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Objective:To explore the classification performance of combined model constructed from CT signs combined with radiomics for discriminating COVID-19 pneumonia and other viral pneumonia.Methods:The clinical and CT imaging data of 181 patients with viral pneumonia confirmed by reverse transcription-polymerase chain reaction in 15 hospitals of Yunnan Province from March 2015 to March 2020 were analyzed retrospectively. The 181 patients were divided into COVID-19 group (89 cases) and non-COVID-19 group (92 cases), which were further divided into training cohort (126 cases) and test cohort (55 cases) at a ratio of 7∶3 using random stratified sampling. The CT signs of pneumonia were determined and the radiomics features were extracted from the initial unenhanced chest CT images to build independent and combined models for predicting COVID-19 pneumonia. The diagnostic performance of the models were evaluated using receiver operating characteristic (ROC) analysis, continuous net reclassification index (NRI) calibration curve and decision curve analysis.Results:The combined models consisted of 3 significant CT signs and 14 selected radiomics features. For the radiomics model alone, the area under the ROC curve (AUC) were 0.904 (sensitivity was 85.5%, specificity was 84.4%, accuracy was 84.9%) in the training cohort and 0.866 (sensitivity was 77.8%, specificity was 78.6%, accuracy 78.2%) in the test cohort. After combining CT signs and radiomics features, AUC of the combined model for the training cohort was 0.956 (sensitivity was 91.9%, specificity was 85.9%, accuracy was 88.9%), while that for the test cohort was 0.943 (sensitivity was 88.9%, specificity was 85.7%, accuracy was 87.3%). The AUC values of the combined model and the radiomics model in the differentiation of COVID-19 group and the non-COVID-19 group were significantly different in the training cohort ( Z=-2.43, P=0.015), but difference had no statistical significance in the test cohort ( Z=-1.73, P=0.083), and further analysis using the NRI showed that the combined model in both the training cohort and the test cohort had a positive improvement ability compared with radiomics model alone (training cohort: continuous NRI 1.077, 95 %CI 0.783-1.370; test cohort: continuous NRI 1.421, 95 %CI 1.051-1.790). The calibration curve showed that the prediction probability of COVID-19 predicted by the combined model was in good agreement with the observed value in the training and test cohorts; the decision curve showed that a net benefit greater than 0.6 could be obtained when the threshold probability of the combined model was 0-0.75. Conclusion:The combination of CT signs and radiomics might be a potential method for distinguishing COVID-19 and other viral pneumonia with good performance.
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Objective:To explore the clinical application value of MRI in quantitative evaluation of anterior cruciate ligament mucoid degeneration (ACL-MD).Methods:From March to July 2020, 40 patients who were scheduled to undergo arthroscopic treatment were prospectively collected in the First Affiliated Hospital of Kunming Medical University.The anterior cruciate ligament tissue from the lateral edge of the tibial end was taken during the operation. Based on the pathologicalre sults, the patients were divided into the ACL-MD group ( n=19) and the normal group ( n=21). The sagittal plane three-dimensional steady-state rapid precession (3D-FIESTA), T 1 mapping, T 2 mapping, and T 2* mapping were performed before the knee joint surgery, and the scanned images were post-processed and analyzed to measure the T 1, T 2, and T 2* values of the tibial end of the anterior cruciate ligament.The relaxation time of the ACL-MD group and the normal group was compared using independent sample t test. The ROC curve was drawn using each parameter and the areas under the curve (AUC) for the diagnosis of ACL-MD were obtained.DeLong test was used to compare the differences of AUCs. Results:The T 1 [(1 291.9±273.4) ms], T 2 [(54.8±10.6) ms], and T 2* values [(30.6±6.4) ms] of anterior cruciate ligaments in the ACL-MD group were significantly higher than those in the normal group [ (1 087.0±121.0), (44.8±7.1), (20.4±4.8) ms; t=3.011, 3.473, 5.658, all P<0.001]. The AUCs of T 1, T 2, T 2* were 0.747, 0.764, 0.912, sensitivity of 63.2%, 63.2%, 100%, and the specificity of 100%, 95.2%, 76.2% in diagnosing ACL-MD. The AUC of the T 2* value was higher than those of the T 1 and T 2 values, and the differences were statistically significant ( Z=1.734, 2.162, P=0.043, 0.031). Conclusion:T 1, T 2, T 2*values measured by MRI quantitative imaging have high performance in assessing knee joint ACL-MD, and T 2* value has the largest AUC and the highest diagnostic efficiency.
