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The present study is based on a retrospective analysis of Gallium-68 (68Ga)-labelled prostate-specific membrane antigen (68Ga-PSMA IT distant disease was found in 14/82 subjects (17.1%, 2 with intermediate-risk and 12 with high-risk PCa). No extraprostatic disease was found in low-risk PCa. SUVmax of primary tumours showed a weak but significant correlation with serum PSA values (r = 0.51, p

Purpose To investigate the relationships between pretreatment volume-based quantitative 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) parameters and overall survival (OS) in patients with malignant pleural mesothelioma (MPM). Materials and methods We retrospectively reviewed data from 201 MPM patients, of whom 38 underwent surgical resection, and calculated the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), including primary tumors and nodal or distant metastatic lesions, on pretreatment 18 F-FDG PET/CT. Relationships between clinicopathological factors (age, sex, performance status, European Organization for Research and Treatment of Cancer [EORTC] score, histological subtype, TNM stage, and treatment strategy), volume-based quantitative PET/CT parameters, and OS were evaluated using a Cox proportional hazards model and log-rank test. Results The median follow-up was 15 months (range, 1–96 months; median, 17 months). In a univariate analysis of all patients, older age (p Conclusions Pretreatment volume-based quantitative 18 F-FDG PET/CT parameters, especially TLG, could serve as potential surrogate markers for MPM prognosis.

Adjuvant treatments for operable breast cancers are determined according to subtypes defined based on estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status. The ER+/HER2− subtype can be divided into luminal A and luminal B usually by Ki67 expression levels. Although tumor size, lymph node metastasis and tumor grade have been widely accepted in daily clinical practice, the identification of further prognostic indicators especially in the ER+/HER2− subtype is warranted. A total of 387 operated breast cancers for which maximum standardized uptake value (SUVmax) on the 18 F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) were available at baseline were retrospectively analyzed. The optimal cutoff value of SUVmax for relapse-free survival (RFS) was determined to be 3.585 by means of the receiver operating characteristics curve with an area under the curve of 0.6795 (95% CI: 0.5972 to 0.7618, p = 0.0006, sensitivity: 78.8%, specificity: 57.1%). The RFS of patients with SUVmax-high (n = 178) was significantly (p = 0.0003) worse compared with those with SUVmax-low (n = 209). This significant association was prominently recognized in the ER+/HER2− subtype. By multivariable analysis, SUVmax (hazard ratio: 3.83, 95% confidence interval: 1.28–11.51, p = 0.017), tumor size (4.22, 1.39–12.82, p = 0.011) and lymph node metastasis (4.44, 1.81–10.87, p = 0.0012) were significant and independent prognostic factors for RFS. The ER+/HER2− subtype demonstrated consistently worse RFS in the SUVmax-high patients both in the luminal A (p = 0.037) and luminal B (p = 0.047) subtypes. Combination of Ki67 and SUVmax appears to be useful for selecting patients who have inferior prognosis and need further adjuvant treatment of the ER+/HER2− subtype.

Coronary flow reserve (CFR), defined as the ratio of maximum coronary flow increase from baseline resting blood flow, is one of the most sensitive parameters to detect early signs of coronary arteriosclerosis at the microvascular level. Myocardial perfusion PET is a well-established technology for CFR measurement, however, availability is still limited. The aim of this study is to introduce and validate myocardial flow reserve measurement by myocardial perfusion SPECT. Methods Myocardial perfusion SPECT at rest and ATP stress (0.16mg/Kg/min) was performed in 10 patients with known coronary artery disease. Immediately after the injection of Tc-99m sestamibi (MIBI), left ventricular (LV) dynamic planar angiographic data were obtained for 90s. Coronary flow reserve index as measured by MIBI SPECT (CFR MIBI ) was calculated as follows: CFR MIBI =Cm s Sbm b /Cm b Sbm s , where subscripts b , s , Cm, and Sbm indicate baseline, during stress, myocardial counts with MIBI SPECT, and integral of LV counts with first pass angiography, respectively. Additionally, standard stress/rest 15 O-water PET to estimate CFR was performed in all patients as standard of reference. Results CFR MIBI increased in conjunction with CFR, but underestimated blood flow at high flow rates. The relationship between CFR MIBI (Y) and CFR PET (X) was well fitted as follows: Y=1.40x(1-exp(1.79/x)) (r=0.84). Conclusions The index of CFR MIBI reflects the CFR by 15 O-water PET but underestimates flow at high flows, maybe as a reflection of pharmacokinetic limitations of MIBI.

Choline is a new positron emission tomography (PET) tracer useful for detection of prostate cancer and metastatic lesions. We report a 70-year-old man with prostate cancer and multiple abdominal, pelvic, and inguinal node metastases. PET scans demonstrated accumulation of 11C-choline in the primary tumor and lymph node metastases but no accumulation of 18F-FDG. Choline PET/computed tomography may be useful for diagnosis of advanced prostate cancer with suspected metastatic lesions and treatment planning.

Integrated positron emission tomography/computed tomography (PET/CT) with 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) has emerged as a powerful tool for the combined metabolic and anatomic evaluation of many cancers. In urological oncology, however, the use of (18)F-FDG has been limited by a generally low tumor uptake, and physiological excretion of FDG through the urinary system. (18)F-FDG PET/CT is useful when applied to specific indications in selected patients with urological malignancy. New radiotracers and positron emission tomography/magnetic resonance imaging (PET/MRI) are expected to further improve the performance of PET in uro-oncology.

To correlate both primary lesion maximum standardized uptake values (SUVmax) of FDG-PET/CT, and apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) with clinicopathologic prognostic factors in patients with breast carcinoma.214 patients with 216 mass-type invasive breast carcinomas underwent whole-body FDG-PET/CT and 3-Tesla breast MRI including DWI before initial therapy. The primary tumor's SUVmax and ADC values were measured using FDG-PET/CT and DWI, respectively. Histologic analysis parameters included tumor size, expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67, nuclear grade, histology subtype, and axillary lymph node (LN) metastasis. The relationships among SUVmax, ADC values, and pathologic prognostic factors were evaluated.The mean SUVmax and ADCmean were 5.63±3.79 (range, 1.2-24.17) and 894±204×10(-6)mm(2)/s (range, 452-1550×10(-6)), respectively. There was a significant but weak inverse correlation between the SUVmax and ADCmean values (correlation coefficient r=-0.30, p0.0001). SUVmax was associated with numerous prognostic factors such as tumor size (p0.0001), expression levels of ER (p=0.00041), PR (p=0.00028), HER2 (p=0.00021), and Ki-67 (p0.0001), nuclear grade (p0.0001), histology subtype (p=0.00061), axillary LN metastasis (p0.0001), and TNM staging (p0.0001). Meanwhile, ADCmean value was associated with tumor size (p=0.013), expression of Ki-67 (p=0.0010), histology subtype (p=0.00013), axillary LN metastasis (p=0.00059), and TNM staging (p=0.0011).Primary tumor SUVmax on FDG-PET/CT has a stronger relationship with known prognostic parameters and may be a more useful for predicting the prognosis of breast carcinoma than ADC values.

