Objective This study aims to obtain a three-dimensional reconstruction model based on magnetic reso-nance imaging(MRI)data of patients with different degrees of unilateral cleft lip and analyze the anatomy and changes in multiple groups of nasolabial muscles under dynamic and static conditions.Methods One normal person and four adult patients with unilateral cleft lip were included,and MRI was performed under static(upper and lower lips closed naturally)and dynamic(pout and grin)conditions.3D Slicer software was used to reconstruct the model and draw the anatomic morphology of nasolabial muscles.The distance between the junction(where the muscle merges into the orbicularis oris)of the levator muscle,zy-gomaticminor muscle,and zygomatic major muscle to the median sagittal plane,the starting point to the junction point,the dynamic and static junction points,and the angle between the connection of dynamic and static junctions and the hori-zontal plane were measured under three kinds of movements,and the ratio was calculated.Results In all patients,un-der dynamic and static conditions,the distance from the muscle junction to the median sagittal plane,their ratios of the cleft side to the non-cleft side were all greater than 1.While the ratios of the distance from the starting point of the mus-cle to the junction point were less than 1.At static conditions,the two ratios of the same muscle increased gradiently with the severity of the cleft,and the ratio of the zygomatic minor muscle was prominent in the same patient.The ratio of the cleft side to the non-cleft side was greater than 1,and the value for comparison was the angle of the line from the static to the dynamic junction and the horizontal plane.Conclusion The symmetry of the insertion site of the orbicularis oris and the linear distance of both sides of the muscle are related to muscle and cleft types.The angle of muscle contraction on the cleft side is greater than that on the non-cleft side.

Objective:To explore the improvement of image quality of different acceleration factors in breath-hold three-dimensional magnetic resonance cholangiopancreatography (3D MRCP) using deep learning (DL) and compressed sensing (CS) technology.Methods:A total of 68 patients who underwent upper abdominal 3D MRCP examination at West China Hospital of Sichuan University from March to August 2023 were prospectively included. The patients were subdivided into three groups randomly with the following paramters: CS group with an acceleration factor of 24 (CS-24); DL-CS group with acceleration factors 24 (DL-CS-24) and 33 (DL-CS-33) respectively. The signal-to-noise ratio (SNR), contrast ratio (CR) and contrast-to-noise ratio (CNR) of the three sets of images were measured, and the overall image quality, background suppression, artifacts, and visibility of bile ducts and pancreatic ducts at all levels were subjectively evaluated. Chi-square test and Friedman test were used to perform statistical analysis on the number of unsatisfactory diagnostic images and subjective and objective indicators of the three groups of sequences respectively.Results:The scanning time of the DL-CS-33 group (9 s) was 30% shorter than that of the CS-24 group and DL-CS-24 group (13s). The images of DL-CS-33 group from 68 patients all met the clinical diagnostic requirements and statistically differences were found between the images from CS-24 group and DL-CS-24 group (all P<0.05). There were no statistically differences in SNR, CR, CNR, overall image quality, artifacts, and visibility scores of bile ducts and pancreatic ducts at all levels between the DL-CS-33 group and the CS-24 group (all P>0.05). The SNR, CR, CNR, intrahepatic bile duct, main pancreatic duct and overall image quality of the DL-CS -24 group were better than those of the CS-24 group (all P<0.05). Conclusions:DL-CS technology could improves breath-hold 3D MRCP image quality with the 24 acceleration factor with no additioanl scanning time. DL-CS technology combined with a high acceleration factor of 33 further reduces scanning time while ensuring overall image quality, providing a fast breath-hold scanning solution.

