Objective:To explore the changes of cerebral blood flow (CBF) perfusion caused by N 2O (laughing gas) abuse. Methods:From December 2017 to October 2018, the CBF perfusion images of 24 patients with laughing gas abuse (9 males, 15 females; age: 18-32(24.0±8.9) years) from China-Japan Friendship Hospital were analyzed retrospectively. The region uptake statistics of different brain regions of interest (ROI) (basal ganglia, central region, cerebellum, cingulate gyrus, frontal lobe, medial temporal lobe, occipital lobe, parietal lobe, temporal lobe) between patients with laughing gas abuse and normal people of the same age group from background software database were calculated automatically. Statistic>1.68 indicated the increase of local CBF perfusion, while statistic < -1.68 indicated the decrease of local CBF perfusion. The correlation between the statistics of bilateral brain regions and the correlation between statistical values and clinical indicators were analyzed by Pearson and Spearman correlation analyses.Results:The correlation of the statistics between bilateral regions of each brain area was significant( r values: 0.503-0.892, all P<0.05). The decreased CBF proportions of frontal and temporal lobes were 62.5%(15/24) and 70.8%(17/24), respectively. The highest proportion of increased CBF was cingulate gyrus (33.3%, 8/24). There were significant correlations between frontal lobe, central brain area and duration of laughing gas abuse ( rs values: 0.375, 0.305, both P<0.05). Conclusion:CBF perfusion imaging is helpful for understanding the changes of CBF in patients with laughing gas abuse.

Objective To study the reliability of 99Tcm-(hydrazinonicotinamide (HYNIC)-BMS-200261) (tricine) (trisodium triphenylphosphine-3,3',3"-trisulfonate (TPPTS)) as a radiotracer for protease activated receptor-1 (PAR-1) expression in breast cancer.Methods Fifteen nude mice bearing MDA-MB-435,MDA-MB-231 and MCF-7 human breast cancer xenografts (5 mice for each cell line) with different PAR-1 expression were used for 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) γ imaging,and tumor/non-tumor (T/NT) ratios were obtained with region of interest (ROI) technique.Afterwards,the biodistribution of 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) was analyzed in tumor-bearing nude mice,and the radioactivity in tumor (percentage activity of injection dose per gram of tissue,％ID/g) was calculated.The immunostaining was performed to examine PAR-1 expression in tumor tissue and semi-quantitative analysis was used.One-way analysis of variance and Pearson correlation analysis were used to analyze data.Results At 2 h postinjection,the T/NT ratios were 3.03±0.32,2.27±0.25 and 1.51±0.13 respectively in nude mice bearing MDA-MB-435,MDA-MB-231 and MCF-7 xenografts;the tumor uptakes of 99Tcm-(HYNIC-BMS-200261)(tricine)(TPPTS) were (1.03±0.15),(0.56±0.14) and (0.30±0.06) ％ID/g;PAR-1 expression levels were (17.22±2.71) ％,(10.78± 1.95) ％ and (2.80± 1.18) ％,respectively (F values:47.66,46.36,62.35,all P＜0.05).The T/NT ratios and tumor uptake of 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) at 2 h post-injection were correlated with PAR-1 expression (r values:0.934 and 0.929,both P＜0.05).Conclusions 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) imaging could be a noninvasive and effective method for monitoring PAR-1 expression in human breast cancer.

Objective:To evaluate the value of 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT/CT imaging for the identification of dystonic muscles in patients with primary cervical dystonia (PCD). Methods:A total of 10 patients with PCD (3 males, 7 females, age (47.3±9.9) years) and 10 healthy subjects (4 males, 6 females, age (43.5±9.4) years; control group) between August 2019 and October 2021 in China-Japan Friendship Hospital were enrolled prospectively. All subjects underwent 99Tc m-MIBI SPECT/CT scan. The SUV max of 8 bilateral representative muscles, including rectus capitis posterior major, obliquus capitis inferior, splenius capitis, semispinalis, sternocleidomastoid, trapezius, musculus scalenus muscle and levator scapulae were evaluated in control group. In PCD group, muscles with abnormal uptake were determined. ROI was drawn and SUV max was measured. Independent-sample t test was used to analyze the differences of SUV max between normal and abnormal muscles. The detecting rates of neck MRI and SPECT/CT for abnormal muscles were analyzed by χ2 test. Results:Normal muscles of healthy subjects showed mild symmetrical radioactivity distribution, with the SUV max of 1.10±0.19. A total of 60 muscles with abnormal uptake in 10 patients were found, including 7 rectus capitis posterior major, 10 obliquus capitis inferior, 8 splenius capitis, 8 semispinalis, 10 sternocleidomastoid, 5 trapezius, 3 musculus scalenus muscle and 9 levator scapulae. The SUV max of muscles with abnormal uptake was 1.81±0.43, which was higher than that of normal muscles ( t=17.05, P<0.001). Only 30 pieces abnormal hypertrophy muscle were found by neck MRI, and the detecting rate was much lower than that of SPECT/CT (18.75%(30/160) vs 37.50%(60/160); χ2=28.03, P<0.001). Conclusion:99Tc m-MIBI SPECT/CT may be a useful method for identifying dystonic muscles and a guide to precision therapy in patients with PCD.

