MRI在膝关节损伤诊断中的临床价值

目的　探讨MRI对于膝关节损伤的临床应用价值。方法　回顾性分析 56例膝关节损伤的MRI资料。结果　韧带损伤48例 ,MRI表现为扁平条带状低信号影增粗 ,边缘模糊或呈波浪状 ,T1 WI 呈低或高低混杂信号 ,T1 WI 呈高信号。半月板损伤 40例 ,表现为三角形低信号影内出现不同形状高信号灶。骨挫伤 1 8例 ,表现为T1 WI 呈低信号或高低混杂信号 ,T2 WI 呈高信号。软骨骨折 8例 ,表现为软骨断续或凹陷 ,软骨层内见短T1 长T2 信号。结论　MRI对于膝关节损伤的诊断具有重要的临床价植     

MRI在膝关节损伤诊断中的临床价值

目的：探讨MRI对于膝关节损伤的临床应用价值。方法。回顾性分析56例膝关节损伤的MRI资料。结果：韧带损伤48例，MRI表现为扁平条带状低信号影增粗，边缘模糊或呈波浪状，T1W1呈低或高低混杂信号，T1W1呈高信号。半月板损伤40例，表现为三角形低信号影内出现不同形状高信号灶。骨挫伤18例，表现为T1W1呈低信号或高低混杂信号，T2W1呈高信号。软骨骨折8例，表现为软骨断续或凹陷，软骨层内见短T1长T2信号。结论：MRI对于膝关节损伤的诊断具有重要的临床价值。     

膝关节外伤的磁共振成像诊断与评价

目的 探讨磁共振成像（MRI）在诊断膝关节外伤中的ll缶床应用价值。方法2003年6月．2005年6月，66例膝关节外伤患者经x线检查后进行MRI扫描，MRI扫描序列包括SE序列T1WI、FSE序列T2WI及STIR序列，按Schatzker骨折分类法分类，比较X线片与MRI诊断的结果，分析膝关节外伤的MRI表现。结果66例膝关节外伤患者中X线检查60例阳性（90．9％）。MRI检查65例阳性（98．5％）；其中合并半月板损伤57例，韧带损伤48例，关节软骨损伤58例，局部骨挫伤34例，关节囊积液或积血61例。结论MRI检查是诊断和评价膝关节外伤较全面的影像学方法。     

MRI在膝关节隐匿性骨折伴半月板及韧带损伤诊断价值

目的 分析磁共振成像（MIR）在膝关节隐匿性骨折（Concealed fracture of the knee joint,CF-KJ）伴半月板及韧带损伤（Ligament injury,LI）诊断中的应用价值。方法 选取2021年3月至2023年3月72例于本院接受治疗的疑似CF-KJ伴半月板及LI患者为研究对象，72例患者均进行多层螺旋CT (MSCT)、MRI检查，比较两种检查方法 CF-KJ伴半月板及LI的影像特征、诊断效能以及不同病变的检出率。结果 MSCT检查发现CF-KJ骨折处可见骨小梁变形，存在骨质连续性断裂或伴骨折线影等情况。MRI检查显示CF-KJ骨折处T1WI序列均表现为低信号，T2WI序列则可显示T1WI序列低信号区域的片状高信号区域，或者镶嵌的高信号区域，且相对应的关节面显示为高信号。以手术结果作为金标准，72例患者中65例患者确诊为CF-KJ伴半月板及LI，以此比较两种检查方法的诊断效能，结果显示，与MSCT检查比较，MRI检查的敏感度、准确率均明显升高（P<0.05）；但两种检查方法特异度比较差异不显著（P>0.05）。与MSCT检查比较，MR...     

MRI在急性膝关节损伤中的应用价值

目的探讨MRI在急性膝关节损伤时的临床应用价值。方法回顾性分析76例急性膝关节损伤的MRI资料。结果交叉韧带损伤38例,MRI表现为扁平条带状低信号影增粗,边缘模糊欠光滑,韧带内出现不均匀高信号。半月板损伤61例,表现为三角形低信号影内出现不同形状高信号灶。侧副韧带损伤38例,表现为韧带连续性中断,断端周围出现不均匀高信号影。关节内骨折25例,其中隐匿性骨折8例。MRI诊断半月板损伤的准确率80.9%;诊断交叉韧带损伤的准确率96.7%。结论MRI可以作为急性膝关节损伤的首选检查方法,其诊断价值高,可减少不必要的关节镜手术,有助于早期外科干预。     

