Myocardial perfusion and left ventricular quantitative parameters obtained using gated myocardial SPECT: Comparison of three software packages.

BACKGROUND: The aim of the present study was to compare Emory Cardiac Toolbox, Myovation, and Quantitative Gated SPECT software regarding the automatic measurements of perfusion and functional left ventricular (LV) quantitative parameters, summed stress score (SSS), perfusion defect score, LV ejection fraction (LVEF), end-diastolic volume, and end-systolic volume (ESV). METHODS AND RESULTS: 99mTc-tetrofosmin gated SPECT studies were performed in 634 consecutive patients based on the one-day stress/rest protocol. Participants were divided into subgroups according to heart size (ESV cut-off value: 25 mL), perfusion (SSS >/≤3), and other patient/protocol-related factors. LVEF was categorized as normal (≥50%), mildly moderately impaired (35-49%), and severely abnormal (<35%). The concordance between the packages was good to excellent, in overall population, ESV ≤25 mL, ESV >25 mL, and SSS >3 subgroups (intraclass correlation coefficients, ICCs 0.73-0.93). In SSS ≤3 subgroup, the correlation was excellent for LV functional parameters, but suboptimal for perfusion variables (ICCs 0.30-0.83). LVEF categorization revealed similar variability (discordance 18.1 and 11.1% for stress/rest LVEF values, respectively). Pair comparisons demonstrated considerable differences concerning all parameters for all patient subgroups. The statistical significance of our findings by ESV and SSS classifications was evaluated. CONCLUSIONS: Despite the significant concordance between software packages, considerable differences in mean values of myocardial perfusion and LV functional parameters were demonstrated.

The impact of transmission-emission misregistration on the interpretation of SPET/CT myocardial perfusion studies and the value of misregistration correction.

OBJECTIVE: Previous studies indicate that the quality of single photon emission tomography/computed tomography (SPET/CT) myocardial perfusion imaging (MPI) is degraded by even mild transmission-emission misregistrations. The purpose of the current study was to investigate the impact of SPET/CT misalignment on the interpretation of MPI and examine the value of a commercial software application for registration correction. SUBJECTS AND METHODS: A total of 255 technetium-99m ((99m)Tc)-tetrofosmin stress/rest MPI examinations in 150 patients were reviewed for SPET/CT misalignment. After registration correction by the software, images were reassessed for interpretation differences from the misregistered study. The diagnostic benefit of reregistration was determined by taking into account the non-attenuation compensated image pattern, combined stress-rest evaluation, gated-SPET data and patient's history. In a phantom experiment and in 3 representative clinical cases, SPET/CT misalignment was purposely created by the software by sequential slice shifts and its effect was evaluated quantitatively. RESULTS: Misregistration ≥1 pixel in at least one direction was observed in 24% of studies. Interpretation of MPI changed after registration correction in 11% of cases with misalignment <1 pixel, in 18% with 1-2 and in 73% with ≥2 pixels. The diagnostic information seemed to improve after registration correction in 58% of studies irrespective of the degree of misregistration. Software-simulated misregistration had dissimilar effects in the phantom and the 3 selected clinical cases. CONCLUSIONS: The impact of SPET/CT misregistration on MPI interpretation although influenced by the degree and direction of slice misplacement, it is also case-specific and hardly predictable. Registration restoration by the software seems worthwhile regardless of misregistration magnitude.

Assessment of absolute Tc-99m tetrofosmin retention in the myocardium as an index of myocardial blood flow and coronary flow reserve by gated-SPECT/CT: a feasibility study.

