This paper reviews ultrasound segmentation methods, in a broad sense, focusing on techniques developed for medical B-mode ultrasound images. First, we present a review of articles by clinical application to highlight the approaches that have been investigated and degree of validation that has been done in different clinical domains. Then, we present a classification of methodology in terms of use of prior information. We conclude by selecting ten papers which have presented original ideas that have demonstrated particular clinical usefulness or potential specific to the ultrasound segmentation problem

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Ultrasound image segmentation: a survey

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/j.molonc.2008.04.001

Imaging and cancer: A review

Elastography is a method that can ultimately generate several new kinds of images, called elastograms. As such, all the properties of elastograms are different from the familiar properties of sonograms. While sonograms convey information related to the local acoustic backscatter energy from tissue components, elastograms relate to its local strains, Young's moduli or Poisson's ratios. In general, these elasticity parameters are not directly correlated with sonographic parameters, i.e. elastography conveys new information about internal tissue structure and behavior under load that is not otherwise obtainable. In this paper we summarize our work in the field of elastography over the past decade. We present some relevant background material from the field of biomechanics. We then discuss the basic principles and limitations that are involved in the production of elastograms of biological tissues. Results from biological tissues in vitro and in vivo are shown to demonstrate this point. We conclude with some observations regarding the potential of elastography for medical diagnosis.

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Elastography: Imaging the elastic properties of soft tissues with ultrasound

OBJECTIVE. Recently, transient elastography (FibroScan) has been introduced for noninvasive staging of liver fibrosis. Here, we investigated a novel approach for noninvasive assessment of liver fibrosis using sonography-based real-time elastography, which can be performed with conventional ultrasound probes during a routine sonography examination.MATERIALS AND METHODS. Real-time elastography was performed in 79 patients with chronic viral hepatitis and known fibrosis stage and in 20 healthy volunteers. A specially developed program was used for quantification of tissue elasticity. Stepwise logistic regression analysis was performed to define an elasticity score using variables with high reproducibility in a preceding analysis of data from 16 different patients. In addition, aspartate transaminase-to-platelet ratio index (APRI) and routine laboratory values were included in the analysis.RESULTS. The Spearman's correlation coefficient between the elasticity scores obtained using real-time elastography and t...

https://www.ajronline.org/doi/pdf/10.2214/AJR.06.0322

Real-time elastography for noninvasive assessment of liver fibrosis in chronic viral hepatitis.

Background: Normal metabolism generates several volatile organic compounds (VOCs) that are excreted in the breath (e.g. alkanes). In patients with lung cancer, induction of high-risk cytochrome p450 genotypes may accelerate catabolism of these VOCs, so that their altered abundance in breath may provide biomarkers of lung cancer. Methods: VOCs in 1.0 L alveolar breath were analyzed in 193 subjects with primary lung cancer and 211 controls with a negative chest CT. Subjects were randomly assigned to a training set or to a prediction set in a 2:1 split. A fuzzy logic model of breath biomarkers of lung cancer was constructed in the training set and then tested in subjects in the prediction set by generating their typicality scores for lung cancer. Results: Mean typicality scores employing a 16 VOC model were significantly higher in lung cancer patients than in the control group ( p< 0.0001 in all TNM stages). The model predicted primary lung cancer with 84.6% sensitivity, 80.0% specificity, and 0.88 area under curve (AUC) of the receiver operating characteristic (ROC) curve. Predictive accuracy was similar in TNM stages 1 through 4, and was not affected by current or former tobacco smoking. The predictive model achieved near-maximal performance with six breath VOCs, and was progressively degraded by random classifiers. Predictions with fuzzy logic were consistently superior to multilinear analysis. If applied to a population with 2% prevalence of lung cancer, a screening breath test would have a negative predictive value of 0.985 and a positive predictive value of 0.163 (true positive rate = 0.277, false positive rate = 0.029).

Prediction of lung cancer using volatile biomarkers in breath.

A new system for prostate diagnostics based on multifeature tissue characterization is proposed. Radiofrequency (RF) ultrasonic echo data are acquired during the standard transrectal ultrasound (US) imaging examination. Nine spectral, texture, first order and morphologic parameters are calculated and fed into two adaptive neuro-fuzzy inference systems (FIS) working in parallel. The outputs of the FISs are fed into a postprocessing procedure evaluating contextual information before being combined to form a malignancy map in which areas of high cancer probability are marked in red. The malignancy map is presented to the physician during the examination to improve the early detection of prostate cancer. The system has been evaluated on 100 patients undergoing radical prostatectomy. The ROC curve area using leave-one-out cross-validation over patients is A(Z) = 0.86 when distinguishing between hyperechoic and hypoechoic tumors and normal tissue and A(Z) = 0.84 when distinguishing between isoechoic tumors and healthy tissue, respectively. Tumors that are not visible in the conventional B-mode image can be located. Diagnosis of the prostate carcinoma using multifeature tissue characterization in combination with US imaging allows the detection of tumors at an early stage. Also, biopsy guidance and therapy planning can be improved.

