Reducing inter-observer variation in thyroid volume calculation using a new formula and technique

Examining the impact of several factors including COVID-19 on thyroid fine-needle aspiration biopsy

OBJECTIVE

The study explores various factors, including coronavirus disease 2019 (COVID-19) history and vaccination status, that influence the classification value of ultrasonography-guided thyroid fine needle aspiration biopsy (TFNAB) by comparing non-diagnostic (Bethesda-I) and diagnostic (Bethesda II-VI) results.

METHODS

We conducted a retrospective observational study in a high-volume tertiary care center involving patients who underwent TFNAB from November 2022 to April 2023. The study retrospectively analyzed the cytopathology of 482 thyroid nodules. Patients were categorized into non-diagnostic (n = 136) and Diagnostic groups (n = 346) based on TFNAB. A comprehensive set of parameters was examined, including demographic, anthropometric and clinical data, thyroid ultrasonography findings, COVID-19 history and immunization status.

RESULTS

The mean age was 55.1 ± 12.1 years in the non-diagnostic group and 53.5 ± 13 years in the Diagnostic group (p = .223). 75.7% (n = 103) of the non-Diagnostic group and 82.9% (n = 287) of the Diagnostic group were male (p = .070). The mean nodule longitudinal diameter of the Diagnostic group was significantly higher than that of the non-diagnostic group (p = .015). The TIRADS score of the nodules showed a statistical difference between the groups (p = .048). The groups had no significant differences regarding other ultrasonographic parameters and COVID-19-related variables.

CONCLUSION

It can be assumed that when the longitudinal diameter of the thyroid nodule is small and in TIRADS categories other than the TIRADS3 category, TFNAB is less likely to be diagnostic. However, future research may be needed to confirm these findings and uncover any long-term effects of COVID-19 or vaccines on thyroid nodule diagnostics.

The Relationship of Thyroid Functions With ADMA, IMA, and Metabolic Laboratory Parameters in Euthyroid Adults With and Without Autoimmune Thyroiditis

OBJECTIVE

To investigate the relationship between thyroid functions and asymmetric dimethylarginine (ADMA), ischemia-modified albumin (IMA), and other metabolic laboratory markers in euthyroid adults and whether narrower thyroidal targets are required for lower metabolic risk.

MATERIALS AND METHODS

Thyroid functions, antithyroid autoantibodies, and metabolic parameters were measured for 115 patients. Forty-seven had autoimmune thyroiditis (AIT). Analyses were performed according to cutoff values of 1, 2, 2.5, and 3 mIU/L for thyrotropin, 0.84 ng/dL for free thyroxine (fT4), and 3.59 ng/dL for free tri-iodothyronine (fT3).

RESULTS

There was no relationship between thyrotropin and fT3 cutoff values and metabolic parameters. Only C-reactive protein was lower in the group with thyrotropin ≤2.5 μIU/L. A weak positive correlation was found between fT4 with IMA and IMA corrected for albumin (r = 0.187, P = .05; r = 0.204, P = .034, respectively). There was no difference between AIT and the metabolic laboratory parameters examined in the study.

CONCLUSION

This study is the first to evaluate ADMA in AIT. Narrower thyroid function targets are not required for better metabolic control in euthyroid adults.

Determination of thyroid volume in infants with suspected congenital hypothyroidism-the limitations of both subjective and objective evaluation

Objective:

To compare two methods of assessing gland size on thyroid ultrasound in newborn infants with suspected congenital hypothyroidism (CH).

Methods:

Images from infants with eutopic glands referred between 2007 and 2013 were evaluated blind by two sets of observers. Subjective gland size was categorised as small, borderline-small, normal, borderline-large and large. Objective gland volume, calculated as the sum of each lobe using the prolate ellipsoid formula (length x width x depth x π/6), was put into corresponding categories: <0.8, 0.81–1.0, 1.1– <2.2, 2.2–2.4 and >2.4 ml, derived from normative Scottish data.

