Hellenic journal of nuclear medicine最新文献

Objective: To investigate the automatic synthesis of β-amyloid (Aβ) positron emission tomography (PET) imaging agent (E) -4- (2- (6- (2- (2-¹⁸F fluoroethoxy) ethoxy) ethoxy) pyridine-3-yl) vinyl) - N-methylaniline (¹⁸F-AV-45) for the diagnosis of Alzheimer's disease (AD) and its clinical application in AD patients.

Materials and methods: Fluorine-18-AV-45 was synthesized with AV-105 as the precursor, and the factors affecting the synthesis efficiency, such as the amount of precursor, nucleophilic reaction temperature were studied. At the same time, ¹⁸F-AV-45 PET/computed tomography (CT) brain scanning was performed in 15 patients with dementia to determine whether AD was the cause of the dementia.

Results: After optimizing the parameters, it was discovered that the highest synthesis efficiency was achieved with a AV-105 dosage of 2mg, a reaction temperature of 130^oC, and 1mL of DMSO. The radiochemical yield (RCP) was greater than 98, and the uncorrected synthesis efficiency was about 31.0%±2.8%. Ten of the 15 patients with dementia showed positive Aβ protein deposition, and the main deposition site of the imaging agent was the gray matter area of the brain, which was consistent with AD diagnosis, while the other 5 patients showed negative Aβ protein deposition, suggesting non-AD dementia.

Conclusion: β-amyloid protein ¹⁸F-AV-45 imaging agent can be easily and quickly prepared by the All in One radiochemical synthesis module. Our preliminary results offer hope that it can effectively detect β-amyloid deposition in the brain of AD patients in order to determine the etiology of dementia.

Objective: The purpose of this study was to evaluate the contribution of single photon emission computed tomography/computed tomography (SPECT/CT) standardized uptake value (SUV) metrics in classifying patients with suspected transthyretin cardiac amyloidosis (ATTR-CA) among the different Perugini grades.

Subjects and methods: One hundred four patients suspected of ATTR-CA underwent planar scintigraphy with bone seeking tracer (^99mTc pyrophosphate-PYP). Patients were classified according to the Perugini scale, the H/CL, H/Bone and H/Bkg ratios. A subset of 48 patients received additional SPECT/CT. Single photon emission computed tomography/CT SUV quantitative parameters, of the heart, myocardium, lungs, liver, soft tissues, bone, and SUV ratios (SUV_maxmyo, SUV_maxlungs, SUV_maxliver, SUV_maxbone and SUV_maxsoft tissue ratios), were evaluated in order to investigate potential metrics that could more clearly differentiate Perugini grades.

Results: A total of 33.7% of patients were considered grade 0, 34.6% grade 1 and 31.7% grade 2/3. A combination of H/CL >1.33 and H/Bone >0.85 showed the highest sensitivity 100%. Standardized uptake value-based metrics clearly differentiated grade 0 or 1 vs grades 2 or 3, whereas no significant difference was found between grades 0 and 1, or between grades 1 and 2. The combined cut-off values H/CL 1.33 and SUV_maxmyo 2.88 yielded 100% sensitivity and 84.6% specificity in differentiating ATTR-CA positives vs negatives. The metric SUV_maxmyo/SUV_maxliver was the best metric to classify patients with grade 1 as negative (grade 0) or positive (grade 2 or 3).

Conclusion: Single photon emission computed tomography/CT SUV metrics could be complementary to planar scintigraphy in classifying patients among the different Perugini grades. The ratio SUV_maxmyo/SUV_maxliver was the only parameter with high affinity to differentiate patients with grade 1, as grade 0 or grade 2/3 for ATTR-CA.

Langerhans cell histiocytosis (LCH) is a haematological disorder, affecting single or multiple organs, characterized by abnormal proliferation of Langerhans cells in children. Accurate tumour delineation (number of lesions, organs involved) is crucial for staging/re-staging, and follow-up (response to therapy). Conventional imaging techniques (computed tomography (CT), magnetic resonance imaging (MRI)) have been employed for initial diagnosis, staging and assessment of response to therapy focusing on the healing effect therapeutic protocols have on the disease. In this case report, whole-body positron emission tomography/computed tomography (PET/CT) was shown either to provide information on the metabolic activity of histiocytes, or identify lesions otherwise asymptomatic. It is clear that PET/CT, combining anatomic and metabolic information, provides data for accurate staging, therapeutic protocol selection and assessment of response to therapy.

Pericardial inflammatory myofibroblastic tumor (IMT) is very rare. Herein, we report fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) findings of pericardial IMT in a 57-year-old woman. On conventional image, it presented as a pericardial mass with heterogeneous delay enhancement. On ¹⁸F-FDG PET/CT image, this lesion had mild ¹⁸F-FDG uptake with a maximum standardized uptake value (SUV_max) of 1.84. The postoperative pathology supported a diagnosis of IMT. Our case hints us that IMT should be regarded as a differential diagnosis when we meet a solitary pericardial mass with ¹⁸F-FDG uptake.

