A comparison of radionuclide thyroid angiography, (99m)Tc-MIBI scintigraphy and power Doppler ultrasonography in the differential diagnosis of solitary cold thyroid nodules

Quantitative dual isotope 123iodine/99mTc-MIBI scintigraphy: A new approach to rule out malignancy in thyroid nodules

BACKGROUND

The aim of this study was to evaluate the role of dual isotope ¹²³Iodine/^99mTc-MIBI thyroid scintigraphy (IMS) in discriminating between malignant and benign lesions in indeterminate nodules using quantitative analysis methods.

METHODS

Thirty-five consecutive patients with thyroid nodules of indeterminate or non-diagnostic cytology and cold on ¹²³Iodine scintigraphy (10 Bethesda I, 24 Bethesda III-IV, 1 in which cytology was impossible) underwent IMS between 2017 and 2019 with uptake quantification at two time points ahead of thyroidectomy: early and late. Images were analyzed by two blinded physicians.

RESULTS

Twelve nodules were malignant and 23 benign on histopathology. Mean uptake values were lower in benign than in malignant nodules at both time points: early, 8.7±4.1 versus 12.9±3.5 (P=0.005); and late, 5.3±2.7 versus 7.7±1.1 (P=0.008). Interobserver reproducibility was excellent. The intraclass correlation coefficient was 0.86 in benign and 0.92 in malignant lesions for early uptake result (ER) and 0.94 and 0.85 respectively for late uptake result (LR). The optimal LR cut-off  to exclude a diagnosis of malignancy was set at 5.9 . The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this cut-off were, respectively, 100%, 65.2%, 60%, 100% and 77.1%.

CONCLUSION

Despite some study limitations, quantitative analysis of ^99mTc-MIBI thyroid scintigraphy had a good reproducibility, which could help to rule out malignancy in non-diagnostic or indeterminate thyroid nodules and thereby reducing the number of patients undergoing unnecessary surgery when LR is below 5.9.

Impact of ultrasound angiography combined with fine needle aspiration for the diagnosis of thyroid nodules

BACKGROUND

This study aims to systematically investigate the impact of ultrasound angiography (UA) combined with fine needle aspiration (FNA) for the diagnosis of thyroid nodules (TNs).

METHODS

The following electronic databases will be searched: MEDLINE, EMBASE, Cochrane Library, PsycINFO, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. We will search them from their inceptions to the present without language limitations. We will consider all case-controlled studies on investigating the impact of diagnosis UA combined FNA for TNs. We will apply Quality Assessment of Diagnostic Accuracy Studies tool to assess methodological quality for all eligible studies.

RESULTS

In this study, outcomes consist of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. All these outcomes will be analyzed to evaluate the diagnostic accuracy of UA combined with FNA for TNs.

CONCLUSION

This study will provide evidence of the diagnostic accuracy of UA combined with FNA for TNs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019138884.

Diagnostic Performance of Technetium-99m Methoxy-Isobutyl-Isonitrile for Differentiation of Malignant Thyroid Nodules: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of the current study was to investigate the diagnostic performance of technetium-99m (Tc-99m) methoxy-isobutyl-isonitrile (MIBI) for differentiation of malignant thyroid nodules (TN) through a systematic review and meta-analysis.

METHODS

The MEDLINE/PubMed and EMBASE database, from the earliest available date of indexing through January 31, 2018, were searched for studies evaluating the diagnostic performance of Tc-99m MIBI for TN. The sensitivities and specificities were determined across studies, positive and negative likelihood ratios (LR+ and LR-) were calculated, and summary receiver operating characteristic curves were constructed.

RESULTS

Across 22 studies (2421 patients), the pooled sensitivity for Tc-99m MIBI thyroid scan was 0.87 [confidence interval (CI) 0.76-0.93] with heterogeneity (I² = 92.3) and a pooled specificity of 0.78 [CI 0.67-0.86] with heterogeneity (I² = 96.4). LR syntheses gave an overall LR+ of 4.0 [CI 2.5-6.3] and LR- of 0.17 [CI 0.09-0.32]. The pooled diagnostic odds ratio was 24 [CI 63-176]. The hierarchical summary receiver operating characteristic curve indicates that the area under the curve was 0.90 [CI 0.87-0.92]. In meta-regression analysis, no definite variable was the source of the study heterogeneity.