OBJECTIVE: Estimation of myocardial blood flow (MBF) and coronary flow reserve (CFR) by SPECT myocardial perfusion imaging (MPI) remains challenging. Our aim was to approximate MBF and CFR by quantifying the absolute Tc-99m tetrofosmin retention in the myocardium via gated-SPECT/CT MPI. METHODS: Tracer retention was calculated on the basis of the microsphere kinetic model and served as an index of MBF at stress and rest (sMBFi, rMBFi). CFR was given by the sMBFi/rMBFi ratio. A planar first-pass acquisition during dipyridamole stress and at rest provided the data for tracer input determination. The input was represented by the integral of a gamma variate fitted on the time-activity curve of the left ventricle. Gated-SPECT/CT was performed 1 h post tracer injection and myocardial activity was measured in attenuation-corrected transaxial slices by a threshold VOI. The input was also compensated for tissue attenuation by measuring the distance from the centre of the left ventricle to the body surface on fused SPECT/CT slices. Input and uptake results were adjusted for planar-SPECT counting geometry differences by the aid of a phantom experiment. Thirty-nine subjects with low probability of coronary artery disease (CAD), age lower than 75 years and normal MPI (control group) were compared with 57 patients with documented CAD (CAD group). RESULTS: CFR and sMBFi values of CAD patients (1.39 ± 0.37 and 1.42 ± 0.35 ml/min/g) were considerably lower (p < 0.0001) than controls (1.68 ± 0.25 and 1.72 ± 0.37 ml/min/g). Significant difference in CFR (p = 0.03) was also noted between CAD patients with normal MPI (1.48 ± 0.38) and controls. However, sMBFi managed to discriminate certain CAD subgroups (normal MPI/ischemia/scar/scar and ischemia) more efficiently than CFR. Maximum heart rate-blood pressure product (RPP) during stress was an independent predictor of sMBFi and CFR. The other independent CFR correlates were resting RPP and diabetes mellitus, while sMBFi was associated with age, sex, smoking, and stress perfusion defects. CONCLUSIONS: Despite the low myocardial extraction fraction of Tc-99m tetrofosmin, an approximation of MBF and CFR is feasible with gated-SPECT/CT MPI. These flow indices together were able to discriminate CAD patients from controls and stratify different patient subgroups.

Tc-99m depreotide SPECT/CT for lymph node staging of non-small-cell lung cancer.

OBJECTIVE: To investigate the potential role of Tc-99m depreotide (Tc-DEPR) in the preoperative lymph node (N) staging of non-small-cell lung cancer (NSCLC). METHODS: Sixty-one patients with NSCLC at the potentially operable stage were enrolled and underwent scintigraphy before surgery (n=56) or mediastinoscopy (n=5). Imaging was performed with a hybrid single photon emission computed tomography/computed tomography (SPECT/CT) system. Depreotide uptake in N stations was evaluated visually and semi-quantitatively and compared to histology. Quantification was carried out in attenuation-corrected SPECT slices. Different sites of normal uptake were used as a reference for comparison with lesional uptake. Receiver operating characteristic analysis was employed to identify the most preferable reference area and the cut-off best discriminating disease-free from disease-involved lymph nodes. RESULTS: With reference to 53 Ν1 hilar and 147 Ν2/Ν3 sampled stations, sensitivity of scintigraphy by visual interpretation was 100 and 94%, specificity 43 and 59% and accuracy 55 and 67%, respectively. No patient was down-staged, but 52% were incorrectly up-staged and 44% were misclassified as inoperable. Compared to scintigraphy, preoperative contrast-enhanced diagnostic CT demonstrated lower sensitivity (36% for hilar and 73% for N2/N3 stations), higher specificity (79 and 75%) and similar accuracy (70 and 75%). Regarding the ultimate N-stage and the prediction of surgical disease, diagnostic CT was wrong in 51 and 34% of cases. Dichotomy of quantitative scintigraphic data by the use of certain N-to-spine ratio cut-offs resulted in a significant increase of specificity (76% for hilar and 89% for N2/N3 stations), while sensitivity remained high (82% in both circumstances) and accuracy for Ν2/Ν3 stations was substantially improved (88%). By this quantitative approach, misclassifications as to the N-stage and patient operability (25 and 16%) were considerably less than that of visual Tc-DEPR and diagnostic CT interpretations. CONCLUSION: Tc-99m depreotide SPECT/CT seems to have a role in the N-staging of NSCLC, mainly because of its high sensitivity and negative predictive value. Quantification of uptake can improve specificity, at a low cost of sensitivity. If F-18 fluoro-deoxyglucose positron emission tomography is not available, this method may be used as a surrogate to conventional staging modalities.

