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Thyroid nodules, with their high prevalence in the general population, represent a diagnostic challenge for clinicians. Ultrasound (US), although absolutely reliable in detecting thyroid nodules, is still not accurate enough to differentiate them into benign and malignant. A promising novel modality, US elastography, has been introduced in order to...
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... than the harder parts [17]. The concept of USE was firstly conceived and realized in 1991 by Ophir et al. [18] and gradually developed into a robust US examination method. It has recently gained great interest and attention and has found rapid diffusion in various diagnostic applications, including the thyroid nodules [19, 20]. As shown by a number of studies, USE of thyroid nodules seems promising in differentiating benign from malignant nodules [21–25]. The American Thyroid Association guidelines in 2009 stated that USE is an emerging and promising technique that requires additional validation with prospective studies [9]. The aim of this review paper is to present the role of strain USE in the differential diagnosis of thyroid nodules based on the available evidence retrieved by systematic literature search of the MEDLINE, EMBASE, and COCHRANE databases including the guidelines established by international societies. A deformation force is applied to tissue resulting in changes in dimensions and shape, which are then used to calculate the stiffness of the tissue. This is the underlying physical mechanism on which all forms of current commercially available USE methods are based. However, the alternative technologies differ according to the method used to deform tissue and the way they display deformation, leading to 3 main types of USE: strain USE, acoustic radiation force impulse (ARFI), and shear wave USE. Detailed information on the physics and technology of the different types of USE is available in part 1 of the EFSUMB guidelines and recommendations for the clinical use of elastography [26]. Strain USE detects the local deformation (strain) under slight pressure and displays it as a relative value in comparison to the strain values of the different tissues within the region of interest. Strain USE is also named real-time ultrasound elastography (RTE), or strain elastography (SE), or free-hand elastography and is the most widely available type of USE. The pressure is performed either by the hand held US transducer or by physiological movements (e.g., carotid pulsation). This results in the elastographic image, also known as elastogram, which is represented as a color coded image superimposed on the B-mode image and displayed next to it on the screen. The quality of the operator’s free-hand pressure is visualized on the screen as a sine-wave or displayed with a numerical scale, allowing the operator to assess the validity of the compression cycles in real-time. For computing strain images without noise, the light and cyclic probe pressure has to be harmonic with a near constant rate of displacement [26]. In general, a rectangular, or elliptic, or rounded region of interest (ROI) is used, large enough to include the entire nodule as well as a large portion of the surrounding thyroid and perithyroid tissue. This technique allows a qualitative and a semiquantitative assessment of nodule elasticity. The qualitative assessment (elastogram) represents a mapping of the amount of tissue strain at each location [18, 27]. Color coding depends on the system and usually blue represents hard, stiff tissue (with lowest elastic strain or no strain), red represents soft tissue (with greatest elastic strain), and green or orange represents intermediate level of stiffness. There is also a semiquantitative measurement method (the strain ratio), which represents the ratio of strains of the area of interest (ROI) to an equally measuring area in the reference tissue. Strain elastograms of nodules are qualitatively evaluated with a stepwise scoring system, according to the prevalent color in the nodule. The two principal scoring systems are those classified by Asteria et al. [28] and Rago et al. [29]. The first one, based on the breast strain USE scale of Itoh et al. [30], includes four different patterns [28] (Figure 3). The thyroid nodules with scores 1 and 2 are considered benign (Figure 1) and those with scores 3 and 4 are classified as suspicious for malignancy [28] (Figure 2). However, some authors have found that assigning benignity to score 3 further increases the specificity of the method for cancer detection ...
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To retrospectively evaluate the diagnostic performance of shear wave elastography (SWE) and thyroid imaging reporting and data system (TI-RADS) in differentiating malignant and benign thyroid nodules. A total of 313 thyroid nodules in 227 patients were included. All thyroid nodules were underwent SWE and TI-RADS before fine needle aspiration biopsy...
Thyroid fine-needle aspiration (FNA) biopsy has been widely accepted as an accurate and cost‑effective tool in the management of thyroid nodules. To avoid unnecessary FNAs and provide appropriate management, patient evaluation should be based on a multidisciplinary approach. For this purpose, the Thyroid Imaging Reporting and Data System (TI‑RADS)...
Citations
... Moreover, the unpredictable nature of the stiffness of a tissue causes higher stiffness measurements. Furthermore, ultrasound is ineffective for nodules with cystic components, as fluid movement does not indicate solid component stiffness [112,113]. ...
