The magnetic anchoring lung nodule positioning device is composed of a target magnet, an anchor magnet, a coaxial puncture needle and a puncture navigation template, through these, a new type of accurate positioning technology for small pulmonary nodules is derived. The device inserts the target magnet into the both sides nearby the lung nodule under the guidance of CT. Helped by the mutual attraction of the two target magnets, they can be fixed in the lung tissue, avoiding the movement in the lung, and accurately positioning the target lung nodule before surgery. In thoracoscopic surgery, the anchor magnet and the target magnet attract each other to achieve the purpose of positioning the target nodule. The device uses the characteristics of non-contact suction of magnetic materials biomedical engineering technology, eliminating the previous procedure of direct interaction with the positioning marks, finally achieves the target of precise positioning of lung nodules and rapid surgical removal.
Humans ; Lung ; Lung Neoplasms ; Magnetic Phenomena ; Magnets ; Solitary Pulmonary Nodule ; Thoracic Surgery, Video-Assisted ; Tomography, X-Ray Computed

Objective:To evaluate the hip C-arm fluoroscopy at primary position in internal fixation of femoral neck fracture.Methods:A retrospective study was conducted of the 69 patients with femoral neck fracture who had been treated from August 2015 to August 2018.They were divided into a primary position group ( n=35) subjected to C-arm hip fluoroscopy at primary position under symmetry traction of bilateral lower limbs for reduction of femoral neck fracture and a control group ( n=34) subjected to C-arm hip fluoroscopy at frog’s position on the healthy side for traction and reduction of the injured hip. The 2 groups were compared in terms of fluoroscopy frequency, times of resetting guide pin, intraoperative blood loss and total operation time. Results:The 2 groups were comparable due to insignificant significances between them in the preoperative general data like gender, age, fracture type, injury cause, or interval from injury to operation ( P>0.05). Compared with the control group, the primary position group showed less intraoperative fluoroscopy (7.2 times ± 0.5 times versus 16.1 times ± 1.2 times), fewer times of resetting guide pin (2.1 times ± 0.31 times versus 4.7 times ± 0.8 times), less intraoperative blood loss (96.8 mL ± 18.6 mL versus 198.1 mL ± 13.2 mL), and shorter total operation time (1.2 h ± 0.2 h versus 1.6 h ± 0.3 h). All the differences were statistically significant ( P<0.05). Conclusions:C-arm hip fluoroscopy at primary position may protect the stability after fracture reduction because bilateral lower limbs are under symmetrical traction and the hip position needs no alteration. Operation of C-arm fluoroscopy is easy and convenient and produces clear images. Therefore, this new mode of fluoroscopy has advantages of less intraoperative fluoroscopy and guide pin resetting, leading to significantly reduced intraoperative blood loss, ineffective operation time and anesthesia time.

