Purpose: CT during hepatic arteriography (CTHA) of cone-beam computed tomography (CBCT) provides valid information in performing transcatheter arterial chemo-embolization (TACE). The usefulness of CTHA with the diluted contrast medium has been reported in some medical conferences. However, the operation becomes somehow complicated for the medical institutions that have angiography injectors with a single head. In this study, we aimed to investigate the clinical equivalence of low-rate injection method and diluted injection method. Methods: The relationship between the injection rate and transit time of contrast medium was tested. Then, we measured the signal values of CBCT and CT values both in varying injection rates and in the case of doubling dilution. Results: The transit time of contrast medium became delayed with decreasing injection rate. The signal values of CBCT in the case of doubling dilution showed almost the same as those at a half of injection rate without dilution. We also obtained the same finding from the comparative investigation of CT values. ROC analysis of digital subtraction angiography (DSA) and CBCT was carried out, and the area under the curve (AUC) of CBCT showed a significantly higher value. Conclusion: It is suggested that CTHA with low-rate injection method offers diagnostic image similar in some degree to the diluted injection method.

It is reported that pharmacokinetics after intravenous injection of ¹²³I-ioflupane may reflect cerebral blood flow. In this study, the early-phase pharmacokinetics of ¹²³I-ioflupane in 10 healthy volunteers was analyzed over time using dynamic single-photon emission computed tomography (SPECT) immediately after intravenous injection. We also examined the correlation between the ¹²³I-IMP imaging and the ¹²³I-ioflupane early-phase image for 14 cases in which both dopamine transporter (DaT) imaging by ¹²³I-ioflupane and cerebral blood flow imaging by ¹²³I-IMP were performed on the same camera. The time-activity curve between cerebellum (CBL) area and each area of anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA) showed distribution characteristics similar to ¹²³I-IMP from immediately after intravenous injection until 20 minutes after administration, and there was no conspicuous washout. The regression line and the correlation coefficient of the Z-score of three-dimensional stereotactic surface projections (3DSSP) (decrease) of the early-phase imaging of ¹²³I-ioflupane and the ¹²³I-IMP imaging are y=0.7546x+0.3562, r=0.8169 (P<0.01) at 0–10 minutes of ¹²³I-ioflupane, and y=0.7412x+0.3027, r=0.8280 (P<0.01) at 0–15 minutes of ¹²³I-ioflupane, and y=0.7400x+0.2456, r=0.8449 (P<0.01) at 0–20 minutes of ¹²³I-ioflupane, showing a strong correlation at all timings. Therefore, ¹²³I-ioflupane early-phase pharmacokinetics after intravenous showed distribution characteristics similar to ¹²³I-IMP, indicating the possibility that early images may be useful in a clinical practice.

Purpose: Spatial normalization is a significant image pre-processing operation in statistical parametric mapping (SPM) analysis. The purpose of this study was to clarify the optimal method of spatial normalization for improving diagnostic accuracy in SPM analysis of arterial spin-labeling (ASL) perfusion images. Methods: We evaluated the SPM results of five spatial normalization methods obtained by comparing patients with Alzheimer’s disease or normal pressure hydrocephalus complicated with dementia and cognitively healthy subjects. We used the following methods: 3DT1-conventional based on spatial normalization using anatomical images; 3DT1-DARTEL based on spatial normalization with DARTEL using anatomical images; 3DT1-conventional template and 3DT1-DARTEL template, created by averaging cognitively healthy subjects spatially normalized using the above methods; and ASL-DARTEL template created by averaging cognitively healthy subjects spatially normalized with DARTEL using ASL images only. Results: Our results showed that ASL-DARTEL template was small compared with the other two templates. Our SPM results obtained with ASL-DARTEL template method were inaccurate. Also, there were no significant differences between 3DT1-conventional and 3DT1-DARTEL template methods. In contrast, the 3DT1-DARTEL method showed higher detection sensitivity, and precise anatomical location. Conclusions: Our SPM results suggest that we should perform spatial normalization with DARTEL using anatomical images.