Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5791_Библиотеки_им_академика_М_И_Перельмана.pdf
1114.7 Ultrasound Elastography
Fig. 4.19 (continued)
112
4 Ultrasound Diagnosis of Breast Cancer
automatic regimen after pressing of a certain key
of the scanner as a rule does not exceed 2–5 s.
After the calculation of the average shear-wave
velocity within the tumor (three to fi ve measurements), the same is carried out in two to three
areas of normal breast parenchyma on the distance
19%
equal
Fig 4.20 Relation of sonoelastographic and grayscale
dimensions of malignant breast lesions
3%
78%
larger smaller
of more than 1–1.5 cm from its border. The comparison of results and analysis usually does not
take more than 1–5 min. The general time of
breast US with the use of complex US options,
including ARFI, does not exceed 10–20 min. The
harder is the tissue (that is more characteristic for
malignant tumors), the higher is the shear-wave
velocity (Piscaglia et al. 2011 ) .
In scanners without shear-wave elastography, the more objective assessment of elasticity
is performed with strain ratio, which is calculated as a ratio of strain index of the lesion to
the same of normal tissue. According to Zubarev
( 2009 ) , intraductal breast carcinoma in situ is
characterized with the strain ratio of 5.2;
in fi ltrative lobular cancer, 16.58; fi broadenoma,
1.02 ± 0.21; and benign intraductal papilloma,
1.37. He reported that the sensitivity of this
method in the diagnosis of breast lesions is
78.9 %, speci fi city is 95.2 %, and diagnostic
accuracy is 90.1 %.
Fig. 4.21 US elastography. Absence of the difference between color patterns of the lesion and surrounding breast
structures
1134.7 Ultrasound Elastography
Fig. 4.21 (continued)
114
4 Ultrasound Diagnosis of Breast Cancer
Fig. 4.21 (continued)
Fig. 4.22 Breast carcinoma.
Sonogram. ARFI technology
Fig. 4.22 (continued)
1154.7 Ultrasound Elastography
116
Fig. 4.22 (continued)
4 Ultrasound Diagnosis of Breast Cancer
Rozhkova et al. ( 2011 ) reported that strain ratio
in 83.2 % of breast carcinomas was higher than
4.3 (22.9 ± 2.14 on the average) and ranges from
4.3 to 102.1 depending histological structure of
the lesion. Strain ratio was lower in noninvasive
tumors (11.33 ± 4.51) than in in fi ltrative types of
cancer (25.51 ± 2.58). Benign breast lesions in
94 % demonstrated strain ratio below 4.3.
According to Rozhkova et al. ( 2011 ) , sonoelastography has a number of limitations.
First of all, it permits assessment of the breast
changes, which can be imaged with routine
US. US in combination with sonoelastography cannot be used as a screening method.
Second, elastography is of low value in cases
of diffuse changes and signi fi cant increase in
its density involving the whole breast (e.g.,
in fi ltrative type of breast carcinoma without any dominant lesion, diffuse mastitis,
and early postradiation changes). Third, it is
thought that the quality of elastogram depends
on the size of a lesion. Elastography is of better value in lesions smaller than 2 cm. Severe
heterogeneity of the lesion, presence of fl uid
collections, large calci fi cations, and small
(subcentimetric) and large lesions are also
associated with certain dif fi culties in correct
measurements of shear-wave velocities with
ARFI (Sencha et al. 2011 ) .
Quantitative US elastography exhibits good
reproducibility and does not implicate signi fi cant
additional time expenses (Evans et al. 2010 and
Mitkov et al. 2011 ) . However, Park et al. ( 2009 )
report very high interobserver variability of free
hand compression sonoelastography. To achieve
better reproducibility compression sonoelastography, the manufacturers of US scanners introduced quality factors, which re fl ect the quality of
received image in real time and the possibility of
its interpretation. The higher the quality factor,
the more reliable data is obtained for assessment.
Some data, which lie below 60 %, cannot be
interpreted at all owing to major artifacts. Such
approach allows not only to introduce the quality
standards for interpreting of elastograms but also
to develop the skills of effective work with sonoelastography in US specialists.
Incorporation of sonoelastography in the diagnostic complex increases the speci fi city of traditional US in diagnosis of breast carcinoma from
76 % to 94.5 % and the sensitivity in impalpable
tumors in particular from 66.7 % to 87.5 %
(Rozhkova et al. 2011 ) .
Perspective directions of the development of
elastographic equipment are three-dimensional
and real-time triplex elastography. Uni fi cation of
ways of shear-wave velocity and elastic modulus
representation requires attention.
1174.8 Other Ultrasound Technologies
4.8 Other Ultrasound Technologies
Panoramic scan enables to reconstruct extended
images that include several adjacent fi elds of
view and are larger than a conventional scan. This
facilitates precise measurements of long objects
(Fig.
4.23 ). The way of presentation of obtained
data in panoramic scan often helps to characterize pathological foci in cases of multicenter
growth, assess invasion, and plan the surgery.
Multislice view (US tomography) is a soft-
ware algorithm, which transforms 3D US image
in a series of consecutive sections of 0.5–5 mm
in any plane similar to CT. It permits more
objective and reliable way of the analysis of the
breast image associated with better accuracy
(Fig. 4.24 ).
Constant improvement of traditional methods
and creation of new technologies is a continuous
process, which results in perfection of diagnostics and healthcare in general.
Introduction in clinical practice of “hybrid”
technologies assuming joint or simultaneous use
of various hi-tech diagnostic procedures and
technologies of US and other imaging methods is
very promising.
Fig. 4.23 Breast carcinoma.
Sonogram. Panoramic scan
118
Fig. 4.23 (continued)
4 Ultrasound Diagnosis of Breast Cancer
1194.8 Other Ultrasound Technologies
Fig. 4.24 Breast carcinoma. Sonogram. Multislice view
120
4 Ultrasound Diagnosis of Breast Cancer
Fig. 4.24 (continued)