Comparison of perfusion 18F-FP-CIT PET and 99mTc-ECD SPECT in parkinsonian disorders.

ABSTRACT: Early and accurate identification of various conditions that can cause parkinsonian symptoms is important for determining treatment policies. Currently dopamine transporter (DAT) imaging using FP-CIT, glucose metabolism imaging using fluorodeoxyglucose, cerebral blood flow image using ethyl cysteinate dimer (ECD), and others are used for differentiation. However, the use of multiple modalities is inconvenient and costly. In the present retrospective study, we evaluated the correlation between regional brain uptake ratios (URs) in perfusion FP-CIT PET and ECD SPECT images.Twenty patients with Parkinson's symptoms underwent perfusion DAT positron emission tomography (18F-FP-CIT PET/CT) and cerebral blood flow tomography (99mTc-ECD SPECT) within a 2-week period. Perfusion 18F-FP-CIT PET/CT and 99mTc-ECD SPECT URs of 19 brain regions (bilateral frontal, temporal, parietal and occipital lobes, bilateral caudate nucleus, bilateral putamen, bilateral insula, bilateral cingulate gyrus, bilateral thalamus, and brainstem) were directly compared and correlations were analyzed.Average 18F-FP-CIT PET/CT regional perfusion URs were higher than 99mTc-ECD SPECT URs. Uptake ratios were well correlated in all 19 regions (except right putamen), and especially in dopamine poor regions (cerebral cortex). In left putamen, URs were significantly correlated, but the correlation coefficient was lower than those of other regions.A single tracer dual phase N-3-fluoropropyl-2-beta-carboxymethoxy-3-beta-(4-iodophenyl) nortropane test seems to be helpful for differential diagnosis of parkinsonian disorders. Large-scale, longitudinal studies on complementary diseases with parkinsonian patterns are required to investigate differences in correlations between perfusion 18F-FP-CIT PET/CT and 99mTc-ECD SPECT over time.

RADIOISOTOPE DIAGNOSTIC ALGORITHM FOR THE RELAPSE AND METASTASES DETECTION IN THE IODINE-NEGATIVE DIFFERENTIATED THYROID CANCER. / RADIONUKLIDNYI DIAGNOSTYChNYI ALGORYTM DLIa VYIaVLENNIa RETsYDYVIV I METASTAZIV U KhVORYKh Z IOD-NEGATYVNYMY FORMAMY DYFERENTsIIOVANOGO RAKU ShchYTOPODIBNOÏ ZALOZY.

OBJECTIVE: Developing of algorithm for the post-surgical management of patients with iodine-negative metastasesof differentiated thyroid cancer (DTC). MATERIALS AND METHODS: The DTC patients with iodine-negative metastases (n = 115) were enrolled in the study.Of them the whole body scintigraphy (WBS) was performed with technetium-99m-hexakis-2-methoxyisobutylisonitrile(99mTc-MIBI) (n = 30), WBS with technetium-99m dimercaptosuccinic acid (99mTc-DMSA) (n = 30), 18FDG PET (n = 30), andcomputer tomography (CT-scan) (n = 25). Complex 99mTc-pertechnetate scans including the dynamic and static scintigraphy was performed supplementary to 99mTc-MIBI WBS in 10 patients to obtain the angiographic curves from DTCmetastatic foci. The non-radioiodine radiopharmaceutical technologies, namely the labeled 99mTc-MIBI, 99mTc-DMSA, 99mTc-pertechnetate, and 18FDG were applied to detect the iodine-negative DTC metastases. Radioisotopic examinationswere performed at the dual-head gamma camera (Mediso Medical Imaging Systems Ltd., Hungary) and single photonemission computed tomography (SPECT) scanner «E.CAM¼ (Siemens, Germany). PET/CT scans were performed on the«Biograph 64 TruePoint¼ imaging platform (Siemens, Germany) in accordance with the European Association of NuclearMedicine (EANM) recommendations for the Siemens imaging devices with 3D-mode data acquisition. RESULTS: The conducted research suggested that it is feasible to use the non-radioiodine (99mTc-MIBI and 99mTc-DMSA)radiopharmaceutical technologies to detect the iodine-negative DTC metastases. 18FDG PET is a highly informativetechnology for the detection of iodine-negative DTC metastases in case of lung involvement in the process. Compareof the non-radioiodine radiopharmaceuticals, CT scan and 18FDG-PET/CT indicated the highest sensitivity of 18FDGPET/CT (p < 0.05). WBS with 99mTc-MIBI and 99mTc-DMSA featured the highest specificity (100 %, p < 0.05). X-ray CTis marked by the significantly lower either sensitivity, specificity, and accuracy rate (p > 0.05). Developing andapplication of algorithm for the post-surgical management of patients with iodine-negative forms of DTC will allowfor the betimes detection of relapses and metastases with administration of adequate surgical, radiation, and targeted treatment. CONCLUSIONS: Obtained results offer the opportunity to optimize the post-surgical management of patients withiodine-negative DTC forms using the options of radionuclide diagnostics with non-radioiodine radiopharmaceuticals. The latter are readily available providing the cost-cutting of diagnostic support in these patients. Place ofmorphological methods of diagnosis is determined and stage of monitoring of patients with the iodine-negativemetastases is established. Possibility of the 18FDG-PET tests for the early diagnosis of iodine-negative metastases inDTC for the first time have been studied and substantiated in Ukraine. A comprehensive radiation algorithm for thelong-term monitoring of this category of patients will allow the timely detection of recurrences and metastases ofDTC and appropriate surgery, radiation and targeted therapy administration. Data obtained as a result of the studyallowed to improve the overall and recurrence-free survival rates in the able-bodied DTC patients and reduce thecosts of follow-up of patients with iodine-negative forms of DTC.