CONCLUSION

The current meta-analysis shows a moderate sensitivity and specificity of Tc-99m MIBI thyroid scan for differentiation of malignant TN. However, the diagnostic odds ratio was relatively low and the LR scattergram indicated that Tc-99m MIBI thyroid scan is not useful for confirming the presence of malignant TN or for its exclusion. Therefore, Tc-99m MIBI thyroid scans should be used restrictively and interpreted cautiously when assessing TN for malignancy.

Diagnostic accuracy of [99mTc]Tc-Sestamibi in the assessment of thyroid nodules

[^99mTc]Tc-Sestamibi (MIBI) is an increasingly used tool for evaluation of thyroid nodules. However, there is a lack of evidence about the accuracy of this method in the European population. The aim of this study was to assess the utility of MIBI for the differentiation of thyroid nodules in a large cohort. 161 patients underwent MIBI, followed by a thyroidectomy. We used a dual phase MIBI protocol. Interpretation of the images included a scoring system from 0 (absent) to 3 (increased); this was to provide a scale for the uptake of the thyroid nodule in comparison to the paranodular tissue. Additionally, we evaluated the tracer uptake trend in late images compared to early images. We used the final histopathology as the reference standard. Scores 0-1 in early images, scores 0-2 in late images, and an absence of increasing uptake in the thyroid nodule in late images, showed the best predictive values to exclude malignancy, respectively (negative predictive value (NPV) 89%). Highest sensitivity (91%) for malignant nodules was evident in early images with a score 1-3. Highest specificity (91%) was obtained when the negative was defined as an absence of uptake-increase, in the late images. This study confirms that the most valuable feature of MIBI is the high NPV. Thus, with the appropriate interpretation method, high sensitivity and specificity, and moderate PPV can be obtained.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography May Exclude Malignancy in Sonographically Suspicious and Scintigraphically Hypofunctional Thyroid Nodules and Reduce Unnecessary Thyroid Surgeries

BACKGROUND

The aim of this study was to evaluate whether ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is useful in the further characterization of sonographically suspicious and scintigraphically hypofunctional thyroid nodules.

METHODS

Sixty-five patients with sonographically suspicious thyroid nodules that were hypofunctional on 99m-Tc-pertechnetate scintigraphy (diameter >1 cm) were retrospectively analyzed. All patients underwent evaluation with FDG-PET/CT. Thyroid nodules were sonographically categorized by Thyroid Image Reporting and Data System (TIRADS) criteria. FDG uptake in the thyroid nodules was visually compared to the remainder of the thyroid tissue and categorized as pathological or non-pathological. In cases of pathologically increased uptake, maximum standardized uptake values (SUVmax) of the suspicious nodule and the perinodular thyroid tissue were determined. Depending on the results of the FDG-PET/CT, patients underwent thyroid surgery (pathological FDG uptake) or follow-up examinations (non-pathological FDG uptake). The endpoints for comparison with the FDG uptake were either histological results or sonographic follow-up examinations of at least five years.

RESULTS

In 18/65 (28%) patients, PET/CT showed visually pathological FDG uptake in the suspicious thyroid nodules (SUVmax 7.1 ± 4.6). Of these nodules, 3/18 (17%) were sonographically categorized as TIRADS 4a, 11/18 (61%) nodules as TIRADS 4b, 3/18 (17%) nodules as TIRADS 4c, and 1/18 (6%) nodule as TIRADS 5. The other nodules without pathological FDG uptake were categorized as TIRADS 4a in 24/47 (51%) patients, as TIRADS 4b in 18/47 (38%), and as TIRADS 4c in 5/47 (11%) patients. Twenty-three patients (18 FDG positive, 5 FDG negative) underwent surgery. The other patients underwent follow-up examinations with stability on observation over at least five years as a surrogate endpoint. Taking into consideration that FDG-PET/CT was rated as true negative in 42/47 patients with stability on sonographic follow-up, sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET/CT in detecting malignancy in the suspicious thyroid nodules were 100%, 87%, 61%, and 100%, respectively.