CT-based attenuation correction in Tl-201 myocardial perfusion scintigraphy is less effective than non-corrected SPECT for risk stratification.

BACKGROUND: Previous studies advocate the use of attenuation correction in myocardial perfusion scintigraphy (MPS) for patient risk stratification. METHODS: Six-hundred and thirty-seven unselected patients underwent Tl-201 MPS by a hybrid SPECT/CT system. Attenuation-corrected (AC) and non-corrected (NAC) images were interpreted blindly and summed stress scores (SSS) were calculated. Study endpoints were all-cause mortality and the composites of death/non-fatal acute myocardial infarction (AMI) and death/AMI/late revascularization. RESULTS: During a follow-up of 42.3 ± 12.8 months 24 deaths, 13 AMIs and 28 revascularizations were recorded. SSS groups formed according to event rate distribution across SSS values were: 0-4, 5-13, >13 for NAC and 0-2, 3-9, >9 for AC. Kaplan-Meier functions were statistically significant between NAC SSS groups for all study endpoints. AC discriminated only between SSS 0-2 and >9 for death/AMI and between 0-2 and 3-9 for death/AMI/revascularization. In the univariate Cox regression abnormal NAC (SSS > 4) was accompanied with much higher hazards ratios than abnormal AC (SSS > 2). In the multivariate model abnormal AC yielded no significance for either endpoint whereas abnormal NAC proved independent from other covariates for the composite endpoints. CONCLUSION: Our results challenge the effectiveness of CT-based AC for risk stratification of patients referred for MPS.

(99m)Tc sestamibi as a prognostic factor of response to first-line therapy and outcome in patients with malignant lymphoma.

INTRODUCTION: Resistance to chemotherapy poses a major problem in cancer patients. Although of multifactorial origin, some of the implicated mechanisms also interfere with (99m)Tc-MIBI uptake and retention in cancer cells. The aim of the current study was to investigate the prognostic value of baseline (99m)Tc-MIBI imaging in lymphoma. METHODS: (99m)Tc-MIBI SPECT was performed in 16 patients with Hodgkin lymphoma and 31 with non-Hodgkin lymphoma (NHL) before chemotherapy initiation. Early (20 minutes), late (120 minutes) tumor-to-background (T/B) ratios, and 2-hour (99m)Tc-MIBI washout were calculated. Follow-up data were obtained for a period of 45.5 ± 23.5 months. Study end points were response to first-line chemotherapy, lymphoma-related death (LRD), and time to disease progression. RESULTS: Of the scintigraphic indices examined, the late T/B ratio correlated best with study end points. A cutoff value of 1.8 determined by receiver operating characteristic analysis discriminated poor from good response and LRD from survival with an accuracy of 87% and 81%, respectively. Kaplan-Meier survivor functions separated by this cutoff differed significantly for both time to disease progression and LRD (P = 0.0001 and P = 0.0015). In the Cox proportional hazards model, the late T/B ratio proved to have an independent and incremental value over clinical prognostic factors (age, lymphoma type, Ann Arbor stage, lactate dehydrogenase levels) and, in NHL patients, over the international prognostic index. Patients with high international prognostic index score could be further stratified into different prognostic categories. CONCLUSION: The current study indicates that baseline (99m)Tc-MIBI SPECT can provide useful prognostic information in patients with lymphoma, particularly NHL, regarding therapy response and final outcome.

Perfusion brain SPECT in assessing motor improvement after deep brain stimulation in Parkinson's disease.