Results:

Of 36 infants, permanent CH was present in 17, transient CH in 17, status uncertain in 2. Mean (SD) intraobserver error for thyroid volume measurement was 0.11 (0.23) ml [8.3%]. Subjective assessment by two observers was discordant in only four (10.8%) infants. However, subjective vs objective evaluation was discordant in 14 (39%). Eight (three permanent, five transient CH) had large glands subjectively but normal glands objectively; and six (four transient CH) had normal glands subjectively but small glands objectively. The former infants all showed a single flattened curve to the anterior thyroid margin, giving an impression of bulkiness. Gland shape was normal in the latter infants.

Conclusion:

Neither subjective nor objective evaluation predicts permanent vs transient CH. Altered gland shape may confound both methods, and undermine use of the conventional formula for measuring lobe volume.

Advances in knowledge:

Until more refined methods are available for assessing thyroid size, both subjective and objective evaluation are recommended in CH.

Determining the Thyroid Gland Volume Causing Tracheal Compression: A Semiautomated 3D CT Volumetry Study

Background and objectives: Increased thyroid gland volume (TV) may bring about tracheal compression, which is one of the causes of respiratory distress. The aim of this study was to investigate the relationship between TV and the severity of tracheal compression independent of patients’ symptoms using semiautomated three-dimensional (3D) volumetry (S3DV) reconstructed from computed tomography (CT) scans. Cut-off TVs leading to different levels of tracheal narrowing were evaluated. Materials and Methods: One hundred sixty-three contrast-enhanced head and neck CT examinations were retrospectively assessed. TVs were measured by S3DV. The degree of tracheal compression was measured at the point where the greatest percent reduction in the cross-sectional area of the trachea adjacent to the thyroid gland was observed. To determine the severity of compression, the tracheal compression ratio (TCR) was defined (TCR = A1 (the narrowest cross-sectional area of trachea)/A2 (the largest cross-sectional area of trachea)). Results: The mean tracheal narrowing was 15% (TCR = 0.85 ± 0.15) in the study population. Patients with more than 15% tracheal compression had significantly higher TV values than those with less than 15% tracheal compression (p < 0.001). In addition, a significant correlation was found between TV and tracheal compression (p < 0.001). Moreover, the receiver operating characteristic (ROC) curve analysis revealed that the cut-off levels for TV that predict a tracheal narrowing of 10%, 20%, 30%, and 40% were 19.75 mL, 21.56 mL, 24.54 mL, and 30.29 mL, respectively (p < 0.05). Conclusions: This study objectively demonstrated that larger thyroid glands cause more severe compression on the trachea. The results may be helpful during the decision-making process for thyroidectomies to be performed due to compression symptoms.

The effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism

AIM

To investigate the effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism.

MATERIAL AND METHODS

This controlled, randomized, prospective cohort was carried out on 40 patients who admitted for surgery due to hyperthyroidism. Cases were randomly assigned to receive either preoperative treatment with Lugol solution (Group 1) or no preoperative treatment with Lugol solution (Group 2). Group 3 (n = 10) consisted of healthy adults with no known history and signs of hyperthyroidism. Blood flow through the thyroid arteries of patients was measured by color flow Doppler ultrasonography. Free T3, free T4, TSH, thyroid volume and the resistance index of the four main thyroid arteries were measured in all patients.

RESULTS

There was not a significant difference between gender, preoperative serum thyroid hormone levels, or thyroid gland volumes between groups 1 and 2. The mean blood flow of the patients in Group 1 was significantly lower than values in Group 2. When age, gender, thyroid hormone, TSH, thyroid volume, blood flow, and Lugol solution treatment were included as independent variables, Lugol solution treatment (OR, 7.40; 95% CI, 1.02-58.46; p = 0.001) was found to be the only significant independent determinant of intraoperative blood loss. Lugol solution treatment resulted in a 7.40-fold decrease in the rate of intraoperative blood loss.

CONCLUSION

Preoperative Lugol solution treatment was found to be a significant independent determinant of intraoperative blood loss. Moreover, preoperative Lugol solution treatment decreased the rate of blood flow, and intraoperative blood loss during thyroidectomy.

