自身免疫性胰腺炎的CT和MRI的影像学表现

目的探讨自身免疫性胰腺炎CT和MRI的影像学特点,提高对自身免疫性胰腺炎的认识和影像学诊断水平。方法回顾性分析45例经激素治疗或手术病理证实的自身免疫性胰腺炎患者的CT和MRI影像学资料,观察胰腺及周围组织、胰管和胆管的影像学表现,总结自身免疫性胰腺炎CT和MRI的影像学特点。结果 45例自身免疫性胰腺炎患者中,男性32例,女性13例,其中37例患者表现为胰腺的弥漫性肿大,8例患者表现为胰腺局限性肿大,CT检查中有27例患者的胰腺病灶平扫密度减低;MRI检查中有16例患者胰腺病灶出现信号的改变,表现为T1WI上低信号,T2WI上稍高信号;45例患者胰腺病灶均表现为延迟强化方式改变。10例患者的CT和7例患者的MRI表现为胰管狭窄,2例患者的CT和1例的患者MRI表现为胆总管狭窄。14例患者的CT及MRI表现胰腺周围的"假包膜"征象。结论自身免疫性胰腺炎在CT和MRI上具有一定的影像学特点,结合实验室相关检查有助于该疾病的诊断。     

CT及MRI在肝脏局灶性结节增生中的诊断价值

目的评价螺旋CT和MRI在肝脏局灶性结节增生(focal nodular hyperplasia,FNH)中的临床诊断价值。方法收集18例(24灶)经手术切除或病理活检确诊为FNH的患者的CT、MRI资料并分析,13例行CT扫描,11例行MRI扫描,6例同时行CT及MRI扫描。结果 13例CT检查出15个病灶,平扫呈低密度12个、等密度3个,其中9个可见中央更低密度瘢痕;增强扫描动脉期所有病灶均明显强化,中央瘢痕组织无强化,病灶边界均显示清晰,无明显包膜;门脉期病灶密度较前降低,呈稍高密度或等密度;延迟期病灶以等密度为主,6个瘢痕组织出现强化。11例MRI检查出14个病灶,平扫T1WI呈等或稍低信号,T2WI呈稍高或等信号;11个见瘢痕组织,在T1WI呈低信号,T2WI呈明显高信号;增强扫描动脉期病灶均匀强化呈高信号,中央瘢痕呈低信号;门脉期及延迟期病灶强化下降呈稍高或等信号,瘢痕组织可见延迟强化。结论 CT及MRI能显示FNH的特征性改变,具有较高的敏感性、准确性,是临床诊断FNH的有效方法。     

胰腺血液系统恶性肿瘤的影像学表现

目的总结胰腺血液系统恶性肿瘤的CT、MRI及正电子发射计算机断层显像(PET)影像学表现,以提高对该类疾病的诊断能,方法检索关于胰腺血液系统恶性肿瘤的影像学研究卡相关文献,总结其影像·学表现。结果胰腺血液系统恶性肿瘤是一类较为少见的胰腺恶性肿瘤,主要包括胰腺淋巴瘤、多发性骨髓瘤、髓系肉瘤、移植后淋巴增生异常和巨大淋巴结增生症①胰腺淋巴瘤:其影像.学特点为胰腺部分或弥漫性均匀增大、包块直径5 cm、低于肾静脉平面的淋巴结肿大及无胰管扩张.淋巴结肿大造成胰腺边界模糊时提示淋巴瘤-②胰腺多发性骨髓瘤:在MRI平扫T1WI图像和T2WI图像上均表现为高信号。③胰腺粒细胞肉瘤:在CT图像上表现为均匀、低强化肿块,胰管扩张少见;在MRI平扫TIWI和T2WI图像上分别表现为等和稍高信号,均匀强化。④移植后淋巴增殖性疾病:常表现为直径5cm、无明强化的肿块,T2WI图像为稍高信号,PET图像上表现为极高代谢。⑤巨大淋巴结增生症主要表现为孤立性作侵袭性肿块,透明血管型可见点状钙化,周围有明显的供应血管:浆细胞型通常强化不明显钙化少见。结论胰腺血液系统恶性肿瘤在CT、MRI及PET图像上各有特点,熟悉其影像学特点打助于早期识別疾病并确定下一步诊疗耕措施     

