Preliminary application of three-dimensional printing in congenital uterine anomalies based on three-dimensional transvaginal ultrasonographic data.

BACKGROUND: The three-dimensional (3D) printing technology has remarkable potential as an auxiliary tool for representing anatomical structures, facilitating diagnosis and therapy, and enhancing training and teaching in the medical field. As the most available diagnostic tool and it is routinely used as the first approach in diagnosis of the uterine anomalies, 3D transvaginal ultrasonography (3D-TVS) has been proposed as non-invasive "gold standard" approach for these malformations due to high diagnostic accuracy. Despite holding promise of manufacturing 3D printed models based on 3D-TVS data, relevant reports about 3D-TVS derived gynecological 3D printing haven't been reported to the best of our knowledge. We found an opportunity to explore the feasibility of building 3D printed models for the abnormal uterus based on the data acquired by 3D-TVS. METHODS: The women suspected with congenital uterine anomalies (CUAs) were enrolled in the study. The diagnose of CUAs were made by 3D-TVS scanning and further confirmed under the hysteroscopy examination. One volunteer with normal uterus was enrolled as control. All subjects underwent 3D-TVS scanning for 3D printing data collection. Acquired images were stored and extracted as DICOM files, then processed by professional software to portray and model the boundary of the uterine inner and outer walls separately. After the computer 3D models were constructed, the data were saved and output as STL files for further surface restoration and smoothing. The colors of endometrium and uterine body were specified, respectively, in the print preview mode. Then the uncured photosensitive resin was cleaned and polished to obtain a smooth and transparent solid model after printed models were cooled down. RESULTS: 3D printing models of normal uterus, incomplete septate uterus, complete septate uterus, uterus didelphys and unicornuate uterus were produced on ultrasonographic data of 3D-TVS. CONCLUSIONS: Our research and practice made the first try in modeling CUAs successfully based on ultrasonographic data entirely, verifying that it's a feasible way to build 3D printed models of high-quality through 3D-TVS scanning.

SUCCESSFUL RESOLUTION OF NUTCRACKER SYNDROME WITH 3D PRINTED PEEK EXTRAVASCULAR STENT IN AN ADOLESCENT BOY.

Three-dimensional printed polyetheretherketone (PEEK) extravascular stent was applied to treat a 14-year-old boy with nutcracker syndrome. Digital subtraction angiography revealed a segment of the left renal vein (LRV) with reduced contrast filling immediately before its inflow into the inferior vena cava, and high-pressure gradient. The three-dimensional reconstruction model demonstrated that the LRV and the duodenum were contracted at the aortomesenteric angle, resulting in LRV compression from the abnormal high-level duodenal compartment. When duodenum courses between the abdominal aorta and superior mesenteric artery (duodenal interposition), the LRV entrapment occurs even at <90 aortomesenteric degrees. Three-dimensional printed PEEK extravascular stent was chosen to elevate the superior mesenteric artery and lower the duodenum position, thus relieving LRV compression. This extravascular application has significant advantages over open surgery, endovascular stenting and artificial vessel procedures with expanded polytetrafluoroethylene. It provides better cellular vitality by ensuring soft tissue proliferation. By reducing external acceleration and centrifugal force, a three-dimensional printed PEEK extravascular stent reduces adverse side effects. Such a stent has a distinctive personalized design, good stiffness, and durability that allows blood vessel growth, preventing stent migration and thrombosis. Therefore, it is suitable for both adult and pediatric patients. According to the abdominal ultrasound and multi-slice computed tomography scan, the postoperative follow-up results were satisfactory one year after surgery. The patient felt well, the blood flow in the LRV was not obstructed, and the blood flow velocity was average. The external stent was in place.

Aortic stiffness evaluated by echocardiography in female patients with Takayasu's arteritis.

