CTA、CE-MRA、DUS对糖尿病下肢动脉病变的诊断价值对比研究

目的比较彩色多普勒超声(DUS)、三维动态增强磁共振血管成像(CE-MRA)、CT血管造影(CTA)对糖尿病下肢动脉病变的诊断价值。方法将本院115例诊断为糖尿病引起的下肢动脉病变(下肢动脉狭窄或闭塞病变)的患者作为观察对象,均行单侧或双侧的CTA、CE-MRA、DUS影像学检查,对其临床资料及影像学资料进行回顾性分析。115例患者中(149条下肢动脉),98条下肢动脉行DUS检查,63条下肢动脉行CE-MRI检查,85例下肢动脉行CTA检查。对血管分支进行分级,其中膝上动脉为1级,膝下动脉为2级,足背动脉为3级。将DSA检查为金标准,分别计算上述DUS、CE-MRA、CTA对评估糖尿病下肢动脉病变狭窄程度的诊断价值。结果 115例患者149条下肢动脉中,按照血管分支分级,其中1级:轻度狭窄79条,中度狭窄41例,重度狭窄或闭塞29条;2级:轻度狭窄51条,中度狭窄48例,重度狭窄或闭塞50条;3级:轻度狭窄98条,中度狭窄37例,重度狭窄或闭塞14条。在行DUS检查的下肢动脉病变中,1、2、3级动脉中度狭窄的灵敏度分别为91.18%、87.23%、78.57%,特异度分别为93.75%、96.08%、98.57%;3级动脉重度狭窄的灵敏度分别为75.00%、81.82%、55.56%,特异度分别为93.02%、90.91%、97.75%。在行CE-MRA检查的糖尿病下肢动脉病变中,CE-MRA诊断1、2、3级动脉中度狭窄的灵敏度分别为91.43%、98.04%、94.74%,特异度分别为89.29%、83.33%、84.00%;CE-MRA诊断1、2、3级动脉重度狭窄的灵敏度分别为90.91%、80.00%、50.00%,特异度分别为94.23%、94.74%、96.23%。在行CTA检查的糖尿病下肢动脉病变中,CTA诊断1、2、3级动脉中度狭窄的灵敏度分别为100.00%、97.56%、93.33%,特异度分别为98.31%、93.18%、95.71%;CTA诊断1、2、3级动脉重度狭窄的灵敏度分别为100.00%、94.12%、85.71%,特异度分别为97.30%、97.06%、98.72%。结论 DUS、CE-MRA、CTA在诊断糖尿病下肢动脉病变方面均具有较高的准确性,其中CTA对评估患者下肢动脉重度狭窄的诊断效能高于其它两种影像学方法。     

CTA、CE-MRA、DUS三种影像学方法对糖尿病下肢动脉病变的诊断价值对比

目的探讨彩色多普勒超声(DUS)、三维动态增强磁共振血管成像(CE-MRA)、CT血管造影(CTA)三种影像学方法对糖尿病下肢动脉病变的诊断价值。方法将本院115例诊断为糖尿病引起的下肢动脉病变(下肢动脉狭窄或闭塞病变)的患者作为研究对象,均行单侧或双侧的CTA、CE-MRA、DUS影像学检查。结果 115例患者149条下肢动脉中,按照血管分支分级,其中1级:轻度狭窄79条,中度狭窄41例,重度狭窄或闭塞29条;2级:轻度狭窄51条,中度狭窄48例,重度狭窄或闭塞50条;3级:轻度狭窄98条,中度狭窄37例,重度狭窄或闭塞14条。在98条行DUS检查的下肢动脉病变中,1、2、3级动脉中度狭窄的灵敏度分别为91.18%、87.23%、78.57%,特异度分别为93.75%、96.08%、98.57%;1、2、3级动脉重度狭窄的灵敏度分别为75.00%、81.82%、55.56%,特异度分别为93.02%、90.91%、97.75%。结论三种不同影像学方法(DUS、CE-MRA、CTA)在诊断糖尿病下肢动脉病变方面均具有较高的准确性,其中CTA对评估患者下肢动脉重度狭窄的诊断效能高于其它两种影像学方法。     