Objective:To explore the impact of artificial intelligence compressed sensing technology (CS-AI) on image quality in three-dimensional proton density weighted imaging (3D PDWI) of the unilateral hip joint.Methods:High-resolution unilateral hip imaging was conducted on 67 healthy volunteers at West China Hospital of Sichuan University from January to July 2023. Imaging was performed by using CS-AI 3D PDWI sequence with acceleration factors (AF) of 4, 6, 8, and 10, respectively. According to the AF, all subjects were divided into 4 groups: CS-AI 4, CS-AI 6, CS-AI 8 and CS-AI 10, with CS-AI 4 serving as a reference. Recording the scan time, the signal and noise intensity of the femoral head, muscle, and subcutaneous fat were measured by a senior radiologist and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were then calculated. Additionally, two observers provided ratings for overall image quality and artifacts in the 4 groups, and statistical analysis was performed using the Friedman rank-sum test.Results:The acquisition times for CS-AI 4, CS-AI 6, CS-AI 8, and CS-AI 10 were 5 min 49 s, 3 min 54 s, 2 min 56 s and 2 min 22 s, respectively. Compared to CS-AI 4, the scanning time for CS-AI 6, CS-AI 8, CS-AI 10 were reduced by 32.95%, 50.14%, 59.31%, respectively. The objective evaluation revealed that the SNR and CNR of the femoral head and muscle in groups CS-AI 6, CS-AI 8, and CS-AI 10 were slightly lower than those in group CS-AI 4 ( P<0.05), and the differences were statistically significant. However, no statistically significant differences were found among the 3 groups ( P>0.05). The subjective evaluation indicated that the overall image quality scores of group CS-AI 8 [3 (3,4)] did not significantly differ from those of group CS-AI 4 and CS-AI 6( P>0.05); The mean scores of group CS-AI 4 and CS-AI 6 were 4 (4, 4); Scores of group CS-AI 10 was 3(3, 3), which statistically significant differ from those of the other groups ( P<0.05). The artifacts rating for groups CS-AI 4, CS-AI 6, CS-AI 8 and CS-AI 10 were 4 (4, 4), 4 (4, 4), 3 (3, 4), and 2 (2, 3) respectively. When AF was set to 10, the images exhibited the most severe artifacts ( P<0.05). For other AF values, artifact ratings did not differ significantly ( P>0.05). Conclusion:The CS-AI 3D-PDWI sequence with acceleration factor 8 can acquire high-resolution images of the unilateral hip joint that meet clinical diagnostic requirements while reducing scanning time.

Objective To investigate the status quo and the needs of medical imaging technicians(MITs)in the radiology department of secondary and tertiary hospitals in China,so as to provide references and support for the development of the medical imaging technology industry and the relevant policymaking by health administrative departments.Methods The questionnaire was developed by the Chinese Society of Imaging Technology.The radiology department of each hospital involved in the survey recommended one MIT to fill out the online questionnaire.The contents included:(a)the basic information of the hospital;(b)a general overview of the MITs in the hospital;(c)daily work;(d)career development and promotion;(e)research status and needs,etc.Differences in the number of MIT staff were compared using the Mann-Whitney U test and the chi-square test was used to compare the differences in the selected numbers of MITs in need between regions or between different levels of hospitals.Results In this investigation,valid questionnaires were finally obtained from a total of 5 403 hospitals in 31 provinces in China.The total number of MITs of the hospitals covered in the sample was 67 481.The number of MITs in each hospital was 9(5,16).The male-to-female ratio was 1.41:1.MITs who were 20 to 40 years old accounted for 78%.The proportions of MITs who had completed doctorate,master's,undergraduate,junior college,and technical secondary school or lower level education were 0.6%,3.3%,60.7%,30.8%,and 4.55%,respectively.The proportions of chief MITs,deputy chief MITs,supervisor MITs,primary MITs,assistant technician and those below were 1.0%,4.21%,22.1%,51.8%,and 20.9%,respectively.The overall professional satisfaction of MITs was good."Lack of opportunities for learning and communication"was quoted as the main problem MITs encountered in regard to improving their job-related competency.59.2% of the respondents had not published any academic papers in the past five years,and only 7.0% of the respondents had published in journals included in the Science Citation Index(SCI)in the past five years.Conclusion MITs in China are on average relatively young and the number of MITs has greatly increased.At this stage,more attention should be given to the cultivation of talents and continuing education of MITs and the construction of the discipline should be further strengthened,so as to provide strong support for the development of the medical imaging technology industry in China.