CONCLUSION

FDG-PET/CT allows stratification of patients with sonographically suspicious and scintigraphically hypofunctional thyroid nodules with a positive predictive value of 61% and negative predictive value of 100%. The absence of visually pathological FDG uptake in suspicious thyroid nodules may be useful for avoiding unnecessary thyroid surgery.

Evaluation of hypofunctioning thyroid nodules with technetium-99m MIBI and ultrasonography

Background: Fine needle aspiration cytology (FNAC) cannot reliably differentiate follicular adenoma from follicular carcinoma (FC), which requires histological evidence of capsular or vascular invasion. FC is the most predominant thyroid cancer in our loco-regional environment, indicating the need for improvement in preoperative diagnostic accuracy of thyroid nodules to ensure appropriate and timely interventions.Objective: The purpose of this study was to assess the role of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy and ultrasonography (USG) in the differential diagnosis of thyroid nodules.Methods: Forty-two patients with hypofunctioning thyroid nodules were prospectively studied with 99mTc-MIBI scintigraphy and USG to differentiate benign from malignant nodules. An injection of 740 MBq of 99mTc-MIBI was intravenously administered, followed by semiquantitative analysis of dual-phase scans using a 4-point (0 to 3) scoring system. USG was subsequently performed and interpretation was based on some sonographic criteria for malignancy. In the following days and weeks, patients underwent FNAC followed by surgery and histopathologic examination.Results: All malignant nodules were positive on 99mTc-MIBI and all but two malignant nodules were positive on USG. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy are, respectively, 100%, 70%, 65%, 100%, and 81% for 99mTc-MIBI scintigraphy; 87%, 78%, 68%, 91% and 81% for USG; and 83%, 100%, 100%, 96% and 64% for FNAC. There was no statistically significant difference between 99mTc-MIBI scintigraphy and USG performance for both benign (p = 0.317) and malignant (p = 0.573) nodules.Conclusion: 99mTc-MIBI scintigraphy and USG are important imaging modalities in the evaluation of thyroid nodules, particularly follicular neoplasms which are frequently associated with non-diagnostic cytology.

Molecular Analysis by Gene Expression of Mitochondrial ATPase Subunits in Papillary Thyroid Cancer: Is ATP5E Transcript a Possible Early Tumor Marker?

BACKGROUND

Cancer development involves an "injury" to the respiratory machinery (Warburg effect) due to decreased or impaired mitochondrial function. This circumstance results in a down regulation of some of the ATPase subunits of the malignant tissue. The objective of this work was to assess and compare the relative expression of mRNA of mitochondrial ATPase subunits between samples of thyroid cancer and benign nodules.

MATERIAL AND METHODS

Samples from 31 patients who had an operation for PTC at the General Hospital of Mexico were snap-frozen and stored at -70°C. Thirty-five patients who had an operation for benign tumors were also included in the study. mRNA expression levels of alpha, beta, gamma, and epsilon subunits of F1 and "c12" of subunit Fo were determined by real-time RT-PCR (by duplicate), in order to determine if abnormal expression of these genes could partially explain the Warburg effect in papillary thyroid cancer (PTC).

RESULTS

ATP5E transcript alteration (down-expression) was highly associated to PTC diagnosis OR=11.76 (95% confidence interval, 1.245-237.98; p=0.04).

CONCLUSIONS

Relative down-expression of ATP5E transcript was highly associated with PTC diagnosis. This transcript alteration may be used as a tumoral marker in papillary thyroid cancer.

Comparison of thyroid blood flow and uptake indices using technetium-99m pertechnetate in patients with graves' disease and euthyroid subjects

Objective: The aim of the present study was to evaluate parameters of early blood flow (EBF) including duration of EBF, perfusion index (PI), uptake indexes 1 and 2 (UI1 and UI2) derived from dynamic thyroid scintigraphy in patients with Graves’ disease (GD), and euthyroid (EI). Maximum instant uptake and maximum uptake of the thyroid gland were also assessed.