OBJECTIVES: The aim of this study was to evaluate the aortic stiffness (AS) in young female patients with Takayasu's arteritis (TAK) and comparable controls by measuring carotid-femoral PWV (PWVcf) using echocardiography with pulse wave Doppler. The clinical feasibility and reproducibility of this echocardiographic method were also investigated. METHODS: Twenty-five TAK female patients (mean age 28.3±6.2 years) and 25 strictly matched healthy controls were included according to rigorous inclusion and exclusion criteria. The PWVcf of all subjects were measured by echocardiography based on the principle that PWVcf could be calculated by pulse wave spreading distance divided by the transmit time. Reproducibility of the echocardiographic measured PWVcf were performed randomly in 15 TAK patients and 15 healthy controls. RESULTS: The patients with TAK had a higher PWVcf value measured by echocardiography, compared with healthy controls (8.37±2.23 vs. 6.46±1.15 m/s; p<0.001). The echocardiographic measured PWVcf was significantly dependent on the TAK (p=0.003), age (p=0.032) and pulse pressure (p=0.025). PWVcf did not correlate with the echocardiographic measured cardiac systolic and diastolic parameters and the laboratory variables in TAK patients (p>0.05 for all). The intra- and inter-observer coefficients of variation were low and the Bland-Altman plots indicated a satisfactory reproducibility. CONCLUSIONS: Our results indicated that AS in female patients with TAK is increased, which may predict a higher cardiovascular risk. This manifestation is prior to the impairment of cardiac diastolic function. This elevated AS can be detected by echocardiographic measured PWVcf with a good reproducibility.

Evaluation of carotid artery elasticity changes in patients with type 2 diabetes.

BACKGROUND: Type 2 diabetes is one of the most common causes of cardiovascular disease as it causes arterial stiffness changes. The purpose of this study is to characterize, in vivo, carotid arterial structural and functional changes by applying radio frequency and X-strain ultrasound techniques. METHODS: Ninety-one subjects were assigned into two groups; a diabetes group and a control group. Structural and functional changes in the common carotid arterial wall were investigated by quality intima-media thickness (QIMT), quality arterial stiffness (QAS), and X-strain analysis with a Mylab Twice ultrasound instrument. The relationships among variables between the two groups were analyzed in this study. RESULTS: There was no significant difference in carotid IMT (626.5 ± 169.1 µm vs. 568.5 ± 122.6 µm, P = 0.1506) between two groups. Pulse wave velocity (PWV) and stiffness index (ß) were remarkably greater (8.388 ± 3.254 m/s vs. 7.269 ± 1.332 m/s; 12.51 ± 14.16 vs.9.279 ± 2.871), while compliance coefficient (CC) decreased significantly in the diabetes group (0.802 ± 0.3094 mm2/Kpa vs. 0.968 ± 0.3992 mm2/Kpa) (P < 0.05). The displacement difference of radial (RD-D), longitudinal (LD-D) and rotation (ROT-D) directions were significantly different between two groups' comparison (P = 0.0212, P = 0.0235 and P = 0.0072, respectively). The time of circumferential peak strain difference (CS-DT) and the time of radial peak strain rate (RSR-T) were found to be significantly different between the two groups (341.9 ± 77.56 ms vs. 369.0 ± 78.26 ms, P = 0.0494; 142.7 ± 22.43 ms vs. 136.2 ± 30.70 ms, P = 0.0474). CS-TD and RSR-T were also found to be positively correlated with CC value (r = 0.3908, P < 0.005 and r = 0.3027, P = 0.0326, respectively). Finally, PWV was negatively correlated with CC with (r = -0.6177, P < 0.001). CONCLUSIONS: In type 2 diabetes, the functional changes in CCA can be identified using the methods presented in this article earlier than the structural changes. Arterial stiffness values provided by QAS and X-strain analysis can be used as indicators of CCA functional lesions in patients with type 2 diabetes.

Ultrasound study of carotid and cardiac remodeling and cardiac-arterial coupling in normal pregnancy and preeclampsia: a case control study.