BACKGROUND: High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an established therapeutic approach for the management of patients with late-stage idiopathic Parkinson's disease (PD). The aim of the present study was to assess regional cerebral blood flow (rCBF) changes related to motor improvement. METHODS: Twenty-one PD patients underwent two rCBF SPECT studies at rest, once preoperatively in the off-meds state and the other postoperatively (at 6 ± 2 months) in the off medication/on stimulation state. Patients were classified according to the UPDRS and H&Y scale. NeuroGam software was used to register, quantify, and compare two sequential brain SPECT studies of the same patient in order to investigate rCBF changes during STN stimulation in comparison with preoperative rCBF. The relationship between rCBF and UPDRS scores was used as a covariate of interest. RESULTS: Twenty patients showed clinical improvement during the first months after surgery, resulting in a 44 % reduction of the UPDRS motor score. The administered mean daily levodopa dose significantly decreased from 850 ± 108 mg before surgery to 446 ± 188 mg during the off-meds state (p < 0.001, paired t test). At the 6-month postoperative assessment, we noticed rCBF increases in the pre-supplementary motor area (pre-SMA) and the premotor cortex (PMC) (mean rCBF increase = 10.2 %, p < 0.05), the dorsolateral prefrontal cortex and in associative and limbic territories of the frontal cortex (mean rCBF increase = 8.2 %, p > 0.05). A correlation was detected between the improvement in motor scores and the rCBF increase in the pre-SMA and PMC (r = 0.89, p < 0.001). CONCLUSIONS: Our study suggests that STN stimulation leads to improvement in neural activity and rCBF increase in higher-order motor cortical areas.

ST-segment depression during vasodilator stress is of minor clinical importance in women with normal myocardial perfusion imaging and low or intermediate risk of coronary artery disease.

PURPOSE: The prognostic value of electrocardiographic (ECG) ST-segment depression during vasodilator stress testing in patients with normal myocardial perfusion scintigraphy (MPS) is based on retrospective studies with controversial results. Moreover, the true incidence of obstructive coronary artery disease (CAD) in these patients is unknown. METHODS: During a 33-month period, all consecutive patients referred for MPS were prospectively evaluated for interpretable ST-segment depression ≥ 1 mm during vasodilator stress testing. Of 1,687 patients with normal MPS and without known CAD, 109 (100 women) aged 65.2 ± 9.2 years demonstrated ST-segment shifts and formed the ECG-positive group. The pretest probability of CAD was low in 56%, intermediate in 39% and high in 5%. They were advised to proceed to coronary angiography. An equal number of patients with normal MPS and no ECG abnormalities matched for CAD predisposing factors comprised the control group. Follow-up of both groups was accomplished through a telephone interview. RESULTS: Fifty-two patients from the ECG-positive group (48%) consented to coronary angiography. Six (11.5%) had obstructive CAD (≥50% lumen stenosis), one with left main artery disease, while three required revascularization. Follow-up was complete in 99 ECG-positive patients for a period of 20.6 ± 8.9 months. One hard event (non-fatal myocardial infarction) and one soft event (revascularization) were observed. No event was recorded in the control group. CONCLUSION: In patients with low-intermediate risk of CAD, "ischaemic" ECG changes during vasodilator stress combined with normal MPS are encountered mostly in women and are associated with a low prevalence of significant CAD and a low cardiac event rate.

Technetium-99m depreotide imaging by single photon emission tomography/low resolution computed tomography in malignant lymphomas: comparison with gallium-67 citrate.

OBJECTIVE: Previous studies have demonstrated the feasibility of targeting lymphoma lesions with somatostatin receptor binding agents, mainly with In-111-pentetreotide. In the present work another somatostatin analog, Tc-99m depreotide, is investigated. METHODS: One-hundred and six patients, 47 with Hodgkin's (HL) and 59 with various types of non-Hodgkin's lymphoma (NHL), were imaged with both Tc-99m depreotide and Ga-67 citrate. Planar whole-body and single photon emission tomography/low resolution computerized tomography (SPECT/CT) images were obtained. A total of 142 examinations were undertaken at different phases of the disease. Depreotide and gallium findings were compared visually and semi-quantitatively, with reference to the results of conventional work-up and the patients' follow-up data. RESULTS: In most HL, intermediate- and low-grade B-cell, as well as in T-cell NHL, depreotide depicted more lesions than Ga-67 and/or exhibited higher tumor uptake. The opposite was true in aggressive B-cell NHL. However, there were notable exceptions in all lymphoma subtypes. During initial staging, 93.3% of affected lymph nodes above the diaphragm, 100% of inguinal nodes and all cases with splenic infiltration were detected by depreotide. On the basis of depreotide findings, 32% of patients with early-stage HL were upstaged. However, advanced HL and NHL cases were frequently downstaged, due to low sensitivity for abdominal lymph node (22.7%), liver (45.5%) and bone marrow involvement (36.4%). Post-therapy, depreotide detected 94.7% of cases with refractory disease or recurrence. Its overall specificity was moderate (57.1%). Rebound thymic hyperplasia, various inflammatory processes and sites of unspecific uptake were the commonest causes of false positive findings. The combination of depreotide and gallium enhanced sensitivity (100%), while various false positive results of either agent could be avoided. CONCLUSION: Except perhaps for early-stage HL, Tc-99m depreotide as a stand-alone imaging modality has limited value for the initial staging of lymphomas. Post-therapy, however, depreotide scintigraphy seems useful in the evaluation of certain anatomic areas, particularly in non-aggressive lymphoma types. The combination with Ga-67 potentially enhances sensitivity and specificity. If fluorodeoxyglucose positron emission tomography is not available or in case of certain indolent lymphoma types, Tc-99m depreotide may have a role as an adjunct to conventional imaging procedures.