Methods: A total of 50 patients with GD and EI were included in this study. Each patient underwent two dynamic scans of 1-minute (20 images at 3 seconds) and 20-minute (20 images at 1 minute) with ^99mTcO4. The time-activity curve of a 1-minute scan was employed to derive EBF parameters; likewise, the time-activity curve of a 20-minute scan was used to determine maximum instant uptake, and the gradient of the curve from the 10th to 20th minute was used to assess maximum uptake.

Results: Values of EBF duration, PI, UI1, UI2, and maximum instant uptake were significantly lower in patients with GD than in those with EI (p<0.05). The calculated gradient of the second half of the curves for all of the patients ranged from 0 to 0.88 and was significantly higher in patients with GD than in those with EI.

Conclusion: Lower values of PI, UI1, UI2 and durations of EBF, along with faster maximum instant uptake in patients with GD in comparison to EI are indicators of a heightened desire for hyper-functioning thyroid glands of patients with GD to absorb ^99mTcO4. Additionally, because of the uprising gradient at the end of the 20-minute time-activity curve, a maximum thyroid uptake of ^99mTcO4 was achieved at more than 20 minutes after the radiopharmaceutical injection.

Technetium-99m methoxyisobutylisonitrile scintigraphy in the assessment of cold thyroid nodules: is it time to change the approach to the management of cold thyroid nodules?

BACKGROUND

Scanning with technetium-99m methoxyisobutylisonitrile (Tc-MIBI) is recommended for evaluating thyroid nodule metabolism. In addition, it may help differentiate between benign and malignant nodules; however, the efficacy of this technique has not been fully elucidated. Therefore, it is not currently performed for routine clinical application. This prospective study was conducted to investigate the clinical significance of Tc-MIBI scintigraphy in the assessment of patients with cold thyroid nodules.

PATIENTS AND METHODS

This prospective study was conducted on 104 patients with cold thyroid nodules greater than 1 cm in diameter as detected on Tc-pertechnetate scintigraphy. Uptake of MIBI in thyroid nodules was compared with that in the surrounding normal thyroid tissue for both early and delayed images, and a score of 0-3 was assigned to each nodule as follows: 0, cold; 1, decreased; 2, equal; 3, increased. The thyroid scan was performed 20 and 40 min after intravenous injection of 555 MBq of Tc-MIBI. The patients underwent fine-needle aspiration cytology (FNAC). Detailed statistical parameters were determined on a per-nodule basis for each qualitative and quantitative scan analysis, as defined by histology.

RESULTS

A total of 104 patients (93 women and 11 men; mean age 40.76±11.40 years, range 20-73) with a total number of 167 cold nodules were included in this study. When Tc-MIBI uptake was regarded as the criterion of malignancy in Tc-MIBI scintigraphy, the accuracy was between 69.46 and 92.21% on using seven different methods. In addition, FNAC findings indicated a sensitivity of 66.66%, a specificity of 100%, a negative predictive value of 95.72%, a positive predictive value of 100%, and an accuracy of 96.06%. Six malignant cold nodules were detected on a positive Tc-MIBI scan, which were determined as benign nodules on FNAC examinations.

CONCLUSION

The study demonstrated that Tc-MIBI scanning can be complementary to other diagnostic techniques in patients with cold thyroid nodules. In addition, because of its availability, rather low cost, simple protocol, and objective semiquantitative information, Tc-MIBI scanning seems to hold promise in routine imaging of cold thyroid nodules.

Quantitative analysis of thyroid blood flow and static imaging in the differential diagnosis of thyroid nodules

OBJECTIVE

To evaluate the performance of combined quantitative analysis of thyroid blood flow and static imaging data in the differential diagnosis of thyroid nodules.

