Differentiation between benign and malignant thyroid nodules using diffusion-weighted imaging, a 3-T MRI study

Background:

Preoperative differentiation of benign from malignant thyroid nodules remains a challenge. Aims: This study assessed the accuracy of diffusion-weighted imaging (DWI) for differentiation between benign and malignant thyroid nodules.

Materials and Methods:

Preoperative DWI was performed in patients with thyroid nodule by means of a 3-T scanner magnetic resonance imaging (MRI). Images were obtained at b value of 50, 500, and 1000 mm²/s to draw an ADC (apparent diffusion coefficient) map. Findings were compared with postoperative histopathologic results. Receiver operating characteristic curve was used to assess the accuracy of different cutoff points.

Results:

Forty-one thyroid nodules (26 benign and 15 malignant) were included in this study. None of static MRI parameters such as signal intensity, heterogeneity, and nodule border was useful to discriminate between benign and malignant lesions. Mean ADC value was (1.94 ± 0.54) × 10^-3 mm²/s and (0.89 ± 0.29) × 10^-3 mm²/s in benign and malignant nodules, respectively (P-value < 0.005). ADC value cutoff of 1 × 10^-3 mm²/s yielded an accuracy, sensitivity, and specificity of 93%, 87%, and 96% to discriminate benign and malignant nodules.

Conclusion:

DWI is highly accurate for discrimination between benign and malignant thyroid nodules.

3T magnetic resonance spectroscopy as a powerful diagnostic modality for assessment of thyroid nodules

OBJECTIVE

Magnetic resonance spectroscopy (MRS) is a powerful tool for structural studies of chemical compounds and biomolecules and also documented promising findings as a potential imaging technology in thyroid oncology. This prospective study was to ascertain the clinical significance of 3 Tesla MRS in the evaluation of patients with thyroid nodules (TNs) as an ancillary diagnostic technique for thyroid carcinoma.

MATERIALS AND METHODS

Magnetic resonance spectroscopy at 3T at echo- times (TEs) 136 and 270 ms was carried out on 15 patients with total number of 32 TNs larger than 1 cm3, which all were surgically resected. Choline (Chol) to creatine (Cr) ratio was assessed at 136 and 270 TEs on each nodule and a receiver operating characteristic (ROC) curve was used to determine optimal cut-off point. The findings were compared with histopathology of thyroid specimens.

RESULTS

There were 23 benign and 9 malignant lesions (7 papillary and 2 follicular thyroid carcinomas). The mean values of Chol/Cr at 136 and 270 TEs was 2.28 ± 3.65 and 1.52 ± 1.67 respectively and the difference between benign and malignant nodules was only significant at 136 TEs. The study revealed that Chol/ Cr ratio cut-off point of 2.5 best correlates with histopathology results (sensitivity = 75%; specificity = 100%; PPV = 100%; NPV= 92%).

CONCLUSION

This preliminary study showed that 3T magnetic resonance spectroscopy might be a specific modality for the evaluation of thyroid nodules in differentiation of benign from malignant thyroid tissue. However, a larger series would give much greater confidence that this state-of-the-art technology will worth pursuing in clinical practice.

A comprehensive musculoskeletal and peripheral nervous system assessment of war-related bilateral upper extremity amputees

BACKGROUND

Upper limb amputations are one of the unpleasant war injuries that armed forces are exposed to frequently. The present study aimed to assess the musculoskeletal and peripheral nervous systems in Iraq-Iran war veterans with bilateral upper extremity amputation.

METHODS

The study consisted of taking a history and clinical examinations including demographic data, presence and location of pain, level of amputation, passive and active ranges of movement of the joints across the upper and lower extremities and spine, manual palpation, neurological examination, blood circulation pulses and issues related to a prosthetic limb. In this study, 103 Iranian bilateral upper extremity amputees (206 amputations) from the Iran-Iraq war were evaluated, and a detailed questionnaire was also administered.