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Objective@#To evaluate the accuracy of a 3D-printed template used to assist the preparation of tibial tunnel in reconstruction of anterior cruciate ligament (ACL).@*Methods@#Twenty healthy adult cadaveric knees were scanned by computed tomography(CT) and magnetic resonance imaging (MRI). The knees were from 11 males and 9 females who had died at an average age of 36 years (range, from 27 to 68 years) and from 8 left and 12 right sides. Individualized 3D reconstruction models of the knee joint were established based on their imaging data. According to the anatomic footprints of the virtual tibial tunnel, 20 individualized navigation templates were designed and printed by 3D printing. The templates were used to assisst preparation of tibial tunnels in the ACL reconstruction for the 20 cadaveric knees. After operation, CT scanning was conducted again to compare the corresponding postitions between the preoperative virtual tunnel and the postoperative actual tunnel. The positions of the tibial tunnel were described by the Tsukada method.@*Results@#The ratio of the distance between the tunnel outlet center and the medial edge of the tibia to the distance between the median and lateral edges of the tibial plateau was 49.7%±2.1% for the preoperative virtual tibial tunnel and 48.8%±2.8% for the postoperative actural tunnel, showing no significant difference between them (t=1.971, P=0.063). The ratio of the distance between the tunnel outlet center and the anterior edge of the tibia to the distance between the anerior and posterior edges of the tibial plateau was 41.3%±1.3% for the preoperative virtual tibial tunnel and 40.3%±3.7% for the postoperative actural tunnel, showing no significant difference between them(t=1.494, P=0.152).@*Conclusion@#3D printing can be used to design and manufacture a navigation template which can accurately assist preparation of tibial bone tunnel in ACL reconstruction.
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Objective To evaluate the accuracy of a 3D-pfinted template used to assist the preparation of tibial tunnel in reconstruction of anterior cruciate ligament (ACL).Methods Twenty healthy adult cadaveric knees were scanned by computed tomography (CT) and magnetic resonance imaging (MRI).The knees were from 11 males and 9 females who had died at an average age of 36 years (range,from 27 to 68 years) and from 8 left and 12 fight sides.Individualized 3D reconstruction models of the knee joint were established based on their imaging data.According to the anatomic footprints of the virtual tibial tunnel,20 individualized navigation templates were designed and printed by 3D printing.The templates were used to assisst preparation of tibial tunnels in the ACL reconstruction for the 20 cadaveric knees.After operation,CT scanning was conducted again to compare the corresponding postitions between the preoperative virtual tunnel and the postoperative actual tunnel.The positions of the tibial tunnel were described by the Tsukada method.Results The ratio of the distance between the tunnel outlet center and the medial edge of the tibia to the distance between the median and lateral edges of the tibial plateau was 49.7％ ±2.1％ for the preoperative virtual tibial tunnel and 48.8％ ± 2.8％ for the postoperative actural tunnel,showing no significant difference between them (t =1.971,P =0.063).The ratio of the distance between the tunnel outlet center and the anterior edge of the tibia to the distance between the anerior and posterior edges of the tibial plateau was 41.3％ ± 1.3％ for the preoperative virtual tibial tunnel and 40.3％ ± 3.7％ for the postoperative actural tunnel,showing no significant difference between them (t =1.494,P =0.152).Conclusion 3D printing can be used to design and manufacture a.navigation template which can accurately assist preparation of tibia] bone tunnel in ACL reconstruction.
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Objective To explore the value of T2-mapping imaging in assessment of lumbar dorsal extensors group (multifidus,longissimus and iliocostalis) function before and after exercises in healthy volunteers.Methods Totally 50 healthy young volunteers underwent T2-mapping imaging before and after exercises.T2 value and cross-section area (CSA) of multifidus,longissimus and iliocostalis were measured at the level of L3 and 14 superior border.Differences of CSA and T2 value were compared between left and right side muscles before and after exercises.The correlation between CSA difference and T2 difference before and after exercises was analyzed.Results At the level of L3 and L4 superior border,CSA and T2 value of bilateral multifidus,longissimus and iliocostalis increased after exercises (all P＜0.05).At the level of L3 superior border,CSA after exercises and CSA difference of left multifidus were higher than those of right side (all P＜0.05).Before exercises,there were statistical differences of T2 values on left and right side of longissimus and iliocostalis at the level of L3 superior border and the longissimus at the level of L4 superior border (all P＜0.05).Positive correlations were found between CSA difference and T2 difference on bilateral iliocostalis at the level of L3 and L4 superior border,as well as on bilateral multifidus at the level of L4 superior border (all P ＜0.05).Conclusion T2-mapping imaging can be used to assess the activity state of lumbar dorsal extensors group before and after exercises.