METHOD

Thyroid blood flow and static imaging were performed in 165 patients with thyroid nodules. Patients were divided into a benign thyroid nodule group (BTN, n=135) and a malignant thyroid nodule group (MTN, n=30) based on the results of post-surgical pathologic examination. Carotid artery thyroid transit times (CTTT), perfusion ratio of thyroid nodule blood/thyroid blood (TNB/TB), and perfusion ratio of thyroid nodule blood/carotid artery blood (TNB/CAB) were measured using thyroid blood flow imaging. The ratios between thyroid nodule and ipsilateral submandibular gland (TN/ SG) and thyroid nodule and normal thyroid tissue (TN/T) were measured from thyroid static imaging. The differences between the BTN and MTN groups were compared.

RESULTS

1) CTTT was markedly lower in the MTN group than the BTN group, the difference being statistically significant. 2) TNB/TB and TNB/CAB were both significantly higher in MTN than BTN groups. 3) TN/T was significantly lower in MTN group than BTN group. 4) TN/SG was lower in MTN group than BTN group, but the difference was not statistically significant. 5) Using the combination of CTTT and TN/T, the sensitivity, specificity and accuracy were 93.1%, 95.3% and 94.9% respectively for the diagnosis of MTN. Using the combination of CTTT, TNB/TB and TN/T, the sensitivity, specificity and accuracy changed to 89.7%, 100%, and 98.1% respectively. 6) Correlation analysis demonstrated a significant correlation between TN/T and TNB/TB (r=-0.384, P=0.036) and TNB/CAB (r=-0.466, P=0.009) in the MTN group.

CONCLUSION

The combination of quantitative markers from thyroid blood flow and thyroid static imaging had high specificity and accuracy in differential diagnosis of benign and malignant thyroid nodules, thus providing an important imaging diagnostic approach.

Diagnostic performance of (99m)Tc-MIBI scan in predicting the malignancy of thyroid nodules: a meta-analysis

Several studies have investigated the diagnostic performance of (99m)Tc-MIBI scan in the evaluation of thyroid nodules suspicious for malignancy with conflicting results. The aim of our study is to meta-analyze published data on this topic. A comprehensive literature search of studies published through December 2012 regarding the diagnostic performance of (99m)Tc-MIBI scan in the evaluation of thyroid nodules suspicious for malignancy was carried out. Pooled sensitivity and specificity of (99m)Tc-MIBI scan on a per lesion-based analysis and the area under the ROC curve were calculated. Pathological reports of thyroid nodules were considered as reference standard. Twenty-one studies were included in the meta-analysis. Pooled sensitivity and specificity of (99m)Tc-MIBI scan in detecting malignant thyroid nodules were 85.1 % [95 % confidence interval (95 % CI): 81.1-88.5 %] and 45.7 % (95 % CI: 42.7-48.7 %), respectively, on a per lesion-based analysis, irrespective of eventual results of previous technetium pertechnetate ((99m)TcO4) or iodine-123 ((123)I) scan. The area under the ROC curve was 0.78. A sub-analysis restricted to data on hypofunctioning nodules on (99m)TcO4 or (123)I scans was performed: pooled sensitivity and specificity of (99m)Tc-MIBI scan in these nodules were 82.1 % (95 % CI: 77.2-86.3 %) and 62.8 % (95 % CI: 58.9-66.7 %), respectively, on a per lesion-based analysis. The area under the ROC curve was 0.81. (99m)Tc-MIBI scan is a sensitive diagnostic tool in predicting the malignancy of thyroid nodules. Therefore, this imaging method could be helpful in patients with thyroid nodules in which malignancy is suspected on the basis of conventional diagnostic techniques. Higher specificity can be reached when hypofunctioning thyroid nodules are considered.

Evaluation of thyroid nodules--combined use of (99m)Tc-methylisobutylnitrile scintigraphy and aspiration cytology to assess risk of malignancy and stratify patients for surgical or nonsurgical therapy--a retrospective cohort study

OBJECTIVE

Thyroid nodules are a common clinical problem, and differentiation between benign and malignant nodules is essential. The aim of this study was to evaluate an approach for cold thyroid nodules including (99m)Tc-methylisobutylnitrile (MIBI) scintigraphy to assess risk of malignancy and stratify patients for therapy.