Ultrasound is a highly adaptable medical imaging modality that offers several applications and a wide range of uses, both for diagnostic and therapeutic purposes. The principles of sound wave propagation and reflection enable ultrasound imaging to function as a highly secure modality. This technique facilitates the production of real-time visual representations, thereby assisting in the evaluation of various medical conditions such as cardiac, gynecologic, and abdominal diseases, among others. The ultrasound modality encompasses a diverse range of modes and mechanisms that serve to enhance the methodology of pathology and physiology assessment. Doppler imaging and US elastography, in particular, are two such techniques that contribute to this expansion. Elastography-based imaging methods have attracted significant interest in recent years for the non-invasive evaluation of tissue mechanical characteristics. These techniques utilize the changes in soft tissue elasticity in various diseases to generate both qualitative and quantitative data for diagnostic purposes. Specialized imaging techniques collect data by identifying tissue stiffness under mechanical forces such as compression or shear waves. However, in this review paper, we provide a comprehensive examination of the fundamental concepts, underlying physics, and limitations associated with ultrasound elastography. Additionally, we present a concise overview of its present-day clinical utilization and ongoing advancements across many clinical domains.
... Nonlinearity of tissue stiffness results in greater stiffness measurements at high degree of compression. Fibrosis within both benign and malignant nodules can increase stiffness 12 . Thyroid nodules greater than 3 cm in diameter may be unable to be adequately compressed in strain imaging. ...
Thyroid disease is of common occurrence, especially in iodine deficient areas. Thyroid nodules are common findings in the general population. It is important to distinguish the subset of thyroid nodules that are malignant, as morbidity and mortality from thyroid cancer increases with disease stage. B-mode ultrasound features are initially used to select thyroid nodules for FNA. Although FNA is considered the gold standard for diagnosis, it is yet imperfect as up to 1530% of samples are considered non-diagnostic or indeterminate. Thyroid ultrasound elastography(USE) is a noninvasive method of assessing thyroid nodules that provides complementary information to B-mode ultrasound and FNA. The combined use of thyroid USE with B-mode ultrasound may improve the ability to discriminate benign from malignant thyroid nodules and reduce the number of needed FNAs. Thyroid USE may also aid with the difficult problem of distinguishing between malignant and benign follicular neoplasm.The elastic properties of tissue have always been of interest in clinical practice. In the past, the identification of structures that were stiffer on physical palpation would raise the suspicion. With the development and advancement of medicine, there proved to be a true correlation in the prediction of malignancy of lesion: malignant disease tends to stiffen the affected tissue, either by increased cell proliferation or fibrosis. Palpation is the oldest method for the detection of thyroid nodules, which if informed by the knowledge that malignant thyroid lesions tend to be much harder than benign ones. Palpation is dependent on the size, location and skill of the physician. Nodules are very small or located in deep regions; there detection by palpation is difficult or even impossible. Although malignant lesion differs in terms of elasticity, it may not have echogenic properties, preventing its detection by conventional ultrasound. Imaging that indicates the stiffness or deformation related to their structural formation. Bangabandhu Sheikh Mujib Med. Coll. J. 2022;1(2):96-98
... Since a change in the elasticity of tissue typically correlates with pathologic features, UE can aid in differential diagnosis [19]. Three methods are distinguished in UE on the basis of the external stimulus: strain-based UE (USE, mechanically induced force, measuring tissue strain), acoustic radiation force impulse (ARFI, ultrasound induced, measuring tissue displacement), and shear wave-based UE (SWE, ultrasound induced, measuring quantitative shear wave propagation) [20,21]. UE reflects the histologic composition of a tissue (i.e., cells, membranes, and ultrastructures). ...
... Another limitation is-comparable to TIRADS-that follicular thyroid cancer may be soft on UE and therefore lead to false negative results [21]. When comparing different elastographic methods, SWE proves to be less operatordependent than SE in most studies [4,20]. ...