DMSA scan for revealing vesicoureteral reflux in young children with urinary tract infection.

OBJECTIVES: The objective of this study was to assess the ability of acute dimercaptosuccinic acid (DMSA) scintigraphy for revealing vesicoureteral reflux (VUR) in young children after a first febrile urinary tract infection (UTI). METHODS: Children aged

Regional cerebral blood flow changes induced by deep brain stimulation in secondary dystonia.

PURPOSE: The purpose of the present study is to investigate the effect of deep brain stimulation (DBS) on regional cerebral blood flow (rCBF) in cases of secondary dystonia as well as to correlate the rCBF changes with clinical outcomes. METHODS: Six patients with medically intractable secondary dystonia who underwent DBS surgery were included in this study. Burke-Fahn-Mardsen Dystonia Rating Scale (BFMDRS) was used for the assessment of dystonia, before and after surgery. Single photon emission computed tomography (SPECT) of the brain was performed postoperatively in the two stimulation states (ON-DBS and OFF-DBS) and the changes of rCBF in the three following brain regions of interest (ROIs): primary motor cortex, premotor and supplementary motor cortex, and prefrontal cortex were evaluated. RESULTS: Two patients exhibited excellent response to DBS, two patients got moderate benefit after the procedure, and in two patients, no clinical improvement was achieved. A mean improvement of 49.1% (0-90.7%) in BFMDRS total scores was found postoperatively. Brain SPECT data analysis revealed an overall decrease in rCBF in the investigated ROIs, during the ON-DBS state. Clinical improvement was significantly correlated with the observed decrease in rCBF in the presence of DBS. CONCLUSIONS: When conservative treatment fails to relieve severely disabled patients suffering from secondary dystonia, DBS may be a promising therapeutic alternative. Moreover, this study indicates a putative role of brain SPECT imaging as a postoperative indicator of clinical responsiveness to DBS.

SPECT neuroimaging and neuropsychological functions in different stages of Parkinson's disease.

PURPOSE: The present study investigated differences and associations between cortical perfusion, nigrostriatal dopamine pathway and neuropsychological functions in different stages of Parkinson's disease (PD). METHODS: We recruited 53 non-demented PD patients divided into four groups according to the Hoehn and Yahr (HY) staging system and 20 healthy controls who were used in the comparison of the neuropsychological findings. Each patient underwent two separate brain single photon emission computed tomography (SPECT) studies (perfusion and dopamine transporter binding) as well as neuropsychological evaluation. Perfusion images of each patient were quantified and compared with a normative database provided by the NeuroGam software manufacturers. Mean values obtained from the cortical areas and neuropsychological measures in the different groups were also compared by analysis of covariance (ANCOVA) controlling for disease duration and educational level. RESULTS: We found cognitive deficits especially in the late PD stages (HY 3, 4 and 5) compared to the early stages (HY 1 and 2) and associations between cognitive decrements and cortical perfusion deterioration mainly in the frontal and posterior cortical areas. Compared with controls, PD patients showed impairments of cognition and cerebral perfusion that increased with clinical severity. Furthermore, we found a significant correlation between the performance on the phonemic fluency task and regional cerebral blood flow (rCBF) in the left frontal lobe. Dopamine transporter binding in the left caudate nucleus significantly correlated with blood flow in the left dorsolateral prefrontal cortex (DLPFC), but not with measures of executive functions. CONCLUSION: There are significant cognitive and perfusion deficits associated with PD progression, implying a multifactorial neurodegeneration process apart from dopamine depletion in the substantia nigra pars compacta (SNc).

