MRI of orbital hydroxyapatite implants

Our aim was to use MRI for the postsurgical assessment of a new form of integrated orbital implant composed of a porous calcium phosphate hydroxyapatite substrate. We studied ten patients 24–74 years of age who underwent enucleation and implantation of a hydroxyapatite ball; 5–13 months after surgery, each patient was examined by spinecho MRI, with fat suppression and gadolinium enhancement. Fibrovascular ingrowth was demonstrated in all ten patients as areas of enhancement at the periphery of the hydroxyapatite sphere that extended to the center to a variable degree. The radiologist should aware of the MRI appearances of the coralline hydroxyapatite orbital implant since it is now widely used following enucleation. MRI is a useful means to determine successful incorporation of the substrate into the orbital tissues. The normal pattern of contrast enhancement should not be mistaken for recurrent tumor or infection.     

眼眶MR成像IDEAL技术脂肪抑制效果和图像质量评价研究

目的:对比分析眼眶三点法非对称回波水脂分离成像(IDEAL)与短反转时间反转恢复序列(STIR)和化学饱和法的脂肪抑制效果和图像质量,探讨IDEAL在眼眶成像中的应用价值.方法:共260例患者进行眼眶MRI扫描,包括143例分别采用化学饱和法(41例)、STIR(52例)和IDEAL(50例)序列行冠状面T2 WI,以及50例和67例分别采用化学饱和法和IDEAL序列行增强后冠状面T1 WI扫描.对眼眶、鼻窦各解剖部位的图像质量和脂肪抑制效果进行主观评分,并且测量颞肌、内直肌和外直肌的信噪比,比较三种脂肪抑制技术的脂肪抑制效果和图像质量.结果:IDEAL组T2 WI对外直肌、内直肌、视神经和海绵窦的图像质量评分高于化学饱和法T2 WI(P＜0.05),对眼眶及邻近骨骼的脂肪抑制效果评分高于化学饱和法T2WI(P＜0.05),但对颞肌间隙脂肪抑制效果的评分低于化学饱和法T2WI(P=0.004).IDEAL T2WI对眼外肌、视神经、海绵窦的图像质量评分高于STIR序列(P＜0.05),对鼻甲、上颌窦内壁的图像质量评分低于STIR序列(P＜0.05);对眼眶、蝶骨大翼和颧骨的脂肪抑制效果评分高于STIR序列(P＜0.05),对颞肌间隙脂肪抑制效果评分低于STIR序列(P=0.000).IDEAL T2WI上颞肌的信噪比高于化学饱和法T2 WI(P=0.013),颞肌、内直肌和外直肌的信噪比高于STIR序列(P=0.000).增强后IDEAL T1WI对内直肌、下直肌、上颌窦内壁的图像质量评分高于化学饱和法T1WI(P＜0.05),对中鼻甲的图像质量评分低于化学饱和法(P＜0.05);对颞肌间隙和翼腭窝的脂肪抑制效果评分高于化学饱和法(P＜0.05),对肌锥外间隙脂肪抑制效果评分低于化学饱和法(P＜0.05).结论:IDEAL对眶内及眶周结构的显示效果优于化学饱和法和STIR序列,是目前眼眶MRI的最佳脂肪抑制技术.     

眼眶原发性淋巴瘤的MRI表现

目的：探讨眼眶原发性淋巴瘤的磁共振影像学表现,以提高其诊断的准确率。方法对11例经手术病理证实的原发性淋巴瘤的临床和影像学资料进行回顾性分析。结果眼眶原发性淋巴瘤的MRI特征如下：①好发于隔前眶周,以眼眶外上象限为主,包括眼睑、泪腺、结膜等;②无包膜,沿眼眶间隙蔓延塑形生长;③平扫T1WI呈等信号,T2WI呈稍高信号,增强呈中-重度强化;④DWI上表现为高信号;⑤边界较清晰,对周围组织结构侵犯、破坏少见;⑥囊变少见,出血、钙化罕见。结论眼眶原发性淋巴瘤MRI表现具有一定的特征性,MRI多方位成像可对肿瘤明确定位,并有助于定性诊断。     

常规MRI联合DWI在良、恶性眼眶孤立性纤维瘤诊断中的应用

目的 分析良、恶性眼眶孤立性纤维瘤(SFT)常规MRI图像和DWI特点,提高本病的认识.方法 回顾性分析29例病理证实的眼眶SFT的MRI平扫、增强和DWI特点,测量病灶实质部分的平均表观扩散系数(mean apparent diffusion coefficient,ADCmean)值进行统计学分析.结果 良性SFT...     