低剂量增强高场MR下肢动脉造影的初步模型实验及临床应用

目的 探讨高场MR下肢动脉增强造影(contrast-enhanced MRA,CE-MRA)使用较低剂量对比剂的可行性及临床应用价值.方法 应用3 T MR仪,测定对比剂Gd-DTPA浓度(0.5～6.0 mmol/L)与CE-MRA信号强度的关系.选定临床可能应用的浓度值(0.5、1.5、2.5、4.0 mmol/L),对人造血管狭窄模型进行CE-MRA扫描并与DSA相对比,依据管腔表现能力初步确定适合于临床应用的对比剂低剂量范围.之后选用较低剂量13 ml Gd-DTPA(相当于1.1～1.3 mmol/L血液浓度)对78例糖尿病患者下肢动脉进行了三段法CE-MRA扫描,对图像质量进行评价,并对小腿动脉狭窄诊断率及其静脉污染影响程度进行了Fisher's确切检验.将其中有DSA检查的22例按照不同动脉节段(共220节段)及狭窄程度(划分为4级)与DSA结果进行了Kappa一致性检验.结果 Gd-DTPA在0.5～6.0 mmol/L范围内,浓度与信号强度呈线性正相关,应用较低浓度(1.5 mmol/L)Gd-DTPA进行CE-MRA可获得血管模型狭窄信息.临床数据分析表明低剂量对比剂对于膝以上动脉成像可诊断率达97.4%(76/78),膝以下动脉造影质量受静脉污染显著影响,污染存在与否其诊断率分别为20.0%(31/155)及43.2%(67/155)(P＜0.01).22例患者以DSA为标准,CE-MRA诊断狭窄的敏感度及特异度分别为96.0%(168/175)及73.3%(33/45)(K=0.72,P＜0.01);但膝以下动脉诊断符合率(K值0.43～0.63)低于膝以上动脉(K值0.75～0.82).结论 低剂量13mlGd-DTPA可以应用于临床下肢动脉狭窄性病变的CE-MRA检查,并且与DSA相比具有较高的诊断敏感度及特异度,但小腿静脉污染是CE-MRA检查中需要克服的缺陷.     

CTA评价糖尿病足下肢动脉病变的价值

目的:探讨MSCTA对糖尿病足下肢各级动脉病变的诊断价值。方法:收集同时行MSCTA及DSA检查的35例糖尿病足患者共38侧下肢动脉,每条下肢分为17段,每段动脉根据狭窄程度分为正常、轻度、中度、重度、闭塞。将下肢动脉分为膝上、膝下、足动脉三部分进行分析。以DSA为金标准,分别计算CTA诊断血管狭窄、闭塞的灵敏度、特异度、准确度,对下肢血管狭窄程度的一致性判定行Kappa检验。结果:以DSA为金标准,CTA评估膝上动脉血管狭窄≥50%的灵敏度、特异度、准确度分别为96.9%、96.8%、96.8%;评估膝下动脉血管狭窄≥50%的灵敏度、特异度、准确度也较高,分别为95.9%、90.8%、93.4%;评估足动脉闭塞时灵敏度、特异度、准确度分别为68.4%、91.2%、88.2%。膝上动脉狭窄≥50%的Kappa值0.929,膝下动脉为0.868,足动脉闭塞者为0.679(P<0.01)。结论:MSCTA对诊断糖尿病足患者下肢膝上及膝下动脉狭窄≥50%的可靠性高,而预测足动脉闭塞的灵敏度相对较低,可以部分替代DSA检查。     

3.0T磁共振CE-MRA在腹部至下肢动脉疾病中的应用价值

目的探讨3.0T超强磁场磁共振三维增强MRA(3D CE-MRA)对腹部、盆腔、下肢血管病变的诊断价值。方法使用GE EXCITEⅡ3.0T双梯度超导磁共振,对61例拟诊腹部至下肢血管病变的受检者行3D CE-MRA检查,其中36例行DSA检查。将腹部至下肢血管分为腹主动脉、髂总动脉、髂外动脉、髂内动脉、股浅动脉、股深动脉、腘动脉、胫前动脉、胫后动脉、腓动脉10个部分,由2位影像学专家独立对3D CE-MRA和DSA资料作出分析。结果61例受检者腹部至下肢血管3D CE-MRA成像均获得满意效果,血管显示清晰。8.2%(5/61)受检者未见异常,91.8%(56/61)受检者显示共计601段血管病变,其中动脉粥样斑块43.4%(261/601),动脉狭窄22.0%(132/601),动脉闭塞29.5%(177/601);动脉迂曲2.7%(16/601);动脉瘤1.5%(9/601);动脉夹层0.5%(3/601);肿瘤压迫或包绕血管0.5%(3/601)。36例3D CE-MRA与DSA比较,3D CE-MRA显示髂总动脉、髂外动脉、股浅动脉、腘动脉、腓动脉血管病变阳性检出率无差异(P>0.05),动脉粥样斑块、动脉狭窄及动脉闭塞3种血管病变显示无差异(P>0.05)。3D CE-MRA显示腹主动脉粥样斑块病变多于DSA(χ2=5.94,P=0.01),髂内动脉、股深动脉、胫前动脉、胫后动脉病变阳性检出率高于DSA(P<0.05),以DSA为标准,3D CE-MRA存在高估。结论3D CE-MRA是一种有效的评价腹部至下肢动脉疾病的方法,其诊断价值可与DSA相媲美,尤其对直径较大的腹主动脉至腘动脉主干(1~3级血管)可基本代替DSA。     