Self-Assembled Hybrid Nanocomposites for Multimodal Imaging-Guided Photothermal Therapy of Lymph Node Metastasis.

Multimodal imaging-guided therapy holds great potential for precise theranostics of cancer metastasis. However, imaging agents enabling the convergence of complementary modalities with therapeutic functions to achieve perfect theranostics have been less exploited. This study reports the construction of a multifunctional nanoagent (FIP-99mTc) that comprises Fe3O4 for magnetic resonance imaging, radioactive 99mTc for single-photon-emission computed tomography, and IR-1061 to serve for the second near-infrared fluorescence imaging, photoacoustic imaging, and photothermal therapy treatment of cancer metastasis. The nanoagent possessed superior multimodal imaging capability with high sensitivity and resolution attributing to the complement of all the imaging modalities. Moreover, the nanoagent showed ideal photothermal conversion ability to effectively kill tumor cells at low concentration and power laser irradiation. In the in vivo study, FIP-99mTc confirmed the fast accumulation and clear delineation of metastatic lymph nodes within 1 h after administration. Attributing to the efficient uptake and photothermal conversion, FIP-99mTc could raise the temperature of metastatic lymph nodes to 54 °C within 10 min laser irradiation, so as to facilitate tumor cell ablation. More importantly, FIP-99mTc not only played an active role in suppressing cancer growth in metastatic lymph nodes with high efficiency but also could effectively prevent further lung metastasis after resection of the primary tumor. This study proposes a simple but effective theranostic approach toward lymph node metastasis.

MM2-type sporadic Creutzfeldt-Jakob disease: new diagnostic criteria for MM2-cortical type.

OBJECTIVE: To clinically diagnose MM2-cortical (MM2C) and MM2-thalamic (MM2T)-type sporadic Creutzfeldt-Jakob disease (sCJD) at early stage with high sensitivity and specificity. METHODS: We reviewed the results of Creutzfeldt-Jakob disease Surveillance Study in Japan between April 1999 and September 2019, which included 254 patients with pathologically confirmed prion diseases, including 9 with MM2C-type sCJD (MM2C-sCJD) and 10 with MM2T-type sCJD (MM2T-sCJD), and 607 with non-prion diseases. RESULTS: According to the conventional criteria of sCJD, 4 of 9 patients with MM2C- and 7 of 10 patients with MM2T-sCJD could not be diagnosed with probable sCJD until their death. Compared with other types of sCJD, patients with MM2C-sCJD showed slower progression of the disease and cortical distribution of hyperintensity lesions on diffusion-weighted images of brain MRI. Patients with MM2T-sCJD also showed relatively slow progression and negative results for most of currently established investigations for diagnosis of sCJD. To clinically diagnose MM2C-sCJD, we propose the new criteria; diagnostic sensitivity and specificity to distinguish 'probable' MM2C-sCJD from other subtypes of sCJD, genetic or acquired prion diseases and non-prion disease controls were 77.8% and 98.5%, respectively. As for MM2T-sCJD, clinical and laboratory features are not characterised enough to develop its diagnostic criteria. CONCLUSIONS: MM2C-sCJD can be diagnosed at earlier stage using the new criteria with high sensitivity and specificity, although it is still difficult to diagnose MM2T-sCJD clinically.

The utility of 99mTc-mebrofenin hepatobiliary scintigraphy with SPECT/CT for selective internal radiation therapy in hepatocellular carcinoma.