Thyroid sonography has made substantial progress over the last decades in terms of spatial resolution and additional parameters including vascularity, perfusion, and elasticity of lesions. The improved depictability of thyroid nodules has led to a more detailed sonographic characterization of malignant thyroid nodules considering features like microcalcification, capsular invasion, and reduced elasticity. Thus, ultrasound (US) has become the most important single tool for risk assessment of thyroid nodules. Predominantly cystic and spongiform nodules as well as many nodules with a mixed composition of solid and cystic components can safely be identified as benign on ultrasound and need no further work-up for risk assessment. Predominantly solid nodules, however, require a structured and consistent sonographic assessment including the evaluation of nodule composition, echogenicity, calcifications, shape, margins, and additional sonographic parameters. One should adhere to one of the TIRADS when reporting ultrasound findings on thyroid nodules categorizing each nodule to a certain risk class. However, the risk of malignancy reported in studies for each class may not be readily transferrable to daily routine, since the prevalence of malignant nodules in tertiary care centers is as high as 20% whereas in primary care units the prevalence may be as low as 1 per mille, thus lowering positive predictive values by one to two orders of magnitude. In addition, some suspicious features found in those studies may not be directly transferable to daily practice: microcalcifications are often difficult to discern from benign colloidal spots, even after having run through learning sessions; a taller-than-wide shape of nodules with contact to the dorsal parts of the thyroid gland does not imply malignancy according to a pole concept which has been recently developed.
Thyroid scintigraphy (TS) has long been an indispensable modality for functional characterization of thyroid nodules. It should be applied to rule out malignancy in a substantial proportion of predominantly solid nodules by showing a hyperfunctioning (“hot”) nodule. Such nodules are almost always benign with few exceptions (e.g., “trapping only” nodules). If laboratory findings and scintigraphic appearance of a hot nodule do not match, further diagnostic work-up is warranted including ¹²³ I ⁻ scintigraphy with late imaging at 24 h and fine-needle aspiration cytology (FNAC). In settings with a rather low prevalence of malignant thyroid nodules such as in primary or secondary care units, a combined use of US and TS may be adopted to rule in suspicious nodules for further work-up by FNAC, including predominantly solid hypofunctioning (“cold”) nodules. MIBI scintigraphy can be used in hypofunctioning nodules with indeterminate cytology and if contraindications preclude patients from FNAC.
TS is a valuable tool to detect functional abnormalities not only in nodules but also in the thyroid gland as a whole by assessing the overall radionuclide uptake. As such, it has long been used to confirm the diagnosis of Graves’ disease and thyroid autonomy. For disseminated autonomy, it is the only tool to definitely verify the diagnosis. In destructive thyroiditis, TS reliably shows a reduced overall radionuclide uptake justifying its application in selected cases with doubtful sonographic or laboratory findings. The user of TS is encouraged to calculate a site-specific normal range for the uptake value normalized to TSH in addition to the raw uptake. Thus, even subtle functional disorders of the thyroid can be detected and graded.
Functional or metabolic imaging is increasingly combined with morphological imaging and is acquired and displayed as volume data rather than planar images including SPECT/CT, PET/CT, and PET/MRI. These combined modalities increase the restricted morphological field of view from ultrasound enabling to reliably image substernal, ectopic, or dystopic localizations of thyroid tissue. Combined modalities also benefit from the increasing spectrum of functional or metabolic tracers including MIBI, iodine isotopes (e.g., 124I-) and newer PET tracers.
... The Thyroid Imaging Reporting and Data System classification (TI-RADS), inspired by the breast BI-RADS classification, could be used to classify nodules according to ultrasound criteria and determine the risk of malignancy [9]. Also, US elastography (USE) has been introduced in the clinical workup of thyroid nodules [10]. ...
Introduction
Thyroid nodules are highly prevalent in the general population; therefore, it is crucial to discriminate benign from malignant nodules. A practical thyroid imaging reporting and data system (TI-RADS) for thyroid nodules and ultrasound elastography are valuable tools not only for characterization of nodules but also for the selection of tumors for fine-needle aspiration cytology (FNAC).
Objective
This study aimed to evaluate the diagnostic accuracy of US evaluation in the prediction of malignant thyroid nodules and evaluate the role of the elastography score, strain ratio (SR), and the TI-RADS scoring system as non-invasive tools in differentiation between malignant and benign thyroid nodules.
Material and methods
A total of 1269 patients were evaluated between February 2017 and April 2020 by a single expert thyroid ultrasound operator. The final diagnosis was achieved from cytological and/or histological evaluation and follow-up for at least 1 year.
