MRI在地中海贫血中的应用

地中海贫血患者肝脾肿大,红骨髓增生,并可出现髓外造血,MRI不仅可清楚显示这些变化,还可检测出早期肝内含铁血黄素的沉着.运用不同的成像序列及选用不同的指标,在不同强度场强的磁共振成像系统上可对肝脏含铁血黄素进行定量测量,与肝穿刺活检测定的肝内铁含量具有较高的相关性,运用MRI定量测量进行追踪可提示疾病的进展及治疗的效果.     

MRI在地中海贫血中的应用

地中海贫血患者肝脾肿大,红骨髓增生,并可出现髓外造血,MRI不仅可清楚显示这些变化,不检测出早期肝出含铁血黄素的沉着。运用不同的成像序列及选用不同的指标,在不同强度场强的磁共振成像系统上可对肝脏含铁血黄素进行定量测量,与肝穿刺活检测定的肝内铁含量具有较高的相关性,运用MRI定量测量进行追踪可提示疾病进展及治疗的效果。     

地中海贫血性骨病变的CT、MRI表现

目的:探讨地中海贫血性骨病变的CT、MRI表现及诊断要点,提高该病的诊断水平。方法:回顾性分析17例地中海贫血性骨病变的CT、MRI资料,结合文献,探讨其影像特点及鉴别诊断。结果:17例胸腰椎椎体及附件均受累,其中4例合并颅骨病变,2例合并股骨及胫腓骨病变,5例合并肋骨、胸骨及肩胛骨病变。MRI见骨髓弥漫性信号异常,T_1WI骨髓高信号弥漫性降低,T_2WI呈等信号,STIR T_2WI呈高信号。CT示胸腰椎椎体呈栅栏状改变,骨小梁减少、增粗;其中5例肋骨、胸骨及肩胛骨膨胀改变,4例颅骨板障增厚、板障间呈放射状排列骨小梁;合并椎旁软组织肿块11例,合并肋骨旁软组织肿块4例,增强扫描肿块轻度均匀强化,穿刺活检示髓外造血组织。结论:地中海贫血性骨病变影像学表现有一定的特征,结合病史,可作出正确诊断。     

地中海贫血的骨髓MRI与X线平片对照分析

目的　对比分析地中海贫血的MRI与X线平片表现 ,研究MRI与X线平片对地中海贫血的诊断价值。方法　对 15例地中海贫血行胸、腰、骶椎矢状面及骨盆、股骨上段冠状面MRT1WI和T2 WI;其中 7例同时行头颅、脊柱及四肢X线平片检查。另选择 2 0例无血液病且年龄相匹配的病例作为对照组 ,并对X线与MRI表现进行比较分析。结果　对照组 2 0例 ,T1WI椎体骨髓表现为等信号 ,其内可见条带状或斑片状高信号。T2 WI均表现为均匀的等信号。 15例地中海贫血组的胸腰椎体、髂骨、股骨上段骨髓T1WI信号均有明显的不同程度的均匀性、弥漫性降低 ,T2 WI信号改变不明显。其中 4例MRI见脊椎附件增粗 ,椎体变扁 ,呈弹头样改变 ;4例见到胸段椎管内外多发软组织肿块 ,压迫脊髓或硬脊膜囊 ,手术证实为髓外造血组织。 7例X线平片检查 ,2例未见骨骼异常改变 ,但MRI发现骨髓信号降低 ;另外 5例 ,出现广泛骨质疏松 ,骨小梁增粗、椎体、肋骨变形等骨骼异常。地中海贫血组平均T1值为 (897 4± 75 4 )ms,对照组平均T1值为 (40 1 5± 2 8 1)ms,两者间差异具有显著性意义 (P <0 0 5 )。结论　 (1)地中海贫血的骨髓MRT1WI表现为信号降低 ;(2 )MRI能明确显示脊椎及其附件增大并突入椎管 ,以及椎管内髓外造血灶压迫脊髓或硬脊膜囊的征象。     