BACKGROUND: Cardiovascular adaptions, such as cardiac and uterine spiral arterial remodeling, and aortic arterial stiffening during pregnancy have been extensively investigated, while the interactions between the elastic artery and the left ventricle are poorly understood. This study was to evaluate the cardiac-arterial coupling in both normal pregnancy and preeclampsia using ultrasound techniques. METHODS: Twenty-three preeclamptic women with no antihypertensive treatment prior to admission, and 40 age- (27.2 ± 3.0 y vs. 29.1 ± 5.7 y, p = 0.0805) and gestational week- (35.6 ± 3.4 wk vs. 34.8 ± 3.6 wk, p = 0.3573) matched normotensive pregnant women were included. All women signed informed consent. All were nulliparas, had singleton pregnancies, and had no other risk factors for arterial stiffening. Carotid and cardiac ultrasound was performed using a MylabTwice ultrasound unit (Esaote, Italy). Cardiac and carotid remodeling and their associations were analyzed. Left ventriculo-carotid coupling was characterized by the ratio between the arterial elastance (Ea) and the left ventricular systolic elastance (Ees). Follow-up study was performed 16-20 months after parturition. RESULTS: Left ventricular and carotid arterial remodeling was seen more frequently in preeclamptic women than in normal pregnant controls (96% vs. 40%, 82% vs. 48%, both p < 0.0001). The relative carotid arterial wall thickness showed no significant difference between the two groups. However, the carotid cross-sectional area, a surrogate for carotid arterial mass, was significantly greater in preeclampsia than that in normal controls (11.23 ± 0.17 mm2 vs. 8.58 ± 1.88 mm2, p < 0.00001). Carotid arterial stiffness and intima-media thickness correlated significantly with cardiac diastolic function parameters and blood pressures (p < 0.05). Both Ea and Ees were significantly greater in preeclampsia, compared with values in normal pregnant controls (Ea: 2.41 ± 0.57 mmHg/ml vs. 1.98 ± 0.46 mmHg/ml, p = 0.0005; Ees: 11.68 ± 9.51 m/s2 vs. 6.91 ± 6.13 m/s2, p = 0.002). However, there was no significant difference in the left ventriculo-carotid coupling index, Ea/Ees, between the two groups. Carotid remodeling persisted in both preeclamptic women and normal pregnant controls 16-20 months after parturition. CONCLUSIONS: Significant cardiac and carotid remodeling and similar left ventriculo-carotid coupling were observed in both preeclampsia and normal pregnancy. Carotid remodeling may persist postpartum. Further studies with larger populations are needed to confirm these findings.

Maternal carotid remodeling and increased carotid arterial stiffness in normal late-gestational pregnancy as assessed by radio-frequency ultrasound technique.

BACKGROUND: The adaption of elastic arteries to transient increase in hemodynamic load in normal pregnancy (NP) remains controversial. The purpose of this study was to investigate the NP carotid remodeling and regional arterial stiffness before and after parturition. METHODS: Fifty-one NP women and 30 age-matched non-pregnant women were included. All women underwent right common carotid artery (RCCA) measurements with MylabTwice ultrasound instrument (Esaote, Italy). Carotid intima-medial thickness (IMT), pulse wave velocity (PWV, m/s), distensibility coefficient (DC, 1/KPa), α, ß, augmentation index (AIx, %) and carotid arterial pressure were obtained by the newly developed ultrasound vascular wall tracking methods: automatic QAS (Quality Arterial Stiffness) and QIMT (Quality Intima-Medial Thickness) Follow up study was performed. RESULTS: Compared to the non-pregnant controls, the arterial pressures were significantly increased and RCCA diameter was significantly enlarged in late gestational NP women. Twenty months after parturition, carotid diameter, DC, AIx, PWV and arterial wall tension were significantly decreased and had no significant difference with those in non-pregnant controls. CONCLUSIONS: Carotid arterial remodeling and stiffening could be seen in the normal pregnant women, which seems to be a physiological adaption and could be recovered post partum. QIMT and QAS together could provide a comprehensive assessment of the maternal carotid arterial changes during pregnancy.

Multidirectional myocardial systolic function in hemodialysis patients with preserved left ventricular ejection fraction and different left ventricular geometry.

