MSCTA对急性肠系膜上动静脉栓塞的诊断价值

目的:探讨MSCTA对急性肠系膜上动静脉栓塞的诊断价值。方法:回顾性分析13例经临床证实的肠系膜血管栓塞患者的急诊CT平扫、CTA及三维重建资料。结果:13例中肠系膜上动脉栓塞(superior mesenteric artery embolism,SMAE)7例、肠系膜上静脉栓塞(superior mesenteric vein embolism,SMVE)6例。直接征象:7例SMAE中,平扫见血栓密度影2例,CTA均见充盈缺损;6例SMVE中,平扫见血栓密度影4例,CTA均见充盈缺损。间接征象:13例中肠梗阻5例,腹水6例。SMAE:血管壁钙化5例,薄纸样肠壁改变2例,肠壁水肿增厚强化减弱3例;SMVE:增强扫描管壁环形强化、管径扩张5例,缆绳征4例;受累肠管、肠系膜广泛水肿增厚,增强扫描可呈明显减弱或未强化特点,肝脏门脉期强化减弱不均匀2例;合并门静脉、脾静脉血栓2例。结论:CTA对肠系膜上动静脉栓塞的诊断敏感性较CT平扫高,对于CT平扫阴性的患者行CTA检查很有价值。     

门静脉栓子的CT征象在肝细胞肝癌诊断中的价值

目的 探讨与肝内肿瘤并存的门静脉栓子的CT征象,及其在肝细胞肝癌诊断中的价值.方法 搜集经CT检查诊断为肝内肿瘤合并门静脉栓子的病例共64例,分为肝细胞肝癌组(36例)和肝脏其他肿瘤组(28例).①用电子尺测量门静脉栓子及相应门静脉的最大直径,分别比较2组栓子与相应门静脉的最大直径.②测量、比较2组门静脉栓子增强前后平均CT值.③观察、比较2组栓子在门静脉系统发生的位置.④观察、比较2组门静脉栓子与肝内肿瘤的关系.结果 ①肝细胞肝癌组门静脉左支、右支及主干内栓子的平均直径均大于同组相应门静脉的平均直径,t值分别为6.00、6.93、4.79,P值均＜0.05.②肝细胞肝癌组门静脉栓子增强扫描平均CT值为(92.39±26.83) HU,高于同组门静脉栓子平扫平均CT值(30.44±7.29) HU,t=13.37,P＜0.01.③肝脏其他肿瘤组门静脉栓子单独发生在主干共7例,发生率高于肝细胞肝癌组(1例),χ2=5.22,P＜0.05.④肝细胞肝癌组肝内肿瘤直接侵犯门静脉的发生率高于肝脏其他肿瘤组,χ2=9.71,P＜0.05.结论 门静脉栓子明显强化并造成相应门静脉的扩张,肝内肿瘤直接侵犯门静脉以及由肝内向肝外的生长方式是肝细胞肝癌门静脉栓子较为特征性的CT征象.     

64层螺旋CT对急性肠系膜血管栓塞的诊断价值分析

目的 探讨64层螺旋CT血管造影对急性肠系膜血管栓塞(AMI)的诊断价值.方法 回顾性分析经64层螺旋CT全腹平扫加多期动态增强扫描诊断的15例AMI.其中,肠系膜上动脉栓塞3例(完全栓塞1例,不完全栓塞2例),肠系膜上静脉栓塞12例.结果 15例AMI直接征象:动脉期显示肠系膜上动脉完全或部分充盈缺损,可诊断为肠系膜上动脉完全或部分栓塞(3例).静脉期显示肠系膜上静脉完全或部分充盈缺损,可诊断为肠系膜上静脉完全或部分栓塞(12例);间接征象“缆绳征”12例,肠系膜水肿10例,肠管壁增厚12例,肠管扩张、积液8例,肠壁强化减弱7例,其中2例可见节段性未强化区,腹水6例,肾前筋膜增厚4例,肠壁积气2例.平扫肠系膜上动脉或上静脉高密度征7例(静脉栓塞6例,动脉栓塞1例),肠系膜上静脉栓塞累及门静脉、脾静脉6例,其中4例在增强扫描时,可见肝脏异常低灌注区.结论 64层螺旋CT平扫加多期动态增强扫描对急性肠系膜血管栓塞的诊断及时准确,应作为临床怀疑肠系膜血管疾病首选检查方法,值得推广应用.     