BACKGROUND: Studies assessing the impact of selective internal radiation therapy (SIRT) on the regional liver function in patients with hepatocellular carcinoma (HCC) are sparse. This study assessed the changes in total and regional liver function using hepatobiliary scintigraphy (HBS) and investigated the utility of HBS to predict post-SIRT liver dysfunction. METHODS: Patients treated with SIRT for HCC between 2011 and 2019, underwent Tc-mebrofenin HBS with single-photon emission computed tomography/computed tomography (SPECT/CT) before and 6 weeks after SIRT. The corrected mebrofenin uptake rate (cMUR) and corresponding volume was measured in the total liver, and in treated and nontreated liver regions. Patients with and without post-SIRT liver dysfunction were compared. RESULTS: A total of 29 patients, all Child-Pugh-A and mostly intermediate (72%) stage HCC were included in this study. Due to SIRT, the cMURtotal declined from 5.8 to 4.5%/min/m (P < 0.001). Twenty-two patients underwent a lobar SIRT, which induced a decline in cMUR (2.9-1.7%/min/m, P < 0.001) and volume (1228-1101, P = 0.002) of the treated liver region, without a change in cMUR (2.4-2.0%/min/m, P = 0.808) or volume (632-644 mL, P = 0.661) of the contralateral nontreated lobe. There were no significant pre-SIRT differences in total or regional cMUR or volume between patients with and without post-SIRT liver dysfunction. CONCLUSION: In patients treated with SIRT for HCC, HBS accurately identified changes in total and regional liver function and may have a complementary role to personalize lobar or selective SIRT. In this pilot study, there were no pre-SIRT differences in cMUR or volume to aid in predicting post-SIRT liver dysfunction.

99mTc-bisphosphonate-coated magnetic nanoparticles as potential theranostic nanoagent.

Novel theranostic nanoplatform is expected to integrate imaging for guiding and monitoring of the tumor therapy with great therapeutic efficacy and fewer side effects. Here we describe the preparation of a multifunctional 99mTc-bisphosphonate-coated magnetic nanoparticles (MNPs) based on Fe3O4 and coated with two hydrophilic bisphosphonate ligands, i.e., methylene diphosphonate (MDP) and 1-hydroxyethane-1,1- diphosphonate (HEDP). The presence of the bisphosphonates on the MNPs surface, enabled their biocompatibility, colloidal stability and successful binding of the radionuclide. The morphology, size, structure, surface charge and magnetic properties of obtained bisphosphonate-coated Fe3O4 MNPs were characterized by transmission electron microscopy, X-ray powder diffraction, dynamic light scattering, laser Doppler electrophoresis, Fourier transform infrared spectroscopy and vibrating sample magnetometer. The specific power absorption values for Fe3O4-MDP and Fe3O4-HEDP were 113 W/g and 141 W/g, respectively, indicated their heating ability under applied magnetic field. Coated MNPs were radiolabeled with 99mTc using stannous chloride as the reducing agent in a reproducible high yield (95% for Fe3O4-MDP and 97% for Fe3O4-HEDP MNPs) and were remained stable in saline and human serum for 24 h. Ex vivo biodistribution studies presented significant liver and spleen uptake in healthy Wistar rats after intravenous administration at all examined time points due to the colloidal nature of both 99mTc-MNPs. Results of scintigraphy studies are in accordance with ex vivo biodistribution studies, demonstrating high in vivo stability of radiolabeled MNPs and therefore results of both methods were proved as accurate information on the biodistribution profile of investigated MNPs. Overall, in vitro and in vivo stability as well as heating ability, indicate that biocompatible radiolabeled bisphosphonate magnetic nanoparticles exhibit promising potential as a theranostic nanoagent.

Towards characterizing the regional cerebral perfusion in evaluating the severity of major depression disorder with SPECT/CT.

BACKGROUND: Major depressive disorder (MDD) is a common mental disorder worldwide, but now there is a lack of clinically effective assessment and management of MDD. In this study, we used technetium-99 m ethylcysteinate dimer ([99mTc]ECD) SPECT/CT to characterize the regional cerebral blood flow (rCBF) status of MDD patients, and to explore an objective image assessment model of MDD which is non- or minimally-invasive, convenient and accurate in a clinical setting. METHODS: The severity of MDD was assessed by three trained psychiatrists, based on scores obtained from HAMD and HAMA. [99mTc]ECD rCBF SPECT/CT was performed in 20 healthy controls and 74 unipolar MDD patients before receiving the treatment. The CT attenuation-corrected SPECT images data were automatically registered, analyzed simultaneously by 3D-SSP and eZIS. RESULTS: The mean score of HAMD and HAMA in the MDD patients was 25.49 ± 6.00, and 23.12 ± 5.83, respectively. There was a positive correlation between two scores. The MDD women had higher HAMD scores than MDD men. The decreased rCBF of MDD patients in frontal lobes (bilateral B11, B47 and right B4, B6, B10, B46), temporal lobe (right B21, B41, B42) and cingulated cortex (bilateral B24, B33), while their increased rCBF in occipital lobe (bilateral B17, B19 and left B18). Additionally, the depression severity was negatively correlated with decreased rCBF in left ventral anterior cingulate cortex B24, and was positively correlated with decreased rCBF in left inferior prefrontal gyrus B47 and increased rCBF in right associative visual cortex B19. The anxiety severity was negatively correlated with decreased rCBF in left subgenual cortex B25. CONCLUSIONS: Although the mechanism underlying the correlation is not yet fully understood, our findings indicated that the rCBF SPECT/CT may provide an objective assessment for MDD severity. It might be used monitoring therapeutic efficacy in the management of MDD.

