Diagnostic Accuracy of Positron Emission Mammography with 18F-fluorodeoxyglucose in Breast Cancer Tumor of Less than 20 mm in Size

Objective(s): To investigate the diagnostic accuracy of positron emission mammography (PEM) and positron emission tomography/computed tomography (PET/CT) for small breast tumors of less than 20 mm in size.Methods: The study was conducted on a total of 100 subjects (i.e., 50 patients with pathologically proven breast cancer and 50 normal cases of medical screening). The total number of tumors was 54 (mean size: 11±5.1 mm, range:4-20 mm). The diagnostic accuracy of PEM alone, PET/CT alone, and combined PET/CT and PEM was evaluated by two nuclear medicine physicians based on visual inspection. The two groups (i.e., tumors of ≤ 10 mm and > 10-20 mm) werecompared in terms of the diagnostic capability of the three modalities (PEM alone, PET/CT alone, and PET/CT+PEM).Results: The sensitivities of PEM alone, PET/CT alone, and combined PET/CT and PEM were 72%, 60%, and 76%, respectively. The specificities of these tests were 98%, 100%, and 98%, respectively. Furthermore, the accuracies of these diagnostic modalities were 85%, 79%, and 87%, respectively. The combined PET/CT and PEM showed significantly higher sensitivity and accuracy than PET/CT alone (P=0.005 and P=0.02, respectively). In addition, PEM demonstrated asignificantly higher sensitivity than PET/CT in the ≤ 10 mm group (P=0.03); however, no difference was observed between the two modalities in the > 10 mm group in terms of sensitivity.Conclusion: 18F-fluorodeoxyglucose PET had limited capability for the detection of small breast cancers of < 10 mm. Combined PET/CT and PEM showed higher sensitivity and accuracy, compared to PET/CT alone

自発的ドック受診者群と企業健診受診者群の脳MRIにおけるT2高信号域個数の比較

he purpose of this study was to evaluate the difference in T2-elongated spots (T2ES) between self-referred and third party-referred subjects.The brain MRI studies of 814 healthy adults were assessed. The subjects were categorized into two groups. Group A included 312 self-referred subjects ranging in age from 49 to 65 years (mean age, 56.5 years). Group B included 502 third party-referred subjects same ranging in age (mean age, 54.3 years). All subjects were asked to complete an interview sheet dealing with current and past diseases. To compare the two groups, an ‘Age-related Grading System\u27 was created.Grade 4 was defined as including patients who had 10 to 14 more T2ESs than their age minus 49; 20.027771275620f Group B and 13.51111400240f Group A (P<0.05) were classified as Grade 4. Diabetes mellitus was present in 15.016010062550f Group A and 9.615734071165f Group B (P<0.05). Hyperlipidemia was present in 18.015710062563f Group A and 9.015035020146f Group B (P<0.01).Although diabetes mellitus and hyperlipidemia were more common in Group A, these diseases were considered to be well controlled. It would appear that the patients in Group A were more health conscious than those in Group B

Simplified Dynamic Phantom for Pediatric Renography: A Description of Instrument and Its Performance

Objective(s): Renography is used for the diagnostic evaluation of pediatric patients with a suspected obstruction of urinary tract or impaired renal function. The recommended dose for children have been released by the European Association of Nuclear Medicine, Society of Nuclear Medicine and Molecular Imaging, and Japanese Society of Nuclear Medicine. Since acquisition counts in dynamic scintigraphy are affected by the administered doses and sensitivity of the scintillation camera, the scan procedure should be determined independently. In this study, we constructed simplified dynamic phantom imitating pediatric renography and tested its performance.Methods: Simplified dynamic phantom consisted of three components (i.e.,infusion, imitated kidney, and drainage sections). The infusion rates (mL/min) were determined by comparing the time activity curves obtained from patientswith normal renal function. The time-points of the maximum counts (Tmax), as well as the two-thirds and one-half of the maximum counts (T2/3 and T1/2) were measured in different doses using the phantom with the best-match infusion rateand duration, and low-energy general-purpose (LEGP) or low-energy highresolution (LEHR) collimators and applying different attenuations.Results: The best-match infusion rates of the phantom to imitate the time activity curve of the normal renal function were 42.0, 1.0, 0.6, and 0.3 mL/min in the arterial, secretory, early-excretory, and late-excretory phases, respectively. When 30 MBq, LEHR collimator and non-water-equivalent phantom were applied, Tmax, T2/3, and T1/2 were 242±15.3, 220±10.0 and 317±25.2 seconds, respectively. Using LEGP collimator and (3 MBq of activity) 5-cm water-equivalent phantom, Tmax, T2/3, and T1/2 values were estimated as 242±5.8, 213±11.5, and 310±17.3 sec, respectively.Conclusion: Our simplified dynamic phantom for pediatric renography could imitate the time activity curves obtained from patients with normal renal function. Tmax, T2/3, and T1/2 could be measured under various settings of dose,collimator, and tissue attenuation