多层螺旋CT对门静脉海绵样变的诊断价值

目的:分析门静脉海绵样变(CTPV)的多层螺旋CT(MSCT)表现和特征,探讨MSCT对该病的诊断价值.方法:使用16排MSCT对30例CTPV患者,行上腹部CT平扫、动态增强扫描,采用多平面重组(MPR)、最大密度投影(MIP)、容积再现 (VR)等图像后处理技术显示异常的门静脉及侧枝血管情况.结果:CTPV的MSCT平扫示门静脉结构不清,肝门区可见多发的结节状软组织影.增强扫描示动脉期10例有肝实质灌注异常;门静脉期18例患者门静脉主干和(或)左右分支增粗,内可见充盈缺损,4例门静脉显示不清;8例门静脉主干和(或)左右分支在正常范围内;1例门静脉主干变细.胆管周围静脉丛(100%)、胆囊静脉(60%)及胃左静脉(23.3%)呈点状、簇状扩张.MPR、MIP、VR可直观地显示各曲张血管的走行及曲张程度.结论:MSCT及图像后处理系统对CTPV诊断具有重要价值,门静脉栓塞及其周围纡曲扩张的侧枝静脉为其特征性表现.     

螺旋CT增强扫描对门静脉癌栓与门静脉血栓的鉴别诊断

目的探讨门静脉癌栓与血栓的CT表现,提高二者鉴别诊断。方法搜集经临床及病理证实的门静脉癌栓40例、血栓40例,均行螺旋CT平扫+增强扫描。结果 40例癌栓平扫低密度22例(55.0%),癌栓完全性栓塞36例(90.0%),门静脉管腔直径增粗30例(75.0%),附栓管壁不光滑、血管壁强化、癌栓有强化27例(67.5%),动-门静脉瘘出现23例(57.5%)。40例血栓平扫等密度22例(55.0%),栓子完全栓塞7例(17.5%),门静脉管腔直径增粗10例(25.0%),附栓管壁连续光滑、无管壁强化、血栓无强化40例;无1例动-门静脉瘘。结论门静脉癌栓与血栓在密度、强化、管壁的侵犯、管腔充盈程度、栓塞位置等方面都有不同表现。     

门静脉栓子的超声造影表现

目的探讨超声造影鉴别良、恶性门静脉栓子的价值.材料和方法回顾性分析14例经穿刺活检病理证实的肝细胞性肝癌合并门静脉瘤栓(其中1例合并血栓)和3例经CT、实验室检查及抗凝治疗证实的门静脉血栓患者的超声造影表现.结果13例门静脉瘤栓患者,超声造影动脉期见瘤栓呈线条状或点状快速增强,门静脉期管腔呈充盈性缺损.1例瘤栓合并血栓形成患者,动脉期栓子部分快速增强,部分始终未见增强,门静脉期管腔呈充盈性缺损.3例门静脉血栓患者,动脉期未见栓子增强,门静脉期管腔呈充盈性缺损.结论超声造影有助于良、恶性门静脉栓子的鉴别诊断.     

A study of the relationship between the portal vein thrombosis and clinical progression in portal hypertension on multi-slice CT portal venography

目的:采用64排螺旋CT门静脉成像探讨肝硬化(LC)门脉高压症(PH)门静脉血栓(PVT)形成对临床病程进展的影响.方法:对183例LC患者行CT检查,其中并发PVT者109例,无血栓者74例,应用MIP、MPR、CPR方法多角度多层面显示门静脉系统血管结构和侧支循环,测量血栓范围和狭窄程度.分别比较PVT组和对照组之间、不同Child-Pugh(CP)分级亚组间的肝功能、凝血功能、门脉系统血管宽度、侧支循环、脾脏大小的差异,分析PVT组各影像特之间及其与肝功能的相关性.结果:PVT组与对照组间的血清总胆红素、门静脉和脾静脉宽度、脾面积、脾/胃-肾分流的差异均有统计学意义(t=-2.830、P=0.005;t=3.576、P<0.001;t=0.780、P=0.043;t=3.491、P=0.001;χ2= 5.350、P=0.021),PVT组平均值均较高,且在CP的B和/或C级下差异有统计学意义(P<0.05),A级中差异无统计学意义(P>0.05);前腹壁静脉曲张在各分级中差异均有统计学意义(χ2=4.485,P=0.034).PVT组肠系膜上静脉血栓与肠壁水肿有一定的相关性(r=0.227,P=0.018);脾静脉与胃左静脉宽度有一定的相关性(r=0.371,P<0.001).结论:门静脉血栓形成与门脉高压症病情密切相关,可能为促进肝硬化临床病程发展的重要因素.     