The insulin-like growth factor-I (IGF-I) generation test as an indicator of growth hormone status.

OBJECTIVE: The aim of the study was to evaluate the IGF-I generation test (IGF-I gen) as a possible indirect test of Growth Hormone (GH) secretory status. METHODS: Sixty-five GH deficient (GHD 1 and 2) and 86 control children were studied. Children in the GHD-1 subgroup (n=33) had low GH values (<10 microg/L) after clonidine and levo-dopa while those in the GHD-2 subgroup (n=32) had normal GH values after pharmacologic provocation but low 24-hour GH secretory rates compared to 187 Normal Statured (NS) children. Of the 86 controls, who underwent IGF-I gen,50 were NS and 36 Short-Statured (SS). Serum IGF-I was measured prior to and daily during hGH administration (hGH 0.033 mg/kg/dayx4 days). RESULTS: The prepubertal and pubertal GHD-1 and GHD-2 children had low baseline IGF-I values but their peak IGF-I values during the IGF-I gen reached those of the controls. The percent increase of IGF-I during the test was greater in the GHD groups than in the controls; in the prepubertal groups: 516+/-58% in the GHD-1, 433+/-50% in the GHD-2, 106+/-12% in the NS, and 102+/-18% in the SS (p=0.001); in the pubertal groups: 191+/-28% in the GHD-1, 141+/-20% in the GHD-2, 48+/-8% in the NS, and 61+/-17% in the SS (p=0.003). CONCLUSIONS: The IGF-I response during the IGF-I gen seems to reflect the GH status in children.

Dopamine transporter SPECT/CT and perfusion brain SPECT imaging in idiopathic basal ganglia calcinosis.

A case of idiopathic basal ganglia calcification in a 56-year-old woman with parkinsonism and cognitive impairment is described. The nigrostriatal dopaminergic pathway and regional cerebral blood flow were evaluated using dopamine transporter (DAT) brain single photon emission tomography combined with a low-dose x-ray computerized tomography transmission (hybrid SPECT/CT) and Tc-99m HMPAO brain perfusion SPECT study, respectively. DAT SPECT/CT imaging revealed a reduction in DAT binding in both striatum regions coinciding with bilateral calcifications in the basal ganglia. Brain perfusion scan showed hypoperfusion in basal ganglia regions, posterior parietal cortex bilaterally, left frontopolar and dorsolateral prefrontal cortex, and left temporal lobe. These findings correlated well with the clinical condition of the patient. Mineralization may play a critical role in the pathogenesis of neuronal degeneration. Cortical perfusion changes in patients may better explain the patient's altered cognitive and motor functions.

Effect of maternal smoking on cord blood estriol, placental lactogen, chorionic gonadotropin, FSH, LH, and cortisol.

AIM: To determine the effect of maternal cigarette smoking on cord blood concentrations of E3, hPL, beta-hCG, FSH, LH, and cortisol. METHODS: Hormone concentrations were measured in term neonates of 100 smoking and 100 non-smoking mothers. RESULTS: The median E3, hPL, beta-hCG, FSH, LH and cortisol cord blood concentrations in the non-smoking mothers' offspring were 212 ng/mL, 2.00 microg/mL, 57.5 mIU/mL, 0.10 mIU/mL, 0.20 mIU/mL, and 14.3 microg/mL, respectively; in the smoking they were 163, 1.39, 45.4, 0.10, 0.20, and 25.1, respectively (P=0.008, 0.004, 0.037, 0.498, 0.286, 0.004, respectively). There was a significant but poor negative correlation between number of cigarettes/day and E3 (r=-0.163, P=0.021), hPL (r=-0.191, P=0.007), and beta-hCG (r=-0.143, P=0.044), whereas the correlation with cortisol was positive (r=0.259, P<0.0001). Multiple linear regression analyses showed that maternal smoking is a determinant of cord blood E3, hPL, beta-hCG, FSH, and cortisol concentrations. CONCLUSIONS: Tobacco smoking is associated with a reduction in cord blood E3, hPL, and beta-hCG concentrations, whereas it is associated with increased cortisol concentrations. The disturbed endocrine equilibrium of the fetus induced by tobacco smoking could have adverse consequences on the fetus and child since fetal brain is a target organ for hormonal actions.

