Serum levels of ghrelin and obestatin in children with symptoms suggestive of delayed gastric emptying of unclear etiology.

BACKGROUND: Ghrelin and obestatin are peptides of the gut-brain axis affecting appetite and gastrointestinal motility. METHODS: We conducted a cross-sectional, case-control study to determine pre- and postprandial serum levels of total ghrelin and obestatin along with gastric emptying scintigraphy in children with symptoms suggestive of delayed gastric emptying time (GET), not attributable to any identifiable cause. RESULTS: Twenty children with symptoms suggestive of delayed GET, of whom 9 had delayed GET, and 20 age-matched healthy children were enrolled. Preprandial ghrelin and obestatin were higher compared to controls (GHR mean level in patients and controls: 1162 pg/mL and 401 pg/mL respectively; P<0.05; OB mean level in patients and controls: 417 pg/mL and 325 pg/mL respectively; not statistically significant). Postprandial ghrelin was significantly decreased in the subgroup of patients with delayed GET (GHR mean level in children with normal and prolonged GET: 1237 pg/mL and 584 pg/mL respectively; P<0.05). CONCLUSION: Obestatin and ghrelin were deranged in children with symptoms indicative of delayed GET of unexplained etiology. Gastric emptying was prolonged in almost half of the patients thus gastric emptying scintigraphy should be considered in the investigation of children with such symptomatology.

Incidence of reversible defect seen on myocardial perfusion scintigraphy using dipyridamole pharmacologic test early after primary percutaneous coronary intervention: how safe is it to perform this protocol?

INTRODUCTION: The purpose of this study was to investigate the safety of performing a dipyridamole stress test and to explore the incidence of reversible perfusion defects on myocardial perfusion imaging, five to six days after primary percutaneous coronary intervention (PCI). METHODS: Forty-one patients underwent myocardial perfusion imaging using a dipyridamole stress test, five to six days after primary PCI. RESULTS: Headache, chest pain, and dizziness were the most common side effects seen after dipyridamole administration. All occurrences were mild and short lasting. ST changes on the electrocardiogram were also seen in 12% of patients. Reversible perfusion defects occurred in 17%. CONCLUSIONS: This is one of the few studies to investigate patients using a dipyridamole stress test early after primary PCI. We conclude that it is safe to perform myocardial perfusion imaging under dipyridamole administration, just a few days after primary PCI. Additionally, a high incidence (17%) of myocardial perfusion defects was seen in this group of patients. According to our investigational protocol, a second myocardial perfusion imaging examination is scheduled for six months later, in order to clarify how many of these patients suffer from restenosis, or whether the finding was merely due to early endothelial dysfunction.

Squamous cell carcinoma in a thyroglossal duct cyst and 99mTc-MIBI findings.

The incidence of carcinomas in thyroglossal duct cysts is extremely low. The vast majority are papillary carcinomas, with only 14 cases of squamous cell carcinomas reported in the literature. A 78 years old male patient presented with an asymptomatic large mass in his anterior neck, considerably immobile, with inflamed overlying skin. Imaging studies confirmed the cystic nature-doughnut shape of the lesion, giving evidence of malignant infiltration of the surrounding tissues, without lymph node enlargement. Fine needle aspiration was positive for a possible squamous cell malignancy. A wide Sistrunk procedure was performed and the mass was excised along with the strap muscles and the infiltrated overlying skin. Histopathology confirmed the diagnosis of a moderately differentiated squamous cell carcinoma. In conclusion, scintigraphy with (99m)Tc-MIBI showed the characteristic doughnut sign. The rarity of this diagnosis along with differential diagnosis dilemmas are the key points of this presentation.

The serum levels of Receptor Activator of Nuclear Factor-κB Ligand, bone-specific alkaline phosphatase, osteocalcin and osteoprotegerin do not correlate with the radiographically assessed severity of idiopathic hip and knee osteoarthritis.