肠系膜上动脉狭窄的双源CT血管成像

目的 探讨双源CT血管成像(CTA)在肠系膜上动脉狭窄诊断中的价值.方法 对11例经数字减影血管造影(DSA)证实的肠系膜上动脉狭窄患者的双源CTA图像进行分析.以DSA为金标准,统计双源CTA诊断肠系膜上动脉不同程度狭窄的敏感度、特异度.结果 双源CTA诊断肠系膜上动脉轻度、中度、重度狭窄及闭塞的敏感度分别为86%、82%、100%,特异度分别为96%、92%、96%.结论 双源CTA能快速、准确地诊断肠系膜上动脉狭窄.     

双源64排螺旋CT血管成像对下肢动脉狭窄及闭塞性病变的诊断价值

目的：通过双源64排螺旋CT血管成像（CTA）与数字减影血管造影（DSA）进行比较,探讨双源64排螺旋CTA对下肢动脉狭窄及闭塞性病变的诊断价值。方法采用德国西门子公司生产的双源64排螺旋CT对30例临床怀疑下肢动脉狭窄及闭塞性病变的患者进行双下肢动脉血管成像检查,扫描范围自腹主动脉下段至足底,扫描层厚0．75 mm,管电压120 kV,管电流250 mAs,将原始图像送入工作站进行图像后处理,主要包括容积再现（VR）、最大密度摄影（MIP）、多平面重建（MPR）、曲面重建（CPR）,并结合原始图像进行分析,所有患者1周后行DSA检查,以DSA作为参考标准,对诊断一致性、敏感性、特异性和狭窄部位的检出准确率进行计算。结果在720个动脉节段中,700个节段在CTA和DSA均可以显示,以DSA作为诊断标准,双源64排螺旋CTA诊断下肢动脉闭塞的敏感性、特异性、准确性分别为99.3％、97．8％、97．8％;对于显示中度以上的狭窄,双源64排螺旋CTA的敏感性、特异性、准确性分别为99．7％、97．6％、95．6％;双源64排螺旋CTA在诊断下肢动脉狭窄及闭塞性病变与DSA结果一致性好（kappa值＝0．937）。结论双源64排螺旋CTA可以作为下肢动脉狭窄及闭塞性病变的首选检查手段,对临床具有重要的指导价值。     

320排动态容积CT血管造影对硬脊膜动静脉瘘的诊断价值

目的 探讨320排动态容积CT诊断硬脊膜动静脉瘘(SDAVF)的价值.方法 对12例临床表现符合脊髓血管畸形患者作CTA(320排CT)和对比增强MRA (CE-MRA)检查,并于1周内作DSA检查,评价CTA成像所示病变范围、供血动脉、瘘口及引流静脉等,并与CE-MRA、DSA检查对照.结果 12例患者经CTA检查均明确显示脊髓异常血管及病变范围,容积再现(VR)、多平面重组(MPR)和最大密度投影(MIP)成像清晰显示畸形血管的供血动脉、瘘口、引流静脉,畸形血管与周围骨性结构空间位置关系.CE-MRA检查显示脊髓畸形血管病变范围,但仅显示8例患者供血动脉及瘘口位置.结论 320排动态容积CT可快速、无创、清晰地显示脊髓血管畸形患者供血动脉、引流静脉及瘘口,弥补了DSA、CE-MRA单一成像的不足,对SDAVF有较高的诊断准确率.     

mDIXON序列 3.0T MRA诊断中心静脉病变：与DSA对照研究

目的:探讨改良水脂分离技术(mDIXON)对比增强3.0T MRA在诊断血液透析患者中心静脉病变中的可行性及应用价值。方法:40例有上肢肿胀、胸壁静脉曲张、内瘘假性动脉瘤等临床症状的中心静脉病变患者在行DSA检查前采用mDIXON技术行CE-MRA检查。由2位MRI医师根据4分法,分别对图像质量进行评分;并根据4级评分标准,对中心静脉的狭窄程度进行评估。采用Kappa检验分析2位MRI医师对图像质量评分、mDIXON CE-MRA和DSA对中心静脉狭窄程度的分级及判断闭塞与非闭塞性病变的一致性。以DSA为金标准,计算mDIXON CE-MRA诊断中心静脉闭塞和非闭塞病变的敏感度、特异度、阳性预测值(PPV)和阴性预测值(NPV)。结果:两位MRI医师对中心静脉图像质量评分、mDIXON CE-MRA与DSA对中心静脉狭窄程度的分级及诊断闭塞病变和非闭塞病变的一致性均较好,Kappa值为分别0.655、0.921和1.000(P值均<0.05)。mDIXON CE-MRA评估中心静脉狭窄程度的符合率为94.74%(36/38),对狭窄程度分级高估率为5.26%(2/38)。mDIX...     