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Objective To investigate the value of MRI in analyzing relationship between compression site of the vascular compression and the facial pain area in patients with primary trigeminal neuralgia (PTN).Methods MRI data of 123 patients with unilateral PTN were retrospectively analyzed,including imaging of three-dimensional-time of flight MRA (3D TOF MRA) sequence,three-dimensional-fast imaging employing steady state acquisition sequence and contrast-enhanced 3D TOF MRA sequence.Neurovascular conflict (NVC) sites were divided into 8 sites according to the sectional anatomy of trigeminal nerve,and the relations between topography of pain and site of NVC were analyzed in 60 PTN patients with a single offending vessel and a single site of NVC.Distance (d) from the root entry point to the site of NVC,the length (L) of cisternal segment of the trigeminal nerve were both measured,and d/L was calculated in 123 patients with 206 NVC points.Results Of 60 patients with single offending vessel and single site of NVC,95.00％ (57/60) sites of NVC matched to topography of pain,5.00％ (3/60) did not,whereas NVC points with d/L≤1/4 accounted for 58.33％ (35/ 60),d/L≤1/2 accounted for 85.00％ (51/60).Among 206 NVC points,the meand was (2.50±1.35)mm,and NVC points with d/L≤1/4 accounted for 44.66％ (92/206),d/L≤1/2 accounted for 74.27％ (153/206).Conclusion MRI is helpful to detecting the offending vessels in PTN patients through judging relationship between the topography of pain and the site of NVC,as well as measuring the distance from the root entry point to the site of NVC.
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Objective To investigate the changes of the regional homogeneity(ReHo)values of spontaneous brain activity in patients with idiopathic trigeminal neuralgia (ITN).Methods Left ITN (LITN)group (n=23)and the healthy control (HC)group (n=33)underwent resting-state functional magnetic resonance imaging(rs-fMRI)scans.The changes of ReHo values between the two groups were compared.Results Compared with HC group,LITN group yielded increased ReHo values in bilateral nucleus accumbens,bilateral caudate nucleus,right putamen, right precentral gyrus (M1),right supplementary motor area (SMA)and right anterior insula (P<0.01).Conclusion The rs-fMRI shows abnormal ReHo values of brain activity in several regions in ITN patients.The regions are related to pain processing-motion,emotion and endogenous regulation.The suggest that brain involves the developing and regulating mechanism of ITN as an importment factor.
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Objective To investigate the value of blood oxygenation level dependent(BOLD)fMRI in assessing the functional changes of the lumbar dorsal extensor muscles before and after exercise in healthy young people.Methods The changes of the R2*value of lumbar dorsal extensor group in 30 healthy young volunteers(15 males and 15 females)before and after exercise was prospectively studied.BOLD-fMRI scans were performed on healthy young volunteers before and after exercise, the exercise mode was to perform the upper body flexion and extension movement with a simple Rome stool.The scanned images were processed and analyzed, the cross-sectional area and R2* value of the lumbar dorsal extensor muscles (including the multifidus,the longissimus and the iliocostalis)were measured at the upper margin of the L3 and L4 vertebral body before and after exercise.The paired t test was used to compare CSA and R2*values of muscles before and after loading. The CSA and R2* value of different muscles in different sides were compared by independent sample t test. Pearson correlation analysis was used to analyze the relevance between CSA and R2* in muscle before and after exercise. Results After exercise, the R2* values of multifidus,longissimus and iliocostalis at the upper margin of the L4 vertebral body were[(39.2±8.6),(38.9± 7.7),(41.6±7.8)]Hz,significantly lower than before exercise[(46.1±6.9),(45.3±6.2),(46.0±6.7)]Hz(P<0.01);the changes of R2*values of the muscles between the left and right sides before and after the movements were not statistically significant(P>0.05).The R2*values of longissimus and iliocostalis at the upper margin of the L3 vertebral body were[(44.2±9.1),(46.6±9.3)]Hz,significantly lower than before exercise[(48.6±7.2),(49.7± 6.8)]Hz (P<0.01), but the R2* values of multifidus after loading was (43.9 ± 9.0)Hz, there was no statistical difference compared with before exercise (46.8 ± 6.6)Hz (P>0.05);there was a significant difference in the changes of R2*value before and after the movement between the left and right side of iliocostalis(P<0.05).A significant negative correlation between CSA and R2*value was found in the iliocostalis on the right side at the upper margin of L3 vertebral body and in the multifidus on the left side at the upper margin of L4 vertebral body,and the correlation coefficients were (-0.697,-0.616).Conclusion BOLD-fMRI can be a new way to assess the functional changes of the lumbar dorsal extensor group before and after exercise.