BACKGROUND: Multidirectional myocardial strain analysis can provide mechanistic insight into the ventricular systolic function and pathophysiology. The aim of this study was to assess the multidirectional systolic function of the left ventricle (LV) and its relationship to LV geometry in hemodialysis patients with preserved left ventricular ejection fraction (LVEF). METHODS: A total of 98 end-stage renal disease patients (age 46 ± 10 years, 60% men) with preserved LVEF (≥50%) on a maintenance hemodialysis program and 18 healthy volunteers were enrolled. The patients were divided into non-hypertrophic groups (classified as normal LV geometry and concentric remodeling) and hypertrophy groups (classified as eccentric and concentric hypertrophy) according to their LV geometries assessed from LV mass/height(2.7) and relative wall thickness in combination. Multidirectional strain analysis was performed by two-dimensional speckle tracking echocardiography. RESULTS: Myocardial systolic strain (longitudinal and circumferential) and stress-corrected midwall fraction shorting (sc-MWFS) were lower in the hypertrophy groups compared with non-hypertrophic groups. Longitudinal strain and strain rate were even lower in the concentric hypertrophy group than the eccentric hypertrophy group (-15.5 ± 2.2% versus -17.8 ± 2.6%, P = 0.001; -0.7 ± 0.2 versus -0.9 ± 0.2s(-1), P = 0.016). Impaired longitudinal strain correlated with higher LV mass index (LVMI), relative wall thickness, pre-dialysis systolic blood pressure (SBP), calcium-phosphate product and lower sc-MWFS (all P < 0.0001) and weakly correlated with higher interdialytic weight gain (P = 0.004). Using multivariate linear regression, the independent predictors of LV longitudinal strain were pre-dialysis SBP, LVMI, relative wall thickness and sc-MWFS. There were no differences in LVEF and myocardial function in radial direction among all groups. CONCLUSIONS: In hemodialysis patients with LV hypertrophy, myocardial function was impaired not only in longitudinal direction but also in circumferential direction despite preserved LVEF. Low longitudinal strain is related to LV hypertrophy, concentric geometry and pre-dialysis blood pressure.

Double-chambered left ventricle in echocardiography.

In this article, we describe a double-chambered left ventricle (LV) in a 37-year-old man. Its accessory chamber attached to the inferior and posterior wall of LV, and had normal systolic contraction without any regional wall motion abnormality. A double-chambered LV was suspected on echocardiography and confirmed by cardiac computed tomography scanning and cardiac magnet resonance imaging. Our aim is to accentuate the value of echocardiography in this rare anomaly

Value of the echocardiographic suprasternal view for diagnosis of patent ductus arteriosus subtypes.

OBJECTIVES: The purpose of this study was to explore the value of the transthoracic echocardiographic suprasternal view in the diagnosis of patent ductus arteriosus subtypes. METHODS: Sixty-five patients with a patent ductus arteriosus were examined using transthoracic echocardiographic suprasternal and parasternal views before ductus arteriosus closure. Diameters of the aortic and pulmonary sides of the ductus arteriosus were measured, and subtype diagnoses were made. The results were compared with those from digital subtraction angiography. RESULTS: The mean diameters ± SD of the aortic side of the ductus arteriosus were 8.31 ± 2.76, 10.87 ± 3.26, and 11.15 ± 3.29 for the parasternal view, the suprasternal view, and digital subtraction angiography, respectively, whereas the diameters of the pulmonary side were 5.69 ± 2.82, 5.75 ± 2.63, and 6.09 ± 2.78 mm. Of the 65 cases, 12, 19, and 19 were the funnel-type patent ductus arteriosus as evaluated with the parasternal view, the suprasternal view, and digital subtraction angiography. Detection on the parasternal view was lower than that on the suprasternal view (χ(2) = 5.14; P < .025). CONCLUSIONS: The diameter of the aortic side of a patent ductus arteriosus can be accurately detected on the superasternal view, which would be helpful for diagnosis of patent ductus arteriosus subtypes.

3D printing technique applied in vaginoplasty: A case report.