Objective To evaluate the effect of deep learning reconstruction algorithm combined with smart metal artifact reduction(DLMAR)on the quality of abdominal CT images in critically ill patients who are unable to raise their arms and require electrocardiographic(ECG)monitoring.Methods A total of 102 patients were retrospectively enrolled.All subjects were critically ill patients who were unable to raise their arms and required ECG monitoring.Images were reconstructed using 6 algorithms,including filtered back projection(FBP),iterative reconstruction(IR),deep learning(DL),FBP combined with smart metal artifact reduction(FBPMAR),adaptive statistical iterative reconstruction-V combined with smart metal artifact reduction(IRMAR),and DLMAR.A quantitative analysis of CT values,noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)was conducted in regions without metal artifacts and regions with metal artifacts in the liver,as well as the tissues,including those from the liver,spleen,pancreas,and aorta,between the two arms.Qualitative analysis of electrode metal artifacts,the visualization of the structures between the two arms,and image noise was performed with a 5-point scoring system(l=worst and 5=best).Results In the regions of the liver with metal artifacts,there was a significant difference between the CT values of the DLMAR group([98.5±9.8]Hounsfield units[H[J])and those of the FBP group([73.7±5.6]HU),the IR group([75.3±7.5]HU),and the DL group([66.3±11.4]HU)(P＜0.01).There was no significant difference between the CT values of the DLMAR group and those of the FBPMAR group([99.8±4.8]HU)and the IRMAR group([99.6±3.4]HU)(P＞0.05).The noise of the DLMAR group was found to be significantly lower than that of the other groups(P＜0.01).Furthermore,the SNR and CNR of the DLMAR group were also found to be higher than those of the other groups(P＜0.01).In the tissue region between the two arms,the differences in CT values among the six groups were not statistically significant(P＞0.05).The noise of the DLMAR group was lower than those of the other groups(P＜0.01),and the SNR and CNR of the DLMAR group were higher than those of the other groups(P＜0.01).In terms of the removal of metal artifacts,the scores of the FBPMAR,IRMAR,and DLMAR groups(4.27±0.32,4.44±0.34,and 4.61±0.28,respectively)were higher than those of the FBP,IR,and DL groups(1.36±0.54,1.32±0.45,and 1.24±0.46,respectively)(P＜0.01).The DLMAR group also had a higher score of 4.62±0.37 in the visualization of structures between the two arms and 4.53±0.39 in the noise reduction of images,both of which were higher than those of the other groups(P＜0.01).Conclusion DLMAR reduces artifacts,decreases noise,and improves the quality of abdominal CT imaging in critically ill patients who are unable to raise their arms and require ECG monitoring.

The Department of Radiology of West China Hospital of Sichuan University provides us a teaching model that image-reading combined with problem-based learning (PBL) for radiographer once a month. Based on the problem images and typical cases, after careful image-reading, radiographer is guided to think positively and propose specific solutions to the problems. Then designated personnel gives a detail lecture on related diseases, imaging performance, diagnostic requirements, conventional scanning schemes, operating specifications, common problems and image post-processing, etc., which aims at taking continuing education for radiographers.

Objective:To preliminarily assess the clinical value of sirolimus combined with prednisone in the treatment of Kaposiform hemangioendothelioma (KHE) complicated by Kasabach-Merritt phenomenon (KMP) .Methods:A retrospective study was conducted. General clinical data and relevant data on efficacy and adverse reactions were collected from 36 patients with KHE complicated by KMP, who received oral sirolimus combined with prednisone in Department of Pediatric Surgery, West China Hospital, Sichuan University from January 2011 to January 2018.Results:Among the 36 patients with KHE complicated by KMP, the male-to-female ratio was 1∶0.8; their average age was 15.0 months (range, 4.0 - 60.0 months) , and the average age of onset was 6.3 months (range, 0.8 - 48.0 months) ; 32 (88.9%) patients were diagnosed with mixed KHE, and 4 (11.1%) with deep KHE; the tumor size ranged from 2.5 cm × 4.0 cm to 20.0 cm × 24.0 cm. During the combined treatment, the average duration of prednisone administration was 6.4 weeks (range, 5.0 - 9.0 weeks) , and that of sirolimus administration was 19.3 months (range, 13.0 - 27.0 months) . After 1-5 weeks of combined treatment, platelet counts and fibrinogen levels of the 36 patients gradually returned to normal. After short-term prednisone combined with long-term sirolimus treatment, the average disease severity score decreased from 4.0 before treatment to 2.4 at 6 months and 1.6 at 12 months. After 12 months of the combined treatment, tumors mostly regressed in 32 (88.9%) patients, partially regressed in 3 (8.3%) , showed no obvious change in 1 (2.8%) . During the treatment, common adverse reactions included gastrointestinal discomfort and oral ulcers, no patient discontinued the treatment due to severe adverse reactions, and no drug toxicity-related death occurred.Conclusion:Sirolimus combined with prednisone is effective and safe for the treatment of KHE complicated by KMP.

