多层螺旋CT辅助OMENS评分法在儿童半侧面部短小症诊断中的应用

目的 探讨MSCT辅助OMENS评分法对半侧面部短小症(HFM)形态学改变的评价情况.方法 选取行MSCT检查的HFM患儿11例,对采集数据进行MPR、MIP及VR图像重组,结合OMENS评分法对HFM各主要畸形进行独立评价.结果 11例患儿中,9例为单侧发病,其中左侧6例,右侧3例.双侧发生者2例,双侧严重程度不等,1例以右侧为著,1例以左侧为著.利用OMENS评分法对11例患者的所有畸形进行逐一评价,均得到了满意的结果.其中颧弓-眼眶畸形累及8例8侧,耳廓畸形累及11例13侧,下颌骨畸形累及9例10侧,软组织畸形累及11例12侧.结论 采用MSCT辅助的OMENS评分法,能够比较全面而准确地对HFM累及的面部畸形进行形态学评价,为临床全面评价该病提供有力的影像学支持.     

Crouzon综合征二例

<正>病例资料病例1,男,43岁,因头痛、抽搐就诊。查体:头颅畸形,前额及下颌突出,鼻梁凹陷呈鹦鹉嘴状鼻,眼距增宽,眼球突出。CT平扫及三维重建:头颅呈舟状头畸形,颅缝已闭合;面部见上颌骨发育形态小,下颌骨形态较大,下颌骨与前额前突,鼻梁凹陷,牙咬合不良;颅内板以颞顶骨显著凹凸不平(脑回压迹),颅底短小,蝶鞍呈垂直状,中颅窝低位;眼距增宽,眼球突出。诊断:Crouzon综合征,合并舟状头畸形(图1)。     

16层螺旋CT三维重建对头颅颌面骨骨折的临床应用分析

目的探讨16层螺旋CT三维（3D）及多平面重建（MPR）成像在头颅颌面骨骨折中的临床应用。方法对60例头颅颌面骨骨折患者行16层螺旋CT薄层扫描,然后采用多平面重建（MPR）及容积再现（VR）、最大密度投影重建（MIP）等三维重建技术成像。结果60例头颅颌面骨骨折中单发性骨折43例,多发骨折17例;23例为粉碎性骨折,37例发生骨折移位。骨折部位：下颌骨骨折15例,其中髁状突骨折8例;颧弓骨折15例,其中伴眼眶、鼻骨及副鼻窦骨折9例;上颌骨骨折17例,其中13例伴上颌窦前壁塌陷及眶下壁、鼻骨、碟骨、筛骨等多处骨折;单纯鼻骨骨折13例。采用16层螺旋CT三维及3D-SSD与MPR、MIP、VR相结合多平面重建成像技术,均获得了非常满意的图像。能够立体直观地显示骨折线的位置、走向、骨折范围、类型及骨折块的移位情况等。结论16层螺旋CT扫描的横断图像及重建图像能准确全面地显示颌面部骨折情况,对头颅颌面骨骨折的诊断治疗具有很高的临床应用价值。     

MSCT在评价颅面部骨纤维异常增殖症中的临床价值

目的探讨MSCT在评价颅面部骨纤维异常增殖症中的临床价值。方法回顾性分析42例经手术病理或活检证实的颅面部FDB的影像学资料及临床资料,所有患者均行64层螺旋CT薄层扫描及三维重建。结果 42例中,单骨型12例,多骨型30例,单骨型以上颌骨居多,多骨型最多累及上颌骨、蝶骨、筛骨;MSCT表现为病变骨不同程度膨胀性增粗、畸形,均未见软组织肿块影,其中磨玻璃样变23例,囊状变15例,弥漫性硬化改变4例,"丝瓜瓤"样表现2例,多数病例呈2种以上表现混合存在。结论 MSCT薄层扫描及MPR及VR图像可全面、清晰、立体、直观显示颅面部FDB的形态结构及与周边关系,对其诊断和治疗都有重要临床意义。     