OBJECTIVES: Determination of the serum levels of Receptor Activator of Nuclear Factor-Κb Ligand, bone-specific alkaline phosphatase, osteocalcin and osteoprotegerin in patients suffering from osteoarthritis of varying severity and healthy controls and correlation of these results with the patients' age and the radiographically assessed severity of the disease. DESIGN AND METHODS: Patients suffering from hip (n=58) or knee (n=117) osteoarthritis and matched controls (n=19) were enrolled in this study. Patients underwent physical examination and standard radiographic evaluation before blood sampling. RESULTS: The serum levels of osteoprotegerin were positively correlated with age in all groups, whereas those of osteocalcin in the 'knee' group only. Osteoarthritis' severity and location did not have a statistically significant impact on the mean serum level of any marker in both groups. CONCLUSIONS: Based on our results, none of the studied markers can serve as a surrogate for radiographic imaging in patients suffering from hip and knee osteoarthritis.

SPECT imaging evaluation in movement disorders: far beyond visual assessment.

Single photon emission computed tomography (SPECT) imaging with (123)I-FP-CIT is of great value in differentiating patients suffering from Parkinson's disease (PD) from those suffering from essential tremor (ET). Moreover, SPECT with (123)I-IBZM can differentiate PD from Parkinson's "plus" syndromes. Diagnosis is still mainly based on experienced observers' visual assessment of the resulting images while many quantitative methods have been developed in order to assist diagnosis since the early days of neuroimaging. The aim of this work is to attempt to categorize, briefly present and comment on a number of semi-quantification methods used in nuclear medicine neuroimaging. Various arithmetic indices have been introduced with region of interest (ROI) manual drawing methods giving their place to automated procedures, while advancing computer technology has allowed automated image registration, fusion and segmentation to bring quantification closer to the final diagnosis based on the whole of the patient's examinations results, clinical condition and response to therapy. The search for absolute quantification has passed through neuroreceptor quantification models, which are invasive methods that involve tracer kinetic modelling and arterial blood sampling, a practice that is not commonly used in a clinical environment. On the other hand, semi-quantification methods relying on computers and dedicated software try to elicit numerical information out of SPECT images. The application of semi-quantification methods aims at separating the different patient categories solving the main problem of finding the uptake in the structures of interest. The semi-quantification methods which were studied fall roughly into three categories, which are described as classic methods, advanced automated methods and pixel-based statistical analysis methods. All these methods can be further divided into various subcategories. The plethora of the existing semi-quantitative methods reinforces the feeling that visual assessment is still the base of image interpretation and that the unambiguous numerical results that will allow the absolute differentiation between the known diseases have not been standardized yet. Switching to a commonly agreed-ideally PC-based-automated software that may take raw or mildly processed data (checked for consistency and maybe corrected for attenuation and/or scatter and septal penetration) as input, work with basic operator's inference and produce validated numerical results that will support the diagnosis is in our view the aim towards which efforts should be directed. After all, semi-quantification can improve sensitivity, strengthen diagnosis, aid patient's follow-up and assess the response to therapy. Objective diagnosis, altered diagnosis in marginal cases and a common approach to multicentre trials are other benefits and future applications of semi-quantification.

Acute effects of recombinant human TSH on bone markers in differentiated thyroid cancer.

Patients suffering from differentiated thyroid cancer receive suppressive of TSH thyroxine treatment of long duration. This study was undertaken to determine changes on bone serum markers after administration of recombinant human TSH in differentiated thyroid cancer patients on thyroxine treatment. Forty-five patients undergoing diagnostic evaluation of their disease and 48 matched controls were investigated: two injections of 0.9 mg of recombinant human TSH were given to the patients (on days 1 and 2). Blood samples were collected the day before first injection (day 0) and days 3, 5 and 10 after recombinant human TSH administration. Blood samples were obtained for serum TSH, bone alkaline phosphatase, osteocalcin, osteoprotegerin, receptor activator of nuclear factor kB ligand and bone tartrate resistant acid phosphatase. Recombinant human TSH induced a significant increase in bone alkaline phosphatase on day 3 up to day 10 in postmenopausal women. A statistically significant increase was also observed in serum receptor activator of nuclear factor kB ligand in both men and postmenopausal women on day 3 while on day 10 these values returned to baseline levels. No significant effects were seen in other parameters at any time of the investigation. In conclusion, we demonstrated significant increases in receptor activator of nuclear factor kB ligand and bone alkaline phosphatase after TSH stimulation. The changes in these bone indices were more prominent in the group of postmenopausal women.