Purpose To assess the clinical usefulness of FDG-PET/CT in the diagnosis of recurrent and metastatic urothelial carcinoma in comparison with contrast-enhanced CT. Materials and methods Eighty-three patients who had undergone treatment for histopathologically proven urothelial carcinoma underwent whole-body FDG-PET/CT and contrast-enhanced CT for suspected recurrence within a time interval of two weeks. Patient-based analysis and lesion sites besides the urinary tract, as interpreted by two experienced readers, were compared between the two modalities using McNemar test. Lesion status was determined on the basis of histopathology, radiological imaging and clinical follow-up for longer than 6 months. Result Patient-based analysis showed that the sensitivity, specificity, and accuracy of FDG-PET/CT were 97.4%, 93.3% and 95.2%, respectively, whereas those of contrast-enhanced CT were 86.8%, 93.3% and 90.4%, respectively. The sensitivity and accuracy of FDG-PET/CT were higher than contrast-enhanced CT without significant difference (p = 0.13). The sensitivity of FDG-PET/CT for diagnosis of bone metastasis was significantly higher than that of contrast-enhanced CT (93.8% vs. 25%, p = 0.0026). Conclusion FDG-PET/CT is a more accurate modality than CT for assessment of recurrence outside the urinary tract in patients with urothelial carcinoma, especially for bone lesion. Cystoscopy, urine cytology, and FDG-PET/CT are complementary procedures and may have a definite management role.

BACKGROUND: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. MATERIAL AND METHODS: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F‑2‑fluoro‑2‑deoxy‑d‑glucose (\(^{18}\)F-FDG) and \(^{125}\)I‑β‑methyl‑iodophenyl‑pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. RESULTS: After cardiac differentiation of hiPSCs, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. CONCLUSIONS: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications.

To investigate the diagnostic and prognostic value of (18)F-FDG-PET/CT for axillary lymph node (LN) staging in breast cancer patients, employing histologic evaluation as the reference.Among 196 patients with biopsy-proven breast cancer who had undergone (18)F-FDG-PET/CT before mastectomy or breast-conserving surgery with sentinel LN biopsy and/or axillary LN dissection, 200 axillae were retrospectively analyzed by visual assessment and quantitatively using SUVmax. LN SUVmax as well as other clinicopathological features were assessed for their prognostic value using the log-rank test and Cox method.Metastasis was diagnosed histopathologically in 56 (28 %) axillae. The sensitivity, specificity, and accuracy of visual PET/CT for diagnosing node metastasis were 55.4, 95.8, and 84.5 %, respectively. When the optimal discriminative SUVmax cutoff was 1.5, these figures were 51.8, 97.2, and 84.5 %, respectively. Fourteen of 55 patients (25.5 %) with LN metastases suffered a recurrence during follow-up (median 39 months). Patients with a high nodal SUVmax (≥1.7) had a significantly lower progression-free survival rate than those with a low SUVmax (p = 0.0499). Axillary nodal and primary tumor SUVmax as well as estrogen receptor status were significantly associated with recurrence.Axillary nodal SUVmax may be a prognostic indicator of disease recurrence in patients with axillary LN metastases.

To determine whether 18F-FDG uptake in breast cancer correlates with immunohistochemically defined subtype and is able to predict molecular subtypes. This retrospective study involved 306 patients with 308 mass-type invasive breast cancers (mean size 2.65 cm, range 1.0–15.0 cm) who underwent 18F-FDG PET/CT before therapy. The correlations between primary tumour 18F-FDG uptake on PET/CT, expressed as SUVmax, and clinicopathological findings and molecular subtype, i.e. luminal A, luminal B (HER2-negative), luminal B (HER2-positive), HER2-positive and triple-negative, were analysed. The predictors of these subtypes were investigated. The mean SUVmax of the 308 tumours was 5.33 ± 3.63 (range 1.15–19.01). Among the subtypes of the 308 tumours, 87 (28.2 %) were luminal A, 111 (36.0 %) were luminal B (HER2-negative), 31 (10.1 %) were luminal B (HER2-positive), 26 (8.4 %) were HER2-positive and 53 (17.2 %) were triple-negative, and the corresponding mean SUVmax were 3.41 ± 2.07 (range 1.18–14.30), 5.17 ± 3.52 (range 1.35–19.01), 6.57 ± 3.84 (range 1.42–15.58), 7.55 ± 3.63 (range 2.30–13.60) and 6.97 ± 4.17 (range 1.15–16.06), respectively. A cut-off value of 3.60 yielded 70.1 % sensitivity and 66.1 % specificity with an area under the receiver operating characteristics curve (AUC) of 0.734 for predicting that a tumour was of the luminal A subtype. A cut-off value of 6.75 yielded 65.4 % sensitivity and 75.2 % specificity with an AUC of 0.704 for predicting a HER2-positive subtype. SUVmax, a metabolic semiquantitative parameter, shows a significant correlation with the molecular subtype of breast cancer, and is useful for predicting the luminal A or HER2-positive subtype.

Ga-pentixafor is a novel radioligand of C-X-C motif chemokine receptor 4. A 55-year-old woman with a history of primary Sjögren's syndrome underwent Ga-pentixafor PET/CT for staging of lymphoma originating from mucosa-associated lymphoid tissue. Whereas no lymphoma manifestation could be detected, imaging revealed bilateral intense radiotracer uptake in both parotid and submandibular salivary glands, consistent with inflammatory cell infiltration.

