|Year : 2019 | Volume
| Issue : 3 | Page : 183-188
Sonoelastographic Evaluation of Uterine Fibroids – Our Initial Experience
Suresh Phatak, Gulam Marfani
Department of Radiodiagnosis, AVBRH Hospital, Jawaharlal Nehru Medical College, Wardha, Maharashtra, India
|Date of Submission||25-Apr-2019|
|Date of Decision||20-Jun-2019|
|Date of Acceptance||10-Jul-2019|
|Date of Web Publication||2-May-2020|
Dr. Gulam Marfani
Department of Radiodiagnosis, AVBRH Hospital, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha - 442 001, Maharashtra
Source of Support: None, Conflict of Interest: None
Context: Real-time elastography is a novel and dynamic imaging technique that is based on the softness or hardness of tissues or organs of interest under the appropriate compression and can be used with conventional ultrasonography(US) probes after performing grayscale imaging and Doppler US. Aims: It was to find out the diagnostic ability of sonoelastography in evaluation of uterine fibroids and whether evaluation with computed tomography (CT) or magnetic resonance imaging (MRI) can be avoided. Subjects and Methods: A prospective study was conducted from August 2017 to August 2018. A total of 87 females were included and underwent sonographic examination and a diagnosis was made, and later, elastogram was obtained and strain ratios were calculated and the final diagnosis was compared to histopathological diagnoses to evaluate the diagnostic accuracy of ultrasound with and without elastography. Statistical Analysis Used:Statistical analysis was done using descriptive and inferential statistics using Chi-square test, Student's unpaired test, sensitivity, and specificity, and software used in the analysis was SPSS 22.0 version and GrafhPad Prism 6.0 version. Results: Out of the total 87 patients, 10 cases were misdiagnosed on ultrasonography compared to 7 on elastography, of which the major pathology was adenomyosis and 1 case submucosal fibroid. Sensitivity, specificity, and diagnostic accuracy of ultrasound were found to be 90.28%, 80%, and 88.5%, respectively. Sensitivity, specificity, and diagnostic accuracy of sonography with elastography were 93.06%, 86.67%, and 91.95%, respectively, showing better results. Conclusions: Sonography coupled with elastography showed better results and can be used to avoid dependency on CT and MRI avoiding radiation exposures and increase cost, especially in a developing country such as India.
Keywords: Adenomyosis, fibroids, sonoelastography, ultrasonography
|How to cite this article:|
Phatak S, Marfani G. Sonoelastographic Evaluation of Uterine Fibroids – Our Initial Experience. J Datta Meghe Inst Med Sci Univ 2019;14:183-8
| Introduction|| |
The anatomic female pelvis is quite complex, as it contains a number of organs and organ systems accomplishing different and independent functions. Pelvic mass of gynecological origin can present at any age group in a lifetime. Uterine fibroids are the most frequently occurring benign tumors originating in the uterus and occur in about 20%–50% of women around the world, with the highest frequency in reproductive age. Leiomyomas are the most frequent benign tumors, with an estimated 0.1%–0.8% risk of malignant transformation into sarcomas. However, malignant leiomyosarcomas are rare and can arise de novo, without leiomyoma as a “base.” Histologically, leiomyomas arise from the overgrowing of the smooth muscle and connective tissue during monoclonal cell proliferation. Fibroids usually arise in the myometrium but may occasionally be found in the cervix, broad ligament, or ovaries., They are multiple in up to 84% of women. A majority of women with fibroids are asymptomatic; however, 20%–50% of them have symptoms such as menorrhagia, pelvic pain and infertility, or complications during pregnancy.,,
Pelvic ultrasound today forms the primary examination mode in the evaluation of pelvic masses. It is the risk of malignancy that propels us for early, accurate, and prompt diagnosis to lessen the mortality and morbidity. Ultrasound (US) is relatively less expensive than other imaging modalities, its diagnostic performance is comparable or better, and it does not involve exposure to ionizing radiation. However, the drawbacks of sonography include technical limitations caused by patient habitues, operator dependence, and technical inability to provide specific characterization. Magnetic resonance imaging (MRI) has proved considerable potential in pelvic imaging. It has high sensitivity and specificity for differentiating benign pelvic masses from malignant ones. MRI is safe because of no radiation exposure as is in the USG, while computed tomography (CT) has a danger of radiation exposure. MRI is increasingly becoming the primary imaging modality for evaluating gynecologic malignancies., However, in a developing country such as India, with most patients comprising rural population, MRI is relatively expensive and is mostly available in tertiary health-care centers, whereas with CT there is a greater risk of radiation exposure. Furthermore, the uses of contrast agents make CT and MRI more expensive and increase the risk factors. Recent advancement in the field of ultrasonography is the introduction of sonoelastography.