Comparative evaluation of 99mTc-depreotide and 201Tl chloride single photon emission tomography in the characterization of pulmonary lesions.

PURPOSE: To compare (99m)Tc-depreotide and (201)Tl chloride SPET in the characterization of pulmonary lesions. METHODS: Fifty-seven pulmonary lesions from 33 patients suspected of malignancy in computed tomography, were assessed by (99m)Tc-depreotide and (201)Tl early and delayed SPET imaging. Images were visually assessed and the tumour-to-normal (T/N) lung activity ratio for early (ER) and delayed (DR) scans and the retention index (RI), were calculated in every lesion. A final diagnosis was reached for all lesions, based either on histology or prolonged clinical and radiological follow-up. RESULTS: Twenty-three lesions were characterized as malignant and 34 benign. In visual analysis, all malignant lesions accumulated both tracers resulting in sensitivity and negative predictive values of 100%. However, false positive interpretations resulted in a specificity of 64.7% and 67.6% for (99m)Tc-depreotide and (201)Tl, respectively. ER and DR of both agents and the RI of (99m)Tc-depreotide were significantly higher in malignant, compared to benign lesions. In defining thresholds of abnormality from ROC analysis, a significant increase in specificity was observed for both tracers in both scan phases (91.2% for all), as compared to visual analysis (P<0.01). There was no significant difference in the diagnostic performance between (99m)Tc-depreotide DR and (201)Tl DR, although the former provided the highest T/N ratio. CONCLUSION: This study demonstrates that (99m)Tc-depreotide and (201)Tl SPET are equally effective and may be useful in the non-invasive determination of lung malignancy. The specificity of both techniques is significantly improved by quantifying radiopharmaceutical accumulation in pulmonary lesions.

The contribution of conventional nuclear molecular imaging in characterising the nature of a growing solitary pulmonary nodule. Report of a case.

The solitary pulmonary nodule (SPN) is a relatively common imaging finding, often representing a diagnostic challenge. Radiological appearance, growth rate calculation during follow up and probability of malignancy assessment by the Bayes' theorem are widely used for identifying the nature of a SPN. Molecular imaging by fluoro-18 deoxy glucose positron emission tomography has revolutionised non-invasive diagnosis of lung cancer, but the low-cost, widely available conventional nuclear imaging modalities still remain valid in the field. We present a case of a growing SPN in a middle-aged male smoker. Growth rate assessment by sequential computed tomography scans, over a follow up period of five years, was suggestive of benign histology, while Bayesian analysis warranted histological confirmation of the nodule's nature. Imaging by both labelled somatostatin analogue technetium 99m-depreotide ((99m)Tc-depreotide) and thallium 201-chloride was almost exclusive of malignancy. The nodule was excised and histology showed a pulmonary hamartoma. We briefly discuss the relative role of invasive and non-invasive methods, with emphasis in conventional radionuclide molecular imaging, for the identification of the nature of SPN.

Effect of quinapril or losartan alone and in combination on left ventricular systolic and diastolic functions in asymptomatic patients with diabetic autonomic neuropathy.