Background: We present the first case report of the treatment of congenital vaginal atresia by 3D-printed patient-specific vaginal scaffold from China. Case presentation: A 17-year-old female patient was referred to our department for treatment of congenital vaginal atresia and complications arising from previous failed operations. Pelvic examination was conducted to understand the morphological characteristics and severity of stenosis, and based on which we designed our prototypes of vaginal scaffold using software UG NX10.0. We finally obtained our patient-specific mold, which was 50 mm in length, 28 mm in diameter, 2 mm of thickness with a whole weight of 7.6 g, and it was made of polycaprolactone. After removing scar tissues caused by vaginal stenosis, an 8 cm long artificial tunnel was created, and then the polycaprolactone (PCL) vaginal mold was placed and sutured. The patient had no discomfort after surgery and was discharged 3 days after the surgery. Follow-up for 1 year after surgery, through hysteroscopy and colposcopy, it was found that the cervix was smooth, the vaginal wall was covered with stratified squamous epithelium, and the vaginal wall was soft and lubricated, which was close to a normal vagina. The incompletely absorbed mold was taken out one year after the operation. Hysteroscopy and colposcopy were performed one year and two years after the mold was taken out. The vagina was unobstructed and the length was about 12 cm. The appearance of the vaginal wrinkles was normal. The patient's quality of sexual life was good. Conclusion: Our team tried to treat congenital vaginal atresia by 3D-printed patient-specific vaginal scaffold, which can effectively reduce patient complications and reduce patient pain. Through long-term follow-up, we found that this technique has achieved favorable results and improved the patient's quality of sexual life.

Effects of cold pressor-induced sympathetic stimulation on the mechanical properties of common carotid and femoral arteries in healthy males.

Our aim was to evaluate the effects of sympathetic excitation and elevation of blood pressure on mechanical properties of common carotid and femoral arteries by wave intensity analysis (WIA). The diameters and arterial stiffness parameters of right common carotid artery (RCCA) and right common femoral artery (RCFA) in healthy young men were measured by WIA at baseline and during cold pressor test (CPT). In addition, the blood pressure and heart rate were recorded simultaneously. The heart rates and blood pressures increased during CPT compared with baseline, while the pulse pressures remained unchanged. The diameters of RCCA increased slightly, while those of RCFA did not change. The Peterson's pressure modulus (Ep), augment index (AI), and pulse wave velocity from ß (PWVß) increased obviously, while arterial compliance (AC) decreased with no change in stiffness index (ß) of both arteries during CPT when compared with baseline. There was an obvious increase in pulse wave velocity from wave intensity (PWV_WI) of RCCA, while the PWV_WI of RCFA showed no significant change during CPT. The sympathetic nervous system exerts a more marked tonic restraint on RCFA than on RCCA. The Ep, AC, AI, PWVß of RCCA, and RCFA are much affected by variations in blood pressure and sympathetic status, while the ß of both arteries are less vulnerable to these factors and are more reliable in reflecting the actual arterial stiffness; The PWV_WI appears to be suitable only for evaluating the stiffness of RCCA instead of RCFA.

Evaluation of transcranial color-coded duplex sonography for cerebral artery stenosis or occlusion.

BACKGROUND AND PURPOSE: Cerebral artery stenosis or occlusion is the most common etiological factor in patients with acute cerebral ischemia, but the rate of early diagnosis is low. The purpose of the study is to evaluate the diagnostic accuracy of transcranial color-coded sonography (TCCS) for cerebral artery stenosis with digital subtraction angiography used as the gold standard of reference. METHODS: Seventy-eight patients who were suspected of cerebrovascular disease were involved in the study. Major cerebral arteries were observed through the transcranial echo window by TCCS. The course, shape of the color blood beam and velocity were given special attention. The hemodynamic parameter was measured and analyzed. The findings of TCCS were compared with the results of digital subtraction angiography, according to a double-blind design. A 4-fold table was used as the statistical analysis method to evaluate TCCS. The indexes included sensitivity, specificity, accuracy and false-positive rate. RESULTS: Imaging of TCCS revealed that the blood flow beam narrowed where the artery had stenosis and looked like girdling. The velocity of the foci increased abnormally, while the velocity before and after the foci decreased. Severe stenosis and the long stenotic segment may show discontinuity of the blood flow beam. The velocity of the foci did not noticeably increase or decrease. The blood flow beam of the occlusive artery cannot be seen and the frequency spectrum cannot be obtained, but the other artery was well visualized at the same time. Analysis of the diagnostic value of TCCS according to the 4-fold table included the validity index, with a sensitivity, specificity, false-positive rate, false-negative rate, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio and Youden index of 72.9%, 82.9%, 17.1%, 27.0%, 78.2%, 79.4%, 77.3%, 4.3, 0.3 and 0.56, respectively. The reliability index included the agreement rate and kappa value, which were 78.2% and 0.56, respectively. CONCLUSIONS: TCCS could be considered a valuable method for the screening diagnosis of cerebral artery stenosis or occlusion.