DESIGN

Retrospective cohort study; 391 patients with at least one cold thyroid nodule were consecutively admitted (between 1 January 2004 and 31 December 2006) and recommended for surgical or nonsurgical therapy.

MEASUREMENTS

Thyroid ultrasonography, (99m)Tc-pertechnetate scintigraphy, laboratory tests, fine needle aspiration cytology (FNAC) and MIBI scintigraphy.

RESULTS

57·3% (224/391) had one cold nodule, 17·9% (70/391) had several cold nodules, and 24·8% (97/391) had both cold and hot nodules. MIBI scintigraphy was classified into 'positive' (16·1%, 63/391), 'weakly positive' (19·2%, 75/391) or 'negative' (64·7%, 253/391). FNAC was classified into benign (87·9%, 247/281), nondiagnostic (6·8%, 19/281) or suspicious/malignant (5·3%, 15/281). 127 patients received surgery, revealing malignancy in 13·3% (17/127), predominantly papillary (64·7%, 11/17) and follicular carcinoma (23·5%, 4/17). MIBI scintigraphy was 'positive' (64·7%, 11/17) or 'weakly positive' (23·5%, 4/17) in most patients with malignant findings. FNAC was unavailable in 23·5% (4/17) with malignancy, positive in 38·5% (5/13) and negative in 61·5% (8/13). Among patients undergoing surgery, sensitivity, specificity, negative and positive predictive values for MIBI scintigraphy were 88·2%, 35·5%, 95·1% and 17·4%, for FNAC 38·5%, 90·6%, 90·6% and 38·5%, respectively, and for the combination (MIBI scan + FNAC) 92·3%, 30·6%, 96·3% and 16·9%. Benign MIBI-positive nodules were predominantly follicular adenomas (68%, 33/48).

CONCLUSION

Evaluation of cold thyroid nodules by MIBI scintigraphy aids therapeutic decisions: MIBI-negative findings support nonsurgical management in about two-thirds of patients, while MIBI-positive findings have an increased risk of malignancy, supporting surgical therapy. However, the positive predictive value was low, which requires further research.

(99m)Tc-sestamibi scanning in thyroid nodules with nondiagnostic cytology

BACKGROUND

Our aim in this study was to assess the relevance of (99m)Tc-sestaMIBI (MIBI) scan in the diagnostic evaluation of thyroid nodules with nondiagnostic cytology.

METHODS

In all, 74 patients with a single nodule and repeatedly nondiagnostic ultrasound-guided fine-needle aspiration cytology (US-FNAC) were enrolled. In all cases thyroid nodules were cold in (99m)Tc-pertechnetate (Tc) scans. Thyroid scans were also acquired 30 and 120 minutes after intravenous administration of MIBI. Nodules that concentrate MIBI were considered as positive (ie, suspicious for malignancy). Histologic findings were obtained after surgery in all patients.

RESULTS

No differences occurred in early and late MIBI images. None of 63 patients with a negative MIBI scan had a final histologic diagnosis of malignancy (ie, no false-negative results). Two patients with a final histologic diagnosis of papillary thyroid carcinoma (PTC) and 1 with follicular thyroid carcinoma (FTC) had a positive MIBI scan. Eight patients with a final histologic diagnosis of benign lesions (3 with follicular adenomas) also had MIBI-positive scans. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were, respectively, 100%, 88%, 89%, 27%, and 100%.

CONCLUSIONS

A negative MIBI scan in a cold nodule accurately excludes malignancy when US-FNAC is reported as nondiagnostic. This avoids the need for more invasive diagnostic procedures (ie, surgery) and positively influences the cost-effectiveness profile. A MIBI scan may be performed by acquiring images 30 minutes after tracer administration alone. Histology is still necessary to distinguish benign from malignant disease in a MIBI-positive nodule but unnecessary surgery could have been reduced from 71 to 8 cases in our series.

Use of color Doppler ultrasonography for the prediction of malignancy in follicular thyroid neoplasms: systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review was to obtain summary estimates of the diagnostic accuracy of color Doppler ultrasonography (CDU) in predicting malignancy in thyroid follicular neoplasms (FNs).