OBJECTIVE: To investigate the effect of angiotensin converting enzyme inhibition (ACE-I) or angiotensin receptor blockade (ARB), and their combination, on both diabetic autonomic neuropathy (DAN) and left ventricular (LV) diastolic dysfunction (LVDD) in asymptomatic patients with diabetes mellitus (DM). MATERIALS AND METHODS: Sixty-two patients (34 women) with long-term DM (24 with Type 1) and DAN, aged 51.7+/-13.9 years, free of coronary artery disease (CAD) or arterial hypertension (HT) at baseline, were studied for a 12-month period. Diagnosis of DAN was established if two or more of the standard cardiovascular reflex tests (CRT) were abnormal. Patients were randomly allocated to quinapril (20 mg/day), losartan (100 mg/day), or quinapril plus losartan (20 mg/day+100 mg/day). LV systolic and diastolic function was assessed using radionuclide ventriculography (RNV) at baseline and after 12 months of treatment. RESULTS: In all three treatment groups, abnormal CRT values were improved. In the quinapril group, the first third filling fraction (1/3FF, 48.9+/-17.8% vs. 39.2+/-12.9% at baseline, P=.005) was increased and the atrial contribution to ventricular filling (25.1+/-6.3 vs. 30.1+/-7.8, P=.027) was reduced in the losartan group; the peak filling rate (PFR) was improved (3.41+/-.62 vs. 3.11+/-.44 volumes/s, P=.05), and in the combination group, the 1/3FF (39.4+/-11.8% vs. 29.6+/-11.9%, P=.018) was markedly increased, while the time to peak filling (TPF; 147+/-42 vs. 184+/-33 ms, P=.02) and the TPF/filling time (TPF/FT; 32.5+/-6.2% vs. 38.2+/-5.7%, P=.016) were reduced. CONCLUSIONS: Early ACE-I or ARB improve both DAN and LVDD in asymptomatic patients with Type 1 or 2 DM, after 1 year of treatment. Their combination may be slightly better than monotherapies on DAN and LVDD. The clinical importance of these effects should be validated by larger studies.

Protein-losing enteropathy as the principal manifestation of constrictive pericarditis.

Constrictive pericarditis represents a rare cause of protein-losing enteropathy due to intestinal lymphangiectasia. We report the case of a patient with an atypical clinical presentation of constrictive pericarditis and protein-losing enteropathy as its principal manifestation; he was successfully treated with pericardiectomy. We conclude that, constrictive pericarditis should be considered in the presence of protein losing enteropathy and also, protein-losing enteropathy should be considered in the differential diagnosis of hypoalbuminemia.

[Right and left ventricular ejection fraction evaluation in patients with chronic pulmonary disease. Comparison of nuclear medicine methods].

UNLABELLED: Our aim was to evaluate right ventricular ejection fraction (RVEF) and left ventricular ejection fraction (LVEF) in patients with chronic pulmonary disease (CPD) during a standard 99mTc-isonitrilium myocardial perfusion study. Forty patients (14 women and 26 men, mean age 67.7 +/- 7 years old) suffering from CPD enrolled in this study. Patients were consecutively submitted to: a) First pass (FP) angiocardiography with 99mTc (Tauc-FP). b) Multigated angiocardiography (MUGA). c) FP with 99mTc-sestamibi (MIBI-FP). d) Gated FP (MIBI-gFP) and GatedSPECT was performed in 23 patients. A simple SPECT study was performed to the rest of them. Our results showed: For the RV: RVEF measured by each method: Tauc-FP =49.09+/-8.4%, MUGA =48.51+/-10.6%, MIBI-FP =49.45+/-7.8 % and MIBI-gFP =52.49+/-6.05%. No difference among these methods was noted (P=0.674). MIBI-FP ejection fraction range was wider than MIBI-gFP and narrower than MUGA. A strong correlation (r=0.88 P<0.01) and good agreement was found between MIBI-gFP and MIBI-FP. Less strong correlation was estimated between not only Tc-FP and MUGA (r=0.76 P<0.01) but MIBI-FP and MUGA (r=0.68 P<0.01) as well with no sufficient agreement. For the LV: LVEF was also measured by each method: Tauc-FP=61,1+/-8,5%, MUGA=61,2+/-10%, MIBI-FP=61,8+/-6%,EF GSPECT=60,2+/-7%. There was a strong correlation (r=0.87 P<0.01) with good agreement between Tauc-FP and MUGA. For all patients, correlation between MIBI-FP and GSPECT was weak (r=0.62 P<0.01) but ameliorated by the exclusion of 4 patients with small end diastolic volumes (EDV) (r=0.82 P<0.01). The correlation between MUGA and GSPECT got stronger (r=0.85 P<0.01) by the same exclusion. Finally, a strong correlation (r=0.81 P<0.01) with sufficient agreement was noted between MIBI-FP and MUGA. IN CONCLUSION: For the RV: simple or gated FP are reliable with good agreement methods of RVEF evaluation in patients with CPD that can easily be performed during every radionuclide isonitrilium myocardial perfusion study. MUGA is proved to be comparative to the FP estimation of RV EF. The gFP affords the narrowest range of RVEF calculated, allowing the more accurate functional identification of RV borders. For the LV: FP (with 99mTc or with sestamibi-99mTc) is a reliable method of LVEF measurement in patients with CPD when compared with MUGA. MuIotaBetaIota-FP can evaluate LVEF during a standard myocardial perfusion study with radionuclide isonitrilium. GSPECT-EF correlation with EF measured by MUGA or FP is strongly affected by EDV.