Metabolic syndrome (MetS) is a combination of clinical disorders that together increase the risk for cardiovascular disease and diabetes. SHRSP.Z-Lepr(fa)/IzmDmcr (SHRSP.ZF) rats with MetS show impaired nitric oxide-mediated relaxation in coronary and mesenteric arteries, and angiotensin II receptor type 1 blockers protect against dysfunction and oxidative-nitrosative stress independently of metabolic effects. We hypothesize that superoxide contributes to functional deterioration in SHRSP.ZF rats. To test our hypothesis, we studied effects of treatment with tempol, a membrane-permeable radical scavenger, on impaired vasodilation in SHRSP.ZF rats. Tempol did not alter body weight, high blood pressure, or metabolic abnormalities, but prevented impairment of acetylcholine-induced and nitroprusside-induced vasodilation in the coronary and mesenteric arteries. Furthermore, tempol reduced the levels of serum thiobarbituric acid reactive substance (TBARS) and 3-nitrotyrosine content in mesenteric arteries. Systemic administration of tempol elevated the expression of soluble guanylate cyclase (sGC) above basal levels in mesenteric arteries of SHRSP.ZF rats. However, acute treatment with tempol or ebselen, a peroxynitrite scavenger, did not ameliorate impaired relaxation of isolated mesenteric arteries. No nitration of tyrosine residues in sGC was observed; however, sGC mRNA expression levels in the arteries of SHRSP.ZF rats were lower than those in the arteries of Wistar-Kyoto rats. Levels of Thr(496)- and Ser(1177)-phosphorylated endothelial nitric oxide synthase (eNOS) were lower in arteries of SHRSP.ZF rats, and acetylcholine decreased Thr(496)-phosphorylated eNOS levels. These results indicated that prolonged superoxide production, leading to oxidative-nitrosative stress, was associated with impaired vasodilation in SHRSP.ZF rats with MetS. Down-regulated sGC expression may be linked to dysfunction, while reduced NO bioavailability/eNOS activity and modified sGC activity due to superoxide production were excluded as pivotal mechanisms.

Background/Aims Gastric motility abnormalities have been considered to be pathophysiological features of functional dyspepsia (FD) that are closely related to dyspepsia symptoms, especially postprandial distress syndrome (PDS). The aims of this study are to (1) investigate the prevalence of gastric motility disorders and (2) evaluate the association between gastric motility abnormalities and dyspeptic symptoms using gastric scintigraphy in the PDS type of FD. Methods Forty healthy subjects and 94 PDS type FD patients were enrolled in the study. The volunteers and patients ingested a radiolabeled (technetium-99m) solid test meal, and scintigraphic images were recorded. Gastric accommodation and emptying were assessed by scintigraphic imaging. The patients' dyspeptic symptoms were also explored using self-completed symptom questionnaires with 10 variables (4 scales, 0-3 points) at the same time. Results In 94 Japanese FD patients, the prevalence of impaired gastric accommodation and delayed emptying were 14.9% (14/94) and 10.6% (10/94), respectively. Gastric motility abnormalities were seen in 25.5% (24/94) of FD patients. There was no association between gastric motility abnormalities and dyspeptic symptoms. Conclusions Gastric motility abnormalities were seen in 25.5% of Japanese PDS type FD patients. However, there was no association between gastric motility abnormalities and dyspeptic symptoms on gastric scintigraphy.

To investigate the relationships between pretreatment volume-based quantitativeWe retrospectively reviewed data from 201 MPM patients, of whom 38 underwent surgical resection, and calculated the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), including primary tumors and nodal or distant metastatic lesions, on pretreatmentThe median follow-up was 15 months (range, 1-96 months; median, 17 months). In a univariate analysis of all patients, older age (p0.05), high EORTC score (p0.001), non-epithelioid histological subtype (p0.001), high T stage (p0.001), positive N/M status (p0.05, p0.001), advanced TNM stage (p0.001), non-surgical treatment (p0.001), and high SUVmax (p0.001), MTV (p0.001), or TLG (p0.001) were associated with significantly shorter OS. A multivariate analysis confirmed non-epithelioid subtype (hazard ratio [HR]: 1.69, 95% confidence interval [CI]: 1.14-2.48; p0.05), non-surgical treatment (HR: 0.58, 95% CI: 0.34-0.95; p0.05), and high TLG (HR: 1.97, 95% CI: 1.14-3.44; p0.05) as independent negative predictors.Pretreatment volume-based quantitative

Adjuvant treatments for operable breast cancers are determined according to subtypes defined based on estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status. The ER+/HER2- subtype can be divided into luminal A and luminal B usually by Ki67 expression levels. Although tumor size, lymph node metastasis and tumor grade have been widely accepted in daily clinical practice, the identification of further prognostic indicators especially in the ER+/HER2- subtype is warranted. A total of 387 operated breast cancers for which maximum standardized uptake value (SUVmax) on the

Purpose To evaluate the added clinical value of pretreatment 18 F-FDG PET/CT compared with conventional contrast-enhanced multidetector-row CT (CECT) alone for staging of advanced gastric cancer Materials and methods We studied 106 patients with locally advanced gastric cancer who underwent pretreatment CECT and 18 F-FDG PET/CT. Two experienced reviewers assessed the diagnostic performance of both CECT alone and the combination of CECT and 18 F-FDG PET/CT for the primary tumor, regional lymph node metastasis (N) and distant metastasis (M), rating their diagnostic confidence with a 5-point scoring system for each location. The two methods were compared using receiver operating characteristic (ROC) curve analysis for histopathologic findings, imaging, and clinical follow-up as the reference standards. Results Among the 106 patients, 96 primary tumors (90.6%) were detected by CECT, while 101 (95.3%) were clearly identified by 18 F-FDG PET/CT (p = 0.074). Patient-based areas under the ROC curves for CECT alone versus the combination of CECT and 18 F-FDG PET/CT for diagnosis of N stage, peritoneal dissemination, liver metastasis, distant lymph node metastasis, bone metastasis, metastasis at other sites and overall M stage were 0.787 vs. 0.858 (p = 0.13), 0.866 vs. 0.878 (p = 0.31), 0.998 vs. 1.0 (p = 0.36), 0.744 vs. 0.865 (p = 0.049), 0.786 vs. 0.998 (p = 0.034), 0.944 vs. 0.984 (p = 0.34), and 0.889 vs. 0.912 (p = 0.21), respectively. The diagnostic performance of primary tumor detection and NM staging was not influenced by the histologic subtype. Conclusion Adding 18 F-FDG PET/CT to CECT provides better diagnostic accuracy for detection of distant lymph node metastasis and bone metastasis in patients with untreated advanced gastric cancer.