A new era in gated myocardial perfusion imaging: Feasibility of data-driven cardiac contraction gating with multiple pinhole CZT SPECT.

BACKGROUND: We previously validated the use of a data-driven cardiac respiratory-motion (RM) correction method (REGAT) applicable to CZT SPECT myocardial perfusion imaging (MPI). In this study, we adapted the same process used with REGAT for RM to generate data-driven cardiac contraction triggers and corresponding cardiac contraction-gated SPECT studies (GSPECT-DD). We aimed to study its feasibility and compare its performances to GSPECT studies generated with ECG monitor-based triggers (GSPECT-ECG). METHODS: We included seven non-consecutive randomly chosen patients addressed for 1-day 99mTc-Tetrofosmin stress/rest MPI acquired with multi-pinhole CZT SPECT. We studied the degree of agreement between GSPECT-DD and GSPECT-ECG for the classification of acquired images into the 16 categories of mean cardiac cycle, and compared between the two methods the cine image quality and global LV systolic function of reconstructed studies. RESULTS: We found almost perfect agreement between cardiac contraction triggers generated with data-driven and ECG monitor-based methods. As compared to GSPECT-ECG, GSPECT-DD provided comparable and well-correlated LV global systolic function parameters and similar cine image quality at both stress and rest. CONCLUSIONS: Data-driven cardiac contraction gating using REGAT is feasible with low-dose and high-dose MPI CZT SPECT. It provides GSPECT-DD studies comparable to GSPECT-ECG.

Designed Host Defense Peptides for the Treatment of Bacterial Keratitis.

Purpose: To limit corneal damage and potential loss of vision, bacterial keratitis must be treated aggressively. Innovation in antimicrobials is required due to the need for empirical treatment and the rapid emergence of bacterial resistance. Designed host defense peptides (dHDPs) are synthetic analogues of naturally occurring HDPs, which provide defense against invading pathogens. This study investigates the use of novel dHDPs for the treatment of bacterial keratitis. Methods: The minimum inhibitory concentrations (MICs) were determined for dHDPs on both Gram-positive and -negative bacteria. The minimum biofilm eradication concentrations (MBEC) and in vitro time-kill assays were determined. The most active dHDP, RP444, was evaluated for propensity to induce drug resistance and therapeutic benefit in a murine Pseudomonas aeruginosa keratitis model. Results: Designed HDPs were bactericidal with MICs ranging from 2 to >64 µg/mL and MBEC ranging from 6 to 750 µg/mL. In time-kill assays, dHDPs were able to rapidly reduce bacterial counts upon contact with as little as 2 µg/mL. RP444 did not induce resistance after repeated exposure of P. aeruginosa to subinhibitory concentrations. RP444 demonstrated significant efficacy in a murine model of bacterial keratitis as evidenced by a significant dose-dependent decrease in ocular clinical scores, a significantly reduced bacterial load, and substantially decreased inflammatory cell infiltrates. Conclusions: Innovative dHDPs demonstrated potent antimicrobial activity, possess a limited potential for development of resistance, and reduced the severity of murine P. aeruginosa keratitis. These studies demonstrate that a novel dHDP may have potential to treat patients with sight-threatening bacterial keratitis.

Degeneration of paramedian nuclei in the thalamus induces Holmes tremor in a case of artery of Percheron infarction.

RATIONALE: Holmes' tremor is an uncommon neurologic disorder following brain insults, and its pathogenesis is undefined. The interruption of the dento-rubro-thalamic tract and secondary deterioration of the nigrostriatal pathway are both required to initiate Holmes' tremor. We used nuclear medicine imaging tools to analyze a patient with concurrent infarction in different zones of each side of the thalamus. Finding whether the paramedian nuclear groups of the thalamus were injured was a decisive element for developing Holmes' tremor. PATIENT CONCERNS: A 36-year-old woman was admitted to our department due to a bilateral paramedian thalamic infarction. Seven months after the stroke, a unilaterally involuntary trembling with irregularly wavering motions occurring in both her left hand and forearm. DIAGNOSIS: Based on the distinct features of the unilateral coarse tremor and the locations of the lesions on the magnetic resonance imaging (MRI), the patient was diagnosed with bilateral paramedian thalamic infarction complicated with a unilateral Holmes' tremor. INTERVENTIONS: The patient refused our recommendation of pharmacological treatment with levodopa and other dopamine agonists based on personal reasons and was only willing to accept physical and occupational training programs at our outpatient clinic. OUTCOMES: We utilized serial anatomic and functional neuroimaging of the brain to survey the neurologic deficit. A brain magnetic resonance imaging showed unequal recovery on each side of the thalamus. The residual lesion appeared larger in the right-side thalamus and had gathered in the paramedian area. A brain perfusion single-photon emission computed tomography (SPECT) revealed that the post-stroke hypometabolic changes were not only in the right-side thalamus but also in the right basal ganglion, which was anatomically intact. Furthermore, the brain Technetium-99m-labeled tropanes as a dopamine transporter imaging agents scan ( Tc-TRODAT-1) displayed a secondary reduction of dopamine transporters in the right nigrostriatal pathway which had resulted from the damage on the paramedian nuclear groups of the right-side thalamus. LESSONS: Based on the functional images, we illustrated that a retrograde degeneration originating from the thalamic paramedian nuclear groups, and extending forward along the direct innervating fibers of the mesothalamic pathway, played an essential role towards initiating Holmes' tremor.

