单纯腹腔网膜脂肪突入食管裂孔上消化道造影表现

目的：探讨单纯腹腔网膜脂肪(PAOF)突入食管裂孔(EH)的上消化道造影(GI)表现。方法收集7例 GI和 MSCT检查发现PAOF突入 EH 患者影像资料,分析 GI表现并与 MSCT对照。结果4例食管下段周围伴较大软组织影,密度浅淡,黏膜相显示食管下段2~4 cm黏膜粗乱,其中1例食管与软组织上缘交界处黏膜线被牵拉吊起;充盈相显示管腔轻度狭窄,管壁软,病变上界可见。3例 His角圆钝,其中1例显示 His角随体位变化。4例 MSCT显示食管下段右旁较大囊状脂肪密度影。3例 GI表现基本正常,其中1例食管膈壶腹持久,MSCT显示食管下段右旁较小囊状脂肪密度影。7例 MSCT多平面重建(MPR)均显示囊状脂肪密度影下部与腹腔脂肪相连,胃左动脉弓状指向或突入 EH。结论食管下段伴较大而密度浅淡软组织影、黏膜和管腔改变轻、病变上缘有分界及 His角圆钝可变为PAOF突入 EH 的 GI特殊表现。     

多层螺旋CT多平面重组诊断食管裂孔网膜疝

目的 探讨MSCT多平面重组(MPR)诊断食管裂子网膜疝(EHOH)的价值.方法 5例经手术证实的EHOH均行MSCT平扫及增强检查,获取亚毫米数据作MPR及最大密度投影(MIP),在贲门部测量食管裂孔(EH)大小.以EH膈上脂肪囊与腹腔网膜脂肪相连、胃左动脉(GLA)穿EH及贲门位置正常作为EHOH诊断标准,由3位不知手术结果的高年资医生分别回顾性分析横断位和MPR图像进行判断.结果 5例横断位均显示EH膈上大小不等囊状脂肪密度影,其中椭圆形2例、类圆形2例及分叶形1例,内见点条状高密度影,增强有强化;1例伴转移性淋巴结肿大,1例伴小网膜转移,3例伴腹腔积液;2例判断准确.5例MPR直观显示脂肪囊与腹腔脂肪相连,4例GLA穿EH,主干僵直和食管支附近呈“∩”形特征形态;5例均作出准确诊断.结论 MSCT MPR清晰显示EH膈上脂肪囊与腹腔网膜脂肪相连及GLA穿EH的形态特征,对EHOH诊断具有重要意义.     

多层螺旋CT多平面重组诊断创伤性膈肌破裂

目的 探讨MSCT MPR方法诊断创伤性膈肌破裂(traumatic diaphragmatic rupture,TDR)的价值.方法 21例手术证实TDR,15例排除TDR的胸腹部创伤患者术前MSCT图像,由3名高年资医师先后对MSCT横断面和MPR图像行盲法回顾分析,以发现横膈异常升高、膈肌中断缺损及"颈圈征"作为TDR诊断依据.对照手术结果计算MSCT横断面及MPR诊断TDR的敏感度、特异度、阳性预测值、阴性预测值和准确度;MSCT横断面和MPR对膈肌中断缺损、"颈圈征"的辨认率差异及其诊断TDR的敏感度、特异度差异采用McNemar检验.结果 MSCT横断面诊断TDR的敏感度、特异度、阳性预测值、阴性预测值和准确度分别为71%(15/21)、80%(12/15)、83%(15/18)、67%(12/18)和75%(27/36);MPR分别为86%(18/21)、93%(14/15)、95%(18/19)、82%(14/17)和89%(32/36).21例TDR中,MSCT显示膈肌中断、缺损横断面12处(9例),采用MPR重组方法除显示上述12处外,还进一步显示8处(6例),共20处(15例),差异无统计学意义(P=0.125).MSCT横断面显示"颈圈征"6例,MPR方法显示14例,二者差异有统计学意义(P=0.021).MSCT横断面上观察膈肌中断缺损诊断TDR的敏感度、特异度分别为43%(9/21)和80%(12/15),MPR分别为71%(15/21)和93%(14/15),差异均无统计学意义(P值分别为0.125和0.500).MSCT横断面上观察"颈圈征"诊断TDR的敏感度、特异度分别为29%(6/21)和100%(15/15),MPR分别为67%(14/21)和100%(15/15),敏感度差异有统计学意义(P=0.021),特异度差异无统计学意义(P=1.000).结论 MSCT诊断TDR具有良好的敏感度、特异度和准确度;MPR是横断面诊断TDR的重要补充,有助于提高TDR诊断水平.     