Objective:To evaluate the influence of the sleeve lengths and implant lengths on accuracy of static computer-assisted implant surgery (sCAIS).Methods:Twenty-eight models of bilateral mandibular single tooth loss were included. Fifty-five implants were placed under the guidance of sCAIS (Straumann Bone Level 4.1 mm×10 mm). According to the height of metal sleeve of static guide plate, 55 implants were divided into 11 groups (free hand group, 1 mm group, 2 mm group, 3 mm group, 4 mm group, 5 mm group, 6 mm group, 7 mm group, 8 mm group, 9 mm group, 10 mm group), with 5 implants in each group. Eight research models were included. Group with 5 mm sleeve guides were used to place implants of different length, (Straumann Bone Level width 4.1 mm, height was 8 mm, 10 mm and 14 mm), 5 implants in each group. Eighteen patients with mandibular single tooth loss were included in the Department of Oral Implantology, Tianjin Stomatological Hospital from October 2018 to June 2019. There were 10 males and 8 females, 18-46(33.7±7.9) years old. A total of 18 implants were implanted and divided into 3 groups (free hand group, 3 mm group and 5 mm group) with 6 implants in each group. Digital software was used to compare the implant positions before and after implantation. Non-parametric Kruskal-Wallis test or one-way ANOVA were used to analyze the results.Results:There was no significant difference in implant vertical deviation between different sleeve height groups (1-10 mm) and free hand group, but the neck deviation in free hand group[(1.04±0.13) mm] was significantly higher than that in different sleeve height groups (1-10 mm) ( P<0.05). The tip deviations of free hand group, 1 mm group and 2 mm group [(1.32±0.43), (0.83±0.10) and (0.78±0.11) mm, respectively] was significantly higher than that of 10 mm group [(0.31±0.14) mm]( P<0.05). The angle deviation of free hand group and 1 mm group (3.99°±0.85° and 2.59°±0.69°), respectively] was significantly higher than that of 10 mm group (0.61°±0.03°) ( P<0.05). The tip deviations of implants in the 14 mm group [(0.83±0.22) mm] was significantly higher than that in the 8 mm and 10 mm groups [(0.44±0.07) and (0.49±0.06) mm, respectively]. Clinical studies showed that there was no significant difference in neck deviation, tip deviation and angle deviation between 3 mm group and 5 mm group ( P>0.05), but deviations were significantly lower than those in free hand group ( P<0.05). Conclusions:The length of the sleeves has significant influence on the accuracy of the surgical guide. There was no significant difference in accuracy of the implant guide with 3 mm or 5 mm metal sleeves. The vitro study has some limitations and needs further systematic research.

Objective To investigate the value of phase-contrast magnetic resonance imaging (PC-MRI)in evaluating pulmonary artery blood flow and right ventricular(RV)function in elderly patients with chronic obstructive pulmonary disease (COPD).Methods Twenty-four elderly patients with COPD admitted to Beijing Anzhen Hospital between February 2016 and June 2017 were enrolled in this retrospective study.Based on pulmonary artery pressure evaluated by right heart catheterization,COPD patients were divided into a pulmonary hypertension group (PH group,n =12)and a non-PH group(n=12).Pulmonary artery blood flow velocity and volume,pulmonary arterial compliance and right heart function parameters including ejection fraction,end diastolic volume,endsystolic volume and cardiac output,and 6-min walking distance evaluated by PC-MRI were compared between the two groups.Results There were significant differences in peak flow velocity[(88.1 ±16.0)cm/s vs.(59.8± 13.8) cm/s,P =0.005],flow volume [(80.7± 22.0) ml/s vs.(53.2± 26.7)ml/s,P=0.012],main pulmonary artery compliance[(42.3± 14.6)vs.(22.7± 10.8),P =0.001],right ventricular ejection fraction [(48.4 ± 13.4) ％ vs.(37.6 ± 11.1) ％,P =0.000],end-diastolic volume[(64.6±22.5)ml vs.(72.5±22.8)ml,P =0.030]and end-systolic volume[(50.6±33.1)ml vs.(41.7±33.1)ml,P =0.040]between the non-PH and PH groups,while there was no significant difference in cardiac output between the non-PH and PH groups[(34.2±10.8)ml vs.(34.4±8.3)ml,P =0.080].Pearson's correlation analysis showed that 6-minute walking distance had good correlations with right ventricular ejection fraction(r =0.49),forced expiratory volume in 1 s(FEV1)(r=0.60)and main pulmonary artery diameter(r=0.61).Conclusions PC-MRI is a noninvasive imaging method for quantitative analysis of pulmonary artery dynamics and right heart function for the elderly with COPD,and it can provide information for evaluating therapeutic effects and prognosis.