重型地中海贫血患者的前肋缘肿块

重型地中海贫血的髓外造血表现为瘤样肿块者常发生于后纵隔,尤以肋骨—脊椎角处多见。其发病机制虽有多种理论,但多数学者认为由于附近脊椎或肋骨的骨髓增生,并越出骨骼向周围扩散蔓延而形成肿块。本文报导3例经肿块部针吸活检证实的本病有髓外造血的患者。其病变不仅于纵隔内、且涉及肋骨前端。X 线表现:极为典型。位于后纵隔者、于脊柱     

磁共振成像在多发性硬化中的应用研究进展

多发性硬化（MS）是由炎性脱髓鞘病变引起的中枢神经系统常见疾病之一。MS病人会出现不同程度的认知功能障碍。近年来出现的扩散加权成像、磁化传递成像、磁共振波谱、磁敏感加权成像和功能磁共振成像等MRI新技术在显示MS特异性征象、进行定量研究、诊断和鉴别诊断、监测病程和疗效以及判断预后等方面取得了重大进展。     

2型糖尿病脑改变的fMRI研究进展

糖尿病为常见代谢性疾病,2型糖尿病(T2DM)患者易罹患认知功能障碍,甚至可进展为痴呆,但T2DM脑部变化特征及发病机制尚未完全阐明.神经影像学为T2DM患者认知功能障碍的发病及进展提供了重要线索,随着MRI技术的进步,扩散张量成像(DTI)、灌注加权成像(PWI)及血氧水平依赖(BOLD)成像等功能磁共振成像(fMRI)广泛应用于T2DM脑病的研究.本文对T2DM相关脑结构、血流及功能改变的fMRI研究进展进行综述.     

RSNA2016中枢神经系统影像学

【摘要】RSNA2016神经系统方面科学报告的热点主要集中在拓展MRI新技术及数据分析方法,主要包括1H-MR血氧定量成像（MOXI）、酰胺质子转移成像（APT）、扩散峰度成像（DKI）、神经突方向离散度及密度成像（neurite orientation dispersion and density imaging,NODDI）等,在中枢神经系统疾病的应用研究主要包括：①1H-MR血氧定量成像（MOXI）测量人脑肿瘤氧张力（PO2）;②MK提供人神经胶质瘤的分子状态的信息;③缺血性卒中病灶酸度分级评估缺血半暗带和侧枝循环的情况;④扩散加权动脉自旋标记（DW-ASL）MRI测量内源性水渗漏评估阿尔茨海默病（AD）脑血管渗漏、定量磁化率成像（QSM）定量分析AD脑内病理性铁沉积;⑤糖尿病脑损伤的认知功能以及精神疾病功能MR成像。本文对相关内容进行简要综述。     

肝脏磁共振扩散加权成像的临床应用

近年来随着计算机软件的开发及磁共振成像(magnetic resonance imaging,MRI)技术的迅速发展,使得MRI扩散加权成像(diffusion weighted imaging,DWI)越来越广泛地应用于肝脏病变的检查,作为一种新发展的MRI功能成像技术,DWI利用组织问扩散系数不同产生的组织对比进行成像,可以在分子水平上反映生物体的组织病理生理、代谢等功能状态.该技术最早用于检测超早期脑梗死,在梗死不超过2 h的时问内脑细胞未发生病理变化而仅有功能上的改变,用DWI能清楚地显示出病变范围.     

磁共振成像新技术在肝脏局灶性病变诊断中的应用

肝脏病变在临床上是一种常见病。MRI技术被认为是诊断肝脏病变最有价值的影像学方法。尤其近年来,新的MRI技术如扩散加权成像、灌注加权成像、波谱成像、弹性成像等技术的快速发展,使MRI不仅用于观察肝脏病变的形态变化特点,而且可以反映肝脏病变的病理过程及分子学的变化。针对MRI新技术在诊断肝脏局灶性病变中的应用及进展进行综述。     

Extramedullary paraspinal hematopoiesis in thalassemia: CT and MRI evaluation.