Different Characteristics of Cognitive Impairment in Elderly Schizophrenia and Alzheimer's Disease in the Mild Cognitive Impairment Stage

We compared indices of the revised version of the Wechsler Memory Scale (WMS-R) and scaled scores of the five subtests of the revised version of the Wechsler Adult Intelligence Scale (WAIS-R) in 30 elderly schizophrenia (ES) patients and 25 Alzheimer's disease (AD) patients in the amnestic mild cognitive impairment (aMCI) stage (AD-aMCI). In the WMS-R, attention/concentration was rated lower and delayed recall was rated higher in ES than in AD-aMCI, although general memory was comparable in the two groups. In WAIS-R, digit symbol substitution, similarity, picture completion, and block design scores were significantly lower in ES than in AD-aMCI, but the information scores were comparable between the two groups. Delayed recall and forgetfulness were less impaired, and attention, working memory and executive function were more impaired in ES than in AD-aMCI. These results should help clinicians to distinguish ES combined with AD-aMCI from ES alone

Prognostic Value of FDG-PET in Patients with Oropharyngeal Carcinoma Treated with Concurrent Chemoradiotherapy

Purpose: The purpose of this study was to evaluate the predictive value of 2-deoxy-2-[F-18] fluoro-D-glucose-positron emission tomography (FDG-PET) following concurrent chemoradiotherapy (CRT) on survival in patients with carcinoma of the oropharynx (OPC). Methods: Eighteen patients with primary OPC who underwent PET pre- and post-CRT were evaluated prospectively for survival. The prognostic performance of post-CRT PET and CT for recurrence was compared. Results: Patients with positive post-CRT PET exhibited significantly lower 2-year cause-specific survival and disease-free survival (50 % vs. 91%, PG0.05 and 0 % vs. 83%, PG0.0001); however, patients with positive post-CRT CT did not exhibit any significant difference (67 % vs. 83%, P= 0.416 and 50 % vs. 75%, P=0.070). Other factors, such as clinical and pre-CRT PET variables, also did not indicate any significant difference. The accuracy of prediction of residual and local recurrence for post-CRT PET and CT (local%/regional%) was 83%/94 % and 83%/78%, respectively. Conclusion: OPC patients with positive post-CRT PET exhibit poor survival. The prognostic accuracy of post-CRT PET is superior to that of CT. The results of post-CRT FDG-PET should be included in the management of the OPC patients

Japanese multicenter database of healthy controls for [¹²³I]FP-CIT SPECT

Purpose: The aim of this multicenter trial was to generate a [¹²³I]FP-CIT SPECT database of healthy controls from the common SPECT systems available in Japan. Methods: This study included 510 sets of SPECT data from 256 healthy controls (116 men and 140 women; age range, 30–83 years) acquired from eight different centers. Images were reconstructed without attenuation or scatter correction (NOACNOSC), with only attenuation correction using the Chang method (ChangACNOSC) or X-ray CT (CTACNOSC), and with both scatter and attenuation correction using the Chang method (ChangACSC) or X-ray CT (CTACSC). These SPECT images were analyzed using the Southampton method. The outcome measure was the specific binding ratio (SBR) in the striatum. These striatal SBRs were calibrated from prior experiments using a striatal phantom. Results: The original SBRs gradually decreased in the order of ChangACSC, CTACSC, ChangACNOSC, CTACNOSC, and NOACNOSC. The SBRs for NOACNOSC were 46% lower than those for ChangACSC. In contrast, the calibrated SBRs were almost equal under no scatter correction (NOSC) conditions. A significant effect of age was found, with an SBR decline rate of 6.3% per decade. In the 30–39 age group, SBRs were 12.2% higher in women than in men, but this increase declined with age and was absent in the 70–79 age group. Conclusions: This study provided a large-scale quantitative database of [¹²³I]FP-CIT SPECT scans from different scanners in healthy controls across a wide age range and with balanced sex representation. The phantom calibration effectively harmonizes SPECT data from different SPECT systems under NOSC conditions. The data collected in this study may serve as a reference database

Consensus recommendations on the use of 18F-FDG PET/CT in lung disease

Positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) has been increasingly applied, predominantly in the research setting, to study drug effects and pulmonary biology and monitor disease progression and treatment outcomes in lung diseases, disorders that interfere with gas exchange through alterations of the pulmonary parenchyma, airways and/or vasculature. To date, however, there are no widely accepted standard acquisition protocols and imaging data analysis methods for pulmonary 18F-FDG PET/CT in these diseases, resulting in disparate approaches. Hence, comparison of data across the literature is challenging. To help harmonize the acquisition and analysis and promote reproducibility, acquisition protocol and analysis method details were collated from seven PET centers. Based on this information and discussions among the authors, the consensus recommendations reported here on patient preparation, choice of dynamic versus static imaging, image reconstruction, and image analysis reporting were reached.                   </p