Real-time elastography is a novel and dynamic imaging technique that is based on the softness or hardness of tissues or organs of interest under the appropriate compression and can be used with conventional ultrasonography (US) probes after performing grayscale imaging and Doppler US. Displacement of soft tissues is greater as compared to the hard tissues, and tissue hardness is displayed as a color-coded image that lays over the grayscale US image translucently. Sonoelastography increases the sensitivity and specificity of ultrasound and adds to the diagnostic confidence. This study was conducted with a view to find out the diagnostic value of sonoelastography and its correlation with laparotomy and histological diagnosis.
| Subjects and Methods|| |
This study was carried out in the department of radiodiagnosis, Acharya Vinoba Bhave Rural Hospital, attached to the Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha, between August 2017 and August 2018 using the standard protocol.
A total number of 87 patients with irregular menses, amenorrhea, mass in the abdomen, dysfunctional uterine bleeding, infertility, irrespective of age, duration of history, and etiology have been evaluated. Real-time transvaginal ultrasound elastography was performed using Hitachi Aloka Arietta 70s ultrasound machine with transvaginal transducer (5–11 MHz) and histopathological sampling was done.
The study protocol was approved by the ethical committee. All the patients gave informed consent to participate. Technique: The patients were informed about the procedure and consent is obtained to perform the procedure. A female attendant always accompanied the patient. A history of the menstrual cycle is taken, and if the patient is bleeding physiological/pathological, the appointment was rescheduled. The patient is placed in a lithotomy position and the transvaginal probe (5–11 MHz) is covered with a condom and then inserted into the vagina. When a pelvic mass is seen gentle, pressure is applied with the transvaginal probe and elastogram is obtained. The principle of the sonoelastographic technique is based on slight external tissue compression on the structures examined, which produces strain (displacement) within the tissue, with subsequent calculation of the strain profile along the axis of compression (using the algorithm to produce the elastography image). The strain profile is converted into an elastic modulus image, i.e., the tissue elasticity distribution, called an elastogram. The calculated elasticity values are then color coded and superimposed on the translucent, corresponding B-mode scan image. The stiffness of the tissue is displayed in a range of color from red (components with the greatest strain, i.e., the softest components) to blue (components with no strain, i.e., the hardest components). The components with average strain are displayed as green. The elastogram was then classified into a 5-point scoring system based on Tsukuba elasticity score and strain ratio (SR) were calculated where ever possible. Where a score of 1 denotes even strain for the entire hypoechoic lesion (i.e., the entire lesion was evenly shaded in green), a score of 2 indicates strain in most of the hypoechoic lesion, with some areas of no strain (i.e., the hypoechoic lesion has a mosaic pattern of green and blue). A score of 3 indicates strain at the periphery of the hypoechoic lesion, with sparing of the center of the lesion (i.e., the peripheral part of the lesion was green, and the central part was blue). A score of 4 indicates no strain in the entire hypoechoic lesion (i.e., the entire lesion was blue, but its surrounding area was not included). A score of 5 indicates no strain in the entire hypoechoic lesion or in the surrounding area (i.e., both the entire hypoechoic lesion and its surrounding area were blue). Furthermore, a Blue-green-red (BGR) pattern was noted which was noted in the cystic lesion. Lesions categorized as elasticity score (ES) 1 and 2 were considered benign, and lesions categorized as ES 4 and 5 were suspicious for malignancy. Calculation of the SR was based on a comparison of the average strains measured in the lesion and adjacent tissue at the same depth. This method may provide another diagnostic method in addition to the 5-point scoring system used with ultrasonic elastography in the future.