胰腺腺泡细胞癌的CT及MRI影像学分析

目的 分析胰腺腺泡细胞癌（ACC）的CT和MRI特征,提高对该病影像学表现的认识。方法 回顾性分析2007年1月至2016年1月在我院经手术病理或穿刺活检证实的7例ACC患者的CT及MRI影像学资料,其中3例行CT平扫及增强扫描,4例行MRI平扫及增强扫描,观察其影像学表现。结果 男4例,女3例,平均年龄51岁;7例均为单发,病灶位于胰体尾部5例,胰头2例;最大直径约2~13 cm,平均直径5.2 cm,边界较清楚;CT平扫为略低密度,病灶内见不规则更低密度区,未见明显钙化。MRI扫描示病灶T1WI上为混杂稍低信号、T2WI上为混杂稍高信号。CT、MRI增强扫描均见瘤内实性成分动脉期轻度强化,门脉期呈渐进性强化,强化程度低于正常胰腺组织。7例中1例肝转移,1例侵犯临近脾脏,2例显示胰管侵犯并扩张,3例出现腹膜后淋巴结转移。结论 胰腺腺泡细胞癌CT、MRI表现具有一定特征性。     

CT与MRI检查对自身免疫性胰腺炎的诊断价值

目的 探讨CT与MRI检查对自身免疫性胰腺炎（AIP）的诊断价值。方法 回顾性分析2011年 6月至2013年12月期间眉山市中医医院收治的14例AIP患者的临床和影像学资料。结果 CT和MRI检查示AIP患者的胰腺弥漫性肿大呈腊肠状,T1WI示胰腺实质信号明显减低,扩散加权成像（DWI）示胰腺实质信号明显增高;增强扫描后动脉期胰腺实质强化幅度明显降低,延迟期呈持续性延迟强化伴包膜征,胆总管胰腺段呈鸟嘴样狭窄。结论 AIP的影像学表现具有一定的特征性,结合临床表现及实验室检查可早期诊断,对选择治疗方案具有重要意义。     

MRI-DWI鉴别诊断肿块型自身免疫性胰腺炎与胰腺导管腺癌

目的分析肿块型自身免疫性胰腺炎(AIP)和胰腺导管腺癌(PC)的影像学表现,探讨MRI-DWI在鉴别诊断二者方面的价值。方法收集2016年3月至2019年6月中山大学孙逸仙纪念医院经病理诊断的胰腺导管腺癌30例,达到临床诊断标准的肿块型自身免疫性胰腺炎15例,回顾性分析上述患者的影像学特征,在DWI上的表现及ADC值的区别。结果肿块型胰腺炎患者中,大部分病灶T2WI呈不均匀的高信号,T1WI表现为等信号和低信号,DWI为等或高信号,不均匀较明显强化。胰腺导管腺癌患者中,大多数病灶T2WI病灶呈稍高信号,T1WI呈低信号,少部分的病灶呈现混杂信号或者等信号,DWI为低信号为主,不均匀低强化为主。二者均可伴有主胰管的扩张,胰腺导管腺癌同时可伴有主胰管的中断。当b值=800 s/mm~2时,肿块型AIP的ADC平均值为(1.38±0.11)×10-3mm~2/s(平均值±标准差),胰腺导管腺癌的ADC平均值为(1.03±0.15)×10-3mm~2/s(平均值±标准差),P0.05,二者间差异有统计学意义。结论肿块型自身免疫性胰腺炎(AIP)和胰腺导管腺癌(PC)的影像学表现有差异,DWI序列及ADC值有助于鉴别诊断二者。     

自身免疫性胰腺炎的CT表现特征(附4例分析)