Extrastriatal accumulation on technetium-99m-([2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]- ethanethiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)])(^99mTc)-TRODAT-1 is unexpected during nuclear medicine nigrostriatal pathway examinations on ^99mTc-TRODAT-1 brain single photon emission computed tomography (SPECT). An 86-year-old female with a history of right hemiparesis, speech expressive difficulties, unstable gait, and bradykinesia on right side was reported. Technetium-99m -TRODAT-1 dopamine transporter SPECT revealed an incidental extrastriatal accumulation of radiotracer in the left anterior frontal region, accompanied by a photopenic area which resulted in the displacement of the left striatum with decreased dopaminergic neuronal function. The brain magnetic resonance imaging (MRI) revealed an invasive meningioma corresponding to the extrastriatal uptake on SPECT, accompanied by edema and mass effect. The patient received surgery and the histopathological results confirmed the diagnosis of atypical meningioma.This study emphasizes the importance of understanding the underlying causes of extrastriatal uptake from ^99mTc-TRODAT-1 brain SPECT, which may indicate an invasive brain tumor.

Direct radionuclide cystography (DRC) is a safe and reliable method for the detection and follow-up of vesico-ureteral reflux (VUR). Since the first DRC was performed, during the early 60^s, the method has undergone many refinements. Themanometric approach, which was first introduced in 1984, provides a correlation between the bladder pressure and VUR visualization. In this study the sources of error that may alter the results of DRC are discussed and a novel, standardized low costmanometric apparatus is suggested.

A 35-year-old woman received a surgery of sigmoid colon highly differentiated mucosal adenocarcinoma with greater omentum and peritoneum metastasis.The follow-up contrast-enhanced computed tomography (CT) revealed a new enhanced nodule on the transverse mesocolon about 6 months after surgery. Fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) and ¹⁸F-fibroblast activation protein inhibitor (FAPI) positron emission tomography (PET)/CT were both performed to evaluate the potential lesions systematically, PET/CT images showed low ¹⁸F-FDG activity but very little ¹⁸F-FAPI activity in the nodule on the transverse mesocolon. Ultimately, the nodule was pathologically proved to be sutures granuloma. Maybe ¹⁸F-FAPI PET/CT is a potential choice to differentiate suture granulomas from metastasis.

Cardiac amyloidosis is a rare condition characterized by the accumulation of abnormal proteins called amyloids in the heart tissue. These amyloids can disrupt the normal functioning of the heart and lead to a variety of symptoms and complications.

Objective: In bone scintigraphy, it is difficult to compare quantitative values, such as standardized uptake value (SUV), obtained from 2 different single-photon emission computed tomography combined with computed tomography (SPECT/CT) devices owing to differences of imaging acquisition and analysis methods. Therefore, the purpose of this study was to compare the SUV obtained from different SPECT/CT devices using the ratio to normal bone, and to analyze the correlation between them.

Subjects and methods: A total of 27 prostate cancer patients who underwent bone scintigraphy either using Symbia T16 or Symbia Intevo (Siemens Medical Solutions, Erlangen, Germany) were retrospectively analyzed. In each patient, spherical voxels of interest were placed on the following 5 reference points: humeral head (humerus), femoral neck (femur), lower part of the ilium (ilium), first lumbar vertebra (L1), fifth lumbar vertebra (L5), and the maximum SUV (SUV_max) and average SUV (SUV_ave) of these regions were measured.

Results: The mean and variance of SUV_ave (humerus) was the smallest on both SPECT/CT. To compare the SUV obtained from the 2 devices, the SUV_ave ratio and SUV_max ratio of each region were calculated as the SUV_ave and SUV_max of each region divided by the SUV_ave of the humeral head in each patient. Median values of the SUV_max ratio and SUV_ave ratio of each region showed similar tendencies in both devices, with correlation coefficients between 0.93 and 1.19.

Conclusion: Our results demonstrated that by expressing the quantitative value of SUV_ave of each region as a ratio to the SUV_ave of the humeral head, accumulation in the targeted bone can be compared even when the imaging acquisition and analysis methodsare different.

Objective: Vitamin D (VitD) plays various roles, promotes musculoskeletal health, maintains parathyroid hormone levels and supports the immune processes. Vitamin D deficiency is common among cancer patients including thyroid cancer. Since some data indicate that preoperative VitD levels in cancer patients correlate with the further prognosis of the disease. Therefore, it is worthwhile to investigate this in the most common cancer of the thyroid gland, papillary thyroid cancer (PTC). The aim of this study was to evaluate serum VitD levels in patients with PTC concerning age, gender, body mass index (BMI), cancer stage, thyroid hormone levels, thyroglobulin concentration and the efficiency of VitD3 supplementation in these patients.

Subjects and methods: Our cross-sectional study included 105 patients, and 34 healthy subjects in the control group. After 12 weeks of VitD3 supplementation (insufficient patients received1000IJ/day, deficient patients 2000IJ/day, severe deficient patient 5000IJ/day) along with the lifestyle and dietary management, the response was evaluated according to the personal characteristics, levels of VitD, free thyroxine (FT4), freetriiodothyronine (FT3) hormones and thyroglobulin (TG).

Results: The responders whose median age was 61-year-old, were mostly women (94%), with BMI below 23.7kg/m³, which indicates that most of the patients were normally nourished. 70% of patients were in the first stage of PTC, 76% had a vitamin D deficiency, while musculoskeletal disorders were present in 30% patients. VitD supplementation improved serum VitD status, FT3 discretely elevated and the TG levels significantly decreased in our PTC patients.

Conclusion: It should be noted that VitD deficiency is presented in 70% of patients with PTC in our study sample. Dietary recommendation applied as lifestyle changes along with oral VitD3 supplementation, corrected VitD status to the recommended serum level. Although the data from our study is not sufficient to evaluate the VitD level as a prognostic factor for cancer, we have shown that it is necessary to examine its level along with an individual dietary approach for each patient with PTC.