膝关节色素沉着绒毛结节性滑膜炎的影像学诊断

目的 分析膝关节色素沉着绒毛结节性滑膜炎(PVNS)影像学表现，评价各种检查方法的优缺点，选择敏感的检查手段。方法 回顾性分析10例经手术病理证实的膝关节PVNS的MRI、X线平片和CT等影像资料，比较和评价PVNS的MRI信号特点，关节内结构侵犯、关节外侵犯和骨质侵蚀等征象。结果 10例膝关节PVNS，8例MRI具有典型的含铁血黄素沉着，T1WI和T2WI呈低信号。MRI可以准确显示X线平片及CT难以显示的关节内软骨和韧带侵蚀以及关节外侵犯的范围。结论 MRI在PVNS诊断中具有特征性的MRI信号及很高的诊断价值。可准确评价PVNS在关节内外的侵犯范围，对指导手术、减少复发率具有重要意义。     

MRI在基层医院膝关节外伤中的诊断价值

目的:探讨MRI在基层医院膝关节外伤中的诊断价值。方法:回顾性分析97例膝关节外伤患者的MRI表现。结果:半月板损伤74例,其中撕裂28例;韧带损伤78例,其中撕裂25例,以前交叉韧带和内侧副韧带损伤为主;骨挫伤76例;骨软骨骨折2例。同时发生半月板、韧带、和骨损伤3类中两者及以上的复合性损伤75例(77%)。关节积液及周围软组织损伤为伴随表现。结论:MRI能准确的显示膝关节外伤后的各种表现,是临床的首选检查方法,对临床治疗及预后评估有重要的指导作用。     

15例膝关节病变的MRI诊断

目的：探讨膝关节病变的MRI诊断及其临床应用价值。方法：对15例利用MRI诊断膝关节病变患者进行回顾性分析。结果：7例出现半月板异常信号，其中2例半月板水平状撕裂并囊肿；关节腔积液8例，有1例积血；韧带损伤1例；滑膜病变2例；神经鞘瘤囊变1例；骨髓水肿4例。结论：膝关节病变的MRI对显示膝关节软骨、韧带、关节囊等软组织有明显优越性，可作为膝关节病变术前诊断的首选方法。     

MRI对膝关节骨挫伤的诊断及临床意义

目的:探讨MRI对膝关节骨挫伤的诊断价值,提高临床医师对骨挫伤诊断及鉴别诊断的认识。方法:收集2008年5月至2009年12月经MRI检查确诊的膝关节骨挫伤47例进行回顾性分析,其中男30例,女17例;年龄12～69岁,平均34.5岁。47例外伤后局部均出现疼痛、压痛和(或)软组织肿胀及功能障碍,MRI检查时间自外伤后6h～30d,平均7d。单纯骨挫伤临床采用保守及对症治疗。结果:47例共显示82个病灶,其中股骨下端39个,胫骨上端(包括胫骨平台)35个,髌骨5个,腓骨上端3个。MRI表现为不规则斑片状或地图样T1WI低信号、T2WI等或略高信号,STIR脂肪抑制序列均呈明显高信号,其中伴半月板撕裂20例,侧副韧带损伤14例,前交叉韧带损伤8例。47例X线、CT检查未见骨折征象。经治疗后临床症状和体征均明显减轻或消失,29例获随访,时间1～12个月,MRI异常信号消失21例,异常信号减弱8例。结论:MRI能揭示膝部骨挫伤的病理改变,并准确判断关节周围韧带及软组织的损伤情况,常规MRI检查并行脂肪抑制序列是诊断外伤性骨挫伤最有价值的方法。     

外伤致膝关节损伤的MRI诊断

目的：探讨MRI对诊断外伤所致膝关节损伤的能力。方法：使用Picker公司1．5T超导MRI装置对50例膝关节进行检查。结果：将MRI所显示的半月板损伤分为三级，明确指出了各级信号特点；提出了韧带损伤的直接和间接征象；并将膝部骨质隐匿性病灶分为五型，其中I－Ⅲ型多见于急性损伤，Ⅳ-Ⅴ型多见于慢性损伤。结论：由于MRI的信号特点及其可进行多平面成像，MRI在显示半月板、韧带、关节软骨及滑膜方面明显优于X线平片，在显示骨质情况尤其是显示隐匿性病灶时，可作为X线性的必要补充。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.