Effects of respiration on pulmonary venous flow and its clinical applications by Doppler echocardiography.

OBJECTIVES: This study was aimed to explore respiratory variations of pulmonary venous flow and its clinical applications and the potential mechanism. METHODS: Pulsed-wave Doppler waveforms of right-upper pulmonary vein were recorded with Siemens Sequoia 512 in 20 healthy young subjects. Electrocardiogram and respiratory tracing were recorded simultaneously. The inspiratory and expiratory pulmonary venous peak flow velocities of S- and D-waves and their velocity-time integrals (VTIs) were acquired and averaged for five consecutive respiratory cycles, respectively. The ratios of velocities and the VTIs of S- to D-waves (S/D, VTIs/VTId) during inspiration and expiration were calculated. RESULTS: The velocity and VTI of S-wave did not vary significantly between inspiration and expiration (58.31 cm/sec +/- 9.22 cm/sec, 58.96 cm/sec +/- 7.79 cm/sec, P = 0.221; 16.29 cm +/- 2.59 cm, 16.54 cm +/- 2.18 cm, P = 0.090), while the velocity and VTI of D-wave increased significantly from inspiration to expiration (48.23 cm/sec +/- 8.32 cm/sec, 51.82 cm/sec +/- 8.72 cm/sec, P < 0.0001; 10.84 cm +/- 1.65 cm, 11.66 cm +/- 1.53 cm, P < 0.0001), resulting in significantly decreased ratios of the velocity and the VTI of S- to D-waves from inspiration to expiration (1.23 +/- 0.22, 1.17 +/- 0.27, P < 0.0001; 1.53 +/- 0.31, 1.43 +/- 0.22, P < 0.0001). CONCLUSIONS: Respiration has significant influence on pulmonary venous flow, which should be taken into account in evaluating left ventricular diastolic function when adopting pulmonary venous flow waveform, especially in diseased settings. The different anatomical positions of left and right heart relative to the thoracic cavity may account for the respiratory variations of pulmonary venous flow.

A minimally invasive alternative for the treatment of nutcracker syndrome using individualized three-dimensional printed extravascular titanium stents.

BACKGROUND: This study was designed to evaluate the clinical and radiographic outcomes of patients with nutcracker syndrome (NCS) who were treated with three-dimensional printing (3DP) extravascular titanium stents (EVTSs). The 3DP EVTS was expected to release the hypertension of the left renal vein (LRV) produced by its compression between the superior mesenteric artery (SMA) and the aorta without causing any complications. METHOD: The pre-operative kidney model of each patient was printed out to enable surgical planning. After that, the EVTS was designed based on the LRV's primitive physiologic structure using computer-aided design software, and each stent was printed out with a precision setting of 20 µm. Seventeen patients who had been suffering from NCS underwent laparoscopic 3DP EVTS placement. The surgical procedure was designed for the placement of EVTS, taking great care in positioning and fixing the stent. Surgical data, which included patient demographic characteristics as well as pre- and post-operative test results, were collected and analyzed. RESULTS: The mean duration of surgery was 75 ±â€Š9 min, and the mean blood loss was 20 ±â€Š5 mL. Computed tomography examinations revealed that the pre- and post-operative angle between the SMA and the aorta ranged from 18.7°â€Š±â€Š4.3° to 48.0°â€Š±â€Š8.8° (P < 0.05); in patients with left varicocele, the mean diameter of the left spermatic vein ranged from 3.7 ±â€Š0.5 to 1.3 ±â€Š0.2 mm (P < 0.05). Moreover, Doppler ultrasound examinations showed that the peak velocity of blood flow at the hilar area ranged from 12.4 ±â€Š3.3 to 18.5 ±â€Š3.4 cm/s (P < 0.05). No side effects were observed in the 24 to 42 months following surgery. CONCLUSION: The findings after 2 years of follow-up suggest that the 3DP EVTS is a safe and effective minimally invasive alternative for the treatment of NCS.

