Real-time elastography and contrast-enhanced ultrasound for the assessment of thyroid nodules.

OBJECTIVE: Work-up of thyroid nodules remains challenging. Recent technologies enable determination of tissue elasticity and perfusion using ultrasound devices. The aim of the present study was to evaluate real-time elastography (RTE) and contrast-enhanced ultrasound with Sonovue (CEUS) for the differentiation of benign and malignant thyroid nodules. MATERIALS AND METHODS: Inclusion criteria were: nodules ≥1 cm, non-functioning or hypo-functioning on radionuclide scanning, and cytological/histological assessment. All patients received conventional ultrasound, RTE and CEUS. RTE was classified as: Elasticity-Score (ES)1 = soft, ES2 = predominantly soft, ES3 = predominantly hard, ES4 = hard nodule. CEUS-video clips were digitally recorded and analyzed using time-intensity-curves within selected regions-of-interest. RESULTS: Fifty-three nodules in 50 patients were available for analysis. Forty-six nodules were benign on cytology/histology, 6 nodules were papillary carcinoma and one nodule was a follicular carcinoma. Nodule margin irregularity was the ultrasound pattern most predictive of malignancy with sensitivity 57% (95% confidence interval: 18-90%) and specificity 85% (71-94% p<0.05). When using ES3&4 for the diagnosis of malignant nodules sensitivity and specificity were 86% (42-99.7%) and 87% (75-95%), respectively (p = 0.0003). The only malignant nodule missed with RTE was a follicular carcinoma. Sensitivity for the diagnosis of papillary carcinoma therefore was 100%. No specific CEUS pattern could be identified to differentiate between benign and malignant nodules. CONCLUSIONS: RTE seems to be a useful tool in the work-up of thyroid nodules to exclude papillary thyroid cancer. However, follicular carcinoma remains a challenging problem. CEUS did not improve the characterization of thyroid nodules in this preliminary study.

Residual kidney function after donor nephrectomy. Assessment by 99mTc-MAG3-clearance.

AIM: We evaluated the long-term residual renal function after donor nephrectomy using 99mTc-mercaptoacetyltriglycin (MAG3)-clearance. DONORS, METHODS: Altogether 49 kidney donors were examined using 99mTc-MAG3-clearance after nephrectomy for donation to a relative (m:f = 11:38; age 55+/-27 years). The donors were examined 16+/-8 years postoperatively (1.5-26 years). 42 donors (86%) showed normal creatinine values, whereas the other seven (14%) exhibited slightly elevated levels. 20 donors were examined pre- and postoperatively and compared intraindividually. The kidney function was compared to the age adapted normal values of healthy persons with two kidneys (67-133% of age related mean). RESULTS: After nephrectomy all donors showed a normal perfusion, good secretion, merely physiological intrarenal transit and a normal elimination from the kidneys. The 99mTc-MAG3-clearance was 69+/-15% of the normal mean value of healthy carriers of two kidneys regardless of the gender. 20 donors with a preoperative examination showed a significantly reduced total renal function from 84+/-15% of the mean normal value preoperatively to 60+/-15% postoperatively (p <0.0005). 15 donors of this group exhibited a significant functional increase of the residual kidney from 40% initially to 60% after nephrectomy (p = 0.003). No correlation was found between the initial-99mTc-MAG3-clearance measured prior to nephrectomy and the clearance levels after nephrectomy. Also, no correlation between the preoperative 99mTc-MAG3-clearance and the postoperative serum creatinine values could be observed. Altogether, 22% of the donors (11/49) developed arterial hypertension 10+/-8 years after donation (1-23 years). This corresponds to the normal age prevalence of hypertension in the carriers of two kidneys. Three donors suffered from arterial hypertension prior to the operation. CONCLUSION: Kidney donors with normal or slightly elevated creatinine values postoperatively show a 99mTc-MAG3-clearance value of 69% of the mean value of healthy carriers of two kidneys. This may serve as a reference value for healthy carriers of one kidney. In our study we demonstrated a good compensation of the contralateral kidney via renal scintigraphy by means of 99mTc-MAG3-clearance.

[Clinical value of positron emission tomography in neuromedicine. Position paper on results of an interdisciplinary consensus conference]. / Klinische Wertigkeit der Positronen-Emissions-Tomographie in der Neuromedizin. Positionspapier zu den Ergebnissen einer interdisziplinären Konsensuskonferenz.

To date, positron emission tomography (PET) is the most powerful method for the in-vivo investigation of human brain metabolism. Besides extensive application of this technology in the neurosciences, PET is also being increasingly used as a clinical tool. However, despite its acceptance in clinical practice a major obstacle is its high costs. The present article reviews the literature on the clinical use of PET in neurology, neurosurgery, and psychiatry in order to substantiate the clinical indications for PET in these specialties as established by an interdisciplinary conference.

Are serum neopterin concentrations superior to other parameters in the differential diagnosis and prognostic assessment of Graves' disease?

There is a lack (1.) of a single criterion for the definitive differentiation between immunogenic (IH) and non-immunogenic hyperthyroidism (NIH), and (2.) also a lack of an unequivocal prognostic predictor for the individual course of patients with immunogenic hyperthyroidism. In 152 patients scheduled for iodine-131 therapy, serum neopterin concentrations were measured using a commercially available RIA, and the neopterin concentrations of IH (n = 84) and NIH (n = 42) patients were compared. Of these patients, 83 and 26 per cent respectively were treated with antithyroid drugs which did not have a significant impact on neopterin levels. In patients with IH and NIH, the concentrations [mean +/- SD] of neopterin were 1.89 +/- 0.79 milligrams and 1.98 +/- 0.9 milligrams, respectively (p = 0.4). After therapy with iodine-131, 28% of the IH-patients were euthyroid, 32% hyperthyroid, and 40% hypothyroid. In finally euthyroid patients, pretherapeutic neopterin concentrations were higher (3.1 +/- 2.8 milligrams) than in finally hyperthyroid (1.8 +/- 0.7 milligrams), or hypothyroid (1.6 +/- 0.7 milligrams) patients. These results argue against a relevant clinical role of neopterin concentrations for the differential diagnosis of IH versus NIH in these patients. However, a prognostic significance of neopterin concentrations in patients with IH is suggested.