18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) is usually used for staging or evaluation of treatment response rather than for cancer screening. However, 18F-FDG PET/CT has also been used in Japan for cancer screening in people with no cancer symptoms, and accumulating evidence supports this application of 18F-FDG PET/CT. Previously, we have observed a correlation between the saliva and tumor metabolomic profiles in patients with oral cancer. Hence, if salivary metabolites demonstrate a significant correlation with PET parameters such as the maximum standardized uptake value (SUVmax), they may have the potential to be used as a screening tool before PET/CT to identify patients with high SUVmax. Hence, in this study, we aimed to explore the relationship between salivary metabolites and SUVmax of 18F-FDG PET/CT using previously collected data. 18F-FDG PET/CT was performed for staging 26 patients with oral cancer. The collected data were integrated and analyzed along with quantified salivary hydrophilic metabolites obtained from the same patients with oral cancer and controls (n = 44). In total, 11 metabolites showed significant correlations with SUVmax in the delayed phases. A multiple logistic regression model of the two metabolites showed the ability to discriminate between patients with oral cancer and controls, with an area under the receiver operating characteristic curve of 0.738 (p = 0.001). This study uniquely confirmed a relationship between salivary metabolites and SUVmax of PET/CT in patients with oral cancer; salivary metabolites were significantly correlated with SUVmax. These salivary metabolites can be used as a screening tool before PET/CT to identify patients with high SUVmax, i.e., to detect the presence of oral cancer.

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Background 18F-fluoromisonidazole positron emission tomography (FMISO-PET) has been used for identification of hypoxic areas in tumors, and since hypoxia causes hypoxia-inducible factor-1 and enhancement of tumor growth, identifying the hypoxic area in the tumor tissue is important. Purpose To evaluate the usefulness of FMISO-PET in the grading of primary brain tumors. Material and Methods FMISO-PET was performed preoperatively on 41 consecutive patients with pathologically confirmed brain tumor. A neuroradiologist retrospectively measured both maximum standardized uptake value (SUVmax) and mean SUV (SUVmean) in the tumor and normal cerebellar parenchyma. Maximum tumor/normal control ratio (T/Nmax) and mean tumor/normal control ratio (T/Nmean) were calculated and analyzed. Results There was a positive correlation between World Health Organization (WHO) grade and both T/Nmax and T/Nmean (r = 0.731 and 0.713, respectively). When all cases were divided into benign (WHO grade II) and malignant groups (III and IV), there were significant differences between the two groups in both T/Nmax and T/Nmean ( P < 0.001). If the cutoff value was defined as T/Nmax = 1.25 and T/Nmean = 1.23, T/Nmax had a sensitivity of 90.0% and a specificity of 90.9% while T/Nmean had a sensitivity of 93.3% and a specificity of 90.9% in differentiating the benign group from the malignant group. Conclusion Both T/Nmax and T/Nmean in FMISO-PET have a positive correlation with primary brain tumor grading, making FMISO-PET useful in diagnosing the malignancy of primary brain tumors.

BackgroundGlioblastoma with oligodendroglioma component (GBMO) is a subtype of conventional glioblastoma (cGBM), which is categorized as WHO grade IV. GBMO can be histopathologically distinguished from cGBM and the prognosis of GBMO is better than that of cGBM. However, no systematic review of GBMO imaging findings has been published to date.PurposeTo clarify the radiological imaging features of GBMO compared with those of cGBM.Material and MethodsThe participants were 15 patients with GBMO and 32 patients with cGBM as a control group, all of whom were histopathologically diagnosed. A radiologist retrospectively reviewed the imaging findings of both computed tomography (CT) and magnetic resonance imaging (MRI) for density, signal intensity, contrast medium enhancement (CE), cortical swelling, and cortical swelling without CE. We statistically analyzed the imaging findings by Chi-squared test.ResultsCortical swelling without CE in GBMO was significantly greater than that in cGBM (P = 0.004). Non-CE and heterogeneous solid enhancement were observed significantly more often in GBMO (P = 0.004). No other findings were significant.ConclusionThere was significant difference in the findings of the CE, which exhibited solid heterogeneous enhancement in GBMO. Cortical swelling without CE can be considered significantly characteristic of GBMO.

