| Background and ObjectiveTurbo spin echo(TSE)sequence is the most commonly used magnetic resonance imaging sequence in the clinical practice.TSE sequence can exhibit the detailed anatomies clearly,but entails long scanning time,averaging 4-5 minutes.The integrated parallel acquisition techinque(i PAT)uses a rectangular FOV to short the scanning time by reducing the required phase code lines and filling them in the K space sparsely.However,due to the signal oversampling constraints,the SNR is poor and which limit its application in the bone joint.Thus,a fast and high-resolution MR imaging technique is of great importance in the muscle-skeletal imaging.In recent years,an emerging fast imaging technique is simultaneous multi-slice(SMS)or multiband(MB).The MB composite RF pulses are applied to excite multiple imaging slices simultaneously while the data were simultaneous acquired,extracted,reconstructed and readout in a two-dimensional format in the SMS technique,which can greatly shorten the scanning time.In addition,The bipped-CAIPIRNHA parallel acquisition technology and the special K-space filling method were used in SMS,which can effectively improve the SNR of images.The combination of SMS and EPI sequences has been widely used in the nervous system.There have been a few reports of the application of SMS in bone and joint system,butthere is still no report about the combination of SMS and TSE sequences in the bone and joint system.The purpose of this study was to assess the combine the SMS and TSE sequences(SMS-TSE)and to compare the image quality and scanning time with the TSE sequences,furthermore,to evaluate the clinical value of SMS-TSE sequences in the bone and joint system.MethodsGeneral information: This prospective study was approved by our Institutional Review Board and written informed consent was obtained from all patients.From July 2015 to February 2017,participants meeting the following criteria were included.Inclusion criteria:(1)Participants were randomly selected from the volunteers who were willing to underwent MR examination.(2)No pacemaker,aneurysm clip and metal implants in the body.(3)Volunteers selected healthy participants without clinical symptoms.(4)Patients who have no history of surgery.(5)Participants were appropriately fixed in the scanning time and without obvious motion artifacts.Finally,82 consecutive participants were included in this study,including 31 cases of knee,25 cases of wrist,15 cases of ankle,and 11 cases of shoulder joints.There were 40 men and 42 women;mean age,38.4±12.9 years;range,20-67 years.MR examination: For all examinations,studies were carried out by using MAGNETOM Prisma 3T MR scanner(Siemens,Erlangen,Germany).The special coils including fifteen-channel knee joint coil,sixteen-channel hand/wrist coil,sixteen-channel foot/ankle coil and sixteen-channel shoulder coil were used in the study.All the participants were underwent the conventional TSE sequences and SMS-TSE sequences with the axial and coronal planes.Acceleration factor of the conventional TSE sequences and SMS-TSE sequences were 0 and 2 respectively.To prevent the bias caused by the different sequences,the parameters of the SMS-TSE sequences were consistent with the conventional sequences.Thus,the comparability of image quality of two sequences is guaranteed.The scanning time were recorded separately.Image analysis: The image quality was compared by quantitative measurement and qualitative scoring analysis.For the quantitative measurement,two experienced musculoskeletal radiologists measured the SNR,CNR and the SNR per minute(SNR/min)of the two sequences.For the qualitatively scoring analysis,a five-point evaluation scale was used to score the image quality of these sequences by two radiologists.Lesion analysis: The imaging signs of the lesions showed on the SMS-TSE sequences were compared with the conventional TSE sequences and which were used as the standard reference.The abnormal imaging signs showed on the conventional TSE sequences were as follows: bone contusion,the pattern or reticular low signal intensity on the TIWI in marrow,which were showed high-signal intensity on T2WI-FSl;articular surface abnormality,cartilage injury,ligament and tendon degeneration or injury,meniscus injury,peripheral soft tissue injury and image artifacts.Statistical analysis: All the statistics analyses were performed by using SPSS17.0 software.The paired-t or rank test was used to compare the SNR,CNR and SNR/min of the two sequences in