Folate-PEG-NOTA-Al18F: A New Folate Based Radiotracer for PET Imaging of Folate Receptor-Positive Tumors.

The folate receptor (FR) has been established as a promising target for imaging and therapy of cancer (FR-α), inflammation, and autoimmune diseases (FR-ß). Several folate based PET radiotracers have been reported in the literature, but an 18F-labeled folate-PET imaging agent with optimal properties for clinical translation is still lacking. In the present study, we report the design and preclinical evaluation of folate-PEG12-NOTA-Al18F (1), a new folate-PET agent with improved potential for clinical applications. Radiochemical synthesis of 1 was achieved via a one-pot labeling process by heating folate-PEG12-NOTA in the presence of in situ prepared Al18F for 15 min at 105 °C, followed by HPLC purification. Specific binding of 1 to FR was evaluated on homogenates of KB (FR-positive) and A549 (FR-deficient) tumor xenografts in the presence and absence of excess folate. In vivo tumor imaging with folate-PEG12-NOTA-Al18F was compared to imaging with 99mTc-EC20 using nu/nu mice bearing either KB or A549 tumor xenografts. Specific accumulation of 1 in tumor and other tissues was assessed by high-resolution micro-PET and ex vivo biodistribution in the presence and absence of excess folate. Radiosynthesis of 1 was accomplished within ∼35 min, affording pure radiotracer 1 in 8.4 ± 1.3% (decay corrected) radiochemical yield with ∼100% radiochemical purity after HPLC purification and a specific activity of 35.8 ± 15.3 GBq/mmol. Further in vitro and in vivo examination of 1 demonstrated highly specific FR-mediated uptake in FR+ tumor, with Kd of ∼0.4 nM (KB), and reduced accumulation in liver. Given its facile preparation and improved properties, the new radiotracer, folate-PEG12-NOTA-Al18F (1), constitutes a promising tool for identification and classification of patients with FR overexpressing cancers.

Miniaturized Radiochemical Purity Testing for 99mTc-HMPAO, 99mTc-HMDP, and 99mTc-Tetrofosmin.

Quick methods are functional in clinical practice to ensure the fastest availability of radiopharmaceuticals. For this purpose, we investigated the radiochemical purity of the widely used 99mTc-hydroxymethylene diphosphonate, 99mTc-hexamethylpropyleneamine oxime, and 99mTc-tetrofosmin by reducing time as compared with the manufacturer's method. Methods: We applied a miniaturized chromatographic method with a reduced strip development from 18 cm to 9 cm for all 3 radiopharmaceuticals. The specific support medium and solvent system of the manufacturer's methods was kept unchanged for 99mTc-hydroxymethylene diphosphonate and 99mTc-tetrofosmin, whereas for 99mTc-hexamethylpropyleneamine oxime the instant thin-layer chromatography (ITLC) polysilicic gel (silicic acid [SA]) was replaced with a monosilicic gel (silicic gel [SG]) in the chromatographic system that uses methyl ethyl ketone as solvent. The method was applied and compared with the routine ITLC insert method in a total of 30 batches for each radiopharmaceutical. The precision of repeated tests was determined by comparison with the results of 10 replications on the same batch. Small volumes of concentrated 99mTcO4-, and 99mTc-albumin nanocolloid were used to produce potential radiochemical impurities. Correlation between the quick methods and the insert methods was analyzed using a nonparametric 2-tailed test and a 2 × 2 contingency table with the associated Fisher exact test to evaluate sensitivity and specificity. A receiver-operating-characteristic analysis was performed to evaluate the best cutoff. Results: The percentage radiochemical purity of the quick methods agreed with the standard chromatography procedures. We found that 99mTcO4 and colloidal impurities are not the only common radiochemical impurities with 99mTc-tetrofosmin, and shortening of the ITLC strip with respect to the manufacturer's method will worsen system resolution and may produce inaccuracy. Conclusion: The miniaturized methods we described represent a fast and reliable alternative for 99mTc-exametazime and 99mTc-oxidronate quality control, with the upper cutoff for acceptable radiochemical purity values being 84% and 95%, respectively. For 99mTc-tetrofosmin radiochemical purity testing, a longer strip as described in the standard method is warranted.