下腔静脉病变的多层螺旋CT诊断

目的 探讨下腔静脉病变的MSCT表现.方法 回顾性分析经手术病理或临床资料证实的69例下腔静脉病变的MSCT表现特征.结果 双下腔静脉8例,MSCT表现为肾静脉水平以下左右下腔静脉分别位于腹主动脉两侧;左位下腔静脉1例,表现为肾静脉水平以下下腔静脉位于腹主动脉左侧;布-加氏综合征1例,主要表现为下腔静脉肝上段狭窄;下腔静脉癌栓44例,表现为管腔内充盈缺损,无或轻中度强化,邻近脏器可见原发灶;血栓8例,表现为管腔内无强化的充盈缺损;静脉内平滑肌瘤病2例,平滑肌肉瘤4例,肉瘤样癌1例,均为管腔内充盈缺损,轻度或明显强化.结论 下腔静脉先天变异MSCT表现具有一定特征,其他性质病变多表现为腔内无/不同程度强化的充盈缺损、管腔扩张增粗及侧枝循环形成等.     

MSCT多平面重组诊断非裂孔性膈疝的价值

目的 探讨多层螺旋CT(MSCT)多平面重组(multiple planar reconstruction,MPR)诊断非裂孔性膈疝(nonhiatus diaphragmatic hernia,NHDH)的价值.资料与方法 回顾分析23例NHDH患者的影像资料,其中Bochdalek疝8例,Morgagni疝3例(1例经手术证实),创伤性膈疝9例(均经手术证实),医源性膈疝3例.23例均行MSCT容积扫描,由3位不知手术结果的高年资医师先后回顾分析MSCT横断位及MPR表现,观察有无横膈异常升高、膈肌连续性中断缺损、"颈圈征"及"内脏依靠征"等征象作为NHDH诊断依据,并分别作出判断.结果 22例MSCT横断位及MPR图像见膈上大小不等的疝囊及内容物,膈肌连续性中断.横断位显示13例,MPR显示22例(t=4.97,P＜0.05).2例Bochdalek疝误诊为膈肌衰老,1例误诊为脂肪瘤,1例较大Morgagni疝误诊为脂肪瘤,4例创伤性膈疝首诊提示诊断,2例医源性膈疝漏诊,术前诊断率56.5%;术后回顾分析横断位14例(60.7%)提示NHDH,结合MPR 21例(91.3%)提示NHDH诊断(t=4.33,P＜0.05).结论 MSCT MPR能够清晰显示NHDH膈肌连续性中断及膈上疝囊与膈肌的关系,对诊断具有决定意义.     

单纯腹腔网膜脂肪突入食管裂孔多层螺旋CT多平面重组的表现及意义

目的:研究单纯腹腔网膜脂肪(PAOF)突入食管裂孔(EH)形态特征,探讨MSCT诊断EH单纯网膜脂肪疝的价值和限度。方法:回顾性分析2008年12月~2012年8月MSCT横断位发现EH膈上脂肪囊41例,获取亚毫米资料作MPR及MIP,观察脂肪囊、胃左动脉(LGA)形态特征及其与EH关系。结果:41例脂肪囊横断位呈类圆形15例,椭圆形17例和分叶形9例,23例囊内显示点条状血管影。MPR上11例脂肪囊呈狭基底形(疝囊形),30例呈广基底形(膨隆形),其底部均与腹腔网膜脂肪相连。囊内血管主要为LGA及其分支,其中9例LGA主干僵直,食管支附近呈对称性"∩"形突入胸腔,脂肪囊均为疝囊形;32例走向自然未进胸腔,30例脂肪囊呈膨隆形(χ2=19.988,P=0.031)。结论:PAOF突入EH横断位表现为膈上类圆/椭圆/分叶形脂肪囊;MPR上大致呈膨隆形和疝囊形两种形态,前者提示EH功能减退,后者结合LGA"∩"形突入胸腔征象有助于网膜脂肪疝诊断。     