Our aim was to determine whether the maximum standardized uptake value (SUVmax) of the primary lesion demonstrated by [18F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is associated with the prognosis of maxillary sinus cancer. The relationships of clinicopathological factors including age, T stage, N stage, histologic type, treatment strategy, and primary tumor SUVmax with progression-free (PFS) and overall (OS) survival were evaluated using the log-rank test and Cox method in 31 patients with maxillary sinus cancer before combined superselective intra-arterial chemotherapy using high-dose cisplatin with concurrent radiotherapy, or radiotherapy alone. The median duration of follow-up was 55.4 (range 9.7–72.6) months. PFS and OS of patients exhibiting a high SUVmax (≥16 and ≥17, respectively) for the primary tumor were significantly lower than those of patients for whom the primary tumor SUVmax was low (p = 0.0010 and p = 0.033, respectively). Multivariate analyses showed that T stage (p = 0.0049) and primary tumor SUVmax (p = 0.026) were independently prognostic of poorer PFS and that only primary tumor SUVmax (p = 0.049) was independently prognostic of poorer OS. SUVmax of the primary tumor determined by FDG-PET/CT before treatment could be a good surrogate marker for prognostication of maxillary sinus cancer.

Positron emission tomography ( PET) with 15O tracers provides essential information in patients with cerebral vascular disorders, such as cerebral blood flow ( CBF), oxygen extraction fraction ( OEF), and metabolic rate of oxygen ( CMRO2). However, most of techniques require an additional C15O scan for compensating cerebral blood volume ( CBV). We aimed to establish a technique to calculate all functional images only from a single dynamic PET scan, without losing accuracy or statistical certainties. The technique was an extension of previous dual-tracer autoradiography (DARG) approach, but based on the basis function method (DBFM), thus estimating all functional parametric images from a single session of dynamic scan acquired during the sequential administration of H215O and 15O2. Validity was tested on six monkeys by comparing global OEF by PET with those by arteriovenous blood sampling, and tested feasibility on young healthy subjects. The mean DBFM-derived global OEF was 0.57 ± 0.06 in monkeys, in an agreement with that by the arteriovenous method (0.54 ± 0.06). Image quality was similar and no significant differences were seen from DARG; 3.57% ± 6.44% and 3.84% ± 3.42% for CBF, and −2.79% ± 11.2% and −6.68% ± 10.5% for CMRO2. A simulation study demonstrated similar error propagation between DBFM and DARG. The DBFM method enables accurate assessment of CBF and CMRO2 without additional CBV scan within significantly shortened examination period, in clinical settings.

In clinical cardiac positron emission tomography using (15)O-water, significant tracer accumulation is observed not only in the heart but also in the liver and lung, which are partially outside the field-of-view. In this work, we investigated the effects of scatter on quantitative myocardium blood flow (MBF) and perfusable tissue fraction (PTF) by a precise Monte Carlo simulation (Geant4) and a numerical human model. We assigned activities to the heart, liver, and lung of the human model with varying ratios of organ activities according to an experimental time activity curve and created dynamic sinograms. The sinogram data were reconstructed by filtered backprojection. By comparing a scatter-corrected image (SC) with a true image (TRUE), we evaluated the accuracy of the scatter correction. TRUE was reconstructed using a scatter-eliminated sinogram, which can be obtained only in simulations. A scatter-uncorrected image (W/O SC) and an attenuation-uncorrected image (W/O AC) were also constructed. Finally, we calculated MBF and PTF with a single tissue-compartment model for four types of images. As a result, scatter was corrected accurately, and MBFs derived from all types of images were consistent with the MBF obtained from TRUE. Meanwhile, the PTF of only the SC was in agreement with the PTF of TRUE. From the simulation results, we concluded that quantitative MBF is less affected by scatter and absorption in 3D-PET using (15)O-water. However, scatter correction is essential for accurate PTF.

1. Metabolic syndrome is an independent risk factor for cardiovascular disease. SHRSP.Z-Lepr(fa) /IzmDmcr (SHRSP fatty) rat, established as a new rat model of metabolic syndrome, spontaneously develops obesity, severe hypertension and shows hypertriglyceridaemia, hypercholesterolaemia and abnormal glucose tolerance. Using SHRSP fatty rats, we examined whether or not oxidative stress was correlated with vascular dysfunction in small and large calibre coronary arteries in ex vivo beating hearts, isolated mesenteric arteries and aortas in comparison with normal rats, Wistar-Kyoto rats (WKY). Vasodilation of coronary arteries was determined by microangiography of the Langendorff heart. 2. Compared with WKY, acetylcholine (ACh) and sodium nitroprusside (SNP)-induced relaxations were impaired in the coronary arteries of SHRSP fatty rats. The mesenteric arteries and aorta of SHRSP fatty rats showed impaired relaxation responses to ACh and SNP, decreased 3',5'-monophosphate (cGMP) production, and reduced soluble guanylyl cyclase protein expression. Superoxide release, angiotensin II and 3-nitrotyrosine contents were increased. 3. SHRSP fatty rats were orally administered olmesartan, an angiotensin II receptor type 1 (AT(1) ) antagonist, and amlodipine, a calcium channel blocker, at doses of 5 and 8mg/kg per day, respectively, for 8weeks. Both olmesartan and amlodipine reduced blood pressure, but only olmesartan prevented the development of abnormal vascular and biochemical parameters in the SHRSP fatty rats. 4. The results showed that in the SHRSP fatty rats, the impaired nitric oxide- and cGMP-mediated relaxation of vascular smooth muscle cells were linked to AT(1) receptor-induced oxidative-nitrative stress, which occurred concurrently with severe hypertension and metabolic abnormalities in vivo.