the knee,wrist,ankle and shoulder joints respectively.The interobserver agreements between two radiologists were compared with Kappa test,for which a value less than 0.4 indicated poor agreement,0.4-0.6indicated moderate agreement,0.6-0.8 indicated substantial agreement,and more than0.8 indicated almost perfect agreement.The Wilcoxon test was used to the compare the qualitative scores of the two sequences.A P value less than 0.05 was considered to indicate a significant difference.In addition,the sensitivity,specificity and accuracy of the SMS sequences toward the knee,wrist,ankle and shoulder joints were calculated by using the conventional sequences as the standard reference.The significant difference of the two sequences was compared by using McNemar test.Results1.Knee joints Compared with the conventional TSE sequences(33.58±2.84?79.95±7.22 ? 85.66±5.55),the SNR of the SMS-TSE sequences(30.96±3.13 ?75.76±5.56?78.96±9.13)were decreased,the difference was statistical significance(t=4.205?P=0.000,t=3.244?P=0.003,Z=-2.469? P=0.014).The CNR of the SMS-TSE sequences were 89.75±6.12 ? 46.45±3.96 ? 43.78±5.62,and for the conventional sequences were 90.65±6.73? 47.92±3.85?43.93±4.11,there was no statistical significance depicted(Z=-1.293?P=0.196,t =-1.495?P=0.145,Z=-0.333,P=0.739).However,compared with the SNR/min of the conventional sequences(10.66±0.90?15.99±1.44?16.07±1.04),the SNR/min of the SMS-TSE sequences(18.76±1.90?30.06±2.20?29.24±3.38)were improved,the difference was statistical significance(t =-24.88?P<0.001,t=-37.05?P <0.05,Z=-4.86?P<0.001).There was no statistical significant difference of the image quality depicted between the conventional TSE and SMS-TSE sequences(P >0.05).The two sequences can clearly depict the bone texture,cartilage,ligament and meniscus.The scanning time of the SMS-TSE sequences(6.87min)were greatly shorten(shorten 49.04%)compared with the conventional sequences(13.48min).The conventional TSE MR sequences was served as the standard reference,there were 15 cases of knee degeneration,2 cases of meniscus injury,3 cases of bone marrow edema,3 cases of cruciate ligament injury,1case of soft tissue contusion and 9 cases of normal knee joint were found on the conventional MR sequences.However,there were 13 cases of knee degeneration,2cases of meniscus injury,3 cases of bone marrow edema,3 cases of cruciate ligament injury,1 case of soft tissue contusion and 9 cases of normal knee joint were found on the SMS-TSE sequences.No statistical significant difference was found between two sequences(P=0.625).The sensitivity,specificity and accuracy for the SMS sequences were 87.50%?85.71%?87.10%,respectively.2.Wrist joints Compared with the conventional TSE sequences(234.16±11.20?115.44±17.46?332.40±104.04?128.89±37.87),the SNR of the SMS-TSE sequences(219.10±14.00 ? 96.56±19.34 ? 284.75±152.97 ? 121.69±26.14)were decreased,the difference was statistical significance(t =6.970,P <0.001,Z=-3.754?P<0.001,Z=-2.516 ?P=0.012,t=1.069 ? P=0.296).The CNR of the SMS-TSE sequences were(187.81±11.10?373.31±113.18?82.68±16.54?76.36±27.24),and for the conventional sequences were(189.75±12.69 ? 398.07±68.37 ? 96.01±19.20 ?73.76±31.91),no statistical significance was depicted(t=0.519?P=0.608,Z=-0.094?P=0.925,t=-0.772?P=0.448,t=0.428?P=0.672).However,compared with the SNR/min of the conventional sequences(t=0.519?P=0.608,Z=-0.094?P=0.925,t=-0.772?P=0.448,t=0.428?P=0.672),the SNR/min of the SMS-TSE sequences(165.99±10.60 ? 64.33±10.18 ? 167.50±89.98 ? 46.80±2.01)were improved,the difference was statistical significance(t =-44.03,P=0.000,Z=-4.372,P=0.000,Z=-4.372,P=0.000,t =-2.753,P=0.011).But no statistical significant difference of the image quality was depicted between the conventional and SMS-TSE sequences,the difference was statistical significance(P <0.05).Both two sequences can clearly depict the bone texture,cartilage,ligament and tendon.The imaging time of the SMS-TSE sequences(14.92min)were greatly shorten 49.60%,compared with the conventional TSE sequences(7.52min).The conventional TSE sequences was served as the standard reference.Compared with the conventional TSE sequences,1 case of wrist carpal tunnel syndrome,3 cases of TFCC injury,2 cases of osteonecrosis,1 case of pigmented villous nodules,8 cases of wrist degeneration,2 cases of ganglion cyst,and 10 cases of normal wrist joint were found on the SMS sequences.However,1case of wrist carpal tunnel syndrome,2 cases of TFCC injury,2 cases of osteonecrosis,1 case of pigmented villous nodules,7 cases of wrist degeneration,2cases of ganglion cyst,and 10 cases of normal wrist joint were found on the conventional TSE sequences.No statistical significant difference was found between two sequences(P=0.500).The sensitivity,specificity and accuracy for the SMS sequences were 88.24%?100%?92%,respectively.3.Ankle joints Compared with the conventional TSE sequences(261.71±74.13?208.33±40.63?197.76±47.45),the SNR of the SMS-TSE sequences(246.01±90.03?182.28±46.58?173.76±35.53)were decreased,the difference was statistical significance(t=2.385?P=0.032,t=3.222?P=0.006,t=2.686?P=0.018).The CNR of the SMS-TSE sequences were(336.21±173.56 ? 