Idiopathic intracranial hypertension: orbital MRI

The case is reported of a patient with idiopathic intracranial hypertension examined with magnetic resonance imaging. Marked enhancement of the optic nerve heads was found, which might be related to blood-retinal barrier breakdown related to a sudden rise in intracranial cerebrospinal fluid pressure.     

Cerebral fat embolism studied with MRI and SPECT

Summary In a patient with fat embolism to the brain CT showed no abnormality. MRI performed after recovery from coma, when the patient had aphasia and quadriparesis, demonstrated multiple high signal abnormalities in the white matter on both T1- and T2-weighted images. HMPAO-SPECT showed left-sided hypoperfusion which resolved in parallel with clinical improvement 1 month later.     

眶壁转移瘤的CT和MRI诊断

目的分析研究眶壁转移瘤的CT和MRI特点,提高诊断准确率.方法回顾性分析23例经手术病理证实的眶壁转移瘤的CT和MRI表现,成人组16例,儿童组7例.所有病例均行CT平扫与MR平扫和增强扫描.结果16例成年患者CT表现均为溶骨性骨质破坏和眼眶不规则肿块,9例骨质破坏区邻近的颅内可见扁平不规则肿块;16例MRI表现为骨质破坏区邻近的眼眶和颅内均可见略长T1、略长T2信号的不规则软组织影,增强后呈明显强化.7例儿童患者CT表现均为溶骨性骨质破坏和眼眶不规则肿块,其中2例可见垂直针状高密度影,3例骨质破坏区邻近的颅内可见扁平不规则软组织肿块;MRI显示7例骨质破坏区邻近的眼眶内和6例颅内可见略长T1、略长T2信号不规则的软组织影,其中1例为双侧,增强后呈明显强化;7例双侧眶骨、4例斜坡和双侧岩尖及1例双侧颞骨鳞部骨髓腔呈略长T1、略长T2信号影,增强后呈明显强化.结论眶壁转移瘤的CT和MRI表现有一些特点,有助于诊断和鉴别诊断.     

Proteus syndrome: craniofacial and cerebral MRI

The Proteus syndrome is a rare hamartoneoplastic syndrome that may affect the brain, skull, and extracranial head and neck. We present a case with severe, characteristic findings. Brain abnormalities are not common in Proteus syndrome; when present, hemimegalencephaly and migrational disorders are typically seen, commonly with an associated seizure disorder. Maxillary and mandibular dysmorphism may occur, including unilateral condylar hyperplasia. Subcutaneous fatty, fibrous, lymphangiomatous masses commonly seen in this syndrome may involve the neck and face, leading to disfigurement and potential airway compromise. Received: 9 September 1998 Accepted: 28 December 1998     

Cranial MRI and MR angiography in Menkes' syndrome

We report two boys with Menkes' syndrome who underwent cranial MRI and MR angiography (MRA). In both, CT and MRI revealed progressive cerebral atrophy with a subdural haematoma or effusion. Delayed myelination or dysmyelination of the white matter was suggested. Tortuosity of the cervical and intracranial vessels was well demonstrated by MRA, obviating more invasive conventional angiography should it be thought necessary to demonstrate the characteristic systemic vascular changes of this syndrome.     

Change in signal intensity on MRI of fat in the head of markedly emaciated patients

The amount of fat in various parts of the body decreases in emaciated patients, but responds differently to disease processes. The order of disappearance of fat in various parts of the head has rarely been studied with MRI. We imaged ten patients with anorexia nervosa and one cachectic patient with a psychiatric disorder with a 1.5 T imager. Signal intensities of bone marrow of the skull, subcutaneous tissue, and orbits were assessed on T1- and T2-weighted images, and correlated with the body mass index (BMI) and haemoglobin concentration (Hb). On T1-weighted images, five patients (BMI 15.6-17.8 kg/m2, mean 16.6 kg/m2; Hb 10.1-14.2 g/dl, mean 13.8 g/dl) showed the normal pattern of fat. One (BMI 13.6 kg/m2, Hb 10.4 g/dl) lost the high signal of bone marrow, but high signal of subcutaneous tissue and the orbits was preserved. High signal from bone marrow and subcutaneous tissue disappeared in three patients (BMI 11.5-13.5 kg/m2, mean 12.5 kg/m2; Hb 7.9-9.7 g/dl, mean 8.7 g/dl), but orbital high signal was preserved. The remaining two patients (BMI 9.3 and 13.5 kg/m2, mean 11.5 kg/m2; Hb 7.6 and 8.9 g/dl, mean 8.3 g/dl) showed complete loss of high signal from fat in the head. The order of disappearance of fat (bone marrow, subcutaneous fat, then orbits) correlated with both BMI and Hb. Atrophy of bone marrow was demonstrated on T2-weighted images in five patients with BMI 13.5 kg/m2 or less, and Hb 9.7 g/dl or less.     