[Portal vein embolization: Present and future]. / Embolisation portale préopératoire : présent et futur.

Portal vein embolization consists of occluding a part of the portal venous system in order to achieve the hypertrophy of the non-embolized liver segments. This technique is used during the preoperative period of major liver resection when the future remnant liver (FRL) volume is insufficient, exposing to postoperative liver failure, main cause of death after major hepatectomy. Portal vein embolization indication depends on the FRL, commonly assessed by its volume. Nowadays, FRL function evaluation seems more relevant and can be measured by 99mTc labelled mebrofenin scintigraphy. Portal vein embolization procedure is mostly performed with percutaneous trans-hepatic access by using ultrasonography guidance and consists of embolic agent injection, such as cyanoacrylate, in the targeted portal vein branches with fluoroscopic guidance. It is a safe and well-tolerated technique, with extremely low morbi-mortality. Portal vein embolization leads to sufficient FRL hypertrophy in about 80% of patients, allowing them to undergo surgery from which they were initially rejected. The two main reasons of non-resection are tumor progression (≈15% of cases) and FRL insufficient hypertrophy (≈5% of cases). When portal vein embolization is not enough to obtain adequate FRL regeneration, hepatic vein embolization may potentiate its effect (liver venous deprivation technique).

Thalamic involvement determined using VSRAD advance on MRI and easy Z-score analysis of 99mTc-ECD-SPECT in Gerstmann-Sträussler-Scheinker syndrome with P102L mutation.

Gerstmann-Sträussler-Scheinker syndrome caused by the P102L mutation in the prion protein gene (GSS102) is usually characterized by the onset of slowly progressive cerebellar ataxia, with dementia occurring much later. Because of the relatively long disease course and the prominence of progressive cerebellar ataxia in the early stage, GSS102 is often misdiagnosed as other neurodegenerative disorders. We present two cases of genetically proven GSS102L, both of which present with atrophy and decreased blood flow of the thalamus as determined by voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) advance software and easy Z-score analysis for 99mTc-ethyl cysteinate dimer-SPECT, respectively. These thalamic abnormalities have not been fully evaluated to date, and detecting them might be useful for differentiating GSS102 from other neurodegenerative disorders.

Reports of 17 Chinese patients with tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO) is a rare acquired form of hypophosphatemic osteomalacia, which is usually attributed to the overproduction of fibroblast growth factor 23 (FGF-23) by benign mesenchymal neoplasms. Localization and thereafter surgical resection of tumors lead to a cure. The present study aimed to investigate the clinical data, diagnostic methods, and follow-up after tumor resection at one medical center in Shanghai to characterize the profile of this rare disorder and to share our successful experience in diagnosis and treatment. Twenty-three patients with adult-onset hypophosphatemia osteomalacia seen in Shanghai Sixth People's Hospital from 2009 to 2014 and 95 normal individuals were enrolled. After taking a medical history and performing a physical examination, we analyzed the laboratory results (including the serum FGF-23 levels) and localized the tumors by 18F-fluorodeoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT), 99mTc-octreotide (99mTc-OCT) scintigraphy, and magnetic resonance imaging (MRI). On the basis of the results of laboratory tests and imaging findings, tumor resection was conducted in 17 patients with a certain diagnosis of TIO. The results demonstrated that the 17 patients (nine men and eight women, average age 46.6 ± 12.9 years) had TIO. FGF-23 level was elevated in 94.1 % of patients (16 of 17 patients) . Serum phosphorus level decreased in 100 % of patients. 18F-FDG PET/CT revealed five tumors, 99mTc-OCT scintigraphy revealed two tumors, physical examination revealed nine tumors, and MRI revealed one tumor, among which 58.8 % of the causative tumors (10 of 17 tumors) were located in the lower extremities. After tumor resection, serum phosphorus levels normalized in 100 % of patients (all 17 patients) in 4-21 days and FGF-23 levels decreased in 90 % of patients (nine of ten patients). We found 64.7 % of the tumors (11 of 17 tumors) were phosphaturic mesenchymal tumors or a phosphaturic mesenchymal tumor mixed connective tissue variant. Measurement of serum phosphorus and FGF-23 levels in patients with suspected TIO is of paramount importance for diagnosing of TIO. 18F-FDG PET/CT, 99mTc-OCT scintigraphy, and physical examination play a considerable role in revealing TIO-associated tumors. TIO-associated tumors were more frequently located in the lower extremities than in other places; thus, the lower extremities need to be carefully checked. Complete surgical resection results in normalization of parameters in laboratory tests and relief of symptoms of TIO patients.

Positive affect and regional cerebral blood flow in Alzheimer's disease.