Carotid and transcranial color-coded duplex ultrasonography for the diagnosis of dural arteriovenous fistulas.

BACKGROUND AND PURPOSE: Dural arteriovenous fistulas (DAVF) can affect a variety of cerebral venous structures and can present at various clinical stages. This study was designed to introduce the characteristic manifestation of DAVF detected with both carotid and transcranial color-coded duplex ultrasonography (CDUS) and to evaluate the diagnostic value of CDUS in DAVF. METHODS: Nineteen patients with DAVF confirmed by cerebral angiography were studied with CDUS. The sonogram and spectrum of the affected area were observed. Hemodynamic parameters such as peak systolic velocity, end-diastolic velocity, mean velocity and resistance index (RI) were measured and recorded in the feeding artery, draining vein and extracranial artery. All results were compared with cerebral angiography. Fifty healthy volunteers were enrolled as a control group. Related hemodynamic changes were compared between the patients and normal controls. RESULTS: The blood flow of fistulas presented as an irregular mosaic color bolus with a clear boundary detected with CDUS. Blood flow imaging of fistulas was abnormal in 12 cases and absent in 7 cases. The detection rate was 63% (12/19). Fifty-three main feeding arteries (73.6%) were detected by ultrasonography. All the venous drainages through the transverse sinus and superior ophthalmic vein were detected, while the ones through the superior sagittal sinus and cortical vein were not. There was a significant difference in average diameter, flow velocity and RI of the occipital artery and superficial temporal artery between the patients and normal controls (p < 0.05). CONCLUSIONS: CDUS could indicate DAVF by analyzing both imaging results of the diseased region and hemodynamic changes of the relative vasculature. It is a promising technique for the diagnosis and follow-up study of DAVF.

A rabbit model with acute thrombo-embolic pulmonary hypertension created with echocardiography guidance.

A rabbit model of acute thrombo-embolic pulmonary hypertension was developed by infusing self-thrombi into the right femoral vein and simultaneously measuring the pulmonary artery pressure via a right heart catheter and echocardiography. The model was used to explore the usefulness of an ultrasound-guided protocol. In the present study, acute thrombo-embolic pulmonary hypertension was produced in 25 of 30 healthy New Zealand rabbits; the success rate was 83%. A significant and positive correlation between the right ventricle-right atrial pressure gradient, an estimate of the pulmonary artery systolic pressure derived from tricuspid regurgitation and the pulmonary artery systolic pressure measured using the right heart catheter (r=0.765, P=0.002) was noted. During the process of establishing a rabbit model of acute thrombo-embolic pulmonary hypertension, it was demonstrated that echocardiography can be used to guide the right heart catheter to obtain pulmonary artery systolic pressure measurements, to quantify the tricuspid regurgitation jet to assess the pulmonary artery systolic pressure and to observe cardiac morphologic changes so as to evaluate cardiac function. Based on the present study, it is clear that echocardiography is valuable in improving the success rate of producing the animal model of acute thrombo-embolic pulmonary hypertension. This could ultimately facilitate preclinical research and clinical research in humans.

Superior vena cava Doppler flow changes in rabbits with acute thromboembolic pulmonary hypertension.