Objective:To explore the value of triple fusion positron emission tomography (PET)/MRI in location of epileptogenic focus in patients with focal cortical dysplasia (FCD).Methods:Three patients with refractory partial epilepsy, admitted to our hospital from December 2016 to June 2017, were chosen in our study. The raw MRI and PET images of these patients were processed using Freesurfer and FSL image processing softwares. After extraction and coregistration, precise PET/MRI fusion images were obtained; and the grey-white matter dividing line was highlighted on this fusion image to form triple-fusion images to observe the hypometabolic area and clarify the location.Results:Triple-fusion images of these 3 patients were acquired. In patient 1, a marked decrease in metabolism was noted in the gyrus region delineated by the gray-white matter boundary in the right cingulate gyrus. In patient 2, the area with slightly increased local signal in the right superior frontal gyrus (MRI FLAIR sequence) was the area with reduced metabolism. In patient 3, an area of local decreased metabolism was noted in the right cingulate gyrus. The preoperative evaluation of all 3 patients showed that the above areas were epileptic foci; the patients were followed up for 2 years after surgical resection, no clinical seizures occurred in all patients, and antiepileptic drugs were gradually stopped. All 3 patients were diagnosed as having FCD by postoperative pathology.Conclusion:Triple fusion PET/MRI is a powerful way to assist FCD diagnosis, especially for those FCD cases which are difficult to be diagnosed by other imaging methods, and has a potential clinical application value in epilepsy patients.

Objective: To investigate the value of ATP stress cerebral blood flow perfusion imaging (CBFPI) in diagnosis of ischemic cerebrovascular disease. Methods: Thirty-two patients with cerebral ischemia and ischemic cerebral infarction (26 males, 6 females, average age: (63.0±8.7) years) in China-Japan Friendship Hospital from November 2016 to February 2017 were enrolled. All subjects underwent ⁹⁹Tc^m-ethylcysteinate dimer (ECD) rest and ATP stress CBFPI. Region of interest (ROI) was drawn in the symmetrical parts of the bilateral frontal lobe, parietal lobe, temporal lobe, occipital lobe and basal ganglia region, and the regional cerebral blood flow (rCBF) was automatically calculated. The images and rCBF of post- and pre-ATP stress CBFPI were analyzed and compared. Paired t test was used for statistical analysis. Results: The positive rates of rest CBFPI, ATP stress CBFPI, and combination of both imaging were 53.1%(17/32), 65.6%(21/32), and 100%(32/32), respectively. In 16 cases with unilateral vascular stenosis, the average rCBF of diseased hemisphere was lower in stress imaging (62.7±13.3) ml·100 g^-1·min^-1 than that in rest imaging ((65.8±13.2) ml·100 g^-1·min^-1; t=3.07, P<0.05). While the average rCBF of the contralateral hemisphere in rest and stress imaging showed no significant difference ((67.4±13.3) vs (65.9±13.0) ml·100 g^-1·min^-1; t=1.90, P>0.05). In the other 16 patients with bilateral multivessel disease, the average rCBF of whole brain in rest imaging was higher than that in stress imaging: (62.5±13.9) vs (57.5±11.6) ml·100 g^-1·min^-1; t=3.50, P<0.05. There were 21 out of the 32 patients presented with a decreased cerebrovascular reserve. Conclusion ATP stress combined with rest CBFPI may improve positive rate remarkably and help to evaluate the cerebrovascular reserve.