The authors report a rare case of slowly progressive neuronal death associated with postischemic hyperperfusion in cortical laminar necrosis after radial artery/external carotid artery–middle cerebral artery bypass graft surgery for an intracavernous carotid artery aneurysm. Under barbiturate protection, a 69-year-old man underwent high-flow bypass surgery combined with carotid artery sacrifice for a symptomatic intracavernous aneurysm. The patient became restless postoperatively, and this restlessness peaked on postoperative Day (POD) 7. Diffusion-weighted and FLAIR MR images obtained on PODs 1 and 7 revealed subtle cortical hyperintensity in the temporal cortex subjected to temporary occlusion. On POD 13, 123I-iomazenil (123I-IMZ) SPECT clearly showed increased distribution on the early image and mildly decreased binding on the delayed image with count ratios of the affected–unaffected corresponding regions of interest of 1.23 and 0.84, respectively, suggesting postischemic hyperperfusion. This was consistent with the finding on 123I-iodoamphetamine SPECT. Of note, neuronal density in the affected cortex on the delayed 123I-IMZ image further decreased to the affected/unaffected ratio of 0.44 on POD 55 during the subacute stage when characteristic cortical hyperintensity on T1-weighted MR imaging, typical of cortical laminar necrosis, was emerging. The affected cortex showed marked atrophy 8 months after the operation despite complete neurological recovery. This report illustrates, for the first time, dynamic neuroradiological correlations between slowly progressive neuronal death shown by 123I-IMZ SPECT and cortical laminar necrosis on MR imaging in human stroke.

Background— Therapeutic effect of stem cell transplantation (SCTx) for myocardial neovascularization has been evaluated by histological capillary density in small animals. However, it has been technically difficult to obtain imaging evidence of collateral formation by conventional angiography. Methods and Results— Peripheral blood CD34+ and CD34− cells were isolated from patients with critical limb ischemia. PBS, CD34− cells, or CD34+ cells were intramyocardially transplanted after ligating LAD of nude rats. Coronary angiography of ex vivo beating hearts 5 and 28 days after the treatment was performed using the third generation synchrotron radiation microangiography (SRM), which has potential to visualize vessels as small as 20 μm in diameter. The SRM was performed pre and post sodium nitroprusside (SNP) to examine vascular physiology at each time point. Diameter of most collateral vessels was 20 to 120 μm, apparently invisible size in conventional angiography. Rentrop scores at day 28 pre and post SNP were significantly greater in CD34+ cell group than other groups ( P P R =0.82, P Conclusions— The SRM, capable of visualizing microvessels, may be useful for morphometric and physiological evaluation of coronary collateral formation by SCTx. The novel imaging system may be an essential tool in future preclinical/translational research of stem cell biology.

To determine whether (18)F-FDG uptake in breast cancer correlates with immunohistochemically defined subtype and is able to predict molecular subtypes.This retrospective study involved 306 patients with 308 mass-type invasive breast cancers (mean size 2.65 cm, range 1.0-15.0 cm) who underwent (18)F-FDG PET/CT before therapy. The correlations between primary tumour (18)F-FDG uptake on PET/CT, expressed as SUVmax, and clinicopathological findings and molecular subtype, i.e. luminal A, luminal B (HER2-negative), luminal B (HER2-positive), HER2-positive and triple-negative, were analysed. The predictors of these subtypes were investigated.The mean SUVmax of the 308 tumours was 5.33 ± 3.63 (range 1.15-19.01). Among the subtypes of the 308 tumours, 87 (28.2 %) were luminal A, 111 (36.0 %) were luminal B (HER2-negative), 31 (10.1 %) were luminal B (HER2-positive), 26 (8.4 %) were HER2-positive and 53 (17.2 %) were triple-negative, and the corresponding mean SUVmax were 3.41 ± 2.07 (range 1.18-14.30), 5.17 ± 3.52 (range 1.35-19.01), 6.57 ± 3.84 (range 1.42-15.58), 7.55 ± 3.63 (range 2.30-13.60) and 6.97 ± 4.17 (range 1.15-16.06), respectively. A cut-off value of 3.60 yielded 70.1 % sensitivity and 66.1 % specificity with an area under the receiver operating characteristics curve (AUC) of 0.734 for predicting that a tumour was of the luminal A subtype. A cut-off value of 6.75 yielded 65.4 % sensitivity and 75.2 % specificity with an AUC of 0.704 for predicting a HER2-positive subtype.SUVmax, a metabolic semiquantitative parameter, shows a significant correlation with the molecular subtype of breast cancer, and is useful for predicting the luminal A or HER2-positive subtype.

An altered state of the cardiac sympathetic nerves is an important prognostic factor in patients with coronary artery disease. The aim of this study was to investigate regional sympathetic nerve damage and restoration utilizing a rat model of myocardial transient ischemia and a catecholamine analog PET tracer, (11)C-hydroxyephedrine ((11)C-HED).Transient myocardial ischemia was induced by coronary occlusion for 20 min and reperfusion in male Wistar rats. Dual-tracer autoradiography was performed subacutely (7 days) and chronically (2 months) after ischemia, and in control rats without ischemia using (11)C-HED as a marker of sympathetic innervation and (201)TI for perfusion. Additional serial in vivo cardiac (11)C-HED and (18)F-FDG PET scans were performed in the subacute and chronic phases after ischemia.After transient ischemia, the (11)C-HED uptake defect areas in both the subacute and chronic phases were clearly larger than the perfusion defect areas in the midventricular wall. The subacute (11)C-HED uptake defect showed a transmural pattern, whereas uptake recovered in the subepicardial portion in the chronic phase. Tyrosine hydroxylase antibody nerve staining confirmed regional denervation corresponding to areas of decreased (11)C-HED uptake. Serial in vivo PET imaging visualized reductions in the area of the (11)C-HED uptake defects in the chronic phase consistent with autoradiography and histology.Higher susceptibility of sympathetic neurons compared to myocytes was confirmed by a larger (11)C-HED defect with a corresponding histologically identified region of denervation. Furthermore, partial reinnervation was observed in the chronic phase as shown by recovery of subepicardial (11)C-HED uptake.

Background: Platelet hyper-aggregability is an important risk factor for leukoaraiosis. In this study we investigated whether aggravation of leukoaraiosis can be controlled by means of long-term correction of platelet hyper-aggregability.Methods:Twenty-one patients with leukoaraiosis and uncorrected platelet hyper-aggregability were compared with 21 controls matched for age, grade of leukoaraiosis and observation period whose platelet hyper-aggregability was corrected. Platelet aggregability was estimated by an optical analytical method with a nine-stage display using two different concentrations each of adenosine diphosphate (ADP) and collagen (the double ADP method).Results:The mean observation period between two magnetic resonance imaging (MRI) scans for both groups was 4.1 years. In the non-corrected group, moderate to severe aggravation of leukoaraiosis was observed in a large number of patients. In the corrected group, only a small number of patients showed generally mild aggravation of leukoaraiosis. The number of patients showing aggravation of periventricular hyperintensity (PVH) was 7 in 21 in the non-corrected group versus 1 in 21 (p=0.022) in the corrected group, and for aggravation of deep white-matter hyperintensity, these values were 9 in 21 versus 4 in 21, respectively. Thus, the difference was more significant if the degree of aggravation was taken into account.Conclusion:The progress of leukoaraiosis is greatly inhibited by long-term correction of platelet hyper-aggregability.