Gastric emptying in children with cerebral palsy and gastroesophageal reflux.

Gastric emptying time is considered a factor in the increased frequency of gastroesophageal reflux in children with cerebral palsy. It is unknown if emptying time influences the severity of reflux. In this study, 76 cerebral palsy patients with reflux indicative symptoms were investigated by 24-hour pH monitoring. Reflux complications were also studied. Emptying time in children with reflux was investigated using gastric scintigraphy. Twenty-eight children with resistant asthma scanned for pulmonary aspiration were studied as control subjects for emptying time. Reflux was diagnosed in 51.3%; it was severe in 53.8%, moderate in 38.5%, and mild in 7.7%. Occurrence of reflux did not differ significantly among different forms of cerebral palsy or between males and females. The most frequent complications in reflux-positive patients were iron deficiency (51.3%), anemia (41.0%), malnutrition (33.3%), recurrent upper respiratory tract infections (28.2%), and low body weight (28.2%). Patients without reflux had less frequent complications. Gastric emptying time measured by gastric scintigraphy in 28 patients with reflux manifested no difference in comparison to the control group (P > 0.05). No relationship was found between emptying time and reflux severity (P > 0.05). In conclusion, reflux (moderate or severe) is common in children with cerebral palsy, frequently leading to complications but no delayed emptying time. The patients described in this report had no delayed emptying time. There was also no relationship between emptying time and severity of reflux.

201Tl gated single photon emission computed tomographic myocardial perfusion imaging in the assessment of global and regional left ventricular function. Would it be favoured over equilibrium radionuclide angiography?

BACKGROUND: This study investigates the clinical performance of routine 201Tl gated single photon emission computed tomographic (201Tl GSPECT) myocardial perfusion imaging. Equilibrium radionuclide angiography (ERNA) was used as the standard for comparison. METHODS AND RESULTS: One hundred and seventy-two consecutive patients were submitted to both myocardial 201Tl GSPECT imaging, at stress and in redistribution, and ERNA. Left ventricular ejection fractions (LVEF) and regional wall motion were assessed from both stress and redistribution 201Tl GSPECT datasets, and from ERNA. Linear regression analysis showed a good correlation between LVEF calculated by ERNA and 201Tl GSPECT (r=0.73 at stress, r=0.75 in redistribution, P<0.0001). However, the 95% prediction intervals of 201Tl GSPECT LVEF from ERNA LVEF were wide (minimum 35.4% at stress and 33.2% in redistribution). Moreover, a difference in LVEF > or =10% between ERNA and 201Tl GSPECT was found in 26.4% of cases at stress and 28.6% of cases in redistribution. A fair agreement between ERNA and 201Tl GSPECT was found in regional wall motion assessment in segments with normal or mildly reduced tracer uptake (kappa=0.32 at stress and kappa=0.33 in redistribution). In segments with moderately to severely reduced tracer uptake, a moderate agreement was found in regional wall motion assessment between ERNA and 201Tl GSPECT (kappa=0.44 at stress and kappa=0.42 in redistribution). CONCLUSIONS: Left ventricular function may be misinterpreted in a significant proportion of patients if the calculation of LVEF is based on 201Tl GSPECT. Moreover, the evaluation of regional wall motion by 201Tl GSPECT appears unsatisfactory.

[Nuclear medicine procedures in lung cancer imaging]. / In Process Citation.

