[Role of CT and MRI image fusion and computer assisted simulation technique in guiding type â ¢ and â £ primary pelvic sarcoma surgeries].

Objective: To explore the possible clinical benefits of CT/MRI image fusion and computer-assisted simulation techniques in guiding type Ⅲ and Ⅳ primary pelvic bone tumor surgeries. Methods: The clinic data of primary bone sarcomas patients treated at Department of Bone and Soft Tissue,Zhenghzhou University Affiliated Cancer Hospital from January 2019 to December 2021 were retrospectively analyzed. Based on whether the CT and MRI image fusion technique was utilized for tumor evaluation and surgical planning,the patients were divided into image fusion group (n=21) or control group (n=27). There were 7 male and 14 female patients included in the image fusion group, with the age of (37.0±10.4) years(range: 18 to 67 years). In the control group, there were 10 males and 17 females with the age of (39.7±15.2) years (range: 16 to 65 years). Both groups included osteosarcoma,chondrosarcoma and undifferentiated polymorphic sarcoma as the pathological diagnosis. Clinical information such as gender,age,pathological diagnosis,location of disease,and metastasis at diagnosis were collected. Surgical related information such as duration of surgery,blood loss,surgical margin,and wound complications were also obtained. Periodical follow-ups every 3 months were performed for all patients to monitor the status of local recurrence,distant metastasis,and survival information. Independent t test and χ² test were used for data comparison between groups. Results: Significant reduced duration of surgery was observed in the image fusion group in comparison with control group both in type Ⅲ and Ⅳ surgeries ((144.0±31.6)min vs. (248.2±56) min,t=-8.084, P<0.01); (173.0±42.0)min vs. (306.1±62.0)min, t=-4.518, P<0.01). Blood loss was significantly reduced in the image fusion group compared with the control group ((484.8±226.3)ml vs. (836.1±359.8)ml,t=-4.130, P<0.01). In addition, significant lower ratio of R1 margin and recurrence rates of type Ⅲ and Ⅳ surgeries were found in the image fusion group comparing with the control group (4.8%(1/21) vs. 22.2%(6/27), χ²=4.214, P=0.040; 4.8%(1/21) vs. 22.2%(6/27), χ²=4.214, P=0.040).In the image fusion group, there were 3 cases of incision infection, 1 of which underwent secondary debridement.And in thecontrol group there were 7 cases of incision infection, 3 of which underwent secondary debridement. There was no significant difference in the incidence of complications between the two groups (14.2%(3/21)vs. 25.9%(7/27), χ²=0.645, P=0.422). Up to the last follow-up, 1 patient died in the image fusion group and 2 patients died in the control group, the difference was not statistically significant (χ²=1.885, P=0.220). Conclusion: Compared with the traditional operation,the image fusion technique can significantly reduce the duration of surgery,blood loss and lower the recurrence rate by achieving better surgical margins.

[Random amplified polymorphic DNA analysis of Cryptosporidium species and strains].

OBJECTIVE: To analyse the genetic heterogeneity of 8 isolates of Cryptosporidium belonging to three species (Cryptosporiduim muris, Cryptosporiduim parvum and Cryptosporidium meleagridis) using RAPD technique. METHODS: DNA extracts of the 8 isolates were amplified by PCR using 26 out of 200 primers. The amplified products were separated by agar electrophoresis followed by staining with ethidium bromide. RESULTS: RAPD analysis revealed; 1. Obvious differences among species were found, the average genetic distance being 7.037; 2. Certain differences among different isolates of the same species were found, the average genetic distance being 5.162. CONCLUSION: RAPD could differentiate the common and respective gene fragments of the 8 isolates of Cryptosporidium.

Reduced MR acquisition time with the CROCUS technique.

A technique to reduce magnetic resonance (MR) image acquisition time by approximately 50% is introduced. The conjugate reconstruction by off-center under-sampling (CROCUS) method samples only every other phase-encoded line in raw data space and uses the conjugate symmetry of the data to reconstruct a real image. If acquisition and image reconstruction were done in the simplest manner, this under-sampling would produce unacceptable image aliasing. However, if the phase-encoded lines are offset from the origin, the assumption of conjugate symmetry allows the image to be calculated without aliasing. Unfortunately, information from all practical MR systems contain phase-shift errors that produce deviations from conjugate symmetry. The CROCUS method incorporates a correction technique, similar to that used in other half-Fourier methods, which uses low-resolution phase-shift information obtained from a few extra lines of phase-encoded data. This paper provides a theoretical derivation of the reconstruction algorithm and correction technique and illustrates the results. Excellent image quality is obtained with no loss of spatial resolution. Image signal-to-noise ratio is reduced by a factor of approximately 1.4 because of the reduced acquisition time. When the imaging circumstances are such that a high signal level is available, CROCUS imaging can be an effective means of reducing imaging time.