Objective To observe the value of optimized temporal parallel acquisition technique (TPAT) sequence in evaluating cardiac structure and function in arrhythmia patients.Methods Totally 33 arrhythmia patients (arrhythmia group) and 48 normal rhythm subjects (normal group) underwent cardiac MRI with conventional cine (balanced steadystate free-precession [bSSFP]) sequence and optimized TPAT sequence.Myocardial thickness,cardiac function,myocardial strain parameters of left ventricle and image quality of 2 sequences were compared in the two groups,respectively.Results In arrhythmia group,there was statistical difference of myocardial thickness in 12 myocardial segments between the 2 sequences (all P ＜ 0.05),as well as peak and average values of myocardial radial and circumferential strain (all P＜0.05).In normal group,there was no statistical difference of myocardial thickness and stain parameters between the 2 sequences (all P＞0.05).Additionally,no statistical difference of cardiac function was found between the 2 sequences in two groups (all P＞0.05).In arrhythmia group,the image quality of optimized TPAT sequence was better than that of bSSFP sequence (P＜0.05).Conclusion For arrhythmia patients,optimized TPAT cine sequence could improve image quality of cardiac MRI.

Objective To evaluate the diffuse myocardial fibrosis of the left ventricle (LV) in patients with atrial fibrillation (AF) by cardiac MR (CMR) T1 mapping methods.Methods Totally 60 subjects (30 paroxysmal AF patients and 30 persistent AF patients) and 59 normal control underwent MR cardiac cine,late gadolinium enhancement,and LV T1 mapping.For T1 mapping,modified Look-Locker inversion recovery sequence was used.Compared with control,pre-contrast ventricular T1 times were quantified and extracellular volume (ECV) was calculated.Results All subjects completed the CMR exam,no myocardial delay enhanced lesion was found.Pre-contrast ventricular T1 time in healthy controls was lower than that in patients with persistent and paroxysmal AF,and the pre-comrast ventricular T1 time in persistent AF patients was higher than that of paroxysmal AF patients (all P＜0.05).The mean LV myocardial ECV had no statistical difference between healthy controls and paroxysmal AF patients (P＞ 0.05),while lower than persistent AF patients (P ＜ 0.05).The mean LV myocardial ECV in patients with persistent AF was larger than that in patients with paroxysmal AF (P＜0.05).LV functional indexes were positive correlated with pre-contrast ventricular T1 time and ECV in patients with AF (all P＜0.05).Conclusion There is LV myocardial fibrosis in patients with AF,and the degree in patients with persistent AF is more severe than that in patients with paroxysmal AF.

Objective To explore the clinical application value of left atrial function with feature tracking cardiac magnetic resonance imaging (FT-CMR) by evaluating preliminarily left atrial strain and strain rate in patients with atrial fibrillation. Methods Thirty patients with paroxysmal atrial fibrillation, thirty patients with persistent atrial fibrillation and twenty-two healthy subjects were enrolled. All the subjects underwent cardiac magnetic resonance imaging with the real steady-state free precession(SSFP) sequence. FT-CMR parameters included left atrial strain and strain rate parameters, left atrial volume and function parameters were detected by using offline cardiovascular analysis software, respectively. Left atrial strain and strain rate parameters included left atrial total strain(Εs), passive strain(Εe), active strain(Εa), peak positive strain rate(SRs), peak early negative strain rate(SRe)and peak late negative strain rate(SRa). Volume and function parameters included maximum of left atrial volume(LAVmax), minimum of left atrial volume(LAVmin), total left atrial emptying fraction(LATEF), passive left atrial emptying fraction(LAPEF)and active left atrial emptying fraction(LAAEF). The differences in the general data among the paroxysmal atrial fibrillation group, the persistent atrial fibrillation group and the control group were compared by usingχ2 test or ANOVA analysis. The differences in all parameters between the atrial fibrillation group and the control group, the paroxysmal atrial fibrillation group and the persistent atrial fibrillation group were compared by using independent t test. Left atrial strain and strain rate parameters on an intra-observer and inter-observer were determined by intraclass correlation coefficient(ICC)analyses. Results Compared to control group, LAVmax and LAVmin in atrial fibrillation group were significantly increased(t=9.737,7.889,P<0.001);The LATEF and LAPEF had no significant difference, the LAAEF in two groups had statistically significant difference(t=-4.762,P<0.001).The absolute value of Es, Ee, Ea, SRs, SRe, SRa in atrial fibrillation group were significantly reduced than in control group(t=-7.732,-6.610,-6.493,-7.546, 6.864, 5.917,P<0.001). Compared with paroxysmal atrial fibrillation group, LAVmax and LAVmin in persistent atrial fibrillation group were increased obviously, LATEF and LAPEF were significantly decreased, and the differences were statistically significant(t=-4.575,-5.524, 4.002, 4.028,P<0.001).The LAAEF in two groups had no statistically significant difference. Compared with strain and strain rate in two groups, absolute value of Es, Ee, Ea, SRs, SRe, SRa in persistent atrial fibrillation group significantly decreased than in paroxysmal atrial fibrillation(t=4.310, 3.128, 4.465, 5.496,-3.290,-3.863,P<0.001). The intra-group and inter-group had well correlation coefficients between the observers in the left atrial strain and strain rate parameters of the subjects(ICC=0.85—0.94,0.81—0.90). Conclusions FT-CMR technique can be used to assess the left atrial strain and strain rate in patients with atrial fibrillation;Left atrial reservoir, conduit and booster-pump functions in patients with atrial fibrillation were impaired. Patients with persistent atrial fibrillation had worse left atrial function throughout the entire cardiac cycle compared with those with paroxysmal atrial fibrillation.