Analysis of tissue surrounding thyroid nodules by ultrasound digital images

Since US is not easily reproducible, the digital image analysis (IA) has been proposed so that the image evaluation is not subjective. In fact, IA meets the criteria of objectivity, accurateness, and reproducibility by a matrix of pixels whose value is displayed in a gray level. This study aims at evaluating via IA the tissue surrounding a thyroid nodule (backyard tissue, BT) from goitres with benign (b-BT) and malignant (m-BT) lesions. Sixty-nine US images of thyroid nodules surrounded by adequate thyroid tissue was classified as normoechoic and homogeneous were enrolled as study group. Forty-three US images from normal thyroid (NT) glands were included as controls. Digital images of 800 × 652 pixels were acquired at a resolution of eight bits with a 256 gray levels depth. By one-way ANOVA, the 43 NT glands were not statistically different (P = 0.91). Mean gray level of normal glands was significantly higher than b-BT (P = 0.026), and m-BT (P = 0.0001), while no difference was found between b-BT and m-BT (P = 0.321). NT tissue boundary external to the nodule was found at 6.0 ± 0.5 mm in cancers and 4.0 ± 0.5 mm in benignancies (P = 0.001). These data should indicate that the tissue surrounding a thyroid nodule may be damaged even when assessed as normal by US. This is of interest to investigate the extranodular effects of thyroid tumors.

[Efficacy and budget impact of the Focus harmonic scalpel compared to the ACS-14C device in total thyroidectomy due to multinodular goitre. A prospective randomised study]

OBJECTIVE

To analyse the potential advantages and outcomes of the new Harmonic Focus™ (Focus) device compared to the Harmonic Scalpel™ ACS-14C in benign thyroid surgery.

METHODS

A controlled randomised study was conducted in which the Focus was compared to former ACS-14C device in patients undergoing total thyroidectomy for multinodular goitre. The primary endpoint was time of surgery. The secondary endpoints were time of use of the device, number of ligatures, blood loss, hypocalcaemia, laryngeal nerve impairment, postoperative pain and quality of life.

RESULTS

Two groups of patients were included, 26 patients in group i (ACS-14C) and 28 in group ii (Focus). There was a 16% reduction in surgical time (78.7 ± 22.01 vs. 66 ± 17.0 min; P<.05) between group i and ii respectively. The Focus was used longer than ACE-14S, both in absolute time (26.0 ± 7.7 vs. 10.0 ± 3.5 minutes; P<.05), as well as in relative time (40.7 ± 11.8% vs. 13.1 ± 4.1%; P<.05), respectively. A significant reduction in number of ligatures in Focus patients was also observed (0,3 ± 0,8 vs. 2.9 ± 3.6; P<.05). Budget impact analysis showed an additional average savings per procedure of 179.74 €.

CONCLUSIONS

Focus ergonomics significantly improved the operation time in thyroidectomy causing a positive impact on the budget. Focus also adds further benefits to those previously achieved by Harmonic technology, and it is by itself more cost-effective in total thyroidectomy than ACS-14C.

Evaluation of two-dimensional and three-dimensional ultrasound in the assessment of thyroid volume of the Indo-Pacific bottlenose dolphin (Tursiops aduncus)

The assessment of thyroid volume plays an indispensable role in the diagnosis and management of different thyroid diseases. The present study evaluates the accuracy of dolphin thyroid volume measurement as determined by four two-dimensional (2D) ultrasound methods (A-D), with a standard of reference using three-dimensional (3D) ultrasound. The measurement accuracy for different recognized thyroid configuration is also evaluated. Inter- and intraoperator variability of the measurement methods was determined. Thyroid ultrasound examinations were conducted in 16 apparently healthy Indo-Pacific bottlenose dolphins (Tursiops aduncus) with 2D and 3D ultrasound under identical scanning conditions. All 2D ultrasound measurement methods yielded high accuracies (79.9-81.3%) when compared with the 3D ultrasound measurement, and had high measurement reproducibility (77.6-86.2%) and repeatability (78.1-99.7%). For 2D ultrasound measurements, Methods A and B were more accurate and reliable than Methods C and D, regardless of thyroid configuration. Ultrasound is useful in the measurement of thyroid volume in bottlenose dolphins. For the first time, a reliable ultrasound scanning protocol for measuring dolphin thyroid volume was developed, which provides a means to establish a normative reference for the diagnosis of thyroid pathologies and to monitor the thyroid volume during the course of treatment in living dolphins. Key words: 3D ultrasound, Indo-Pacific bottlenose dolphin, thyroid volume measurement, Tursiops aduncus.