RESULTS

The most common level of amputation was the finger or wrist level (108, 52.4 %). Based on clinical examination, we found high frequencies of limited active and passive joint range of movement across the scapula, shoulder, elbow, wrist and metacarpophalangeal, interphalangeal and thumb joints. Based on muscle strength testing, we found varying degrees of weakness across the upper limbs. Musculoskeletal disorders included epicondylitis (65, 31.6 %), rotator cuff injury (24, 11.7 %), bicipital tendonitis (69, 33.5 %), shoulder drop (42, 20.4 %) and muscle atrophy (19, 9.2 %). Peripheral nerve disorders included carpal tunnel syndrome in 13 (6.3 %) and unilateral brachial plexus injury in 1 (1 %). Fifty-three (51.5 %) were diagnosed with facet joint syndrome at the level of the cervical spine (the most frequent site). Using a prosthesis was reported by 65 (63.1 %), both left and right sides. The back was the most common site of pain (71.8 %).

CONCLUSION

The high prevalence of neuro-musculoskeletal disorders among bilateral upper extremity amputees indicates that they need regular rehabilitation care.

Evaluation of humoral immune function in patients with bronchiectasis

Bronchiectasis is a chronic debilitating condition characterized by abnormal dilated thick-walled bronchi. To investigate humoral immune function in bronchiectatic patients, this study was performed. Forty patients with established diagnosis of bronchiectasis, who were referred from two tertiary care pulmonology centers in Tehran, were investigated in this study. Immunoglobulin isotypes concentrations and IgG-subclasses were measured by nephelometry and enzyme-linked immunosorbent assay (ELISA) methods, respectively. All patients received unconjugated pneumococcal vaccine, and blood samples were taken before and 21 days after vaccination. Specific antibodies against whole pneumococcal antigens were measured using the ELISA method. Fifteen (37.5%) out of 40 patients were diagnosed to have defects in antibody mediated immunity including 5 (12.5%) patients with immunoglobulin class deficiency (2 with common variable immunodeficiency and 3 with IgA deficiency), 3 (7.5%) with IgG subclass deficiency and 7 (17.5%) patients had Specific antibody deficiency (SAD) against polysaccharide antigen despite normal levels of serum immunoglobulins and IgG subclasses. Our study along with several other studies confirmed that all patients with bronchiectasis should undergo thorough immunological evaluation in order to identify the presence of the underlying immunologic defect. This evaluation should include serum immunoglobulins, IgG subclasses concentrations and also determination of serum antibodies against pneumococcal antigens. Early diagnosis and appropriate treatment will prevent the subsequent complications and improve quality of life of affected individuals.

Site-specific effects of sympathectomy on the adrenergic control of lipolysis in hamster fat cells

Regional variations in the response of adipose tissue to lipolytic stimuli have been suggested to be involved in the development of visceral adiposity-related morbidity and mortality. Moreover, studies in humans and in laboratory rodents such as hamsters have shown that the response of adipocytes to catecholamines depends on their anatomical origin. The aim of the present study was to investigate the relative involvement of the adrenal medulla and of the sympathetic nervous system on regional differences in the adrenergic control of lipolysis in isolated adipocytes from inguinal and epididymal adipose tissues. For this purpose, we carried out adrenal demedullation or chemical sympathectomy in hamsters. The results confirmed that epididymal adipocytes were significantly more responsive to to a beta-adrenergic stimulation than inguinal adipocytes (p < or = 0.05). This site specificity could originate at a step distal to receptors since tissues exhibited a similar number of binding sites for [125I]cyanopindolol. No significant regional differences were observed in the alpha2-adrenergic antilipolytic response, with the exception of the clonidine EC50. A 14-day sympathectomy significantly increased the beta-adrenergic lipolytic response only in inguinal adipocytes (p < or = 0.05), and increased the alpha2-adrenergic response only in epididymal adipocytes (p < or = 0.05). On the other hand, adrenal demedullation had no effect on both adrenergic pathways. These results suggest that the sympathetic tone of adipose tissues could be involved in the alpha2- and beta-adrenergic site-specific response in hamster fat cells. The 33% increase of the beta-response in inguinal fat cells and the 38% increase of the alpha2-response in epididymal fat cells also suggest that the sympathetic pathway favors the lipolytic activation of the epididymal adipose tissue.