Results
There were 1088 females and 181 males with a mean age of 44 ± 10 SD. The final diagnosis was 1197 benign nodules and 72 malignant nodules. Most malignant nodules were scored elastography score 4 (83.3%) and TI-RADS category 5 (86.11%). We found that nodules with antero-posterior to transverse (A-P/T) diameter > 1, have 21 times more risk to be malignant than those with A-P/T diameter < 1, patients with solitary thyroid nodules have 4.5 times to develop malignancy compared to those with multinodular goiter (MNG), nodules with absent halo have 4 times more risk of malignancy. Furthermore, microcalcifications in thyroid nodules increase the risk of malignancy 9 times compared to those without calcifications. SR was found to be an excellent discriminator to differentiate between benign and malignant nodules with P < 0.001. Also, we found that for every unit increase in SR, the risk of malignancy increased by 20%. We reported that the accuracy of ultrasonography in the detection of malignant thyroid nodules had a sensitivity of 89%, specificity of 98%, 70% PPV, and 99.3% NPV, with an overall accuracy of 97.2%.
Conclusion
The application of ultrasonographic non-invasive criteria for thyroid nodules in clinical practice might significantly reduce the number of unnecessary FNAC. Elastography, SR, and TI-RADS classification could be good predictors for malignant thyroid nodules.
... Ultrasound Elastography is a technique that takes advantage of the biomechanical characteristics of the tissue, measuring such characteristics by applying an external force (i.e., compression or shear) and analyzing how the tissue changes in shape and size; these changes relate to the tissue's stiffness (1). The commercially available ultrasound elastography methods differ from each other by how they generate this force to deform the tissue and how they display this deformation; the methods available include strain elastography (SE), acoustic radiation force impulse (ARFI) elastography, and shear-wave elastography (SWE) (1,2). ...
... Ultrasound Elastography is a technique that takes advantage of the biomechanical characteristics of the tissue, measuring such characteristics by applying an external force (i.e., compression or shear) and analyzing how the tissue changes in shape and size; these changes relate to the tissue's stiffness (1). The commercially available ultrasound elastography methods differ from each other by how they generate this force to deform the tissue and how they display this deformation; the methods available include strain elastography (SE), acoustic radiation force impulse (ARFI) elastography, and shear-wave elastography (SWE) (1,2). When applying these techniques to thyroid nodules (TN), the premise is that these biomechanical properties will vary between benign and malignant nodules; therefore, thyroid elastography and its measurements (both qualitative and quantitative) can be used as a biomarker to differentiate malignancy in TN. ...
... As mentioned before, the available elastography techniques differ in the way they apply the force and the measurement or quality they display after the application of that force (1,2). Strain elastography (SE) uses a quasi-static force usually generated by pressing with the imaging transducer or by internal forces (i.e., arterial pulsations) which generate strain and displays it; acoustic radiation force impulse (ARFI), in contrast, uses a dynamic force generated by an ultrasound radiation force impulse that causes a targeted displacement of the tissue; in both shear-wave elastography (SWE) and point shear-wave elastography (pSWE) a dynamic force is generated by an ultrasound radiation force impulse which causes shear-waves that travel across the tissue, the difference is that pSWE measures the speed of localized and transient shear-waves whereas SWE produces two-or threedimensional quantitative images of shear-wave speed (2). ...
Objective
A prospective cross-sectional investigation of 170 thyroid nodules (TN) between January 2020 and December 2021 at Alpha Imagen was conducted to determine cut-off points (C/O) for elastography measurements and their diagnostic accuracy.
Methods
Nodules were categorized by ACR TI-RADS, Alpha Score (AS), and Bethesda; all were evaluated using 2D Shear Wave Real Time Elastography (RT-SWE), point Shear Wave (pSWE), and Strain Elastography (SE). Data was assessed with ROC curves, the Shapiro-Wilk test, T test, Chi-square test, and ANOVA.
Results
C/O were as follows: RTSWE Emax of 115kPa and 6.5 m/s, Emean of 47.5 kPa and 4.1 m/s, pSWE (average) of 52.4 kpa and 4.15 m/s; sensitivity of 81.2% and specificity of 57.6%, with a PPV of 72.4% and NPV of 70.0%. SE Value A had a C/O of 0.20%, with a sensitivity of 84%, specificity of 57%, PPV of 72.4% and NPP of 73.6%. The Strain Ratio nodule/tissue C/O was calculated as 2.69, with a sensitivity of 84%, specificity of 57%, PPV of 72.3%, and NPV of 73.5%. The RLBIndex quality control must be at least 92%; for pSWE, we suggest a mean interquartile ratio of ≤15.7% for kPa and 8.1% for m/s. The recommended depth is between 1.2 and 1.5 cm, and commonly used ROI boxes were 3x3 and 5x5mm.