目的探讨自身免疫性胰腺炎(AIP)的CT表现特征。方法收集4例经临床、实验室检查和类固醇激素治疗有效的AIP患者的CT资料。CT检查包括平扫、双期(动脉期和门静脉期)增强扫描,在CT图像上观察胰腺的形态、大小、质地、强化程度、胰管、胰腺边缘、胰周及腹膜后各间隙等情况并分析AIP的CT表现特征。结果3例AIP表现为胰腺弥漫性肿大,1例为胰头的局限性肿大;病变区域胰腺实质在动脉期强化减弱但出现明显的延时强化;2例在胰腺病变区周围环绕包膜样结构;2例伴胆总管胰头段狭窄,1例ERCP显示胰管不规则狭窄;经类固醇激素治疗后,CT复查显示胰腺情况明显好转。结论AIP的CT表现具有一定的特征性。     

骨盆软骨肉瘤的影像学表现

[目的]探讨骨盆软骨肉瘤的影像学特点,提高影像诊断的准确性.[方法]回顾分析17例经病理证实骨盆软骨肉瘤的影像学资料,其中15例行DR(digital radiography)拍片,14例行CT检查,12例患者行MRI(magnetic resonance imaging)检查.[结果]15例DR检查中13例DR片清晰显示不规则骨质破坏,11例DR片清晰显示病灶内有大小不一钙化.14例CT表现骨质呈溶骨性或膨胀性破坏,周围不均匀密度软组织肿块,可见不规则钙化或骨化.12例MRI表现为骨质破坏,周围软组织肿块,边界不清;T1WI呈低信号,T2WI呈高、低混杂信号,脂肪抑制序列T2WI呈混杂高信号,增强扫描呈周边强化或分隔样强化.[结论]软骨肉瘤影像学特征表现为骨质不规则破坏,伴软组织肿块内钙化.DR、CT、MRI三者相结合有助于骨盆软骨肉瘤的诊断.     

自身免疫性胰腺炎的影像表现:7例报道及文献复习

目的:探计自身免疫性胰腺炎(AIP)在动态对比的增强CT(DCE-CT)和内镜逆行胰胆管造影(ERCP)中的影像学特点.方法:对7例AIP患者进行动态增强CT及ERCP检查,并采用超声(US)随访AIP类固醇治疗的效果.结果:治疗前ERCP检查,主胰管狭窄段和无病变胰管显示清楚;各例AIP均显示主胰管弥漫性、阶段性或多处局限性狭窄,狭窄段上游胰管轻中度扩张;4例合并胆总管下端狭窄或阻塞.DCE-CT,胰腺显示弥漫性或局限性肿胀,其中3例病灶边缘可见包膜样低密度表现.类固醇治疗后,胰腺肿胀减轻、胆管狭窄的改善.结论:AIP的形态学改变具有一定特征性,ERCP与DCE-CT相结合有助于AIP的诊断.     

骨梗死影像学表现与鉴别诊断

目的探讨骨梗死不同时期的影像学特点及其鉴别诊断,以提高对骨梗死的诊断水平。方法对15例骨梗死患者行X线、CT及MRI检查,将骨梗死分为早、中、晚三期,总结其影像学特征。结果 15例患者病变累及双侧者6例,单侧者9例;病变共累及23个部位。早期4例,X线未见明显异常或仅骨小梁模糊,MRI表现为病变区中央T_1WI呈等或稍低信号,T_2WI呈等或稍高信号,病变区边缘为蜿蜒迂曲的T_1WI低信号、T_2WI高信号带。中期7例,X线、CT表现为阴性和局部的斑片状钙化,MRI表现为病变中央T_1WI呈等或稍低信号,T_2WI呈等或稍高信号,病灶边缘清楚呈典型的地图样改变,在压脂T_2WI序列上可见明显的"双线征"。晚期4例,X线及CT表现为不规则、蜿蜒状骨质硬化,MRI T_1WI及T_2WI上均呈低信号。结论骨梗死各期有不同的影像学表现,MRI发现早、中期病变较X线和CT敏感,晚期X线、CT和MRI均具有特征性表现。MRI是骨梗死最好的检查手段。     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.