儿童神经母细胞瘤颅面骨转移的影像表现

目的 探讨儿童神经母细胞瘤颅面骨转移的影像表现.方法 回顾性分析12例经组织学证实的儿童神经母细胞瘤的影像表现.其中 10例患儿行CT平扫,6例行MRI,7例行全身SPECT骨扫描.结果 行CT检查的10例患儿中,9例表现为颅面骨溶骨性骨质破坏伴软组织肿块,其中8例可见骨膜反应,3例表现为特征性的针状骨膜反应;另l例cT未发现异常但骨扫描显示异常.行MR检查的6例患儿均表现为颅面骨骨髓腔信号异常伴周围软组织肿块,其中5例行增强扫描,骨髓腔异常信号影和软组织肿块呈明显不均匀强化.7例行全身骨扫描,均可见颅面部放射性浓聚区,其巾6例伴有全身其他部位的骨转移.结论神经母细胞瘤颅面骨转移有一定的影像特征,可提示诊断.     

儿童神经母细胞瘤颅面骨转移的CT和MRI表现

目的：探讨神经母细胞瘤颅面骨转移的CT和MRI特征性表现。方法：回顾性分析6例经病理证实的神经母细胞瘤颅面骨转移患者的CT和MRI资料,分析其影像学特征。6例均行头颅CT平扫,其中2例行头颅MRI平扫和增强检查,6例中5例行腹部CT平扫及增强检查,1例行腹部MRI平扫及增强检查。结果：6例均为双侧颅面骨受累,主要CT表现为颅面骨骨质破坏、骨膜下垂直骨针和软组织肿块,软组织肿块中可见钙化;主要MRI表现为颅骨骨质破坏并软组织肿块,其内有钙化灶,肿块于T1WI上呈等信号,T2WI呈稍高信号,增强后可见肿块和邻近脑膜有不均匀轻度强化。5例腹部CT显示腹膜后肿块并钙化,增强后有不均匀强化。1例MRI显示腹膜后肿块。结论：神经母细胞瘤颅骨转移的CT和MRI表现有一定特征性,CT和MRI对本病的诊断有重要价值。     

儿童神经母细胞瘤伴骨转移的MSCT诊断

目的 探讨儿童神经母细胞瘤(NB)伴全身骨转移的临床特征及MSCT诊断.方法 回顾性分析10例NB伴骨转移患儿的临床及MSCT资料,分析其影像学特征.10例均行腹部CT平扫及增强检查,其中胸部和头颅CT平扫及增强检查分别为3例和4例.结果 10例NB患儿均伴有骨转移,其中3例伴有肝转移,另3例伴有远处淋巴结转移.4例为颅面骨转移,4例为骨盆转移,2例为脊柱转移,均表现为溶骨性骨质破坏,其周软组织肿块可见钙化及垂直状骨针.增强后软组织肿块及邻近脑膜有不均匀轻度强化.结论 NB骨转移的临床及MSCT均有一定特征性,MSCT对本病的诊断有重要价值.     

Crouzon综合征颅面部的CT表现(附8例报告)

目的 总结Crouzon综合征颅面部的CT表现,提高对该病的认识.资料与方法 回顾性总结分析8例Crouzon综合征颅面部CT征象.结果 CT均表现为眼眶、鼻腔鼻窦、颞骨、颌骨及颅底的异常.眼眶:眶腔变浅,眶外壁夹角增大,眶距增宽以及眼球突出16眼,视神经迂曲7眼,眼外肌增粗10眼;鼻腔鼻窦:鼻腔狭窄伴鼻中隔偏曲8例,鼻窦发育差6例,鼻咽腔变窄7例;颞骨:壶腹型内耳道8例,乳突气化差4例,乳突炎4例;颌骨:上颌骨发育不良,硬腭高拱,口腔顶壁呈倒"V"字形6例;颅底:颅骨内板弥漫性深大脑回压迹,蝶骨大翼狭长菲薄,颞窝变小,前颅窝底低位,颈静脉球窝增大8例,蝶鞍异常5例,乙状窦前位4例.结论 CT能够为Crouzon综合征颌面部的异常改变及其并发症的评估提供客观依据.     

