| Thyroid nodule is a common clinical disease with very high incidence. According tothe American Thyroid Association survey,4%-10%of the general population has thyroidnodules detected by palpation. In recent years with high resolution ultrasound, thedetection rate can be as high as19%-67ï¼…. The rate in autopsy (60years and above) isabout50%. But only about5%of thyroid nodules are malignant[1]. Therefore, judgment ofbenign or malignant thyroid nodules has important clinical significance for treatmentselection and prognosis.B ultrasound is a fast, economic, and noninvasive method for auxiliary examinationof thyroid nodules, and can be used to determine the location and size of thyroid nodules,membrane integrity, intra-nodal flow, and occurrence of calcification. B ultrasound canalso be used to check the relationships of thyroid nodules with larynx and trachea, and thesize of cervical lymph node. B ultrasound also facilitates the dynamic follow-up of thyroid nodule. The ultrasonic elastography (UE) as a new diagnostic ultrasonography in recentyears has been increasingly helpful in the studies and diagnosis of thyroid nodule (TN).The basic principle of UE is: first cause the organizations to deform under external force(manual compression or high-energy pulsed push), then detect the deformation by usingspecial algorithm and computer technology, and display the relative deformation degree inthe gray-scale and color coding. The results show the hardness of mass qualitatively orquantitatively, which is traditionally estimated by doctors through palpation. This ispropitious to distinguish between benign and malignant thyroid nodules. Since thethyroidea tissues can ingest131I and99mTC specifically, it can judge the thyroid lesionsbased on the distribution of radioactivity within the thyroidea shown by the Emissioncomputed tomography (ECT). UE can provide some diagnostic information for cliniciansas reference to draw up a therapeutic plan, because it is a Nuclear medical examinationwith advantage of functional imaging. It will remind clinicians to pay special attention andto take appropriate therapeutic plan actively. The Fine needle aspiration cytology (FNAC)is a minimally-invasive diagnostic technique used to assess the characteristics of thyroidnodule. It has an advantage of diagnosing the malignant thyroid tumors early, so that thepatients who have benign thyroid tumor can avoid unnecessary operations. But it isdifficult to find the pathognostic cells in some smears or hard to fully reflect the multipleconcurrent lesions in the thyroid, so the places of aspiration are limited.In this study, several methods in diagnosis of thyroid nodules were compared. Therelated literatures in recent years were collected, and a quantitative meta-analysis wascarried out. The results are as follows.Part oneMeta-analysis of three diagnostic methods for systemic evaluationof thyroid nodulesObjectiveTo compare ultrasound, FNAC, and radionuclide scan in diagnosis of thyroid nodules through meta-analysis.MethodsRelated literatures in Pubmed and Embase about diagnosis of thyroid nodules byultrasound, FNAC and Radionuclide scanning were searched. Finally the results ofdiagnostic experiments were compared. The literatures were evaluated and screenedaccording to the QUADAS standards. Meta-disc1.4was used to merge the includedresults.Results4953cases in FNAC diagnosis were included, with a sensitivity of89.6, a combinedspecificity of95.3, and weighted SROC area under the curve (AUC) of0.9627.1540casesof scanning diagnosis were incorporated, with a sensitivity of90.7, a combined specificityof25, and weighted SROC AUC of0.4449.4502cases of ultrasound diagnosis wereincluded, with a sensitivity of80.6, a combined specificity of86.2, and weighted SROCAUC of0.8817. Ultrasound and FNAC were compared by z-test (Z=2.837, P<0.05) to besignificant different. The scanning and FNAC (Z=1.982, P<0.05) show significantdifference. The ultrasound and scanning (Z=1.665, P>0.05) do not show significantdifference.ConclusionsThe above results show that FNAC has higher accuracy in diagnosis of thyroidnodules. Although Ultrasound is not as good as FNAC, it is simple and non-traumatic andhas other advantages, so it is the first-choice screening tool in clinic for diagnosis ofbenign and malignant thyroid nodules. Scanning has poor specificity and low accuracy,but it is recommended for thyroid nodule patients with low serum TSH, because very fewfunctional nodules were malignant and shall not be re-checked by FNAC. Part twoThe values of Ultrasound Elastography and fine needle aspirationcytology in diagnosis of thyroid nodules: a meta-analysisObjectiveTo evaluate the values of ultrasound elastography and FNAC in diagnosis of thyroidnodules.MethodsCNKI, WANFANG and VIP databases during1990to2012were searched toidentify all diagnostic test studies that met pre-stated inclusion/exclusion criteria. Qualityevaluation was conducted by the QUADAS entry. Meta-Disc1.4was used to generate thereceiver operating characteristic curve (SROC) and to calculate the area under the curve.ResultA total of60literatures involving5,232cases about ultrasound elastography and2,673cases about FNAC were included. The sensitivity of Ultrasound Elastography andFNAC was0.87(95%CI:0.85-0.88) and0.86(95%CI:0.83-0.88), respectively; Thespecificity was0.85(95%CI:0.84-0.86) and0.96(95%CI:0.95-0.97), respectively; thearea under SROC curve was0.9265and0.9565, respectively. Ultrasonic elastography andFNAC (Z=2.467, P<0.05) were compared by z-test to be significantly different.ConclusionThe SROC curve of FNAC is closer to the left upper corner and has a larger AUCcompared with the curve of UE. Therefore, FNAC is more accurate than UE in diagnosisof thyroid nodules, and provides a good foundation for Chinese clinicians in diagnosis ofthyroid nodules. |
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