A comparison of portable ultrasound and fully-equipped clinical ultrasound unit in the thyroid size measurement of the Indo-Pacific bottlenose dolphin

Measurement of thyroid size and volume is a useful clinical parameter in both human and veterinary medicine, particularly for diagnosing thyroid diseases and guiding corrective therapy. Procuring a fully-equipped clinical ultrasound unit (FCUS) may be difficult in most veterinary settings. The present study evaluated the inter-equipment variability in dolphin thyroid ultrasound measurements between a portable ultrasound unit (PUS) and a FCUS; for both units, repeatability was also assessed. Thyroid ultrasound examinations were performed on 15 apparently healthy bottlenose dolphins with both PUS and FCUS under identical scanning conditions. There was a high level of agreement between the two ultrasound units in dolphin thyroid measurements (ICC = 0.859-0.976). A high intra-operator repeatability in thyroid measurements was found (PUS: ICC = 0.854-0.984, FCUS: ICC = 0.709-0.954). As a conclusion, no substantial inter-equipment variability was found between PUS and FCUS in dolphin thyroid size measurements under identical scanning conditions, supporting further application of PUS for quantitative analyses of dolphin thyroid gland in both research and clinical practices at aquarium settings.

Correlação entre volume tireoidiano determinado pelo método de ultrassonografia versus cintilografia e sua implicação em cálculos dosimétricos na terapia com radioiodo na doença de Graves

INTRODUÇÃO: A doença de Graves (DG) é a causa mais comum de hipertireoidismo e, entre as abordagens terapêuticas mais utilizadas para o tratamento do hipertireoidismo por doença de Graves, encontram-se a cirurgia, o uso de drogas antitireoidianas e a radioiodoterapia. No cálculo dosimétrico para determinação da dose de radioiodo a ser utilizada, é possível empregar a ultrassonografia e a cintilografia para avaliar o volume tireoidiano. OBJETIVO: O presente estudo visa correlacionar essas metodologias com ênfase no volume obtido e nas implicações dosimétricas. SUJEITOS E MÉTODOS: Foram incluídos no estudo 103 pacientes com diagnóstico de DG encaminhados para radioiodoterapia. Esses foram submetidos à ultrassonografia da tireoide e à cintilografia tireoidiana, com cálculo de volume pela cintilografia baseado na fórmula de Allen. RESULTADOS E CONCLUSÕES: Observou-se boa correlação entre os dois métodos, porém com massa estimada pela cintilografia sistematicamente maior que a estimada pela ultrassonografia, o que pode acarretar em menor estimativa de dose absorvida quando utilizado o método cintilográfico.

Local reference ranges of thyroid volume in sudanese normal subjects using ultrasound

This study aimed to establish a local reference of thyroid volume in Sudanese normal subjects using ultrasound. A total of 103 healthy subjects were studied, 28 (27.18%) females and 75 (72.82%) males. Thyroid volume was estimated using ellipsoid formula. The mean age and range of the subjects was 21.8 (19–29) years; the mean body mass index (BMI) was 22.3 (16.46–26.07) kg/m². The overall mean volume ± SD volume of the thyroid gland for both lobes in all the patients studied was 6.44 ± 2.44 mL. The mean volume for both lobes in females and males were 5.78 ± 1.96 mL and 6.69 ± 2.56 mL, respectively. The males' thyroid volume was greater than the females'. The mean volume of the right and left lobes of the thyroid gland in males and females were 3.38 ± 1.37 mL and 3.09 ± 1.24 mL, respectively. The right thyroid lobe volume was greater than the left. The values obtained in this study were lower than those reported from previous studies.