Statistical analysis was done using descriptive and inferential statistics using Chi-square test, Student's unpaired test, sensitivity, and specificity, and software used in the analysis was SPSS 22.0 version (Chicago, Illinois, USA) and GrafhPad Prism 6.0 version (GraphPad Software, Inc).
| Results|| |
[Table 1] shows age-wise distribution of patients. A maximum number of patients were found in the age group of 41–50 years accounting for 44 (50.57%), followed by the age group of 31–40 years accounting for 32 patients (36.78%) and then followed by the age group of 51–60 and 21–30 years.
[Figure 1] depicts bar diagram showing presenting complaints of patients with uterine fibroid. The most common presenting complaint was found to be abnormal uterine bleeding in 71% of the patients, followed by 10% each of infertility and pelvic pressure-related complaints such as urinary incontinence or urgency and constipation, followed by abdominal mass or lump (5%) and abdominal pain (4%).
[Figure 2] depicts pie diagram showing histopathological spectrum of diseases in the study. Uterine fibroids were found in 80 patients (91.95%) and 7 were diagnosed as others which included adenomyosis and endometrial polyps.
[Table 2] shows the distribution of patients based on the parity. Based on the parity, a maximum number of lesions were found in patients with parity 1 accounting for 31 (35.63%) and the least number of lesions was found in patients with parity 4 accounting for 4 (4.59%).
[Table 3] shows menstrual cycle status of patients presenting with uterine fibroids. Most common benign lesions were found in reproductive age group accounting for 77 patients (88.50%) and postmenopausal age group accounting for 10 patients (11.50%).
[Table 4] shows ultrasound characterization of the lesion such as solid, cystic, and mixed. Based on the nature of lesions, solid lesions were predominantly found accounting for 80 patients (91.95%), followed by cystic and mixed lesions.
[Table 5] shows types of uterine fibroids. Out of the total 87 fibroids, maximum were found to be intramural accounting for 67 cases (77.01%) followed by 10 patients (11.11%) each of subserosal and submucosal.
[Table 6] shows Tsukuba elastography score for pelvic masses. The maximum number of patients were found to have a Tsukuba elasticity score of 4 accounting for 45 patients (51.72%) was followed by a score of 2 in 27 patients (31.03%) found in group 4 accounting for 45 patients (51.72%) followed by score of 1 and BGR pattern characteristic of a cystic lesion.
[Table 7] shows SR of fibroids. Based on the SR, the range was found to be 1–8 with a maximum number of patients in the range of 1–3.0 accounting for 50 patients (87.47%) and the least in the range of 5.1–8.0 accounting for 7 patients (8.04%).
[Table 8] shows sensitivity, specificity, and accuracy of ultrasound.
|Table 8: Table showing different aspects of ultrasonography in diagnosing uterine pathologies|
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[Table 9] shows sensitivity, specificity, and accuracy of elastography.
|Table 9: Table showing different aspects of elastography in diagnosing uterine pathologies|
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| Discussion|| |
A total of 87 patients who presented with pelvic mass were part of the study spread over a period of 2 years. Out of the 87 patients, 7 cases were incorrectly diagnosed on elastography compared to ultrasound that had incorrectly diagnosed 10 cases. Sensitivity, specificity, and diagnostic accuracy of elastography were 93.06%, 86.67%, and 91.95%, respectively. Sensitivity, specificity, and diagnostic accuracy of ultrasound were found to be 90.28%, 80%, and 88.5%, respectively.
Out of the total 87 patients, maximum number of patients were found in the age group of 41–50 accounting for 44 (50.57%) followed by the age group of 31–40 years accounting for 32 patients (36.78%) and then followed by the age group of 51–60 and 21–30 years, with a vast majority of patients being in the reproductive age group. It is mainly attributed to the effect of estrogen, the levels of which are high during this age group. The presence of uterine fibroids in patients showed an inverse relationship with parity with a decrease in the incidence with increasing parity. The results were coherent with the study conducted by Khan et al. that proved estrogen as a predisposing factor in the development of uterine fibroids. As estrogen is an independent risk factor, a majority of the patients were found in the reproductive age group as compared to postmenopausal age group. Furthermore, the incidences of uterine fibroid decreased with increase in the parity of the patient.