Combined growth hormone-releasing hormone and growth hormone-releasing peptide-6 test for the evaluation of growth hormone secretion in children with growth hormone deficiency and growth hormone neurosecretory dysfunction.

BACKGROUND: The combined growth hormone-releasing hormone and growth hormone-releasing peptide-6 (GHRH + GHRP-6) test is most potent in evaluating GH secretion. AIMS: To assess its capability in children with GH deficiency and low spontaneous GH secretion (GH neurosecretory dysfunction). METHODS: 35 children with GH <10 microg/l after levo-dopa/clonidine (GHD), 15 with normal provocative tests but abnormal 24-hour spontaneous GH secretion (GHND), and 20 controls (C) were given 1 microg/kg of GHRH and GHRP-6 i.v. and GH (microg/l) was measured at -15, 0, 5, 10, 15, 30, 45 and 60 min. RESULTS: Six were nonresponders to the combined test, with significantly lower peak GH 20.7 (7.8-31.8) than C and the rest of the patients (responders). Peak GH was similar between prepubertal (PP) controls 167 +/- 88, GHD 202 +/- 110 and GHND 155 +/- 83. Pubertal (P) controls had higher peak GH 328 +/- 149 than P-GHD 203 +/- 105 and P-GHND 186 +/- 105. While P-C had higher peak GH than PP-C, PP and P children had similar responses within the GHD and GHND groups. CONCLUSIONS: The GHRH + GHRP-6 test detects children with severe GH insufficiency. Patients with GHD respond similarly to those with GHND, indicating a possible hypothalamic GH neuroregulatory dysfunction in GHD. Responders to the combined test may be eligible for treatment with a synthetic GH secretagogue.

Is mucociliary transport velocity related to symptoms in chronic rhinosinusitis patients?

Mucociliary transport velocity (MTV) measured by rhinoscintigraphy is considered a reliable measure of mucociliary clearance, one of the mechanisms that are distorted in chronic rhinosinusitis (CRS). The aim of this study was to investigate possible correlation of MTV with the severity of patients' symptoms. We have studied thirty-seven CRS patients who completed the 20-item sinonasal outcome test (SNOT-20) form, a reliable measure of health related quality of life and were also examined by rhinoscintigraphy with technetium-99m macroaggregated albumin. Our findings showed that the MTV of our patients ranged from nil to 4.17mm/min with a mean value of 1.74+/-1.055 mm/min. The SNOT-20 scores varied from 0.3 to 3.7 with a mean of 1.6+/-0.922. The correlation between SNOT-20 score and MTV was not statistically significant (Spearman's r=-0.191). In conclusion, although rhinoscintigraphy is widely accepted as a reliable test of mucociliary velocity and clearance, it did not correlate with subjective measures of the severity of CRS.

Comparison between 180 degrees and 360 degrees acquisition arcs with and without correction by CT-based attenuation maps in normal hearts at rest.