We present a comparative CT and MRI study of the paraspinal extramedullary hematopoiesis in 32 thalassemic patients. The patients were classified into four groups according to the MRI and CT imaging findings. Active recent extramedullary paraspinal hematopoietic masses show soft tissue behavior in both CT and MRI. Older inactive masses reveal iron deposition or fatty replacement. Combined imaging findings of paraspinal extramedullary hematopoiesis revealed the phase of its evolution and the correct diagnosis.     

Clinical and imaging findings in thalassemia patients with extramedullary hematopoiesis

The purpose was to analyze the imaging features of thalassemia with extramedullary hematopoiesis in 17 patients. The 17 patients were analyzed and examined retrospectively by X-ray, ultrasonography, computed tomography, and magnetic resonance imaging. Nine cases appeared with hepatic enlargement; 12 cases presented with megalocardia or hypodensity; 15 cases had skeletal manifestations, with involvement of the ribs (66.7%), spine vertebra (40.0%), skull (46.7%), and other bones (20%). Five cases showed nonskeletal manifestations, and extramedullary hematopoiesis was found in three cases. A case presented with cholelithiasis, and hemosiderosis of the liver was found in three cases. The signs of the skeletal manifestations and nonskeletal manifestations may be useful for clinical diagnosis.     

Tc-99m nanocolloid scintigraphic imaging of intracranial meningeal extramedullary hematopoiesis in a patient with idiopathic myelofibrosis

Meningeal extramedullary hematopoiesis (EMH) is a rare finding in idiopathic myelofibrosis. Intracranial EMH is typically asymptomatic and sites are usually found by chance. Diagnosis of EMH is difficult, based on clinical circumstances and the use of different diagnostic imaging modalities, such as CT, MRI or radionuclide imaging. We present a case with intracranial medullary hematopoiesis due to idiopathic myelofibrosis diagnosed with Tc-99m nanocolloid scintigraphy. Cranium SPECT images that were performed with Tc-99m nanocolloid showed increased radiotracer uptake in the bilateral parietal, bilateral frontal and left occipital bones and especially in falx cerebri of sinus sagittalis superior. In Tc-99m MDP bone scintigraphy, increased osteoblastic activity in the left frontal and parietal bones, in shoulders, knee and ankle joints, and in both metatarsal bones were seen. After gadodiamid injection, Tl weighted MRI showed diffuse contrast increased in the meningeal areas surrounding the brain. A biopsy of the mass revealed extramedullary hematopoiesis composed of erythroblasts, mature and immature myeloid cells, and megakaryocytes. It was deduced that these described foci of EMH.     

Thoracic localizations of extramedullary erythropoiesis]

A series of 8 patients affected with hemolytic beta thalassemia with intrathoracic extramedullary hematopoiesis is reviewed. All patients were studied with conventional radiologic techniques and with CT and MR imaging. There was good correlation between conventional radiology findings and MR and CT results. CT and MR imaging were useful to evaluate not only the topographic localization of the masses of extramedullary hematopoiesis, but also their functional status. On CT, masses in the active phase exhibit high density and marked enhancement after i.v. administration of contrast medium; in the remission phase, the masses are hypodense, due to fat substitution, and unenhanced. On MR images, the active phase is characterized by a relatively low signal in both T1 and T2, while in the remission phase high signal is observed in both T1 and T2. A sign is seen on MR images which is considered as pathognomonic: a peripheral ring with high signal. The use of CT and MR imaging allows detailed information on the evolution of the hemolytic disease to be obtained. These pieces of information cannot be obtained with conventional radiology, which allows, at any rate, the correct diagnosis to be made.     

Mass-like extramedullary hematopoiesis: imaging features

Purpose

To report the imaging appearances of mass-like extramedullary hematopoiesis (EMH), to identify those features that are sufficiently characteristic to allow a confident diagnosis, and to recognize the clinical conditions associated with EMH and the relative incidence of mass-like disease.

Materials and methods

We retrospectively identified 44 patients with EMH; 12 of which (27%) had focal mass-like lesions and formed the study group. The study group consisted of 6 male and 6 female subjects with a mean age of 58?years (range 13–80?years). All 12 patients underwent CT imaging and 3 of the 12 patients had undergone additional MR imaging. The imaging characteristics of the extramedullary hematopoiesis lesions in the study group were analyzed and recorded. The patient’s clinical presentation, including any condition associated with extramedullary hematopoiesis, was also recorded.