However, extracranial and intracranial arterial bypass surgery (EC/IC BYPASS) was denied by the randomized study, some patients may be suitable for surgery after selecting areas of misery perfusion. Steady-state O-15 positron emission tomography (PET) showed cerebral blood flow of 31.6±4.1 (ml/100 g/min) with acetazolamide reactivity of 30.6±5.4 (%) in misery perfused areas. The authors examined whether or not patients could be selected for surgery through combining cerebral blood flow (CBF) measurements with vasoreactivity determined by I-123 IMP (IMP; N-isopropyl-p-[I-123]-iodoamphetamine) single-photon emission-computed tomography (SPECT), which has good linearization at high flow ranges. Cerebral blood flow was quantified immediately after PET in 24 patients by counting I-123 IMP in arterial blood 10 min after injection. The CBF in the middle-cerebral arterial territories (MCA) was obtained by selecting regions of interest and comparing the fit between O-15 H2O and I-123 IMP using a nonlinear PS model curve. In 48 MCA areas, the CBF correlation between brain PET and IMP brain SPECT was close according to the equation, PET=12.4+0.46×IMP; r=0.743 (p

Background: We investigated the relationship between silent ischemic lesions, defined as hyperintense lesions on T2-weighted magnetic resonance imaging scans of brain white matter and cerebral hemodynamics (baseline cerebral blood flow and cerebral vasoreactivity). Methods: Between January 2007 and December 2012, 61 patients with asymptomatic internal carotid artery stenosis were evaluated for asymptomatic silent ischemic lesions, acute infarction, and cerebral hemodynamics. Patients were divided into 2 groups based on silent ischemic lesion distribution; the Symmetry group (n = 34) included patients who showed symmetrical distribution of lesions (or had no lesions), and the Asymmetry group (n = 27) included patients with a greater number of lesions in the ipsilateral than that in the contralateral hemisphere. The Asymmetry group was further divided into Internal (n = 15) and External (n = 12) types. Results: Two External-type patients (17%) showed spotty asymptomatic acute infarction in the ipsilateral hemisphere. There were no significant differences in patient characteristics, histopathological findings, vascular risk factors, or cerebral blood flow values between the groups. The mean cerebral vasoreactivity value in the ipsilateral hemisphere for the Internal type was 13.0 ± 15.2% (range: −11.4% to 41.6%), which was significantly lower than values of the contralateral hemisphere (36.7 ± 20.8%; range: 3.9% to 75.7%; P

The spatial resolution of conventional angiographic systems is not enough to predict diabetic microangiopathy in arterioles (20-200 µm).To determine whether fingertip synchrotron (SR) radiation microangiography has enough spatial resolution to quantitate arteriolar diameter changes, and whether an arteriolar paradoxical vasoconstriction is a characteristic observation for diabetic microangiopathy, diameter reduction as arteriolar branching and difference of the diameter changes induced by acetylcholine between control (n = 5) and diabetic rats (n = 5) were analyzed.Fingertip SR microangiography visualized the arterioles with a diameter range of 30-300 µm and demonstrated vascular diameter reduction as branching with a fixed ratio (r = 0.93, P0.004 and r = 0.73, P0.001). A vasodilatory reaction was induced by acetylcholine in the control (142.4 ± 61.9 to 190.9 ± 73.5, P0.05, n = 25), in contrast, paradoxical vasoconstriction in diabetic rats (201.6 ± 83.0 to 16 0.4 ± 67.9, P0.05, n = 37). Histological angiopathy was noted only in the diabetic rats.In conclusion, the fingertip SR microangiography is useful to predict diabetic micrangiopahty.

Background: The ivy sign is sometimes seen on fluid-attenuated inversion recovery (FLAIR) images in moyamoya disease (MMD). In recent studies using single-photon emission computed tomography, ivy sign proliferation correlated with decreases in cerebrovascular reserve. However, a decreased vascular reserve is not concrete. The purpose of this study was to evaluate the correlation between ivy sign proliferation and the findings of 15O gas positron emission tomography (PET). Methods: In 19 MMD patients (12 women, age 31-69 years) with ischemic symptoms, FLAIR magnetic resonance imaging and 15O gas PET were performed. We classified the middle cerebral artery (MCA) territory into 2 regions in each hemisphere, and the degree of the ivy sign (ivy sign score) in each region was classified into 3 grades (0-2), where grade 0 indicated an absence of the ivy sign, grade 1 indicated that the ivy sign was seen on less than half of the cortical surface in each region, and grade 2 indicated that the ivy sign was seen on more than half of the cortical surface. We examined the relationship among the ivy sign score, the severity of ischemic symptoms and PET parameters in 76 MCA regions of 19 patients. Results: Ivy sign scores of the regions were 0 (n = 19), 1 (n = 40), and 2 (n = 17). Total ivy sign score of a hemisphere increased as clinical symptoms became more severe. Cerebral blood flow (CBF) values were lower, cerebral blood volume (CBV) values were higher, and CBF/CBV values were lower than those of controls as symptoms became severe (p < 0.05). CBF and CBF/CBV values decreased and CBV values increased as the ivy sign score increased, and were significantly higher and lower, respectively, than control values (p < 0.05). No significant differences in cerebral metabolic rate of oxygen and oxygen extraction fraction were found between the 3 ivy sign scores. A positive correlation was found between ivy sign score and increases in CBV (p < 0.01), and a more obvious negative correlation was found between ivy sign score and decreases in CBF/CBV (p < 0.001). Conclusions: We evaluated the correlation between ivy sign proliferation and the findings of 15O gas PET. We suggested that ivy sign proliferation was associated with both dilated pial vasculature and the slow flow of developed leptomeningeal collaterals in patients with MMD.