Ultrasonic multifeature tissue characterization for prostate diagnostics.

We describe a novel recording system for the acquisition of multicompression strain images of the human prostate in vivo. The force at the tip of an ultrasonic transrectal probe is measured continuously, and ultrasonic RF-images are acquired consecutively at specified levels of compression. The acquired image sequence is processed by conventional cross-correlation techniques to obtain time shift estimates and corresponding strain images. We present phantom measurements as well as in vivo results and discuss the advantages and restrictions of the proposed system.

A new system for the acquisition of ultrasonic multicompression strain images of the human prostate in vivo

Aim Prostate tumours are often of harder consistency than the surrounding tissue. During digital rectal examination, this fact can be used not only to detect hypertrophy but also localized hardenings. The examination by digital palpation is inaccurate and, even in combination with PSA-value and a transrectal ultrasonic examination, the result is often not reliable. Ultrasound elastography enables us to measure and visualize the elastic properties of a tissue region and is a useful supplement to the examination by digital palpation. Ultrasound elastography is able to measure and visualize the elastic properties of a tissue region, therefore it is a useful supplement to commonly used diagnostic procedures. Method We have developed a new system for elastographic prostate diagnosis which can be used during the transrectal ultrasonic examination. During the examination a sequence of ultrasonic images is acquired while the organ is slightly compressed by the ultrasound probe. Using numerical analysis of image pairs for the acquired sequence we calculate the tissue strain which represents the spatial elasticity distribution of a specific cross-section of the organ. This enables us to distinguish hard areas in the tissue. Image artifacts resulting from lateral motion components, i.e., orthogonal to the direction of the applied force, are compensated for by a special approach. Results We present results obtained from a typical elastography phantom and also the first in vivo images from patients who were undergoing radical prostatectomy. Our images prove that ultrasound elastography has the potential to detect malignant tissue areas, which are inconspicuous in the B-mode image. Our findings are confirmed by the corresponding histological specimens.

/pdf/ultrasound-elastography-of-the-prostate-a-new-technique-for-12eag7ncmn.pdf

Ultrasound elastography of the prostate. A new technique for tumor detection

The incidence of the prostate carcinoma is one of the highest cancer risks in men in the western world. Its position in cancer mortality statistics is also among the highest. The prostate carcinoma is only curable at an early stage. Therefore, early detection is extremely important. At an early stage the prostate carcinoma is limited to the prostate capsule and can hence be cured performing radical prostatectomy. The different types of diagnostics that are used today (digital rectal examination, transrectal ultrasound and PSA value analysis) lack reliability and are therefore not sufficient. Even a combination of these three methods is not sufficiently reliable. Diagnosis of the prostate carcinoma using multi-feature tissue characterization in combination with ultrasound allows the detection of tumors at an early stage. Also biopsy guidance and planning can be improved. This results in reduced costs for cancer treatment.

Ultrasonic multifeature tissue characterization for the early detection of prostate cancer

Fruherkennungsmasnahmen haben im letzten Jahrzehnt zu einer verbesserten Prostatakarzinomdetektion gefuhrt. Dies ist einerseits auf ein gestiegenes Krankheitsbewusstsein und andererseits auf eine verbesserte Diagnostik zuruckzufuhren. Das prostataspezifische Antigen (PSA) ist gegenwartig der wichtigste diagnostische Parameter. Der transrektale Ultraschall konnte im Gegensatz dazu die in ihn gesetzten Erwartungen nicht erfullen. Zielsetzung der vorliegenden Arbeit war es, ein System zu entwickeln und klinisch zu erproben, das es erlaubt, die Ultraschallelastographie hinsichtlich ihrer Einsatzmoglichkeiten in der Prostatakarzinomdiagnostik zu beurteilen. Eine rechnergestutze Aufarbeitung von hochfrequenten Ultraschallsignalen, die an einem handelsublichen Ultraschallgerat mit technischen Modifikationen abgegriffen wurden, erlaubte uns eine erste klinische Evaluation. Die durchgefuhrten Untersuchungen an Patienten konnten zeigen, dass die Elastographie die Lokalisation und Ausdehnung eines Prostatakarzinoms genauer erfasst als es mit dem konventionellen Ultraschall moglich ist. Das gewahlte Abbildungsverfahren nutzt eine unterschiedliche Gewebeelastizitat zwischen Tumor und normalem Gewebe und erkennt auch Tumoren, die im B-Bild iso- oder hyperechoisch zur Darstellung kommen.

H.-J. Sommerfeld

Papers

Ultrasonic multifeature tissue characterization for prostate diagnostics.

A new system for the acquisition of ultrasonic multicompression strain images of the human prostate in vivo

Ultrasound elastography of the prostate. A new technique for tumor detection

Ultrasonic multifeature tissue characterization for the early detection of prostate cancer

Prostatakarzinomdiagnostik durch Ultraschallelastographie