MR pharmacokinetic modeling of the patellar cartilage differentiates normal from pathological conditions

PURPOSE: To study the pharmacokinetic parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of the patellar cartilage under normal and pathological conditions. MATERIALS AND METHODS: DCE-MRI was obtained in 22 cases. There were 17 patients with degenerative patellar conditions (eight with chondromalacia and nine with osteoarthritis) and five normal subjects. The cartilage pharmacokinetic parameters of K(trans) (vascular permeability), k(ep) (extraction ratio), upsilon(e) (extravascular extracellular space [EES] volume fraction), and upsilon(p) (intravascular space volume fraction) were extracted. RESULTS: Statistically significant differences were observed between the different groups (normal cartilage, chondromalacia and osteoarthritis) for K(trans) and upsilon(e). K(trans) values were (mean +/- SD) 1.06 +/- 0.62, 11.97 +/- 8.91, and 21.21 +/- 16.03 mL x minute(-1) x 100 mL(-1) (P < 0.02), respectively; and upsilon(e) values were 0.71 +/- 0.69, 3.59 +/- 2.21, and 10.51 +/- 8.20% (P < 0.002). Reproducibility of the pharmacokinetic calculations was assessed with a second set of analyses of 10 random cases one week after the first analysis, showing a test-retest root mean square (RMS) coefficient of variation of 9.78% for K(trans) and 14.72% for upsilon(e). CONCLUSION: The vascular permeability and EES fraction of cartilage increases with the severity of the degeneration. Pharmacokinetic models allow to study the vascular properties of the cartilage and may have applications as a surrogate index in longitudinal studies to quantify the evolution of drug trials.     

MR angiography of the pedal arteries with gadobenate dimeglumine, a contrast agent with increased relaxivity, and comparison with selective intraarterial DSA

PURPOSE: To compare gadobenate dimeglumine (Gd-BOPTA)-enhanced MR angiography (i.e., contrast-enhanced MRA [CE-MRA]) of the pedal vasculature with selective digital subtraction angiography (DSA) in patients with peripheral arterial occlusive disease (PAOD). MATERIALS AND METHODS: A total of 22 patients with PAOD were prospectively examined at 1.5T. For contrast enhancement, 0.1 mmol/kg body weight of Gd-BOPTA were applied. MRA consisted of dynamic imaging with acquisition of six consecutive data sets. Acquisition time for each data set was 24 seconds, voxel size was 1.0 x 1.0 x 1.3 mm(3). A total of 20 out of 22 patient underwent selective DSA, two patients fine-needle DSA. DSA and MRA were performed within seven days. Image analysis was independently done by two observers with assessment of overall image quality, motion artifacts, detection of patent vessel segments of the distal calf and pedal vessels, and the number of patent metatarsal arteries. After four weeks, a consensus reading of DSA images was done. A second consensus reading of CE-MRA was performed after a further six weeks. RESULTS: Consensus readings of MRA and DSA revealed higher image quality and fewer motion artifacts for MRA (P = 0.021 and P = 0.008, respectively, sign test); interobserver agreement was good (kappa = 0.78) for image quality, and moderate (kappa = 0.46) for motion artifacts. There were no differences between CE-MRA and DSA in detecting patent vessel segments with a high degree of agreement (kappa = 0.89), and interobserver agreement for MRA was substantial (kappa = 0.89). Significantly more vessels were assessed as partially occluded on DSA than on CE-MRA (P = 0.004). There was a good agreement between DSA and CE-MRA for assessment of relevant vessel stenosis (kappa = 0.61); interobserver agreement for MRA was good (kappa = 0.65). CE-MRA detected significantly more patent metatarsal arteries than did DSA (P < 0.001). CONCLUSION: Gd-BOPTA-enhanced MRA is comparable to DSA for assessment of the pedal vasculature, and is able to delineate significantly more patent vessels without segmental occlusions and more metatarsal arteries than selective DSA.     

两种子宫输卵管造影方法发生对比剂逆流的比较

目的:探讨子宫输卵管造影(HSG)检查使用宫颈塞法和双腔球囊导管法发生逆流的差别。方法:我院HSG检查457例,其中宫颈塞法210例,占46%,双腔球囊导管法247例,占54%。结果:两种方法发生逆流的比率为11.4%和18.2%,组间差异有显著性意义(P<0.05)。两种造影方法中逆流的类型比较,淋巴逆流、静脉逆流、混合逆流发生比率为25.0%、20.8%、54.2%和26.7%、20.0%、53.3%,组间差异无显著性意义(P>0.05)。结论:两种方法发生逆流的比率有显著性差异,发生的类型比率无明显差异,双腔球囊导管法操作方法不恰当会增加发生逆流的机会。     

3D CE MRA对诊断下肢血管病变的应用

目的探讨三维对比增强磁共振血管成像（3DCEMRA）对下肢血管病变诊断的应用价值。方法搜集25例临床怀疑或诊断下肢血管疾病的患者行3DCEMRA检查，并对其影像表现进行分析。结果25例中22例诊断为动脉硬化闭塞症，下肢动脉可见不同程度的狭窄及闭塞，其中11例经手术或DSA证实，另有静脉曲张1例，正常表现为2例。结论3DCEMRA对下肢血管病变的显示具有独特的优势，是一种无创伤性、安全的、准确性高的检查方法，甚至是首选的方法。     

Intraoperative ultrasound for the colorectal surgeon: current trends and barriers