OBJECTIVE: To investigate the effect of acquisition arc (180 degrees or 360 degrees ) and attenuation correction (AC), in artifact occurrence and image uniformity of myocardial perfusion SPECT studies in normal hearts. METHODS: Twenty male and 44 female patients with primary hyperparathyroidism and low probability of resting perfusion abnormalities were analysed. Tc-sestamibi myocardial perfusion studies were performed at rest with a hybrid SPECT/CT system. An anthropomorphic phantom was also imaged. RESULTS: Without AC, a 360 degrees orbit resulted in significantly lower artifact rates compared to the standard 180 degrees in both gender groups. Differences persisted (P<0.001) even after adjusting reconstruction filter settings to compensate for disproportionate count statistics between the two arcs. However, gender-related variation was not considerably decreased and sub-diaphragmatic activity was augmented with a 360 degrees arc. After AC with either arc, substantially lower defect scores and minimal gender-related differences were obtained compared to the standard technique. A 360 degrees arc yielded lower defect rates and count variability than did the 180 degrees arc (P<0.05). These differences were small and were eliminated after weighting for dissimilar count statistics. Sub-diaphragmatic signal was amplified, particularly with 360 degrees ; severe bowel-myocardial activity overlap complicated image interpretation in 14% of cases with 360 degrees versus 8% with 180 degrees . In certain aspects, phantom imaging findings diverged from patient studies. CONCLUSION: Without AC there is significant disparity between 180 degrees and 360 degrees concerning artifact occurrence. After CT-based AC differences between arcs in defect rate and image uniformity seem less critical. However, 180 degrees is favoured by less intensification of intestinal activity.

Increased cortisol concentrations in the cord blood of newborns whose mothers smoked during pregnancy.

AIM: To investigate the effect of tobacco smoke on cord blood cortisol concentrations. METHODS: Cortisol concentrations were measured in cord blood from 211 term newborns of smoking and 211 term newborns of nonsmoking mothers; 48 and 36 newborns were delivered by cesarean section, respectively. In 16 cases, in addition to cord blood, maternal venous blood was obtained at delivery. RESULTS: The median cord blood cortisol concentration in neonates of the smoking and the nonsmoking mothers was 23 and 13 microg/dL, respectively (P<0.0001). Cortisol concentrations were greater in the newborns whose mothers smoked, when compared to corresponding controls, whether they were delivered vaginally or by cesarean section. In the newborns delivered by cesarean section, there was a positive correlation between number of cigarettes smoked/day and cortisol concentrations, as well as a negative correlation between cortisol concentrations and neonatal length. There was no significant correlation between cortisol concentrations and birth weight or head circumference. Cortisol concentrations in the cord blood of neonates whose mothers were smokers and nonsmokers were by 29% and 45% lower from those measured in their mothers, respectively. CONCLUSIONS: Although a causal relationship between maternal smoking and high cortisol concentrations in cord blood was not established, the findings are in accordance with previous reports indicating elevated stress-hormones in newborns whose mothers smoked during pregnancy.

The value of scintigraphy and ultrasonography in the preoperative localization of parathyroid glands in patients with primary hyperparathyroidism and concomitant thyroid disease.

UNLABELLED: Parathyroid scintigraphy and high-resolution ultrasonography are frequently used as preoperative localization procedures in primary hyperparathyroidism. However, when thyroid disease coexists, their diagnostic accuracy is probably abated. DESIGN: 56 patients with primary hyperparathyroidism were prospectively evaluated with parathyroid scintigraphy (with either thallium or technetium-99m agents or both) and 44 of them were also evaluated with ultrasonography. RESULTS: 33 patients (59%) had coexistent thyroid disease. Upon operation, 48 patients were found to have a solitary parathyroid adenoma and were all cured. One patient had a carcinoma and 7 had multiglandular parathyroid disease. Regarding solitary lesions, the sensitivity of parathyroid scintigraphy with Tc-agents was 97% and thallium 78%, while that of ultrasonography was 74%. The false positive rate was 2.6%, 18%, and 22%, respectively. Concomitant thyroid disease had a non-significant effect on the results of parathyroid scintigraphy and ultrasonography. The efficiency of both modalities in diagnosing multiglandular disease was low (only 3/7 patients, 43%). CONCLUSIONS: Parathyroid scintigraphy, in conjunction with Sestamibi or Tetrofosmin, constitutes the most sensitive localizing technique as regards solitary lesions. Ultrasonography is also useful in confirming scintigraphic findings, offers more precise anatomic information, and is valuable in the evaluation of concomitant thyroid disease. The complementary use of parathyroid scintigraphy and ultrasonography is beneficial and efficacious in areas with high prevalence of thyroid disease. The value of these modalities is considerably lower in multiglandular disease.