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Objective Toexplore the application value of diffusion tensor imaging (DTI) in evaluating evaluation offunctional changes of the in patients with primary trigeminal neuralgia caused (PTN) by neurovascular compression. Methods 40 unilateral PTN patients and 40 healthy volunteers were enrolled in ourstudy.They allAll patients underwent the general sequences and DTI ,and then to measured the ADC and FA values of the trigeminal nerves. Results (1) Compared with contralateral side (0.408 ± 0.054)and bilateral sides in control group(0.423 ± 0.057), FA value of the ipsilateral side in PTN group(0.330 ± 0.056) was significant lower (P< 0.05)compared with the contralateral side (0.408 ± 0.054) and bilateral sides in control group (0.423 ± 0.057).The ADC value of ipsilateralside (2.052 ± 0.473)× 10-3 mm2/s was significantly higher (P < 0.05) thancompared withthe contralateral side (1.541 ± 0.266) ×10-3 mm2/s and bilateral sides in control group(1.431 ± 0.308) ×10-3 mm2/s. (2) An There's a nnegative correlation was found (r = -0.613,P < 0.001) between the loss of FA and the increase of ADC (r = -0.613,P < 0.001). Conclusion DTI could be used to evaluate the changes of neuratrophy and demyelination ,so it canmight be used of in diagnosis and treatment of PTNin further way.
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Objective To investigate the clinical and MRI characteristics of reversible splenial lesion syndrome (RESLES).Methods The clinical data,MRI features and follow-up results of 18 patients with RESLES were analyzed retrospectively.Results The average age of the patients was younger,and 5 cases were below 1 5 years old.Clinical history and MRI features were characterized.About 67%(12/18)patients had fever,headache,encephalitis,history,without long history of alcohol abuse.MRI revealed that the lesions of splenial of corpus callosum were solitary nodule with clear boundary.The lesions were slightly hyperintensity on T2 WI and obviouslyhyperintensity on FLAIR and DWI,while the they show hypointensity on ADC with the ADC value <1×10-3 mm2/s.No edema or significant enhancement were observed.The lesions may completely disappear or relief on DWI after short treatment.Conclusion RESLES is a rare entity with a broad clinicoradiological spectrum.The MRI features are characteristic,and it will provide helpful information for diagnosis, differential diagnosis and clinical treatment.
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Objective To investigate the clinical value of stereotactic biopsy in the diagnosis of the multiple intracranial lesions, and explore the operation methods, technical points and clinical experiences to reduce surgical complications. Methods Twenty-three patients in the first affiliated hospital of Kunming Medical University underwent stereotactic biopsy from January 2009 to June 2013 were analyzed retrospectively. The patients were aged between 11 and 73 years (the mean age of 34.6 years) . There were 12 males and 11 females. Operations were performed by thin thickness of spiral CT scan, ASA-602S and Leksell-Frame-G stereotactic frame, Sedan side-cutting needle, Backlund side-cutting needle and neuroendoscope of STORZ. Routine histopathological examinations of specimens were conducted. The immunohistochemical staining of the histopathological section of specimens was performed if necessary. Results The diagnostic yield was 91.3% (21 cases) . The result of pathological diagnosis was inflammatory granuloma in 1, inflammatory lesion in 1, calcification in 1, hyperplasia of colloid cells in 6, astrocytoma in 1 (WHOⅠ-Ⅱ), astrocytoma in 2 (WHOⅡ), astrocytoma in 1 (WHOⅡ-Ⅲ), mixed oligoastrocytoma in 1 (WHOⅠ-Ⅱ), glioblastoma multiforme in 3 (WHOⅣ), germinoma in 1, brain metastases in 1, diffuse large B-cell lymphoma in 1, intracranial granulomatousarteritis in 1 and negative in 2. There were no serious complications, such as coma, hemiparalysis, infection and intracranial hematoma. Conclusion Stereotactic biopsy is an important method in the diagnose of multiple intracranial lesions. It has the advantages of precise location, less damage, safe performance, and reducing the complication effectively. It is worth promoting.
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This paper introduces the forming of the metrology control network which attracts great attention of the hospital's leadership.The result indicates that the metrology knowledge training is strengthened,its level is raised,and the metrology control becomes more scientific,effective and standardized.Now a new atmosphere appears in our hospital that every staff values and participates in the metrology work.Both the examined rate and qualified rate of the measuring appliances reach 100%.Accurate,reliable,safe and effective measuring appliances are provided for the clinical work.