Subphrenic abscess secondary to Actinomycosis meyeri and Klebsiella ozaenae following laparoscopic cholecystectomy

A case is reported of a subphrenic abscess 12 months post-laparoscopic cholecystectomy in a 72-year-old male with identification of Actinomyces meyeri and the oropharyngeal commensal Klebsiella ozaenae. The first organism is exceptionally rare following laparoscopic cholecystectomy and is presumed to be a result of inadvertent gallstone spillage. The second organism has not previously been reported in a subphrenic abscess. The etiopathogenesis and management of this condition are presented.

The characteristics of concomitant thyroid nodules cause false-positive ultrasonography results in primary hyperparathyroidism

BACKGROUND

Concomitant thyroid nodules are the most common reason for false-positive ultrasonography (US) results in primary hyperparathyroidism. The aims of this prospective clinical study were to evaluate false-positive US results according to the characteristics of concomitant thyroid nodules and to determine which characteristics of thyroid nodules are important.

STUDY DESIGN

This prospective study included 120 consecutive patients with primary hyperparathyroidism. The patients were divided into 2 groups according to preoperative US results. Group 1 consisted of 32 patients with false-positive US results and group 2 consisted of 88 patients with true-positive US results.

RESULTS

The risk for false-positive US result was increased 25-fold for patients with parathyroid adenoma weight of more than 500 mg (odds ratio [OR], 25; 95% confidence interval [CI], 8.6-74.5), 75-fold for more than 1 posteriorly located thyroid (OR, 75; 95% CI, 19.3-293.4), 358-fold for the presence of exophytic thyroid nodules (OR, 358; 95% CI, 42.3-3036), and 423-fold for the presence of posteriorly located thyroid nodules (OR, 423; 95% CI, 49-3662).

CONCLUSION

Although there was no particular characteristic of concomitant thyroid nodules that contributes to false-positive US results, the posteriorly located thyroid nodules were the strongest correlate for the false-positive US results to other features.

Thyroid volumetric quantification: comparative evaluation between conventional and volumetric ultrasonography

OBJECTIVE

Thyroid volume quantification is an important parameter for radiotherapy dosing in cases of major thyroid diseases such as thyroiditis and carcinoma. In clinical practice, this calculation is performed by means of ultrasonography on the basis of an ellipsoid formula obtained from the 3 axes. The aim of our study was to compare the accuracy of volume calculation between B-mode ultrasonography and volumetric ultrasonography (VUS).

METHODS

Between April and May 2007, 27 consecutive patients selected for thyroidectomy were prospectively evaluated. One expert ultrasound operator calculated each thyroid volume with standard B-mode ultrasonography on the basis of the 3 axes of each lobe, and then the patients were analyzed with an offline workstation equipped with volumetric probes (VUS). On the offline workstation, 2 separate blinded operators (VUS1 and VUS2) calculated the thyroid volume with virtual organ computer-aided analysis. Data acquired were then compared with pathologic anatomy (PA).

RESULTS

The mean time for B-mode analysis was 6 minutes, whereas VUS analysis needed a mean time of 16.5 minutes. Interobserver variability between the median VUS1 and VUS2 measurements was 0.36 mL (interquartile range [IQR], -0.79 to 0.37 mL; P < .156). The median variability between B-mode ultrasonography and PA was -9.6 mL (IQR, -16.7 to 1.5 mL; P < .001), and that between VUS and PA was -2.87 mL (IQR, -11.97 to 9.51 mL; P = .019). The overall performance of B-mode ultrasonography in comparison with PA was -29.1% (IQR, -47.5% to -5.9%), and that of VUS in comparison with PA was -6.3% (IQR, -26.3 to 13.7%; P < .001).