MSCT门静脉成像对门脉高压症中门静脉血栓形成与临床病情关系的研究

目的:采用64排螺旋CT门静脉成像探讨肝硬化(LC)门脉高压症(PH)门静脉血栓(PVT)形成对临床病程进展的影响。方法:对183例LC患者行CT检查,其中并发PVT者109例,无血栓者74例,应用MIP、MPR、CPR方法多角度多层面显示门静脉系统血管结构和侧支循环,测量血栓范围和狭窄程度。分别比较PVT组和对照组之间、不同Child-Pugh(CP)分级亚组间的肝功能、凝血功能、门脉系统血管宽度、侧支循环、脾脏大小的差异,分析PVT组各影像特征之间及其与肝功能的相关性。结果:PVT组与对照组间的血清总胆红素、门静脉和脾静脉宽度、脾面积、脾/胃-肾分流的差异均有统计学意义(t=-2.830、P=0.005;t=3.576、P<0.001;t=0.780、P=0.043;t=3.491、P=0.001;χ2=5.350、P=0.021),PVT组平均值均较高,且在CP的B和/或C级下差异有统计学意义(P<0.05),A级中差异无统计学意义(P>0.05);前腹壁静脉曲张在各分级中差异均有统计学意义(χ2=4.485,P=0.034)。PVT组肠系膜上静脉血栓与肠壁水肿有一定的相关性(r=0.227,P=0.018);脾静脉与胃左静脉宽度有一定的相关性(r=0.371,P<0.001)。结论:门静脉血栓形成与门脉高压症病情密切相关,可能为促进肝硬化临床病程发展的重要因素。     

64层螺旋CT对急性门静脉和肠系膜上静脉血栓的诊断价值

目的 探讨64层螺旋CT对急性门静脉和肠系膜上静脉血栓的诊断价值.资料与方法回顾性分析经手术及临床确诊的19例急性门静脉和肠系膜上静脉血栓形成患者的64层螺旋CT表现.19例均行平扫,14例加行增强扫描,并应用多平面重组(MPR)、曲面重组(CPR)、最大密度投影(MIP)和容积再现(VR)行多层螺旋CT血管成像(MSCTA).结果 19例平扫均显示门静脉和肠系膜上静脉增粗,12例肠系膜周围脂肪密度增高,13例管腔内高密度,10例有不同程度腹腔积液,14例肠管扩张、积气积液,10例肠壁增厚水肿;14例增强扫描均显示静脉内低密度充盈缺损,门静脉和肠系膜上静脉管壁环形强化,肠管管壁强化呈"靶征",3例肠管未强化,5例显示肝脏一过性供血不足,门静脉期供血减少.结论 64层螺旋CT平扫及增强扫描,以及三维重组技术相结合能够早期发现急性门静脉和肠系膜上静脉血栓形成.     

MSCT在延迟性小肠破裂早期诊断中的应用

目的 探讨多层螺旋CT(MSCT)对延迟性小肠破裂的早期诊断价值及临床意义.方法回顾性分析16例临床经手术证实的小肠破裂患者的临床资料和CT表现,其中男12例,女4例.所有病例早期腹膜刺激征不明显,均在受伤后24 h~1周内进行手术治疗;术前均行MSCT腹部薄层扫描及重建检查,其中平扫12例,平扫+增强扫描4例.结果所有病例均手术证实小肠破裂,其中合并其他腹部脏器损伤3例(3/16),单纯小肠损伤13例(13/16).MSCT术前诊断阳性15例(15/16),其中局限于肠系膜间隙渗出积液、点状游离积气9例(9/15),单纯肠间积液4例(4/15),肠系膜间隙游离小气泡2例(2/15);伴肠管肿胀、管壁增厚11例(11/15).术前诊断阴性1例(1/16),经剖腹探查证实.受伤24 h后CT诊断小肠破裂3例(3/16),受伤后3 d内诊断者10例(10/16),受伤后1周内诊断者2例(2/16),其中受伤后3 d内作出诊断者共13例(13/16).结论 MSCT检查在延迟性小肠破裂的早期诊断中具有较高价值,对指导临床诊治具有重要参考价值.     

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.     

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     

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.     

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.