双源CT 诊断下肢动脉阻塞性疾病的临床价值

目的：探讨双源C T在下肢动脉阻塞性疾病诊断中的临床应用价值。方法选择76例下肢动脉阻塞性疾病患者采用下肢动脉血管成像（CTA）检查,在CT 检查后1～2天内26例行数字减影血管造影（DSA）检查。将下肢血管分成12段,并将每个动脉狭窄程度分为5级：正常（无狭窄）,轻度狭窄（狭窄程度＜50％）：中度狭窄（狭窄程度50％～74％）;重度狭窄（狭窄程度75％～99％）;闭塞（完全闭塞）。对比CTA和DSA检查结果。结果在76例下肢动脉阻塞性疾病患者中26例患者接受DSA检查,其中行双下肢检查8例,单侧检查18例,将CTA检查结果与DSA进行一致性分析显示К＝0．887,К值分析结果表明CTA与DSA在检测下肢动脉阻塞性疾病方面有良好的一致性。结论双源CT在诊断下肢动脉阻塞性疾病方面与DSA具有良好的一致性,可以作为下肢动脉阻塞性疾病诊断的可靠方法。     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

Uterine contractions: Possible diagnostic pitfall at MR imaging

A total of 206 nongravid patients with various gynecologic problems underwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent–enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endometrial configuration on serial images obtained during the same MR examination. In 20 MR examinations (all in women of reproductive age), endometrial distortion due to myometrial bulging was noted on T2-weighted or contrast-enhanced T1-weighted images. It was absent on other MR images obtained at different times. Myometrial bulging exhibited low signal intensity in 18 examinations. The finding resembled adenomyosis or leiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and transient low-intensity myometrium in the nongravid uterus. This phenomenon is thought to represent uterine contraction. Clinicians should be aware of the potential presence of transient low-signal-intensity myometrial bulging that could present diagnostic problems in the normal uterus.     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Right-side aortic arch with aneurysm of aberrant left subclavian artery: MR imaging appearance.

Reports of aneurysms of the subclavian artery in both normal and anomalous aortic arches have been rare. The authors describe a patient with a right-side aortic arch and an aneurysm of the aberrant left subclavian artery, which, to the authors' knowledge, is a previously unreported association. At presentation, the aneurysm appeared as a calcified left superior mediastinal mass. Magnetic resonance imaging enabled preoperative diagnosis and guided surgical planning.     

MR angiography of congenital heart disease: Value of segmented two-dimensional inflow technique and maximum-intensity-projection display

Magnetic resonance (MR) angiography of the cardiovascular system was evaluated in 41 patients with congenital heart disease by using a two-dimensional (2D) inflow technique based on a magnetization-prepared gradient-echo pulse sequence with segmented k-space data acquisition and electrocardiographic gating at 0.5 T. Inversion and saturation prepulses were used to suppress stationary tissue and enhance intravascular signal. Presaturation slabs were applied where certain vascular structures had to be suppressed. Sequence parameters were optimized by evaluating signal intensity and contrast characteristics for various flip angles and inversion and saturation delay times. The heart and intrathoracic vasculature were encompassed with 40–50 overlapping sections. Both 2D angiograms and maximum-intensity-projection images were evaluated. Combining data sets acquired in the sagittal and transverse orientations provided the most satisfactory information about the pulmonary arteries. The highest signal-to-noise ratios were obtained with a flip angle of 65° and short prepulse delay times. Two-dimensional MR angiography can provide useful diagnostic information but requires a thorough understanding of in-plane and hemodynamically induced signal intensity changes.     

Adrenal tissue characterization with 0.5-T MR imaging: Value of T2*-weighted images

The authors investigated the value of magnetic resonance (MR) imaging at 0.5 T for distinguishing adrenal adenomas from adrenal metastases. The series included 23 adrenal adenomas (18 nonhyperfunctioning, five hyperfunctioning) and 23 adrenal metastases from various organs. Adrenal tumor–liver signal intensity ratios on T1-, T2-, and T2*-weighted images were calculated for adrenal tissue characterization. Adrenal adenomas were more precisely distinguished from adrenal metastases on T2*-weighted images (21 of 23, 91%) than on T2-weighted images (15 of 23, 65%). T1-weighted images were not useful for this distinction. In conclusion, T2*-weighted images were better than routine T2-weighted images for distinguishing adrenal adenomas from adrenal metastases. It can be postulated that the total signal intensity of adrenal adenomas, which contain some fat components, decreased on T2*-weighted images because of an out-of-phase effect.     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.