外伤患者眼眶内侧壁解剖性凹陷与骨折的CT鉴别诊断

目的 探讨外伤患者眼眶内侧壁解剖性凹陷与骨折好发部位的CT征象，为鉴别诊断提供依据。方法 选取外伤患者的头颅CT资料，检出眼眶内侧壁解剖性凹陷及眼眶骨折患者共161例，包括眶内壁解剖性凹陷138例、眶内壁骨折23例，对其好发部位、CT表现(骨质异常、邻近关系、间接征象)进行比较。结果 解剖性凹陷好发于眼眶内侧壁中后部，骨折好发于前中部(P<0.05)。眼眶内侧壁解剖性凹陷的CT表现为骨质凹陷/曲度改变，但骨折的CT征象为骨质断裂，伴有眶内积气、软组织肿胀、眼肌或脂肪疝等。结论 眼眶内侧壁解剖性凹陷与骨折的好发部位比较差异有统计学意义；二者CT征象的差异也较明显，可根据有无骨质断裂、眶内积气、软组织肿胀等进行鉴别，鉴别困难时需依靠临床表现、后期随访等。     

多层螺旋CT的多平面重建对眼眶爆裂骨折的诊断价值

目的 探讨多层螺旋CT(MSCT)的多平面重建(MPR)对眼眶爆裂骨折的诊断价值.方法 80例眼眶爆裂骨折的患者行MSCT容积扫描得到常规轴位图像后,通过重建得到MPR图像.结果眼眶爆裂骨折的直接MSCT征象表现为:51例眶壁骨质连续性中断、4例可见粉碎骨折及25例眶壁骨质凹陷及曲度失常;间接征象为56例眶内软组织受压移位、8例见上颌窦内结节状或息肉状突起及34例副鼻窦内积液等.眶内壁骨折以横断面显示最佳(34/80),眶下壁骨折以冠状面及矢状面显示最佳(13/80),混合性骨折以冠状面图像显示最佳(4/80). 结论 MSCT容积扫描的多平面重建能全面、准确地诊断眼眶爆裂骨折,为临床治疗和评估预后提供重要的参考价值.     

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.     

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.     

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.     

Pericerebellar fluid collections in infancy,sequelae of birth injury? A retrospective CT study

Summary Retrospective analysis of axial CT scans from 600 consecutive pediatric patients revealed 37 patients (6%) with abnormal low density pericerebellar spaces. Fourteen of these 37 patients (38%) were diagnosed as cerebellar atrophy, whereas 23 of the 37 patients (62%) were diagnosed as mass-like pericerebellar fluid collections. Detailed analysis of the morphology of these spaces suggests that the CT criteria proposed in this paper distinguish between (a) those low attenuation pericerebellar spaces that represent cisternal dilatation caused by cerebellar atrophy (Group I — Atrophy) and (b) those low attenuation pericerebellar spaces that represent low density mass-like collections of fluid which distort a relatively normal cerebellum (Group II — Collections). Analysis of the medical records of the patients in Group II — Collections reveal a high incidence of prematurity, developmental delay, difficult birth and head trauma, possibly indicating that such collections represent sequelae of birth.     

Localized proton MR spectroscopy of the brain in children

Small-voxel (3.0–8.0 cm³), magnetic resonance (MR) imaging–guided proton MR spectroscopy was performed in 54 patients (aged 6 days to 19 years) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched control subjects without brain disease. A combined short TE (18 msec) stimulatedecho acquisition mode (STEAM) and long TE (135 and/or 270 msec) spin-echo point-resolved spatially localized spectroscopy (PRESS) protocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), choline-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors were readily differentiated from cerebrospinal fluid (CSF) collections. All tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegenerative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with neuronal loss, gliosis, demyelination, and amino acid neuro-toxicity. Preliminary experience indicates that proton MR spectroscopy can contribute in the evaluation of central nervous system abnormalities of infants and children.