Vogt-小柳-原田综合征眼部MRI表现

目的 探讨Vngt-小柳-原田综合征(VKHS)的眼部MRI表现及其诊断价值.方法 对14例(男7例,女7例,年龄10～62岁)经临床确诊的VKHS患者的眼部MRI表现进行回顾性分析.结果 14例(28眼)在MRI均表现为视网膜.脉络膜复合体增厚,呈等T1、等T2信号.6例(12眼)伴有视网膜脱离,5例(10眼)伴有睫状体的异常增厚和强化,2例(4眼)伴有视神经炎.11例(22眼)行增强扫描,可见病变呈明显均匀强化.结论 MRI可很好地显示该病的眼部表现和累及范围,有助于VKHS的诊断及随访观察.     

肝脏炎性假瘤MRI表现（附21例分析）

目的：探讨肝脏炎性假瘤的MRI表现并分析其鉴别诊断。方法：21例均行MRI平行与增强扫描,且经手术病理证实。结果：21例计23个病灶,多位于右叶,呈圆或类圆形。平扫T1WI为等或稍高信号,增强后动脉期多不强化,而门静脉及延迟扫描为周边环状强化为主。结论：肝脏炎性假瘤MRI表现有其特殊性,有助于与其他病变的鉴别诊断。     

Hallervorden-Spatz综合征的MRI诊断

目的：探讨Hallervorden-Spatz综合征的颅脑M RI诊断价值，提高对该病的认识。方法回顾性分析2007年2月～2012年4月经临床证实为 Hallervorden-Spatz综合征的4例患者颅脑MRI资料。结果 Hallervorden-Spatz综合征颅脑M RI表现为：双侧苍白球、黑质T2 WI像对称性低信号，苍白球低信号的前内侧出现斑点状高信号，即典型的“虎眼征”。SWI像上病灶呈低信号，MRS检查可见NAA、NAA/Cr及Cho/Cr下降。结论 Hallervorden-Spatz综合征具有典型的MRI表现，MRI检查在Hallervorden-Spatz综合征中有重要的诊断价值。     

Klippel-Trenaunay综合征的MRI诊断

目的分析Klippel—Trenaunay综合征（KTS）的MRI影像表现，评价其在KTS诊断中的作用。方法对经临床和影像检查符合KTS诊断标准的31例KTS患者患肢进行MR常规扫描、MR血管成像（MRA）、静脉血管成像（MRV）和X线顺行静脉造影（XRV）检查，并观察肢体及静脉病变情况。结果12例MRI发现肢体软组织内血管瘤。软组织肥大27例。浅静脉曲张21例。静脉畸形27例。20例同时行MRV与下肢XRV的患者显示浅静脉曲张和特征性坐骨神经均分别为17和11例。下肢XRV检查显示静脉属支增多10例；MRV显示静脉属支增多15例和静脉行径异常4例。MRV显示深静脉异常8例，下肢XRV显示深静脉异常7例。结论MRI是诊断KTS有效和可靠的影像检查方法。     

MRI of orbital schwannomas

The literature on MRI of orbital schwannomas is limited. The appearances in three patients with an orbital schwannoma were reviewed. A superior orbitotomy through a subfrontal craniotomy revealed a schwannoma in all cases. MRI characteristics of very low signal on T 1-weighted images and homogeneous postcontrast enhancement may be helpful for differentiating schwannomas from other intraconal masses. Received: 21 June 1999/Accepted: 20 September 1999     