Objective To explore the clinical application value of second-generation dual-source CT combined with intelligent modulation and iterative reconstruction in emergency aortic dissection imaging.Methods A total of 40 emergency patients with clinical suspected aortic dissection were included in this study.Conventional scanning was performed in the control group,and large-pitch intelligent modulation and iterative reconstruction were performed in the test group.The mean CT value,mean noise,signal noise ratio(SNR),contrast noise ratio(CNR),effective dose,image quality and aortic root image quality were evaluated and analyzed.Results Totally 40 patients successfully completed CT aortic dissection imaging.There was no difference in image quality between the two groups (P＞ 0.05).The quality of aortic root images in the test group was better than that in the control group,and the difference was statistically significant(x2=22.556,P＜0.05).The mean CT value and mean noise of aorta in the control group were slightly higher than those in the test group.However,SNR and CNR in the test group were higher than those in the control group,and the difference was statistically significant (t =-21.042,-15.924,8.530,11.495,P＜0.05).The effective dose of the control group [(10.59±3.89)mSv] was significantly higher than that [(6.39±0.81) mSv] of the test group,the difference was statistically significant (t =-12.327,P＜0.05).Conclusions The combined intelligent modulation technique and iterative reconstruction technique with dual-source CT large pitch scanning can meet the requirements of image quality and reduce the effective dose,and can be used as a conventional imaging method for emergency CT of aortic dissection.

Objective To investigate the feasibility of chemical exchange saturation transfer (CEST) imaging in the measurement of myocardial creatine (Cr) metabolites in phantom model using 3.0 T MR. Methods Five phantoms were made according to the volume percentage of Cr ranging from 10 to 50 mmol/L with an interval of 10 mmol/L. 3.0 T MR examinations with base protocol sequence,sequence with and without ECG were performed. Signal to noise,CrEST effect and Z spectra were analyzed. Comparison of signal noise ratio (SNR) among the three methods was performed using an analysis of variance. Bivariate correlations were obtained through Pearson analysis. Results Phantom studies demonstrated that different concentrations of Cr exhibited significant CEST effect with the three sequences. The SNR obtained by sequences with and without ECG were both higher than that of base sequence (both P<0.05). Moreover,no significance of SNR was found between sequences with and without ECG (P>0.05). There were positive correlation of MTR between sequences with ECG,sequences without ECG and base protocol sequence (r2= 0.974 and 0.997, both P<0.05). Conclusion Compared with base protocol sequence, the optimized sequence with ECG can acquire higher SNR CrEST images,indicating that myocardial CrEST imaging could be performed in clinical practice.

OBJECTIVE: To compare the image quality of three-dimensional time-of-flight (TOF) magnetic resonance angiography (MRA) with sparse undersampling and iterative reconstruction (sparse TOF) with that of conventional TOF MRA. MATERIALS AND METHODS: This study included 56 patients who had undergone sparse TOF MRA for intracranial artery evaluation on a 3T MR scanner. Conventional TOF MRA scans were also acquired from 29 patients with matched acquisition times and another 27 patients with matched scanning parameters. The image quality was scored using a five-point scale based on the delineation of arterial vessel segments, artifacts, overall vessel visualization, and overall image quality by two radiologists independently, and the data were analyzed using the non-parametric Wilcoxon signed-rank test. Contrast ratios (CRs) of vessels were compared using the paired t test. Interobserver agreement was calculated using the kappa test. RESULTS: Compared with conventional TOF at the same spatial resolution, sparse TOF with an acceleration factor of 3.5 could reduce acquisition time by 40% and showed comparable image quality. In addition, when compared with conventional TOF with the same acquisition time, sparse TOF with an acceleration factor of 5 could also achieve higher spatial resolution, better delineation of vessel segments, fewer artifacts, higher image quality, and a higher CR (p < 0.05). Good-to-excellent interobserver agreement (κ: 0.65–1.00) was obtained between the two radiologists. CONCLUSION: Compared with conventional TOF, sparse TOF can achieve equivalent image quality in a reduced duration. Furthermore, using the same acquisition time, sparse TOF could improve the delineation of vessels and decrease image artifacts.
Acceleration ; Arteries ; Artifacts ; Humans ; Magnetic Resonance Angiography