Up to two thirds of patients diagnosed with colorectal cancer (CRC) develop colorectal liver metastases (CRLMs) and one quarter of patients present with synchronous metastases. Early detection of CRLM widens the scope of potential treatment. Surgery for CRLM offers the best chance of a cure. Current preoperative staging of CRC relies on computerized tomography and magnetic resonance imaging. Intraoperative ultrasound (IOUS) scans and contrast‐enhanced IOUS (CE‐IOUS) have been demonstrated to detect additional metastases not seen on routine preoperative imaging. IOUS is not widely used by colorectal surgeons during primary resection for CRC. Confident use of IOUS/CE‐IOUS during primary resection of CRC may improve decision‐making by providing the most sensitive form of liver staging even when compared with magnetic resonance imaging. This may be particularly important in the era of laparoscopic resections, where the colorectal surgeon loses the opportunity to palpate the liver. There are several implied barriers to the routine use of IOUS/CE‐IOUS by colorectal surgeons. These include time pressure, familiarity with techniques, a perceived learning curve, cost implications and limitation of the modality due to operator variations. Inclusion of IOUS in the training of colorectal surgeons and further investigation of potential benefits of IOUS/CE‐IOUS could potentially reduce these barriers, enabling usage during primary resection for CRC to become more widespread.     

多期动态CT增强扫描平台型强化方案对孤立性肺结节的诊断效能

目的探讨多期动态CT增强扫描平台型强化方案对孤立性肺结节(SPN)的诊断效能。方法选取80例肺内SPN病例作为实验组,行CT平扫及平台型强化方案多期动态CT增强扫描,绘制时间-密度曲线(TDC),观察曲线形态及对比剂到达峰值时间(TTP)。随机选取同期SPN病例80例作为对照组,行常规增强扫描。对两组的CT影像诊断符合率进行比较。结果实验组中肺癌52例,炎性结节12例,肺结核16例,三者间平扫、增强后各时间点CT值及最大净增值差异均有统计学意义(P均0.05),两两比较,差异亦有统计学意义(P均0.05)。肺癌52例、炎性结节10例及1例肺结核TDC曲线呈台阶型,2例炎性结节呈双峰型,15例肺结核为平坦型,三者TDC类型的差异有统计学意义(χ~2=85.026,P0.001)。以增强扫描CT最大净增值20HU且60 HU为恶性SPN诊断阈值,实验组CT诊断敏感度为94.23%(49/52),特异度为89.29%(25/28),符合率为92.50%(74/80)。实验组64s的CT诊断符合率为92.50%(74/80),分别与对照组30s(70/80,87.50%)、120s(71/80,88.75%)比较,差异均无统计学意义(P均0.05)。结论多期动态CT增强扫描平台型强化方案对SPN的诊断及鉴别诊断具有较高的应用价值。     

水溶性造影剂在粘连性小肠梗阻治疗中的价值

【摘要】 目的 探讨水溶性造影剂(泛影葡胺)在粘连性小肠梗阻治疗中的价值。方法〓明确诊断为小肠梗阻的患者,不合并肠穿孔、腹膜炎及绞窄性肠梗阻等需要急诊手术的情况。采用前瞻性研究方法,将入组的57例患者分为2组:对照组与治疗组。对照组给予常规治疗,如禁食、胃肠减压、灌肠、静脉补液等;治疗组除常规保守治疗方法外,患者口服或均经胃肠减压管注入76%泛影葡胺60~100 mL并夹管1小时,观察两组非手术治疗的有效率、小肠梗阻缓解时间、住院时间以及并发症的发生情况。结果〓应用泛影葡胺的治疗组非手术治疗的有效率明显高于对照组(83.3% VS 55.6%),差异有统计学意义;非手术治疗有效的两组患者中,治疗组患者在肠鸣音恢复时间9.56±3.47 h VS 19.67±3.90 h)、肛门排气时间(11.24±3.15 h VS 22.6±4.14 h)、每日胃肠减压量(179.20±68.79 mL VS 323.33±91.31 mL)、住院时间(5.0±1.83 d VS 8.20±2.15 d)均明显小于对照组,各指标间的比较均有显著性差异。两组均未出现严重并发症。结论〓泛影葡胺治疗小肠梗阻疗效确切,值得推广应用。     

适当低浓度对比剂在冠状动脉CTA成像中的应用价值

目的 探讨适当低浓度对比剂在冠状动脉CTA成像中的应用价值.方法 对136例拟行冠状动脉CTA检查的患者行前瞻性研究,按所用对比剂浓度不同分为三组,所用对比剂浓度分别为320 mgI/ml、350 mgI/ml、370 mgI/ml,将扫描所得原始数据进行后处理重组,然后对重组后的冠状动脉图像质量进行主观评价,并对主动脉起始部及同层面降部的CT值进行测量,对其结果分别进行统计学分析.结果 三组冠状动脉图像质量的主观评价差异无统计学意义(x2 =0.785,P=0.675).采用前瞻性心电门控扫描的三组患者主动脉起始部CT值的分析结果为:F值=0.992、P值=0.376;主动脉降部CT值的分析结果为:F值=1.527、P值=0.224,采用回顾性心电门控扫描的三组患者主动脉起始部CT值的分析结果为:F值=1.206、P值=0.307;主动脉降部CT值的分析结果为:F值=1.703、P值=0.191,各组CT值的差异无统计学意义.结论 适当低浓度对比剂(320 mgI/ml)能够满足冠状动脉CTA的诊断要求,在行冠状动脉CTA检查时推荐使用.