Lung cancer is nowadays one of the most common malignancies and the leading cause of cancer mortality worldwide. Its early diagnosis and treatment is therefore the target of extensive research. Although radiologic imaging methods, especially CT, are the most widely used, they have well known constraints, including solitary pulmonary nodule characterisation, mediastinal lymph node staging, characterisation of the remaining tissue after chemo- or radiotherapy and early diagnosis of relapse. The main reason for these drawbacks is that radiologic methods primarily rely upon morphologic and anatomic criteria, which usually have little relevance to the biological status of a pulmonary lesion. The radiopharmaceuticals used in nuclear medicine, exploit special pathophysiologic localization mechanisms and provide unique functional information for their target tissues. Thus, many of the above mentioned problems can be elucidated. This is obvious in the published figures of sensitivity and specificity of the radionuclidic methods, which are often superior to those of CT [Table 1: see text]. In this article the main nuclear medicine procedures in the field of lung cancer imaging are reviewed. Emphasis is given in newer developments such as (99m)Tc-sestamibi, labeled somatostatin analogues and positron emission tomography with (18)F-FDG. We especially describe the "weaknesses" of the anatomic-radiologic imaging modalities and how the attending physicians, i.e. the pneumonologists, oncologists and thoracic surgeons can overcome them, by using the functional imaging methods of nuclear medicine.

Left ventricular systolic and diastolic function in normotensive type 1 diabetic patients with or without autonomic neuropathy: a radionuclide ventriculography study.

OBJECTIVE: To investigate the relation between diabetic autonomic neuropathy (DAN) and left ventricular (LV) function in type 1 diabetic patients. RESEARCH DESIGN AND METHODS: A total of 57 type 1 diabetic patients free of coronary artery disease and arterial hypertension were studied. Diagnosis of DAN was established by autonomic nervous function (ANF) tests, and LV systolic and diastolic functions were assessed by radionuclide ventriculography at rest. RESULTS: There were 24 patients who had definite DAN, established by the presence of two or more abnormal ANF tests, and 33 subjects were without DAN. DAN patients had impaired LV filling pattern, obvious by a reduced peak filling rate (3.1 +/- 1.1 vs. 3.7 +/- 0.7 end-diastolic volume [EDV]/s, P = 0.011) and first third filling fraction (35.3 +/- 19.5 vs. 50.8 +/- 16%, P = 0.002) as well as an increased time to peak filling (159.4 +/- 45.1 vs. 134.2 +/- 33.4 ms, P = 0.02) after correction for age and heart rate. There were no differences between the two groups with regard to ejection fraction, cardiac output, and cardiac index, whereas the peak emptying rate was greater in DAN patients (4.1 +/- 0.8 vs. 3.6 +/- 0.8 EDV/s, P = 0.019), suggesting LV hypercontractility. DAN patients had an increased heart rate (83.4 +/- 11.9 vs. 72.7 +/- 9.3 bpm, P = 0.001) and slightly higher systolic blood pressure. As a result, LV working load at rest was higher in DAN patients (11,109 vs. 9,096 bpm x mmHg, P < 0.001). Moreover, a correlation was found between abnormal LV systolic and diastolic indexes and the number of abnormal ANF tests. CONCLUSIONS: At rest, DAN patients have impaired LV filling pattern, slightly increased LV systolic function, and a higher LV working load, in comparison to non-DAN type 1 diabetic patients.

Low-grade chondrosarcomas: a difficult target for radionuclide imaging. Case report and review of the literature.

Bone scan with Tc-99m (technetium) diphosphonate is sensitive, but non-specific for musculoskeletal tumors. Tl-201 (thallium), Tc-99m-sestamibi, Tc-99m-tetrofosmin, and F-18-fluorodeoxyglucose (F-18-FDG) can visualize tumors more specifically and are therefore useful in orthopedic oncology. However, cartilaginous tumors are characterized by histological and biological features, which potentially impair specific radionuclide imaging. A case of a patient with a low-grade primary chondrosarcoma of the femur and a false negative Tl-201 scan is presented. Tc-99m-based tumor-localizing compounds (sestamibi, tetrofosmin), as well as metabolic and receptor-imaging radiopharmaceuticals have also been reported to fail in low-grade chondrosarcomas imaging. Low cellularity, mitochondrial specialization and the presence of an efflux membrane pump may contribute to poor imaging. A negative Tl-201 or Tc-99m-sestamibi scan should be interpreted with caution, when the possibility of a chondrosarcoma is not negligible.