Conclusion
2D-SWE and pSWE with Emax and Emean demonstrated C/O with excellent diagnostic accuracy. To maximize the correct classification of TN, we suggest combining ACR TI-RADS and AS with any of the elastography measurements assessed here.
... Andere Schilddrüsenmalignome, insbesondere das FTC, aber auch medulläres Schilddrüsenkarzinom (MTC) oder Metastasen wurden als relativ weich beschrieben mit geringer SW-Geschwindigkeit bzw. niedrigem Wert des E-Modulus [27]. ...
Zusammenfassung
Hintergrund Die Elastografie ist eine bildgebende Methode, um die Elastizität von Gewebe zu untersuchen. Inzwischen wurden verschiedene Elastografie-Verfahren entwickelt, die nach der Art des angewandten Stimulus unterteilt werden. Prinzipiell ist zwischen der Strain-Elastografie (SE) und Scherwellen-Elastografie (SWE) zu unterscheiden. Beide Methoden bieten neben der konventionellen B-Mode-Sonografie eine weitere Möglichkeit zur Beurteilung von Schilddrüsenerkrankungen.
Ziel der Arbeit Es soll ein Überblick über die Elastografie-Verfahren einschließlich der physikalischen Grundlagen vermittelt werden sowie ihre Bedeutung im Abklärungsalgorithmus von Schilddrüsenknoten.
Material und Methoden Internationale Leitlinien sowie aktuelle Arbeiten zur Elastografie wurden selektiv recherchiert.
Ergebnisse Die Elastografie liefert zusätzliche Informationen gegenüber der konventionellen B-Mode-Sonografie. Der wesentliche physikalische Mechanismus, dem der Gewebekontrast in allen Elastogrammen zugrunde liegt, ist die Änderung der Schersteifigkeit. Neben der qualitativen Erfassung der Elastizität in der SE ist mit der SWE eine Quantifizierung möglich. In der internationalen Literatur wurde die Elastografie als einzelne Methode oder im Vergleich bzw. in Kombination zur konventionellen B-Mode-Sonografie und insbesondere mit der Standardisierung mittels eines Risikostratifizierungssystems (RSS, TIRADS) analysiert. Die Ergebnisse zeigten sich durchaus kontrovers. Bei Knoten mit unklaren Befunden der Feinnadelbiopsie (Bethesda III/IV) führte die Kombination aus morphologischen Kriterien und Elastografie zu einer Verbesserung der diagnostischen Genauigkeit. Insbesondere der hohe negative prädiktive Wert weicher Knoten stellt einen relevanten Mehrwert dar. Diese Stärke der Methode kann bei der Abklärung von Knoten mit mittlerem Malignomrisiko oder von unklaren FNB-Ergebnissen eine wichtige Rolle spielen. Die Elastografie wurde bisher nur in das (überwiegend durch das EU-TIRADS abgelöste) French-TIRADS integriert. Obwohl das Verfahren im EU-TIRADS als Komplementärmethode Erwähnung findet, wurde eine Integration nicht beschrieben. Limitationen des Verfahrens sind idealisierte Grundannahmen, Hersteller- und Untersucherabhängigkeit sowie Artefakte.
Schlussfolgerung Die Elastografie kann bei der Beurteilung von Schilddrüsenknoten die standardisierten Diagnostikverfahren sinnvoll ergänzen, insbesondere bei Knoten mit mittlerem Malignomrisiko und unklaren Ergebnissen in der Feinnadelpunktion.
... However, ultrasound may has limited in evaluating invasion to adjacent structures, evaluation of lymph nodes at low cervical levels (such as levels VI and upper mediastina), substernal goiter, and thyroid nodules with coarse calcifcations that may reduce the quality of ultrasound image of its internal and surrounding structure [7]. In addition, previous studies have shown that ultrasound has a relatively low diagnostic performance in diferentiating between benign and malignant thyroid nodules [8,9]. ...
