to be truly effective; issues with software compatibility as well as image registration and tracking currently limit such technologies. However, image-guided robotics is a fast-growing area of research that combines the improved ergonomics of robotic systems with the improved visualization of modern imaging modalities. Although the benefits of a real-time image-guided robotic system to improve the precision of surgical interventions are being realized, the clinical usefulness of many of these systems remains to be seen.

Ultrasound elastography of the prostate: state of the art

Prostate cancer is the cancer exhibiting the highest incidence rate and it appears as the second cause of cancer death in men, after lung cancer. Prostate cancer is difficult to detect, and the treatment efficacy remains limited despite the increase use of biological tests (prostate-specific antigen [PSA] dosage), the development of new imaging modalities, and the use of invasive procedures such as biopsy. Ultrasound elastography is a novel imaging technique capable of mapping tissue stiffness of the prostate. It is known that prostatic cancer tissue is often harder than healthy tissue (information used by digital rectal examination [DRE]). Two elastography techniques have been developed based on different principles: first, quasi-static (or strain) technique, and second, shear wave technique. The tissue stiffness information provided by US elastography should improve the detection of prostate cancer and provide guidance for biopsy. Prostate elastography provides high sensitivity for detecting prostate cancer and shows high negative predictive values, ensuring that few cancers will be missed. US elastography should become an additional method of imaging the prostate, complementing the conventional transrectal ultrasound and MRI. This technique requires significant training (especially for quasi-static elastography) to become familiar with acquisition process, acquisition technique, characteristics and limitations, and to achieve correct diagnoses.

Application of real-time ultrasound elastography for discrimination of low- and high-grade serous ovarian carcinoma

OBJECTIVES

The purpose of this study was to evaluate real-time qualitative ultrasound elastography as an adjunct to conventional sonography for discrimination of low- and high-grade serous ovarian carcinoma.

METHODS

Eighty-six patients suspected of having serous ovarian cancer on the basis of clinical and biochemical evaluations underwent transvaginal and transabdominal sonography and then elastography and later underwent surgery.

RESULTS

Histopathologic analysis revealed 64 serous ovarian carcinomas (74.4%): 39 (60.9%) high grade and 25 (39.1%) low grade. The mean elasticity score ± SD was statistically significantly higher for low-grade lesions (3.40 ± 0.76) than high-grade lesions (2.08 ± 0.58; P < .001). There was a trend for high-grade lesions to be less stiff than low-grade lesions due to rapidly developing necrosis; conversely, low-grade lesions developed relatively slowly so that their solid areas were stiffer and less elastic. The median elasticity score for low-grade lesions (based on a 4-point scale used to grade cervical lymph nodes) was 4 (stiffest), and the score for high-grade lesions was 2. When the score of 4 was used for diagnosis of low-grade carcinoma, elastography had 56.0% sensitivity, 100% specificity, a 100% positive predictive value, a 78.0% negative predictive value, and 82.8% accuracy. When the score of 2 was used for the diagnosis of high-grade carcinoma, elastography had 66.7% sensitivity, 84.0% specificity, an 86.7% positive predictive value, a 61.8% negative predictive value, and 73.4% accuracy.

CONCLUSIONS

Our results suggest that ultrasound elastography could be helpful for discrimination of low- and high-grade serous ovarian carcinoma. Low-grade lesions are stiffer and not as elastic as high-grade lesions.

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 ng/mL

The actual gold standard for the diagnosis of prostate cancer includes the serum prostate-specific antigen, the digital rectal examination, and the ultrasound-guided systematic prostate biopsy sampling. In the last years, the real-time elastography has been introduced as an imaging technique to increase the detection rate of prostate cancer and simultaneously reduce the number of biopsies sampled for a single patient. Here, we evaluated a consecutive series of 102 patients with negative digital-rectal examination and transrectal ultrasound, and prostate-specific antigen value ranging between 2.5 ng/mL and 10 ng/mL, in order to assess the impact of real-time elastography versus the systematic biopsy on the detection of prostate cancer. We found that only 1 out of 102 patients resulted true positive for prostate cancer when analysed with real-time elastography. In the other 6 cases, real-time elastography evidenced areas positive for prostate cancer, although additional neoplastic foci were found using systematic biopsy sampling in areas evidenced by real-time elastography as negative. Although additional studies are necessary for evaluating the effectiveness of this imaging technique, the present study indicates that the limited accuracy, sensitivity, and specificity do not justify the routine application of real-time elastography in prostate cancer detection.

Current status of transrectal ultrasound techniques in prostate cancer

PURPOSE OF REVIEW

Present the current status of transrectal ultrasound imaging in prostate cancer (PCa) and discuss the latest techniques now under preclinical evaluation.

RECENT FINDINGS

Three-dimensional ultrasound and quantification techniques are superior to two-dimensional ultrasound in visualizing PCa and can be beneficial in staging prior to operation. Doppler-guided biopsies are more likely to yield positive results, especially when high Gleason scores are present. Furthermore, Vardenafil usage strengthens Doppler enhancement and can help in increasing the diagnostic accuracy of Doppler. Multiple studies show elastography to be a promising new addition to the ultrasound investigations for detection of PCa. Especially the recently introduced Shear Wave Elastography shows decreased user dependency and increased PCa detection rates. MRI can also aid in the diagnostics of PCa. However, MRI-guided biopsies are more complicated compared to ultrasound guidance. MRI/ultrasound fusion combines best of both techniques and, although just recently emerged, the studies available show promising PCa detection rates.

SUMMARY

Technical improvements in classical ultrasound modalities (2D/3D-greyscale, Doppler) and new modalities (elastography/MRI/ultrasound fusion) raised the accuracy of PCa detection. Especially latest elastography and MRI/ultrasound fusion are showing promising results in PCa visualization.