80.47±40.81 ?136.34±36.20),and for the conventional TSE sequences were(376.99±113.72 ?150.98±88.27 ? 153.32±37.69),no statistical significance was depicted(t=1.233 ?P=0.238,t=-0.360 ? P=0.724,t=-2.312 ? P=0.036).However,compared with the SNR/min of the conventional TSE sequences(52.66±14.92 ? 37.88±7.39 ?56.22±13.56),the SNR/min of the SMS-TSE sequences(96.47±35.31?64.41±16.46?95.47±19.53)were improved,the difference was statistical significance(t=-8.025?P=0.000,t=-8.590?P=0.000,t=-11.147?P=0.000).But no statistical significant difference of the image quality was depicted between the conventional TSE and SMS-TSE sequences,the difference was statistical significance(P <0.05).Both two sequences can clearly depict the bone texture,cartilage and ligament.The imaging time of the SMS-TSE sequences(7.20min)were greatly shorten 48.46%,compared with the conventional sequences(13.97min).The conventional TSE sequences was served as the standard reference.Compared with the conventional TSE sequences,6cases of ankle degeneration,2 cases of fibular fractures,3 case of ankle joint effusion,1 case of ankle osteochondritis dissecans,3 cases of normal ankle were found on the SMS-TSE sequences.However,5 cases of ankle degeneration,2 cases of fibular fractures,3 case of ankle joint effusion,1 case of ankle osteochondritis dissecans,4cases of normal ankle were found on the conventional TSE sequences.No statistical significant difference was found between two sequences(P=1.000).The sensitivity,specificity and accuracy for the SMS sequences were 100% ? 75% ? 93.33%,respectively.4.Shoulder joints Compared with the conventional TSE sequences(56.22±13.56?109.38±31.18?59.34±10.57?63.61±8.72),the SNR of the SMS-TSE sequences(95.47±19.53?93.60±38.69?49.51±8.99?55.57±7.84)were decreased,the difference was statistical significance(t=-11.147?P=0.000,t=3.198?P=0.010,Z=-2.845?P=0.004,t=4.299?P=0.002).The CNR of the SMS-TSE sequences were(124.27±78.77?88.85±23.28?35.56±7.86?41.34±9.30),and for the conventional sequences were(141.48±96.13?70.95±27.54?41.50±10.42?44.50±11.26),no statistical significance was depicted(t=-2.459 ? P=0.034,t=-3.708 ? P=0.004,Z=-1.867?P=0.062,t=-1.130?P=0.285).However,compared with the SNR/min of the conventional TSE sequences(18.30±10.41?21.45±6.90?12.63±2.25?16.31±2.24),the SNR/min of the SMS-TSE sequences(31.63±17.35?36.42±15.06?20.89±3.79?42.10±5.94)were improved,the difference was statistical significance(t=-5.805?P=0.000,Z=-2.934?P=0.003,t=-6.713?P=0.000,t=-18.656?P=0.000).But no statistical significant difference of the image quality was depicted between the conventional and SMS-TSE sequences(P<0.05).Both two sequences can clearlydepict the bone texture,cartilage and ligament.The imaging time of the SMS-TSE sequences(8.64min)were greatly shorten 52.86%,compared with the conventional sequences(18.33min).The conventional TSE sequences was served as the standard reference.Compared with the conventional TSE sequences,5 cases of shoulder degeneration,2 cases of shoulder rotator cuff injury,4 cases of normal shoulder joint were found on the SMS sequences.However,4 cases of shoulder degeneration,2cases of shoulder rotator cuff injury,5 cases of normal shoulder joint were found on the conventional TSE sequences.No statistical significant difference was found between two sequences(P=1.000).The sensitivity,specificity and accuracy for the SMS sequences were 100%?80.00% and 90.91%,respectively.Conclusion1.It is feasible for rapid and high resolution imaging of SMS-TSE MR sequences in the knee,whist,ankle and shoulder joints,which the scanning time is greatly shortened under the guaranteed image quality.2.The SMS-TSE sequences is of important clinical value for knee,wrist,ankle and shoulder joints,which can be used as an alternative imaging modality of the conventional TSE sequences. |
PDF Full Text Request