OBJECTIVE: The purpose of this study was to explore the superior vena cava (SVC) Doppler flow changes in rabbits with acute thromboembolic pulmonary hypertension (ATEPAH) and its value in evaluating pulmonary pressure. METHODS: The systolic peak flow velocity (SPV), ventricular reverse peak flow velocity (VrPV), diastolic peak flow velocity (DPV), and atrial reverse peak flow velocity (ArPV) of the SVC were measured on end expiration with pulsed wave Doppler echocardiography in 30 rabbits with different degrees of ATEPAH. Linear regression and the Bland-Altman method were used to analyze the correlation of Doppler flow velocities of the SVC to the catheter-measured pulmonary arterial systolic pressure (PASP). RESULTS: The SPV values of all groups were significantly lower after pulmonary embolism (PE) than before PE (P < .05). The VrPV values of the mild and the moderate groups but not the severe group were significantly higher after PE than before PE. The DPV values of the severe ATEPAH group were significantly lower after PE than before PE, but they were not lower in the other 2 groups. The SPV had a significantly negative relationship with the PASP (r = -0.692; P < .0001). The VrPV/SPV ratios of all groups showed a significant positive correlation with the PASP (r = 0.698; P < .0001). The end-diastolic diameter of the SVC gradually enlarged with the rapidly increased PASP and showed a significantly positive relationship in all groups (r = 0.594; P = .002). CONCLUSIONS: Analysis of the Doppler flow SPV and VrPV, the VrPV/SPV ratio, and the diameter of the SVC might provide an alternative method for catheterization in estimating pulmonary pressure.

Grey scale enhancement by a new self-made contrast agent in early cirrhotic stage of rabbit liver.

BACKGROUND: The development of new ultrasound contrast agents (UCAs) has become one of the most promising fields in ultrasound medicine. This paper evaluates a new self-made contrast agent enhancement effect developed to study the fibrotic stages of the liver in perfusion models in vivo. METHODS: We constructed experimental models of hepatic fibrosis involving five stages from F0 to F4 via administration of CCL4 (0.01 ml/kg BW) every 3 days for 3 months. The intrahepatic circulatory time of the contrast agent was analyzed via an image and Cine-loop display. Calculations of the perfusion-related parameters including the peak signal intensity (PSI) and peak signal intensity time (PIT) of the portal vein and parenchyma were obtained from an analysis of the time-acoustic intensity curve. RESULTS: Hepatic artery to vein transmit time (HA-HVTT) was significantly shorter at F4 stage (mean 5.1 seconds) compared with those in other stages (mean 8.3 s, 7.5 s, 6.9 s, 6.6 s, P < 0.01). The average PSI difference of PV-parenchyma was 13.62 dB in F4 stage, demonstrating significant differences between F4 stage and other early stages (P < 0.001). CONCLUSION: These results indicate that the new self-made contrast agent is capable of indicating intrahepatic hemodynamic changes. HA-HVTT and the PSI difference of the microbubble perfusion in liver parenchyma and PV were considered to differentiate the degree of hepatic fibrosis between F4 and other early stages.

Establishment of a rabbit model of superior vena cava obstruction.

OBJECTIVE: To explore a method of establishing a rabbit model of superior vena cava obstruction (SVCO) by injecting VX2 tumor cell suspension transcutaneously under ultrasound guidance. METHODS: A suspension of VX2 tumor cells was prepared under sterile conditions. Fifteen adult healthy New Zealand White rabbits were enrolled in the experiment. Under ultrasound guidance, about 0.1 ml of the living tumor cell suspension was transcutaneously injected in front of the anterior wall of the right superior vena cava (SVC). The lumen, wall, blood flow of SVCs and adjacent tissues were examined with gray-scale and color Doppler ultrasonography, every 3 days starting from the 9th day after injection. Meanwhile, CT scanning and digital subtraction angiography (DSA) were also performed. The rabbits were dissected immediately after death and tissue samples were collected for pathologic examination. RESULTS: Fourteen out of 15 rabbits developed tumors that were located close to SVCs and/or SVCs cavity, which was shown by ultrasonography. The diameters of the tumors were 80.7 +/- 4.3 mm. These tumors grew close to SVCs area and resulted in compression and infiltration of SVCs. CT scanning and DSA confirmed the establishment of the SVCO model. The achievement rate of the SVCO model was 93.3%. No rabbit died of complications. CONCLUSION: A method of establishing a rabbit SVCO model by injecting VX2 tumor cell suspension under ultrasonographic guidance was established successfully, and it proved to be simple, effective and repeatable. The imaging characteristics of this model are in good accordance with those of SVCO in patients.