Quality of life (QOL) has been recently recognized as the central purpose of healthcare, and positive affect is one of the core dimension of QOL. However, positive affect among patients with dementia or Alzheimer's disease (AD) has not received much attention in the medical research field. One hundred sixteen consecutive patients with AD were recruited from the outpatient units of the Memory Clinic of Okayama University Hospital. The positive affect score was evaluated using the positive affect domain of the Quality of Life questionnaire for Dementia (QOL-D). Patients underwent brain SPECT with 99mTc-ethylcysteinate dimer. Positive affect scores were inversely related to apathy scores, subjective depressive scores, and delusion scores. After removing the effects of age, sex, duration of education, and cognitive function, positive affect scores showed a significant correlation with regional cerebral blood flow in the left premotor and superior frontal gyri. The left premotor and superior frontal area is significantly involved in the pathogenesis of the decrease of positive affect in AD. Apathy and depression are closely related to the prefrontal area in AD, and they may affect the relationship between positive affect and the left prefrontal area.

Tc-99m-ECD SPECT as the measure for therapeutic response in patients with cobalamin deficiency: Two case reports.

BACKGROUND: Cobalamin (Cbl) is an essential vitamin for human health. While an increasing body of evidence supports the negative impact of Cbl deficiency on cognition, the causality has yet to be determined, and the reported therapeutic responses after Cbl supplement therapy have been inconsistent. Besides, few reports have described neuroimaging characteristics associated with the therapeutic response. METHODS: To describe and compare technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (Tc-99m-ECD SPECT) findings in 2 patients with Cbl deficiency with distinct therapeutic responses. RESULTS: Case 1 scored 12/30 in the mini-mental state examination (MMSE) and 34/100 in the cognitive abilities screening instrument (CASI). Profound deficits in mental manipulation, drawing, short-term/long-term memory, and verbal fluency were noted. Case 2 scored 24/30 in the MMSE and 78/100 in the CASI, mainly due to impaired mental manipulation, abstract thinking, and borderline performance in short-term memory and verbal fluency. While both cases showed widespread hypoperfusion within bilateral frontotemporal regions and thalamus on Tc-99m-ECD SPECT, Case 2 demonstrated relatively preserved radio-uptake in the frontal regions, especially the anterior cingulate cortex (ACC) and prefrontal cortex (PFC), consistent with the better therapeutic response (Case 1: 12/30 to 11/30 in the MMSE; Case 2: 24/30 to 28/30 in the MMSE). CONCLUSION: Given that the ACC integrates the limbic system and frontosubcortical circuits and the PFC governs executive function, the extent and severity of hypofrontality may be responsible for the worse prognosis. Our Tc-99m-ECD SPECT observations revealed that the negative impact on cerebral metabolic tone is relevant to the severity of Cbl deficiency, and the functional integrity of the ACC and PFC is highly associated with the preservation of global cognitive function in our cases with Cbl deficiency.

99mTc-EDDA/HYNIC-TOC in the diagnosis of differentiated thyroid carcinoma refractory to radioiodine treatment.

BACKGROUND: In majority of cases of differentiated thyroid carcinoma (DTC), the ablative radioiodine treatment shows high efficacy. In a small number of patients, mechanism of selective iodine uptake by the DTC cells is insufficient and alternative methods of diagnosis and treatment are needed. As demonstrated in vitro, DTC cells show expression of somatostatin recep-tors. Radiolabeled somatostatin analogs are widely used in the diagnosis of neuroendocrine tumors. The aim of the study was to evaluate the utility of peptide receptor scintigraphy with the use of 99mTc-EDDA/HYNIC-TOC in the diagnosis of DTC in patients with elevated thyroglobulin concentrations (Tg), negative WBS and no effect of the consecutive radioiodine therapies. MATERIAL AND METHODS: Whole body scintigraphy as well as SPECT of neck and chest were performed 3 and 24 h after i.v. administration of 740 MBq 99mTc-EDDA/HYNIC-TOC. The obtained images were compared with other radionuclide and ra-diological imaging methods. Forty-three patients with DTC after surgery and ablative radioiodine treatment with negative WBS and elevated Tg were qualified. Patients' age: 18-83 years (mean 58.0). RESULTS: SRS showed foci of tracer accumulation in 29 cases (67.4%). Sensitivity was 69.0% specificity 78.6%. SRS correctly identified local recurrence in 8 pts., metastatic lymph nodes in 19 pts., lung metastases in 12 pts. and bone metastases in 5 pts. SRS showed high sensitivity in the detection of metastatic lymph nodes (100%) and bone metastases (83.3%) and lung metastases (63.2%). Positive SRS was found in pts. with higher Tg concentrations (130 ± 144 vs. 30 ± 54 ng/ml). CONCLUSION: Scintigraphy with the use of the studied technetium-99m-labeled somatostatin analog is useful in the evaluation of patients with advanced DTC. It shows relatively good sensitivity and specificity but not high enough to be recommended as a routine imaging method. The role of somatostatin receptor scintigraphy in DTC is complementary to other imaging modalities.