METHODS

We searched Medical Subject Headings together with the search terms "follicular," "thyroid," and "Doppler" in the MEDLINE, Web of Science, and Excerpta Medica databases as well as the Latin American and Caribbean Health Sciences Literature database, after which we performed manual searches of the reference lists to locate additional studies. There were no language restrictions. We included studies that assessed the diagnostic accuracy of CDU in identifying malignancy in thyroid FNs. The assessments of the quality and extraction of data were performed by 3 independent reviewers.

RESULTS

We included 4 studies, which collectively evaluated 457 thyroid FNs, 67 of which had been classified as malignant based on the evaluation of surgical biopsy samples. Moderate, rich, predominant, or exclusive internal flow on CDU of thyroid FNs was considered indicative of malignancy. The overall sensitivity of CDU was 85% (95% confidence interval [CI], 74%-93%), with an overall specificity of 86% (95% CI, 82%-89%). The overall prevalence was 14.7%, and the positive and negative predictive values were 51% and 97%, respectively. The positive likelihood ratio was 6.07, and the negative likelihood ratio was 0.18.

CONCLUSIONS

Predominant internal flow seen on CDU is associated with malignancy of thyroid FNs. Absence of internal flow or predominantly peripheral flow indicates a low probability of thyroid FN malignancy.

FAIR true-FISP perfusion imaging of the thyroid gland

PURPOSE

To evaluate the feasibility of quantitative perfusion MRI of the thyroid gland using an arterial spin labeling (ASL) method.

MATERIALS AND METHODS

An ASL technique with flow-sensitive alternating inversion-recovery (FAIR) spin preparation and a true fast imaging in the steady state (TrueFISP) signal readout strategy was implemented on a 1.5T whole-body unit. Anatomical and perfusion imaging of the thyroid gland was performed in eight healthy volunteers and one patient with functioning adenoma. Quantitative perfusion maps were calculated using the extended Bloch equations.

RESULTS

In all subjects the perfusion images showed diagnostic image quality. The mean examination time was 24 minutes for multiplanar perfusion imaging of the entire thyroid gland. Individual perfusion values ranged between 341 +/- 91 and 640 +/- 90 mL/100 g/minute, with a mean perfusion of 461 +/- 90 mL/100 g/minute. The functioning adenoma showed markedly reduced perfusion compared to normal thyroidal parenchyma. No perfusion was noticeable inside four detected thyroid cysts.

CONCLUSION

Quantitative ASL perfusion imaging of the thyroid gland using a FAIR-TrueFISP sequence leads to perfusion maps that may provide important information for assessing thyroid gland pathologies and monitoring therapeutic treatment.

Cytological and histological diagnoses of recurrent thyroid carcinoma with monoclonal antibody JT-95, which can detect modified fibronectin

Although fine needle aspiration (FNA) cytology has increasingly gained importance as a tool in thyroid diagnosis over the recent years, up to 20% of thyroid carcinomas, in particular follicular tumors and follicular variant tumors, are inconclusive by FNA. The monoclonal antibody (MoAb) JT-95 detects the modified fibronectin, expressed in most thyroid carcinomas. Consequently, it has been applied to FNA and tissue section specimens obtained from thyroid tumors during surgery. For FNA specimens of 57 thyroid tumors followed-up for more than 10 years postoperatively and stained with both the Papanicolaou and the immunoperoxidase technique using MoAb JT-95, we retrospectively compared the sensitivity, specificity, and diagnostic accuracy of the two procedures. Histological specimens stained with HE and investigated by JT-95 were also re-evaluated. The pathological results of aspirated specimens, after a change in diagnosis following recurrence, revealed that 43 of 47 malignant lesions were positive, while nine of 10 benign tumors remained unreactive using MoAb JT-95. Sensitivity was 91.4%, specificity 90.0%, and diagnostic accuracy 91.2% by JT-95 cytology. By contrast, sensitivity ascertained by the Papanicolaou technique was 78.1%, specificity 100%, and accuracy 82.4%. Of the six examples that recurred during the 10-12-year follow-up period, tissue sections of all six and aspirated materials of five of the six were stained by JT-95.