Background:
Gemstone spectral contrast-enhanced CT with virtual noncontrast (VNC) images and iodine maps can potentially reduce the number of required CT scans for thyroid lesions. However, data regarding the clinical utility of VNC images and iodine maps in characterizing thyroid lesions and distinguishing thyroid papillary carcinoma from nodular goiter are still limited.
Purpose:
To determine whether VNC images and iodine density could reliably aid in characterizing thyroid lesions and distinguishing thyroid papillary carcinoma from nodular goiter compared with true noncontrast (TNC) images.
Methods:
This retrospective study included patients with thyroid papillary carcinoma or nodular goiter who underwent TNC and contrast-enhanced gemstone spectral CT scans. The consistency of qualitative parameters, including intralesional calcification, necrosis, lesion boundary, thyroid edge interruption, and lymph node metastasis, between TNC and VNC images, was analyzed using the kappa statistic. TNC attenuation, VNC attenuation, absolute attenuation between TNC and VNC, and iodine density were compared between thyroid papillary carcinoma and nodular goiter by using Student's t-test. The diagnostic performance for distinguishing papillary carcinoma from nodular goiter was evaluated by using the area under the receiver operating characteristic curve (AUC) value, sensitivity, and specificity.
Results:
VNC and TNC imaging showed comparable performance in delineating calcification, necrosis, lesion boundary, thyroid edge interruption, and lymph node metastasis (all k > 0.75). Papillary carcinoma showed significantly lower absolute attenuation between VNC and TNC than nodular goiter (7.86 ± 6.74 vs. 13.43 ± 10.53, P=0.026), which was similarly observed for iodine density (31.45 ± 8.51 vs. 37.27 ± 10.34, P=0.016). The iodine density showed higher diagnostic performance (AUC = 0.727), accuracy (0.773 vs. 0.667), sensitivity (0.750 vs. 0.708), and specificity (0.786 vs. 0.643) than the absolute attenuation between TNC and VNC images (AUC = 0.683).
Conclusions:
VNC imaging, a promising substitute for TNC imaging, has comparable diagnostic efficacy for reliably characterizing thyroid lesions. Iodine density could be valuable for distinguishing thyroid papillary carcinoma from nodular goiter.
... The assessment of tissues using SE involves a comparison between the targeted and surrounding tissues after external pressure has been induced by an ultrasound operator. The semi-quantitative results of SE are presented as a colour-coded elastogram, a map illustrating elastic strains with colour gradation [12][13][14]. The stiffness thresholds for specific equipment should not be utilised for other equipment [15]. ...
Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that mainly affects developed countries, but the number of cases in developing countries is increasing. We conducted a narrative review on the potential application of ultrasound elastography in the diagnosis and monitoring of UC, as this newly emerging method has promising results in other gut diseases. This review fulfilled the PRISMA Statement criteria with a time cut-off of June 2022. At the end of the review, of the 1334 identified studies, only five fulfilled all the inclusion criteria. Due to the small number of studies in this field, a reliable assessment of the usefulness of ultrasound elastography is difficult. We can only conclude that the transabdominal elastography examination did not significantly differ from the standard gastrointestinal ultrasonography examination and that measurements of the frontal intestinal wall should be made in the longitudinal section. The reports suggest that it is impossible to estimate the clinical scales used in disease assessment solely on the basis of elastographic measurements. Due to the different inclusion criteria, measurement methodologies, and elastographic techniques used in the analysed studies, a reliable comparative evaluation was impossible. Further work is required to assess the validity of expanding gastrointestinal ultrasonography with elastography in the diagnosis and monitoring of UC.
... Thyroid nodules are very common, and their incidence is gradually increasing [1,2]. Most are benign; however, malignancy occurs in 5% to 15% of cases [1]. ...
... Thyroid nodules are very common, and their incidence is gradually increasing [1,2]. Most are benign; however, malignancy occurs in 5% to 15% of cases [1]. Thyroid nodules are usually discovered when patients present for physical examination after feeling an enlarged nodule in their neck or experiencing visible neck swelling. ...
... Ultrasound-guided elastography (USE) is a noninvasive test used to assess a tissue's biomedical properties (e.g., elasticity) [1,8]. It is helpful in various diagnostic applications, including thyroid nodules. ...
Introduction
Strain ultrasound-guided elastography (USE) could be used to differentiate malignant from benign thyroid lesions if its sensitivity and specificity are significantly high. Data on whether to rely on USE in differentiating thyroid nodules are unavailable, and fine-needle aspiration cytology (FNAC) remains the gold standard. However, FNAC carries a significant financial burden on hospitals and psychological stress on patients. Therefore, we conducted this study to determine the diagnostic accuracy of strain USE in thyroid lesions.