[Evaluation of 99mTc-ECD SPECT/CT brain imaging with scenium analysis in patients with generalized anxiety disorder].

OBJECTIVE: To assess the perfusion changes in brains of patients with varying levels of generalized anxiety disorder (GAD). METHODS: A total of 38 GAD outpatients of Department of Psychiatry at our hospital from February to August, 2014 and 10 healthy controls received a 99mTC-ECD SPECT/CT scan with scenium analysis. Differences between brain perfusion and anxiety levels were analyzed by SPSS 16. 0 with one-way ANOVA, Pearson's Chi-square, t test and Spearman's correlation. RESULTS: They were grouped according to the levels of anxiety severity, i. e. mild (n = 11) , moderate (n = 16) and severe (n = 11). They had significantly lower blood flow in right superior frontal medial gyrus, right precuneus, right putamen, bilateral paracentral lobule and bilateral supplementary motor area (t = -2.19, -2.14, -2.22, -2.34, -2.08, -3.26, -2.72, P < 0.05). Individuals had significantly greater blood flow in mild group than those of control group in right olfactory (t = 2.09 P = 0.05). Individuals of moderate group had significantly lower blood flow than those of control group in left superior frontal gyrus medial orbital, right superior frontal gyrus medial orbital and left supplementary motor area, but greater in right olfactory (t = -2.16, -2.24, -2.49, 2.17, P = 0.04, 0.04, 0.02, 0.04). Individuals had lower blood flow in severe group than those of control group in left frontal lobe, right putamen, left paracentral lobule, right paracentral lobule, left precuneus, right precuneus, left parietal lobe, left precentral, right precentral, right postcentral, left rolandic operculum, left supplementary motor area, right supplementary motor area and left central region (t = -2.32, -2.11, -3.16, -2.61, -2.39, -2.18, -2.32, -2.67, -2.14, -2.11, -2.25, -4.38, -3.54, -2.38, P = 0.03, 0.05, 0.01, 0.02, 0.03, 0.04, 0.03, 0.02, 0.05, 0.05, 0.04, 0.00, 0.00, 0.03). Statistical differences existed in right middle frontal gyms orbital part (mild: 0.96 ± 0.07, moderate: 1.03 ± 0.06, severe: 0.98 ± 0.08, P = 0.04) and left paracentral (mild: 0.91 ± 0.07, moderate: 093 ± 004 severe: 0.87 ± 0.07, P = 0.02). There was a tendency of negative correlation between perfusion in right middle cingulate and paracingulate gyri, left precuneus, right precuneus and left thalamus and anxiety scores by Spearman's correlation analysis (r = -0.28, -0.28, -0.27, -0.29, P = 0.09, 0.09, 0.10, 0.07). CONCLUSION: Scenium software provides quantitative measurements for diagnosis of GAD in different anxiety levels. Also larger samples are required for confirming the results in further studies.

Decreased regional cerebral blood flow in the bilateral thalami and medulla oblongata determined by an easy Z-score (eZIS) analysis of (99m)Tc-ECD-SPECT images in a case of MM2-thalamic-type sporadic Creutzfeldt-Jakob disease.

We report a case of autopsy-verified MM2-thalamic-type sporadic Creutzfeldt-Jakob disease (sCJD) in a 46-year-old patient with a 16-month history of abnormal behavior, progressive dementia, insomnia, and speech disturbances without family history. Neurological examination revealed progressive dementia, frontal signs, insomnia, speech disturbance, gait disturbance and bilaterally exaggerated tendon reflexes. Both brain MRI and cerebrospinal fluid examinations, including 14-3-3 protein, yielded normal results. An easy Z-score (eZIS) analysis for (99m)Tc-ethyl cysteinate dimer-single photon emission computed tomography ((99m)Tc-ECD-SPECT) revealed decreased regional cerebral blood flow in the bilateral thalami and medulla oblongata. PRNP gene analysis revealed methionine homozygosity at codon 129 without mutation. Neuropathological examinations revealed severe neuronal loss, gliosis, and hypertrophic astrocytosis in the medial thalamus and inferior olivary nucleus. A slight depletion of Purkinje cells was observed. PrP immunostaining showed no obvious PrP deposits in the basal ganglia, thalamus, cerebellum, or brainstem; however, mild synaptic-type PrP deposits with some smaller plaque-like structures were only partially observed in the localized region of the frontal lobe with the spongiform change. Western blot analyses of protease-resistant PrP showed a type 2 pattern. In conclusion, eZIS analysis of (99m)Tc-ECD-SPECT images is useful for detecting both thalamic and medullary lesions. This is the first case of medullary lesions detected in a live patient with MM2-thalamic-type sCJD using SPECT.