Objective: To retrospectively analyze the potential correlation between cardiac magnetic resonance (CMR) imaging and clinical features and idiopathic arrhythmia in patients with straight back syndrome (SBS). Methods: Patients receiving CMR imaging examination from April 2015 to March 2016 at our department (n=1 432) were screened, 76 patients met the diagnosis criteria of flat chest (anteroposterior diameter/transthoracic diameter (APD/TTD) ratio<0.37 at the T8 vertebra). After excluding 33 patients with structural heart disease, 43 SBS patients were divided into two groups: SBS without obvious morphological change in the heart (group A, n=19) and SBS with morphological change of the heart (group B, n=24). CMR images were analyzed, focusing the heart morphological changes induced by SBS. The clinical data were collected to comprehensively analyze the medical history, electrocardiogram and electrophysiological examination in order to observe the relationship between SBS induced heart morphological change and the arrhythmia type and origin. Results: There were 21 male patients in this cohort, mean age was (28.5±11.5) years (13-58 years). APD/TTD ratio was similar between the two groups (0.30±0.03 vs. 0.29±0.04, P>0.05). LVEF tended to be lower in group B than in group A ((47.48±12.77)%vs. (59.31±9.04)%, P>0.05) . In group B, there were 15 patients with left ventricular enlargement, 2 with left ventricular wall thickening, 5 with uncoordinated ventricular wall motion, 5 with tricuspid regurgitation, 3 with mitral regurgitation, 2 with myocardial fibrosis, 5 with increased trabecular and 16 with decreased left ventricular function. Direct compression sign of right ventricle (disappeared precordial fat tissue space, secondary right atria enlargement and tricuspid regurgitation) and left atria (with or without secondary left ventricular enlargement and mitral regurgitation) were evidenced in patients of group B. CMR revealed that the arrhythmia origin corresponded the compression site of the heart in 8 cases (42.1%) in group A and 13 cases (54.2%) in group B, not corresponded to the compression site in 6 patients (31.6%) in group A and in 7 patients (29.2%) in group B, not attributable in 5 patients (26.3%) in group A and 4 patients (16.7%) in group B. The percent of arrhythmia origin corresponded the compression site of the heart tended to be higher in group B as compared to group A (P>0.05). Conclusion SBS can induce changes of cardiac morphology and cardiac function. SBS induced cardiac compression is linked with the development of arrhythmias and might be one of the reasons of arrhythmias in these patients.