Methodology
We conducted a descriptive cross-sectional study at the Radiology Department, Benazir Bhutto Hospital, Rawalpindi, from December 6, 2020, to June 5, 2021. The study included adult patients aged between 20 to 70 years who were referred with thyroid nodules or lesions found clinically or on routine neck ultrasound. The study excluded patients who had previous history of surgery or previously diagnosed with malignant thyroid lesions and recurrent thyroid nodules. Strain USE was performed on thyroid nodules, and the degree of strain was color-coded on a scale from red (soft, greatest elasticity) to green (intermediate, average strain) to blue (hard, no elasticity/strain). Lesions were given an elasticity score on a five-point scale. The lesion was given a score of one if the entire lesion was uniformly shaded in green. A lesion with mosaic pattern of green and blue was scored as two. A score of three denoted a lesion with green periphery and blue center on strain elastography. A score of four indicated uniform blue in the entire lesion, with green in the lesion's periphery. The highest score of five was given if the lesion and its surroundings demonstrated blue color. Ultrasound-guided FNAC of the thyroid nodules was performed following USE. Data was analyzed using IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp. Mean ± standard deviation for calculating quantitative variables. Frequencies and percentages were calculated for qualitative variables. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of strain USE was calculated taking FNAC as gold standard. We also conducted a receiver operating characteristic curve analysis to quantify the diagnostic accuracy of strain USE in thyroid lesions.
Results
The study included 207 adult patients (117 women, 56.52%; 90 men, 43.48%). The study population's mean age was 50.0 ± 11.8 years (range, 20 to 70 years). Most patients (56.52%) were aged 46 to 70 years. FNAC confirmed malignant thyroid nodules in 100 cases (true positive), and nine cases (false positive) had no malignant lesions on FNAC. In USE-negative patients, 91 were true negative, while seven were false negative. Strain USE's overall sensitivity was 93.46%, specificity was 91.0%, PPV was 91.74%, NPV was 92.86%, and diagnostic accuracy was 92.27% compared to the gold standard FNAC.
Conclusions
Strain USE in thyroid lesions is a noninvasive modality of choice with high diagnostic accuracy and has dramatically improved our ability to diagnose malignant thyroid nodules preoperatively. Strain USE also helps the surgeons in proper decision-making. Strain USE should be used routinely in all patients with thyroid lesions to help diagnose malignant thyroid nodules preoperatively and inform proper surgical and treatment plans.
... Studies have shown that it has a wide range of sensitivity (54%-95%) and specificity (60%-94%). 4 Although it gives a low false-negative (5%) and falsepositive (3%) result, about 10% to 50% of cytology falls under the indeterminate or suspicious category. Usually, a typical cells or cells suggestive of follicular neoplasm is seen, and this carries 10% to 30% risk of malignancy. ...
INTRODUCTION: Ultrasound has been widely used to assess thyroid nodules. Although ultrasound elastography has been developed to improve detection of thyroid malignancy, it has received mixed responses. This study aimed to determine the efficacy of ultrasound elastography in detecting malignant thyroid nodules. MATERIALS AND METHODS: Patients with thyroid nodules were assessed using conventional ultrasound and elastography followed by fine-needle aspiration and or hemithyroidectomy. The ultrasound findings were compared with the cytology or histopathology for statistical analysis. RESULTS: Out of 156 nodules from 92 patients included in the study, 12 (7.7%) were malignant and 144 (88.8%) were benign. The elastography was found to be an independent predictor of malignancy (OR 10.35, 95% CI [1.31, 81.6], p = 0.03). Other independent predictors were taller shape and central Doppler pattern obtained using conventional ultrasound. A combination of the three independent predictors was shown to improve the sensitivity of detecting malignant thyroid nodules up to 100%, 95% CI [73.5,100] with NPV of 100%. A new scoring system incorporating the three variables was developed and an algorithm using the scoring system was proposed. CONCLUSION: Thyroid elastography is an independent predictor of thyroid malignancy. Its performance is comparable to conventional ultrasound when used alone and improved when used in combination with conventional ultrasound. It is valuable as screening and risk-stratification tools for patients with thyroid nodules.