CONCLUSIONS

Volumetric ultrasonography is a valid tool that compares better with PA than does B-mode ultrasonography.

A mathematical formula to estimate in vivo thyroid volume from two-dimensional ultrasonography

BACKGROUND

The determination of thyroid volume (TV) is required for the management of thyroid diseases. Since two-dimensional ultrasonography (2D-US) has become the accepted method for the assessment of TV (2D-US-TV), we verified whether it accurately assesses postsurgical measured TV (PS-TV).

METHODS

In 92 patients who underwent total thyroidectomy by conventional cervicotomy, 2D-US-TV obtained by the ellipsoid volume formula was compared to PS-TV, determined by the Archimedes' principle.

RESULTS

Mean 2D-US-TV (23.9 +/- 14.8 mL) was significantly lower than mean PS-TV (33.4 +/- 20.1 mL). Underestimation was observed in 77% of cases, and it was related to gland multinodularity and/or nodular involvement of the isthmus, while 2D-US-TV matched the PS-TV in the remaining 21 cases (23%). A mathematical formula, to estimate PS-TV from US-TV, was derived using a linear model (Calculated-TV = [1.24 x 2D-US-TV]+ 3.66). Calculated-TV (mean value 33.4 +/- 18.3 mL) significantly (p < 0.01) increased from 21 (23%) to 31 (34%) of the cases that matched PS-TV. In addition, it significantly (p < 0.01) decreased from 77% to 27% the percentage of cases where PS-TV was underestimated as well as the range of the disagreement from 245% to 92%.

CONCLUSIONS

This study shows that 2D-US does not provide an accurate estimation of TV and suggests that it can be improved by a mathematical model different from the ellipsoid model. If confirmed in prospective studies, this may contribute to a more appropriate management of thyroid diseases.

Interobserver and Intraobserver Variability in the Sonographic Measurement of the Size of the Thyroid Gland by Extended Field-of-View Sonography

Significant intra- and interobserver variation has been reported for estimating the dimensions and the volume of the thyroid gland by conventional sonography in adults. This study aimed to assess the role of extended field-of-view (EFOV) sonography for evaluating the size of the thyroid gland. The mediolateral, anteroposterior, and craniocaudal diameters of both thyroid lobes as well as total thyroid volumes of 30 female patients with the clinical diagnosis of goiter were measured three times by three radiologists with the EFOV sonography technique. Based on these findings, the correlation between the measurements of different operators and different measurements of the same operator was investigated. The interobserver variations for craniocaudal diameters of the right and left thyroid lobes were 3.3% ± 1.9% (mean ± SD) and 2.8% ± 1.3% (mean ± SD), respectively ( P = .012), which were lower than the variations calculated for transverse and mediolateral diameters. The interobserver variation for the calculation of the total glandular volume was 6.3% ± 3.8% (mean ± SD). The intraobserver variations for the three radiologists assessing the total thyroid volume were 4.9% ± 3.0%, 4.2% ± 2.4%, and 4.5% ± 1.7% (all mean ± SD), respectively ( P = .521). EFOV sonography should be considered as an alternative technique for the dimension measurements of the thyroid gland, particularly in cases with goiter.

Determination of remnant thyroid volume: comparison of ultrasonography, radioactive iodine uptake and serum thyroid-stimulating hormone level

Purpose:

We aimed to evaluate the accuracy of ultrasonography, radioactive iodine uptake and serum thyroid-stimulating hormone level in predicting the volume of remnant thyroid gland.

Methods:

Sixty-six thyroidectomy patients were divided into two groups according to their functional status, i.e. those operated upon for nontoxic multinodular goitre (group one) and those operated upon for hyperthyroidism (group two). Ultrasonography, radioactive iodine uptake and thyroid-stimulating hormone assay were performed in all patients during the first post-operative month. The two groups were subdivided according to the amount of remnant thyroid volume detected on ultrasonography: <2 ml, 2–5 ml and >5 ml.