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Background Granulocyte colony stimulating factor (G-CSF) is known to cause vasculitis, mainly in the small vessels. Several cases of large-vessel vasculitis (LVV) caused by G-CSF have recently been reported in the literature; we retrospectively suspect that some cases of LVV in our institution were associated with administration of G-CSF. Purpose To evaluate the clinical and radiological findings in our cases and to compare them with those in previous reports. Material and Methods We retrospectively evaluated clinical and radiological findings in four cases of LVV that occurred after administration of G-CSF in our institution. We also reviewed papers on G-CSF-related LVV and compared their findings to ours. Results G-CSF-related LVV occurred in patients aged > 50 years and more frequently in women. Most patients developed vasculitis within 15 days after the last administration. While 14/16 patients were symptomatic, the remaining two patients were asymptomatic and diagnosed incidentally. In all cases, laboratory inflammatory markers increased, but there were no autoantibodies that clearly indicated other autoimmune vasculitis. Computed tomography revealed elevated soft tissue density around the affected vessels. Conclusion LVV is among the potential adverse events of G-CSF administration. We should keep this outcome in mind when we interpret medical images of patients with previous G-CSF treatment history even if they are asymptomatic.

Introduction: Multisection motion sensitized driven equilibrium (MSDE) can completely suppress any flow signal and uses gadolinium-based contrast medium. Therefore, 3-dimensional MSDE with contrast medium (3D-CE-MSDE) can visualize only abnormal enhancements. Our purpose is to determine the usefulness of 3D-CE-MSDE for primary malignant brain tumors. Method:We used a 3.0 Tesla MRI unit. The subjects were 29 consecutive patients with primary malignant brain tumors, including patients with recurrent cancer (mean age: 56.2 ± 25.2 years; 13 men and 16 women). Both 3-dimensional T1 turbo field echo with the contrast medium (3D-CE-T1TFE) and 3D-CE-MSDE were performed as preoperative studies on the same day. We calculated the contrastto-noise ratio (CNR) for each sequence. Two radiologists (A, B) independently evaluated the number of enhanced intraaxial and disseminated lesions observed in each sequence. We statistically analyzed the results using a paired t-test. Result:The 3D-CE-MSDE CNR was significantly higher than that of 3D-CE-T1TFE (p < 0.01). Radiologist A found that 3D-CE-MSDE was superior to 3D-CE-T1TFE in detecting both intraaxial lesions and disseminations (p=0.04 and p<0.01, respectively). Radiologist B found that 3D-CE-MSDE was superior to 3D-CE-T1TFE in detecting intraaxial lesions (p=0.01). For disseminated lesions, no significant difference in detectability was observed (p=0.097). Conclusion:In primary malignant brain tumors, 3D-CE-MSDE is useful for detecting enhanced lesions because it completely suppresses flow signals and high CNR.

Cerebrospinal fluid (CSF) mask correction has been developed to reduce the influence by CSF area dilatation for 123I-FP-CIT accumulation. In this study, we assessed the effect of CSF mask correction on the specific binding ratio (SBR) for 25 patients with idiopathic normal pressure hydrocephalus (iNPH). The SBRs with and without CSF mask correction were calculated, and changes in quantitative values were verified. Additionally, the volume removed from striatal and background (BG) volume of interest (VOI) by the CSF mask correction was calculated, the volumes removed were compared to verify their effect on SBR. Twenty and five patients had low and high SBRs, respectively, after CSF mask correction. The images of 20 and 5 patients with SBRs that were decreased and increased, respectively, by CSF mask correction showed that the volumes removed from the BG region VOI were higher and lower, respectively, than those in the striatal region. In conclusion, the SBR before and after CSF mask correction was associated with the ratio of the volume removed from the striatal and BG VOIs, and the SBR was high or low according to the ratio. The results may indicate that CSF mask correction is effective in patients with iNPH. This study was registered in the UMIN Clinical Trials Registry (UMIN-CTR) as UMIN study ID: UMIN000044826.