鼻眶部软骨肉瘤的CT和MRI诊断

目的探讨鼻眶部软骨肉瘤的CT和MRI表现,提高其诊断准确性.方法回顾性分析12例经病理证实的鼻眶部软骨肉瘤的影像学资料.结果12例中起源于鼻腔4例,鼻窦5例,眼眶3例.普通型软骨肉瘤8例,去分化型和间叶型软骨肉瘤各2例.CT表现：肿瘤呈卵圆形2例,分叶形6例,不规则形4例;内见散在点、环、结节、斑片状或不定型钙化;边界清楚9例,模糊3例;3例增强后呈不均匀低度强化.7例鼻软骨肉瘤出现骨质破坏,并侵犯周围结构;眼眶软骨肉瘤骨质破坏1例,并侵犯同侧额部.MRI表现：普通型和去分化型软骨肉瘤在T1WI上表现为低信号6例（与脑组织比较,以下同）,等信号4例,T2WI表现为高信号8例,等信号2例,信号不均匀,内见散在低信号区,增强后呈轻到中度不均匀强化,其中5例普通型软骨肉瘤边缘及间隔呈明显强化,内部不强化,呈斑驳状3例,蜂窝状2例;间叶型软骨肉瘤在T1、T2WI均呈等信号,增强后呈均匀和不均匀显著强化各1例.结论CT是鼻眶部软骨肉瘤诊断和鉴别的主要影像检查方法;典型间隔及边缘强化的MRI表现也能够提示诊断,MRI可更清楚、准确地显示病变侵犯的范围,为治疗提供可靠依据.     

Tay's syndrome: MRI

Tay's syndrome is a trichothiodystrophy associated with congenital ichthyosis. We report the findings on MRI and spectroscopy in a young girl with sparse, short, ruffled hair, dry skin and delayed milestones. T2-weighted images showed prominent diffuse confluent increase in signal symmetrically in all the supratentorial white matter. These findings are similar to those in a previously described case, and consistent with dysmyelination. Spectroscopy showed increased myoinositol and decreased choline. Received: 7 March 2000 Accepted: 13 April 2000     

马凡综合征主动脉病变MRI诊断的研究

目的：评价ＭＲＩ对马凡综合征主动脉病变诊断的价值。材料与方法：分析了２０例马凡综合征主动脉病变的ＭＲＩ所见，并与１１例非马凡综合征所致的升主动脉扩张或动脉瘤进行对照研究。结果：主动脉窦和近段升主动脉瘤样扩张是马凡综合征最重要而常见的心血管病变，“瘤体”与正常段或轻度扩张的主动脉分界清楚是颇具特征性的马凡综合征心血管病变，继发于主动脉瓣狭窄和（或）关闭不全的升主动脉扩张大多呈普遍轻度扩张，而主动脉窦大多无明确扩张，其ＭＲＩ所见与马凡综合征升主动脉病变明显不同。结论：ＭＲＩ在马凡综合征主动脉病变的诊断中有优良的价值。     

MRI of the postoperative lumbar spine: triple-dose gadodiamide and fat suppression

In ten patients who had undergone lumbar laminectomy, visual assessment of epidural scar enhancement and diagnostic confidence was performed after 0.1 mmol/kg gadodiamide intravenously, again after a further 0.2 mmol/kg, and once more using a fat-suppression sequence. The single-dose contrast-enhanced T1-weighted images showed clear enhancement of epidural scar in eight cases, and clearly improved diagnostic confidence as regards scar and/or disc herniation in six. Triple-dose contrast-enhanced images showed further increase in epidural enhancement clearly in only two cases and marginally in six, with no significant increase in diagnostic confidence. Fat-suppression, performed in eight cases, showed a further clear increase in epidural enhancement in seven cases, but again no increase in diagnostic confidence. In one patient with arachnoiditis contrast enhancement and diagnostic confidence increased only slightly after each contrast injection, and again with the fat-suppression sequence. Increasing contrast medium dose was thus not useful following laminectomy when epidural scarring obscures a possible recurrent disc herniation. Use of fat suppression may, however, permit reduction of the dose of contrast medium necessary to provide adequate scar enhancement. Received: 30 August 1996 Accepted: 24 October 1996     

MRI in a patient with the Worster-Drought syndrome

We describe a patient with the Worster-Drought syndrome (congenital suprabulbar paresis), thought to be a failure of development of the corticobulbar tracts. MRI showed bilateral perisylvian cortical dysplasia. Received: 5 April 1999 Accepted: 15 December 1999