Results:

The remnant thyroid volume was positively correlated with the radioactive iodine uptake (rs = 0.684, p = 0.0001). The increase in remnant thyroid tissue radioactive iodine uptake was significantly greater in the patients operated upon for hyperthyroidism compared with those operated upon for nontoxic multinodular goitre (p = 0.0001). There was a negative correlation between remnant thyroid volume and post-operative serum thyroid-stimulating hormone level (rs =  −0.865, p = 0.0001) and between remnant thyroid tissue radioactive iodine uptake and post-operative serum thyroid-stimulating hormone level (rs = −0.682, p = 0.0001).

Conclusion:

Ultrasonography is a more accurate measure of remnant thyroid volume than radioactive iodine uptake in patients operated upon for hyperthyroidism, compared with those operated upon for nontoxic multinodular goitre.

Effect of lugol solution on thyroid gland blood flow and microvessel density in the patients with Graves' disease

CONTEXT

Although some endocrine surgeons administer Lugol solution to decrease thyroid gland vascularity, there is still not an agreement on its effectiveness.

OBJECTIVE

The aims of this clinical trial are to evaluate thyroid blood flow and microvessel density in patients with Graves' disease who received Lugol solution treatment preoperatively.

DESIGN

This was a prospective clinical trial.

SETTING

This clinical trial took place at a tertiary referral center.

METHOD

Thirty-six patients were randomly assigned to receive either preoperative treatment with Lugol solution (group 1, n = 17) or no preoperative treatment with Lugol solution (group 2, n = 19).

MAIN OUTCOME MEASURES

Blood flow through the thyroid arteries of patients with Graves' disease was measured by color flow Doppler ultrasonography. The microvessel density (MVD) was assessed by immunohistochemical and Western blot analysis of the level of expression of CD-34 in thyroid tissue. The weight and blood loss of the thyroid gland were measured in all patients.

RESULTS

The mean blood flow, MVD, CD-34 expression, and blood loss in group 1 patients were significantly lower than those in group 2 patients. There was a negative correlation between Lugol solution treatment and blood flow (r(s) = -0.629; P = 0.0001), blood loss (r(s) = -0.621; P = 0.0001), MVD (r(s) = -0.865; P = 0.0001), and CD-34 expression (r(s) = -0.865; P = 0.0001). According to logistic regression analysis, Lugol solution treatment resulted in a 9.33-fold decreased rate of intraoperative blood loss.

CONCLUSION

Preoperative Lugol solution treatment decreased the rate of blood flow, thyroid vascularity, and intraoperative blood loss during thyroidectomy.

Measuring thyroid gland volume: should we change the correction factor?

OBJECTIVE

In the assessment of thyroid volume with sonography (formula of an ellipsoid), a correction factor is used. Whereas previously 0.524 was used, the World Health Organization has recently changed (after the first review) this correction factor to 0.479. We compare volume measurement of the thyroid using different correction factors to automated volume measurement using MDCT, and we define an optimal correction factor in thyroid volume assessment.

CONCLUSION

Acceptable correction factors are situated in the range of 0.494-0.554. We propose a correction factor of 0.529 when using the ellipsoid formula.

Ultrasonography estimated thyroid volume: a prospective study about its reliability

Ultrasonography is supposed to provide a reliable preoperative estimate of thyroid volume. This prospective study compares the estimated thyroid volume (EV) to real volume (MV), obtained by measuring the excised gland after surgery. One hundred one patients undergoing total thyroidectomy were selected for the study. Indications for surgery were: multinodular goiter, diffuse toxic goiter (DTG), uninodular disease. In all cases, ultrasound was repeated 1 month after surgery to verify complete thyroid removal. EV was underestimated in 89 cases; it perfectly matched the MV in 5 and was overestimated in 7. Mean EV was 28.3 mL (range, 7-50) and mean MV 36.2 mL (range, 7-76); this difference was statistically significant (p < 0.0001). Patients were then divided in groups according to EV (< or > than 25 mL) and thyroid morphology. Highly significant differences were found between all groups (p < 0.0001) except the DTG population, where the difference was less significant (p < 0.042). The study demonstrates that a correct preoperative measurement of the thyroid gland is not achievable because the volume estimated by ultrasound is largely underestimated in comparison to the real volume of the excised gland. Nevertheless ultrasound is more reliable in DTG than in other thyroid diseases. Increasing the number of cases may help to verify a new mathematical model.