Imaging-guided prostate biopsy: conventional and emerging techniques

Transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations owing to the operator's inability in most cases to directly visualize and target prostate lesions. Magnetic resonance (MR) imaging of the prostate overcomes many of these limitations by directly depicting areas of abnormality and allowing targeted biopsies. Accuracy in the detection of prostate cancer is improved by the combined use of standard T2-weighted MR imaging and advanced MR imaging techniques such as diffusion-weighted imaging, dynamic contrast-enhanced imaging, and MR spectroscopy. Suspicious-appearing regions of the prostate seen on MR images can be targeted at real-time transrectal US-guided biopsy to improve the diagnostic yield. MR imaging also can be performed for real-time guidance of transrectal prostate biopsy. Studies among patients who underwent at least one transrectal US-guided biopsy with a negative result before undergoing an MR imaging-guided biopsy showed improved detection rates with MR imaging-guided biopsy in comparison with the detection rates achieved with a repeat transrectal US-guided biopsy; however, MR imaging-guided biopsy is a more time-consuming procedure. A technique known as fused MR imaging- and transrectal US-guided biopsy, which relies on the coregistration of previously acquired MR images with real-time transrectal US images acquired during the procedure, shows promise but is limited by deformation of the prostate; this limitation is the subject of ongoing investigation. Another technique that is currently under investigation, MR imaging-guided prostate biopsy with robotic assistance, may one day help improve the accuracy of biopsy needle placement.

Transrectal sonoelastography in the detection of prostate cancers: a meta-analysis

What's known on the subject? and What does the study add? The accuracy of transrectal sonoelastography (TRSE) in the detection of prostate cancer is variable, with a sensitivity ranging from 51.1 to 91.7% and specificity ranging from 62.2 to 86.8%. This is the first meta-analysis to assess the overall accuracy of TRSE in the detection of prostate cancer.

OBJECTIVE

• To assess the overall accuracy of transrectal sonoelastography (TRSE) targeted biopsy in the diagnosis of patients suspected of having prostate cancer (PCa).

METHODS

• A systematic search of electronic databases, including PubMed, Embase and The Cochrane Library, and manual bibliography searches were performed. • All relevant studies assessing the diagnostic accuracy of TRSE in PCa detection were included in our meta-analysis. • The data were pooled and sensitivity, specificity, area under the curve (AUC), positive likelihood ratio (LR) and negative LR were calculated.

RESULTS

• Pooled patient data analysis: the pooled (95% confidential intervals [95% CI]) sensitivity of TRSE targeted biopsy in patients suspected of having PCa was 62 (55-68) %; specificity was 79% (74-84%); AUC was 0.7696; positive LR was 2.92 (2.28-3.74); and negative LR was 0.49 (0.41-0.59). • Pooled core data analysis: pooled (95% CI) sensitivity, specificity, positive LR and negative LR were 34% (30-38%), 93% (91-95%), 5.07 (3.91-6.57) and 0.71 (0.66-0.75), respectively.

CONCLUSION

• Transrectal sonoelastography is a promising technique in PCa detection and can be considered to be a valuable supplemental method to systemic biopsy.

Quantification of cervical elastography: a reproducibility study

OBJECTIVES

To assess a new method for numerical quantification of cervical elastography during pregnancy and to evaluate the repeatability of the measurements.

METHODS

Cervical elastography was carried out twice by a single operator in 112 singleton pregnancies at a median of 21 (range, 12-40) weeks' gestation. In 50 of the cases a second operator performed another elastography measurement. The intraobserver and interobserver repeatability of measurements in different parts of the cervix were assessed using intraclass correlation coefficients with 95% CI and by Bland-Altman analysis.

RESULTS

There were no statistically significant differences in the elastography measurements made by the same and by two different observers in each area measured, except in the area that receives the force of the transducer directly. The distribution of elastographic measurements obtained in different regions of the cervix demonstrated that the external and superior parts were significantly softer than the internal and inferior parts.

CONCLUSION

It is possible to provide an objective quantification of elastographic colors in the cervix. The measurements obtained by elastography may be a mere reflection of the force being applied by the transducer to different parts of the cervix. It is too premature to suggest that the measurements of rate-of-change in tissue displacement reflect histological changes that could provide a measure of cervical ripening.

Endoscopic ultrasound elastography

Endoscopic ultrasound (EUS) is a reference technique for diagnosing and staging several different diseases. EUS-guided biopsies and fine needle aspirations are used to improve diagnostic performance of cases where a definitive diagnosis cannot be obtained through conventional EUS. However, EUS-guided tissue sampling requires experience and is associated with a low but not negligible risk of complications. EUS elastography is a non-invasive method that can be used in combination with conventional EUS and has the potential for improving the diagnostic accuracy and reducing the need for EUS-guided tissue sampling in several situations. Elastography measures tissue stiffness by evaluating changes in the EUS image before and after the application of slight pressure to the target tissue by the ultrasonography probe. Pathologic processes such as cancerization and fibrosis alter tissue elasticity and therefore induce changes in elastographic appearance. Qualitative elastography depicts tissue stiffness using different colors, whereas quantitative elastography renders numerical results expressed as a strain ratio or hue histogram mean. EUS elastography has been proven to differentiate between benign and malignant solid pancreatic masses, as well as between benign and malignant lymph nodes with a high accuracy. Studies have also demonstrated that the early changes of chronic pancreatitis can be distinguished from normal pancreatic tissues under EUS elastography. In this article, we review the technical aspects and current clinical applications of qualitative and quantitative EUS elastography and emphasize the potential additional indications that need to be evaluated in future clinical studies.