Out of the total 87 patients, based on ultrasonography features, the lesions were characterized as solid accounting for the maximum 80 patients (91.95%) followed by cystic and mixed nature of the lesion. Fibroids tend to undergo cystic degeneration and are known to appear as a cystic or a solid cystic mass lesion.
Typically on USG, fibroids appear as well-defined, solid masses with a whorled appearance. These are usually of similar echogenicity to the myometrium but sometimes may be hypoechoic. They cause the uterus to appear bulky or may cause an alteration of the normal uterine contour. On elastography, fibroids appear as well-circumscribed, encapsulated mass that shows a characteristic swirled pattern and is composed of dense myometrial tissues which imparts hardness and on elastography appears dark blue [Figure 3]., The results were in agreement with the study conducted by Ami et al.
|Figure 3: There is evidence of well-defined, encapsulated hypoechoic lesion in the posterior myometrial wall which is showing a mosaic pattern of blue and green color (elastography score 2) due to stiff tissues as seen in cases with fibroid with strain ratio of 3.89|
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Out of the total 87 patients, based on Tsukuba elasticity score, a vast majority of the lesions were scored as 4 accounting for 45 patients (51.72%), followed by a score of 2 accounting for 27 patients (31.03%) followed by a score of 1 and BGR pattern characteristic of cystic lesion. The Tsukuba elasticity score of 4 is usually denoting malignancy due to stiffer tissues, however, as fibroid is composed of smooth uterine muscles which are stiffer, making the fibroids appear dark blue on elastography. Its implication in differentiating fibroids with adenomyosis and endometrial polyps can be referred to as a promising tool.
In our study, SR for fibroids was ranging from 1 to 8 with a majority of the patients in between 1 and 3 (48.27%) and it was found that SRs further added to the diagnostic confidence in diagnosing fibroids. The results were in agreement with the study conducted by Ami et al. that observed 10 women with uterine fibroids with transvaginal elastosonography. They calculated SRs and concluded that this technique offers complementary diagnostic information. The SR values in our study were in contrary to the study conducted by Szkodziak et al. where it was found that the SR for intramural fibroid was between 1.22 and 1.75.
Areas of adenomyosis had a spotted, irregular color pattern and appeared brighter than the adjacent normal myometrium. Often foci of adenomyosis with a red center surrounded by a yellow and a green irregular border could be seen [Figure 4]. These findings were identical with the study conducted by Woźniak, the findings of which are that in one group of patients, elastography showed that the stiffness of the lesion was similar to the endometrium and softer than the myometrium, so diagnosing it as endometrial polyps. In another group of patients, sonoelastography depicted that the stiffness of the lesion was identical to that of the myometrium and comparatively harder than that of the endometrium which helped in the diagnoses of submucosal fibroid. In conclusion, endometrial polyps were derived from endometrial tissues that were softer compared to submucosal fibroids that were made of stiff muscle tissues, making elastography a tool to differentiate between such lesions.
|Figure 4: There is evidence of asymmetric thickening of the anterior myometrial wall with poor definition of endometrial myometrium border and globular uterine fundus and showing predominantly soft colors in anterior myometrium on elastography (red and green) suggestive of adenomyosis|
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The main limitation of our study was the small sample number as an initial experience, and further investigation on a larger series in multiple centers is needed. Sonoelastography techniques require experienced and trained operators to perform valid cyclic compressions which can produce reliable and reproducible. The presence of arterial pulsations generated variable amount of tissue deformations and the ratio index may be altered leading to potential pitfalls in the strain elastography (SE) evaluation. The strain indices of mass lesions could not be compared to those of the reference values as there is limited research on the application of elastography in pelvic masses of gynecological origin. Now, there are a growing number of studies about the use of elastography within the field of gynecology, but data are still rare. Only a few studies have been published about the assessment of uterine myomas. In the published literature, we used a simplified 5-point color scale based on previous breast, thyroid, and cervical lymph nodal elastographic studies.
| Conclusions|| |
The present conducted on 87 patients suffering from uterine myomas inferred that sonoelastography is a new and can be a valuable tool in differentiating them from other closely resembling pathologies such as adenomyosis in a developing country like India.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9]