In moyamoya disease (MMD), surgical revascularization may be complicated with postoperative hyperperfusion. We analyzed cerebral perfusion and metabolism using positron emission tomography (PET) or single-photon emission computed tomography (SPECT) before and after bypass surgery on 42 sides of 34 adult patients with MMD. In seven cases (16.7%) with symptomatic hyperperfusion, diagnosed by qualitative 123I-iodoamphetamine (IMP) SPECT, a subsequent PET study during postoperative subacute stages revealed significantly increased cerebral blood flow (CBF) from 34.1 ± 8.2 to 74.3 ± 12.8 mL/100 g per minute ( P < 0.01), a persistent increase in cerebral blood volume (CBV)from 5.77 ± 1.67 to 7.01 ± 1.44 mL/100 g and a significant decrease in oxygen extraction fraction (OEF) from 0.61 ± 0.09 to 0.40 ± 0.08 ( P < 0.01). Mean absolute CBF values during symptomatic hyperperfusion were more than the normal control +2 standard deviations, the predefined criteria of PET. Interestingly, two patients with markedly increased cerebral metabolic rate of oxygen (CMRO2) at hyperperfusion were complicated with postoperative seizure. Among preoperative PET parameters, increased OEF was the only significant risk factor for symptomatic hyperperfusion ( P < 0.05). This study revealed that symptomatic hyperperfusion in MMD is characterized by temporary increases in CBF >100% over preoperative values caused by prolonged recovery of increased CBV.

Limited evidence exists on the relationships between severity of white-matter lesions (WMLs) and cerebral hemodynamics in patients without major cerebral artery disease. To examine changes of cerebral blood flow (CBF), oxygen metabolism, and vascular reserve capacity associated with severity of WML in patients with lacunar stroke, we used a positron emission tomography (PET). Eighteen lacunar patients were divided into two groups according to the severity of WMLs, assessed by Fazekas classification; grades 0 to 1 as mild WML group and grades 2 to 3 as severe WML group. Rapid dual autoradiography was performed with 15O-labeled gas-PET followed by 15O-labeled water-PET with acetazolamide (ACZ) challenge. Compared with the mild WML group, the severe WML group showed lower CBF (20.6 ± 4.4 versus 29.9 ± 8.2 mL/100 g per minute, P = 0.008), higher oxygen extraction fraction (OEF) (55.2 ± 7.4 versus 46.7 ± 5.3%, P = 0.013), and lower cerebral metabolic rate of oxygen (CMRO2) (1.95 ± 0.41 versus 2.44 ± 0.42 mL/100 g per minute, P = 0.025) in the centrum semiovale. There were no significant differences in the ACZ reactivity between the two groups (48.6 ± 22.6% versus 42.5 ± 17.2%, P = 0.524). Lacunar patients with severe WMLs exhibited reduced CBF and CMRO2, and increased OEF in the centrum semiovale. The ACZ reactivity was preserved in both patients with severe and mild WMLs in each site of the brain.

Not only is the degree of stenosis important for optimal treatment of carotid stenosis, plaque characteristics, are also important factors to be considered. Various modalities of plaque imaging using ultrasound, magnetic resonance imaging (MRI), and positron emission tomography (PET) have been introduced to clinical practice recently. Here, we provide an overview of the recent progress of such modalities in relation to their clinical significance and future perspective.

SPECT can provide valuable diagnostic and treatment response information in large-scale multicenter clinical trials. However, SPECT has been limited in providing consistent quantitative functional parametric values across the centers, largely because of a lack of standardized procedures to correct for attenuation and scatter. Recently, a novel software package has been developed to reconstruct quantitative SPECT images and assess cerebral blood flow (CBF) at rest and after acetazolamide challenge from a single SPECT session. This study was aimed at validating this technique at different institutions with a variety of SPECT devices and imaging protocols. Methods: Twelve participating institutions obtained a series of SPECT scans on physical phantoms and clinical patients. The phantom experiments included the assessment of septal penetration for each collimator used and of the accuracy of the reconstructed images. Clinical studies were divided into 3 protocols, including intrainstitutional reproducibility, a comparison with PET, and rest–rest study consistency. The results from 46 successful studies were analyzed. Results: Activity concentration estimation (Bq/mL) in the reconstructed SPECT images of a uniform cylindric phantom showed an interinstitution variation of ±5.1%, with a systematic underestimation of concentration by 12.5%. CBF values were reproducible both at rest and after acetazolamide on the basis of repeated studies in the same patient (mean ± SD difference, −0.4 ± 5.2 mL/min/100 g, n = 44). CBF values were also consistent with those determined using PET (−6.1 ± 5.1 mL/min/100 g, n = 6). Conclusion: This study demonstrates that SPECT can quantitatively provide physiologic functional images of rest and acetazolamide challenge CBF, using a quantitative reconstruction software package.

1. Metabolic syndrome is an independent risk factor for cardiovascular disease. SHRSP.Z-Lepr(fa) /IzmDmcr (SHRSP fatty) rat, established as a new rat model of metabolic syndrome, spontaneously develops obesity, severe hypertension and shows hypertriglyceridaemia, hypercholesterolaemia and abnormal glucose tolerance. Using SHRSP fatty rats, we examined whether or not oxidative stress was correlated with vascular dysfunction in small and large calibre coronary arteries in ex vivo beating hearts, isolated mesenteric arteries and aortas in comparison with normal rats, Wistar-Kyoto rats (WKY). Vasodilation of coronary arteries was determined by microangiography of the Langendorff heart. 2. Compared with WKY, acetylcholine (ACh) and sodium nitroprusside (SNP)-induced relaxations were impaired in the coronary arteries of SHRSP fatty rats. The mesenteric arteries and aorta of SHRSP fatty rats showed impaired relaxation responses to ACh and SNP, decreased 3',5'-monophosphate (cGMP) production, and reduced soluble guanylyl cyclase protein expression. Superoxide release, angiotensin II and 3-nitrotyrosine contents were increased. 3. SHRSP fatty rats were orally administered olmesartan, an angiotensin II receptor type 1 (AT(1) ) antagonist, and amlodipine, a calcium channel blocker, at doses of 5 and 8mg/kg per day, respectively, for 8weeks. Both olmesartan and amlodipine reduced blood pressure, but only olmesartan prevented the development of abnormal vascular and biochemical parameters in the SHRSP fatty rats. 4. The results showed that in the SHRSP fatty rats, the impaired nitric oxide- and cGMP-mediated relaxation of vascular smooth muscle cells were linked to AT(1) receptor-induced oxidative-nitrative stress, which occurred concurrently with severe hypertension and metabolic abnormalities in vivo.