MSCT多平面重组诊断单纯性横膈网膜疝

目的探讨MSCT多平面重组（multipleplanarreconstruction,MPR）诊断单纯性横膈网膜疝（simpleomentaldiaphragmatichernia,SODH）的价值。方法31例SODH均行MSCT容积扫描并作亚毫米重组,3名不知手术结果的高年资医师回顾性分析横断位和MPR图像,以发现膈肌中断缺损、膈上脂肪疝囊、“狭颈征”及“阳性血管征”作为诊断SODH依据;横断位及MPR征象显示及诊断差异采用x。检验。结果31例SODH中Bochdalek疝15例、Morgagni疝4例、医源性膈疝3例、食管裂孔疝6例及腔静脉裂孔疝3例,膈肌中断缺损、膈上疝囊、“狭颈征”及“阳性血管征”横轴位和MPR依次分别显示：6例和22例6．67,P〈O．01）、31例和31例、6例和28例（x2=31．52,Pd0．01）及3例和11例（x2=5．90,Pd0．05）。横轴位诊断12例,MPR全部明确诊断（x2=27．40,P〈0．01）。结论MSCTMPR清晰显示SODH多种特征性征象,对诊断具有决定意义。     

多层螺旋CT多平面重组图像在胸骨骨折中的诊断价值

目的 探讨MSCT多平面重组(MPR)图像对胸骨骨折的诊断价值. 方法 回顾性分析48例胸骨骨折患者的MSCT资料,均对胸骨进行横断面MPR、矢状位MPR和冠状位曲面MPR (CPR)成像,比较不同方位MPR图像对不同类型胸骨骨折的诊断价值.结果 48例胸骨骨折中,矢状位MPR图像对骨折的检出率为100％,明显高于横断面MPR (58.3％)和冠状位CPR (83.3％)图像的检出率(P =0.000).对胸骨横断骨折,尤其是无错位的横断骨折,矢状位MPR图像明显优于横断面MPR和冠状位CPR图像(P =0.000).而对错位性骨折、斜行骨折和粉碎性骨折,三种方位MPR图像对骨折的检出率未见显著性差异(P＞0.05).结论 MSCT的MPR图像可准确地检出胸骨骨折,尤其是矢状位MPR图像可避免对无错位横断骨折的漏诊.     

布加综合征下腔静脉阻塞直径30 mm大球囊扩张的可行性研究

目的探讨直径30mm大球囊导管扩张治疗下腔静脉(IVC)阻塞型布加综合征(BCS)的可行性与安全性。方法经彩色多普勒超声(彩超)和IVC造影证实IVC阻塞的连续146例BCS,其中多层螺旋CT平扫及三期增强扫描47例,经皮经腔血管成形术(PTA)治疗除1例体形矮小使用直径25mm的球囊导管外,余145例均使用直径30mm大球囊导管,PTA后IVC造影观察管腔通畅情况及管壁完整性。术后1周彩超探查胸腹部、心脏和IVC。结果术前多层螺旋CT检查除1例因阻塞段与右心房过近而无法测量外,余46例BCS横断面图像测量IVC近心段的横径平均为(17.57±3.93)mm,纵径平均为(25.09±6.09)mm。使用直径30mm的大球囊导管扩张IVC后造影全部显示血流通畅,无一例破裂。术后1周彩超发现右侧少量胸腔积液2例,心包积液4例,未见腹腔出血。结论使用直径30mm大球囊导管扩张治疗IVC阻塞型BCS安全可行。     

单纯食管裂孔网膜疝

目的：探讨单纯食管裂孔网膜疝（simple esophageal hiatus omental hernia ,SEHOH）的MSCT影像特点。方法回顾性分析7例手术证实的SEHOH ,均作了MSCT平扫及增强检查,获取亚毫米数据作MPR及MIP。结果横断位7例均显示食管裂孔（EH）膈上大小不等纯脂肪血管囊,其中呈椭圆形和类圆形各3例,分叶形1例,多位于食管右前方;矢状位表现为心后区铸型脂肪密度影,形态由正中矢状位的半月形或三角形逐渐过渡到旁中央矢状位的三角形或半圆形;冠状位呈椭圆形3例、倒梨形2例和分叶状2例。脂肪血管囊下部呈“狭颈样”与腹腔网膜脂肪连续,上极被撑开的膈食管膜与食管相连成角状。MIP均显示胃左动脉（GLA）主干僵直,食管支附近呈对称“∩”形穿越EH。贲门均位于膈下。结论心后纯脂肪血管囊膨胀性和可塑性形态,紧贴食管并与腹腔网膜相连;GLA主干僵直,食管支附近呈对称“∩”形并穿越EH是SEHOH特征性影像表现,对诊断具有重要意义。     

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.     

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     

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.     

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.     

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.     

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.