Results

Ten of the 12 (83%) patients had one or more masses located along the axial skeleton. Of the 10 patients with axial masses, 9 (90%) had multiple masses and 7 (70%) demonstrated internal fat. Eight patients (80%) had paraspinal masses and 4 patients (40%) had presacral masses. Seven patients (70%) had splenomegaly. Eleven of the 12 patients had a clinical history available for review. A predisposing condition for extramedullary hematopoiesis was present in 10 patients and included various anemias (5 cases; 45%), myelofibrosis/myelodysplastic syndrome (4 cases; 36%), and marrow proliferative disorder (1 case; 9%). One patient had no known predisposing condition.

Conclusion

Mass-like extramedullary hematopoiesis most commonly presents as multiple, fat-containing lesions localized to the axial skeleton. When these imaging features are identified, extramedullary hematopoiesis should be strongly considered, particularly when occurring in the setting of a predisposing medical condition.     

Clinical usefulness of In-111 chloride and Tc-99m Sn colloid scintigraphy in the diagnosis of intrathoracic extramedullary hematopoiesis

We report a case of intrathoracic extramedullary hematopoiesis associated with hemolytic anemia. While the paravertebral localization of the lesions demonstrated on CT and MRI was suspicious of intrathoracic extramedullary hematopoiesis, In-111 chloride and Tc-99m Sn colloid bone marrow scintigraphies showing a bone marrow element of the lesion were useful to confirm the diagnosis.     

快速FLAIR技术在椎管内病变MRI中的应用及价值

目的介绍快速FLAIR技术在椎管内病变MRI中的应用并评价其价值。方法用0．5T超导型MR扫描仪在常规T     

Painful Spinal Cord Compression as a Complication of Extramedullary Hematopoiesis Associated with β-Thalassemia Intermedia

BACKGROUND: Spinal cord compression due to extramedullary hematopoiesis (EMH) is a rare manifestation of thalassemia. General therapeutic recommendations do not exist. CASE REPORT: We report a 23 year old male with beta-thalassemia intermedia and back pain resistant to analgetic medication. Multiple extradural mass lesions on MRI of the lumbar spine were identified. Hypertransfusion was initiated with no relief of symptoms. Low dose irradiation with 20 Gy had to be added to achieve adaequate response. RESULT: With the combination of transfusion therapy and irradiation a rapid and long-lasting relief of symptoms was achieved. 12 month post irradiation the patient is free of pain and neurological symptoms. CONCLUSION: Clinical awareness of this phenomenon and knowledge of the available treatment option is essential for successful outcome. In treatment refractory symptoms irradiation could successfully contribute to a rapid therapeutic response.     

MRI features of epidural extramedullary hematopoiesis

A case of beta-thalassemia intermedia with spinal cord compression due to extramedullary hematopoiesis, which was successfully treated by blood transfusion, is presented. Emphasis was made on the MRI appearance of extramedullary hematopoiesis on different pulse sequences. The theories that aimed to explain the involvement of the epidural space by extramedullary hematopoiesis are discussed.     

Fat-containing lesions of the liver: cross-sectional imaging findings with emphasis on MRI

OBJECTIVE: The purpose of this pictorial essay is to identify different types of liver lesions that contain fat. Cross-sectional imaging findings of fat- or lipid-containing lesions can help in characterizing focal liver lesions. We searched our archive retrospectively and reviewed the literature for fat-containing liver lesions and identified 16 different types. CONCLUSION: These lesions can contain macroscopic fat (i.e., angiomyolipoma, lipoma, liposarcoma, hydatid cyst, lipopeliosis, adrenal rest tumor, pseudolipoma, hepatic teratoma, pericaval fat, extramedullary hematopoiesis, and metastases) or intracellular lipid (i.e., focal steatosis, adenoma, focal nodular hyperplasia, regenerative nodules, and hepatocellular carcinoma). CT, MRI, and sonographic findings of these lesions can help in characterization by allowing specific diagnosis or narrowing the differential diagnosis of liver lesions.