Microdomains such as lipid raft and caveolae are organized as functional compartments in plasma membrane of cells. In this study, we note the functional platform of caveolae with dual functions, internalization of external substances and cell signalings leading to nitric oxide release, and hypothesize that the switching of enzyme activity of endothelial nitric oxide synthase can be achieved by targeting caveolae with nanoparticles. We prepared polysiloxane nanoparticles and studied cellular uptake of the nanoparticles and its concomitant influence on the nitric oxide release in human aortic endothelial cells. We found that polysiloxane nanoparticles were endocytosed via caveolae in human aortic endothelial cells and that enhanced nitric oxide release was followed by the cellular uptake of the nanoparticles. Furthermore, we confirmed that endothelial nitric oxide synthase was activated during cellular uptake of the nanoparticles. These findings support our idea that delivery of the polymeric nanoparticles to endothelial cells can lead to the induction of nitric oxide release.

For diagnosing patients with ischemic cerebrovascular disease, non-invasive count-based method with (15)O(2) and H (2) (15) O positron-emission tomography (PET) data is widely used to measure asymmetric increases in oxygen extraction fraction (OEF). For shortening study time, we have proposed dual-tracer autoradiographic (DARG) protocol in which (15)O(2) gas and C(15)O(2) gas are sequentially administrated within short period. In this paper, we evaluated feasibility of the non-invasive count-based method with the DARG protocol.Twenty-three patients [67.8 +/- 9.9 (mean +/- SD) years] with chronic unilateral brain infarction were examined by the use of measurements of asymmetric OEF elevation. As DARG protocol, (15)O(2) and C(15)O(2) gases were inhaled with 5-min interval and dynamic PET data were acquired for 8 min. Quantitative OEF (qOEF) image was computed with PET data and arterial input function. Ratio image of (15)O(2) and C(15)O(2) phases of PET data was computed as count-based OEF (cbOEF) image. The asymmetric indices (AI) of qOEF (qOEF-AI) and cbOEF (cbOEF-AI) were obtained from regions of interest symmetric placed on left and right sides of cerebral hemisphere. To optimize the summation time of PET data for the cbOEF image, qOEF and cbOEF images with various summation times were compared.Image quality of cbOEF image was better than that of qOEF image. The best correlation coefficient of 0.94 was obtained when the cbOEF image was calculated from 0 to 180 s of (15)O(2) summed image and 340 to 440 s of C(15)O(2) summed image.Using the appropriate summation time, we obtained the cbOEF image with good correlation with qOEF image, which suggests non-invasive cbOEF image can be used for evaluating the degree of misery perfusion in patients with chronic unilateral brain infarction. The count-based method with DARG protocol has a potential to dramatically reduce the examination time of (15)O PET study.

Metabolic syndrome refers to a clustering of cardiovascular disease risk factors. We investigated the characteristics of vascular endothelial function in coronary arteries of rats using a microangiography technique. For this study, we developed a microangiography system using a real-time imaging system and a third generation synchrotron radiation source at SPring-8. An X-ray direct-conversion type detector with 6-mum spatial resolution was used for real-time biomedical imaging. For synchrotron radiation radiography, a long source-to-object distance and a small source spot can produce high-resolution images. Microangiographic images were obtained without image blurring and were stored in a digital frame memory system at a maximum speed of 30 frame/s with a 1024 x 1024-pixel, 10-bit format. The vasorelaxation response in the coronary arteries was determined using coronary microangiography of ex vivo beating hearts for evaluating vascular endothelial dysfunction in metabolic syndrome. In imaging experiments, the small coronary arteries were visualized after iodine contrast agent injection into the coronary artery. We assessed the magnitude of coronary artery vasorelaxation before and after administration of drugs that modulate endothelial control of the coronary arteries in the rat model.

Early detection and correct assessment of disease activity are critical for the optimal management of patients with cardiac sarcoidosis (CSRD). There are some recent reports showing F-18 FDG (FDG) uptake by sarcoid granulomas. In the present study, we estimated the significance of cardiac FDG PET imaging in 47 patients (57+/−11 years, 16 males and 31 females) with proven diagnosis of CSRD and receiving steroid therapy (30 – 60 mg prednisolone on alternate days) based on clinical signs of acute myocardial involvement. We interpreted regionally enhanced myocardial FDG uptake as positive in the 5-hr fasting FDG PET imaging. In addition, we determined standardized uptake value (SUV) of the FDG uptake. Before steroid therapy, positive myocardial finding was 89% (42/47) in FDG PET, 55% (21/38) in Tc-99m pyrophosphate tomographic imaging, 68% (30/44) in Ga-67 tomographic imaging, 49% (23/47) in echocardiographically estimated septal wall thinning and 35% (13/37) in biopsy. SUV was above 2.5 in all with positive FDG finding. In 3 patients with severe heart failure and with positive finding in biopsy, myocardial FDG uptake showed diffuse patterns and was hardly interpreted positive. The follow-up studies after steroid therapy revealed that the enhanced FDG uptake gradually reduced and disappeared in 6 months in most of the patients, while positive Ga-67 uptake disappeared soon after therapy. Afterwards, recurrence of active inflammation was symptomatically suspected in 4 patients. Performing FDG PET imaging, they all showed re-enhancement of myocardial FDG uptake, which contributed to decision-making of increasing steroid dose. These results suggest that the FDG PET imaging is a sensitive means in detecting disease activity of CSRD and contributes to the decision-making and evaluation of steroid therapy.

Visualization of vasoconstriction and vasodilatation of coronary arteries with vasoactive agents is a useful research tool for evaluation of coronary vascular reserve. Microangiography with spatial resolution in the micrometer range was carried out to depict coronary vascular response in a rat heart under Langendorff perfusion using a high-speed imaging system and a third generation synchrotron radiation source at SPring-8. The imaging system was composed of an X-ray direct-conversion type detector incorporating an X-ray SATICON pickup tube and a high-speed X-ray shutter using a galvanometer based scanner. Microangiographic images were obtained without image blur and stored in a digital frame memory system with a 1024/spl times/1024-pixel, 10-bit format. In imaging experiments, the isolated rat heart was mounted on a steel cannula and perfused with oxygenated perfusion fluid. After iodine contrast agent injection into the ascending aorta, vasodilatation in small arteries was visualized in response to acetylcholine.