Three-dimensional ultrasound measurement of thyroid volume in asymptomatic male Chinese

This study was undertaken to determine the accuracy and reliability of volume measurements using 3-D ultrasound (US). Variation of thyroid gland volume with age in asymptomatic Chinese men was also investigated. Volumetric measurements of the phantoms and thyroid glands were performed with a commercially available US machine in conjunction with the 3-D SonoScan Pro workstation. Ten tissue phantoms with volumes of 1.5 to 6.5 mL were measured with 3-D US. A water displacement method was used to measure the actual volume of the phantoms. The measured volumes were compared to the actual volumes. Volumes were measured by four operators to investigate interobserver variation. Thyroid US examinations were performed in 38 asymptomatic male Chinese subjects ages 21 to 72 years. The subjects were categorized into four age groups. In each subject, the volume of the left and right lobes and the isthmus of the thyroid gland were measured with 3-D US, and any variation with age was evaluated. Results showed that the actual volume of the tissue phantoms was highly correlated with the volume measured by the four operators (r = 0.9912 to 0.9977, p < 0.05). Interobserver variation in the volumetric measurements of the tissue phantoms was not significant (ICC = 0.9861). The range of thyroid volume of the subjects was 8.81 to 17.25 mL (mean 12.78 +/- SD 2.483), and there was no significant difference in thyroid volume between subjects of different age groups (p > 0.05). 3-D US is an accurate and reliable method by which to measure thyroid volume.

Technical observations on the assessment of thyroid volume by palpation and ultrasonography

OBJECTIVE

The diagnosis of increased thyroid volume, in field studies of goiter prevalence, has been based on inspection and palpation of the thyroid. Because clinical examination, compared with ultrasonography, has a low positive predictive value for the presence of a goiter, it overestimates goiter prevalence. It also has the problem of marked interobserver variability. This led to the use of ultrasonographic scanners in field studies. The problem with the latter is the cost and skill required for the complicated linear measures and their translation to lobe volume and then thyroid volume. We studied patients to determine whether this complicated assessment could be simplified.

METHODS

We studied palpation in 31 patients with thyroid disease in whom individual ultrasonographic linear dimensions were also obtained in their 62 thyroid lobes to determine their relationship to thyroid lobe volume.

RESULTS

Palpation revealed poor discrimination of smaller thyroid sizes as determined by ultrasonography. Stepwise linear regression (backward selection) revealed that of the 3 thyroid dimensions, only the lateromedial dimension of the thyroid lobe had a significant correlation to lobe volume, accounting for 82.5% of the variability in lobe volume. The lobe volume (in milliliters) is given by the lobe lateromedial dimension (in centimeters) multiplied by 13 minus a constant of 15.

CONCLUSIONS

A simple linear ultrasonographic measurement of the thyroid lateromedial dimension, which can be done with little training, is as good as more complicated measures of thyroid volume estimation by ultrasonography and is an ideal method for identifying goiters in field surveys.

Quantitative image analysis: software systems in drug development trials

Multi-dimensional image analysis is being used increasingly to arrive at surrogate end-points for drug development trials. Various imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and ultrasound are used to analyze treatments for diseases such as cancer, multiple sclerosis, osteoarthritis, and Alzheimer's disease. However, extracting information from images can be tedious and is prone to high user variability. The medical image analysis community is moving towards advanced software systems specifically designed for drug development trials. These systems can automatically identify the anatomy of interest in medical images (segmentation methods), can compare the anatomy over time or between patients (registration methods) and allow the quantitative extraction of anatomical features and the integration of the data and results into a database management system, automatically tracking the changes made to the data (audit trail generation). In this article, we present a case study using a prototype system that is used for quantifying multiple sclerosis lesions from multivariate MRI.