Objective To investigate the value of contrast enhancement T1 mapping in detection of diffuse myocardial fibrosis in cardiomyopathy, and the relationship between myocardial fibrosis and cardiac function. Methods From September 2013 to September 2014, 76 cases of cardiomyopathy patients (including myocarditis) and 33 cases of healthy controls were enrolled in our study. All the subjects underwent cardiac MR (CMR) examination. Scan sequences included cine MR, pre-contrast and post-contrast T1 mapping and late gadolinium enhancement (LGE) imaging. The pre-/post-contrast left ventricle average T1 value and cardiac function of patients and controls were measured and compared by using independent-samples t test. According to the LGE imaging, all the subjects were subsequently divided into LGE positive group, LGE negative group and control group. The myocardial average T1 value and cardiac function among the three sub-groups were compared by using one-way ANOVA, and the relationship among them were analyzed by using Pearson correlation. Results Among the 76 cases of non-ischemia cardiomyopathy patients, 51 cases (67.1%) had LGE. Compared with controls, cardiomyopathy patients presented with higher pre-contrast T1 value [(1 306.4 ± 84.6)ms vs. (1 266.6 ± 57.3)ms, t=2.10, P<0.05] and lower post-contrast T1 value [(483.6 ± 112.0)ms vs. (534.1 ± 92.7)ms,t=-0.27, P<0.05]. Pre-contrast and post-contrast average T1 value of LGE positive patients were (1 322.2 ± 85.8) and (459.7 ± 132.2)ms respectively;pre-contrast and post-contrast average T1 value of LGE negative patients were (1 267.0 ± 68.5) ms and (521.0±95.2)ms, there were statistical significant differences of T1 value between LGE positive and LGE negative patients (P<0.01), however, there were no statistical significant differences of T1 value between LGE negative patients and controls (P>0.05). There were correlation between pre-/post-contrast left ventricle T1 value and ejection fraction (EF) in cardiomyopathy patients (r=-0.252,-0.217, P<0.01), however no statistical correlation with other cardiac function parameters (P>0.05). Conclusions The average pre-/post-contrast T1 value in left ventricle myocardium are helpful for detection of diffuse fibrosis in cardiomyopathy patients. The LGE positive is a sign that can greatly change the T1 value of the myocardial tissue, meanwhile, myocardial fibrosis is negative correlated with ejection fraction in cardiomyopathy patients.

Objective To compare the curative effect of internal fixation treatment between reconstruction-type intramedullary nailing and long anatomic proximal femoral locking plate for patients with ipsilateral femoral proximal and shaft fractures. Methods Twenty-six patients with ipsilateral femoral proximal and shaft fractures were selected, among whom 12 patients were treated with reconstruction-type intramedullary nailing internal fixation treatment (group A), and 14 patients were treated with long anatomic proximal femoral locking plate internal fixation treatment (group B). The fracture to operation time, operation time, intraoperative blood loss, fracture healing time and hip joint function according to Majeed function score were compared between 2 groups. Results The fracture to operation time, operation time, intraoperative blood loss, proximal femoral fracture healing time, femoral shaft fracture healing time and Majeed function score in group A were (6.65 ± 4.11) d, (131.08 ± 20.70) min, (470.83 ± 96.43) ml, (17.83 ± 2.70) weeks, (20.08 ± 3.97) weeks and (83.83 ± 8.13) scores, and those in group B were (7.13 ± 4.56) d, (141.86 ± 27.30) min, (553.57 ± 127.80) ml, (18.29 ± 5.12) weeks, (21.55 ± 4.19) weeks and (83.21 ± 9.58) scores, and there were no statistical differences (P>0.05). According to Majeed function score, in group A excellent was in 7 cases, good in 4 cases, and general in 1 case; in group B excellent was in 9 cases, good in 3 cases, and general in 2 cases. Conclusions A fixation device fixes two fracture is preferred. Both treatment methods used in the present study could achieve satisfactory curative effect, and should be chosen according to the fracture type of the patients and the surgeon′s familiarity for the methods of internal fixation chosen. The proximal femoral fracture should preferably be reduced and stabilized first. A delay of 5 - 6 d would not affect the ultimate curative effect.