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 evaluate the therapeutic effect with peter-williams intramedullary nail on children with humerus deformity due to osteogenesis imperfecta.Methods Data of 9 patients with humerus deformity due to osteogenesis imperfecta were retrospectively analyzed from Jun.2009 to Dec.2012.There were 7 males and 2 females,aged from 6 years to 10 years and 7 months(average 8 years and 3 months).There were 7 unilateral humerus deformity and 2 bilateral humerus deformity with severe radius and ulna deformity.The humerus fracture frequency was from 4 to 13 times (average,7.9 times)There were 2-3 deformity points in 9 patients (average 2.09 deformity points).The deformity angle ranged from 20°-100° (average 57.3°).The Constant-Murley scores were 16-24 scores (average 20.44).According to revised Sillence classifications,there were 6 cases of Type Ⅲ and 3 cases of Type Ⅳ.Eleven humerus of 9 patients were osteotomied and fixed with peter-williams intramedullary nail.Results All of 9 children were followed up for 12-66 months(average 22 months).The bone healing time were 8-12 weeks (average 9.5 weeks).Parents of 9 children were satisfied with surgical operation effect and deformity correction.The Constant-Murley scores ranged from preoperative average of (20.44 ± 2.79) points (16-24 points) to postoperative average of (35.56 ± 2.60) points(30-38 points) at the latest follow-up of patients,there was a statistically significant in score before and after treatment(t =0.20,P ＜0.05).Number 4 patient,one patient was found suffering from dorsal thumb numbness postoperatively after 3 days back stretching limitation.Considering the radial nerve stretching injury,treatment with neurotrophic drug for 3 months,symptoms disappeared.There was no infection,or osteomyelitis,no vascular damages.Epiphyseal plate injury or premature closure and affecting growth were not found in all of the patients at the latest follow-up examination.Conclusions Treatment with osteotomy and peter-williams intramedullary nail fixation on children with humerus deformity due to osteogenesis imperfecta is advantaged.It gets less damages,no intruding shoulder joint,less bleeding.The greatest degree of correction of the deformity can be achieved,and the shoulder joint function and the quality of life can be improved.

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 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

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.