低场MRI在跟腱损伤中的应用价值

目的 探讨低场MRI在跟腱损伤诊断及术后随访中的应用价值.方法 15例跟腱损伤患者经低场四肢专用磁共振多序列检查,其中7例行缝补术后随访,分析其低场MRI表现,并与5例正常跟腱比较.结果 5例正常跟腱矢状面各序列显示呈条带状均匀低信号.1例利器切割伤显示跟腱下段大部分中断,断面整齐.5例部分撕裂显示跟腱增粗,内部信号不均匀,部分纤维束连续.9例完全性撕裂均显示跟腱连续性完全中断,2例表现为肌腱普遍增粗、形态不规则,T1WI 、T2WI上信号弥漫增高,7例表现为肌腱局部增粗、断裂,断端回缩呈＂杵＂状改变或扭曲,T1WI 、T2WI上中断处呈高信号.7例术后随访显示高信号强度逐渐下降.结论 低场磁共振能够明确地显示跟腱损伤的部位、程度及形态、信号改变,在跟腱损伤的诊断和术后随访方面能提供重要价值.     

广州管圆线虫病患者头颈部MR检查

目的 分析广州管圆线虫感染人体后有症状患者的头颈部MRI表现.方法 对74例有症状患者进行MRI和CT检查.MRI检查包括常规T1WI、T2WI、T2-FLAIR序列以及静脉注射钆对比剂后T1WI增强扫描.脑部CT检查均为平扫, 分析CT和MRI所见.对影像表现异常的患者,MR 随访1~3次.结果 33例患者MRI表现异常,包括单纯软脑膜异常强化17例,单纯脑实质异常信号3例,单纯脊髓异常信号1例,脑实质与软脑膜同时受累11例,脊髓与软脊膜同时受累1例.脑实质与脊髓内病变多表现为长T1、长T2信号,灶性分布;T1WI增强扫描时病灶多呈结节状强化.5例脑实质和脊髓的长T1、长T2异常信号无强化表现.结论 头颈部MRI检查有助于了解中枢神经系统广州管圆线虫病的病变程度,但绝大多数MRI所见缺乏特征性.     

Focal nodular hyperplasia of the liver: detection and characterization with plain and dynamic-enhanced MRI

Background: We compared nonenhanced and dynamic gadolinium (Gd)–enhanced magnetic resonance imaging (MRI) appearances of hepatic focal nodular hyperplasia (FNH) as depicted with breath-hold MR sequences and assessed the detectability of the individual MR sequences used. Methods: We retrospectively reviewed 48 consecutive patients with FNH. All patients underwent nonenhanced (T1 fast low-angle shot [FLASH] and T2 half-Fourier acquisition [HASTE]) and dynamic Gd-enhanced (T1 FLASH) MRI between December 1997 and March 2000. Individual MR sequences were analyzed separately for number of lesions, signal intensity features, dynamic enhancement pattern, and the presence and enhancement profile of a central scar. Ninety-five percent confidence intervals of absolute discrepancy were calculated to define differences in lesion detection. Results: Seventy-seven lesions were found in 48 patients. Nonenhanced FLASH imaging depicted 59 (76.6%) lesions in 45 patients. HASTE images showed 55 (71.4%) lesions in 44 patients. On T1- and T2-weighted images, lesions appeared predominantly hypointense (69.5%) and hyperintense (72.7%), respectively. Arterial and portal venous dominant phase Gd-enhanced MRI demonstrated all 77 lesions (100%), most of which showed hypervascular (94.8%), homogeneous (97.4%), and incomplete (except the central scar: 58.4%) enhancement in the arterial phase. Portal venous phase images showed lesion isointensity (50.6%) or moderate hyperintensity (46.8%) with complete enhancement (central scar: 94.8%). A central scar was detected on nonenhanced T1-weighted images (hypointense: 100%), T2-weighted images (hyperintense: 100%), arterial phase (hypointense: 59.7%) and portal venous phase (hyperintense: 71.4%) Gd-enhanced images in 78%, 69.1%, 77.9%, and 75.3% of tumors, respectively. Conclusion: Arterial and portal venous phase Gd-enhanced T1-weighted sequences are superior to nonenhanced images in the detection of FNH. Typical MRI appearances include hypointensity on T1-weighted and hyperintensity on nonenhanced T2-weighted images. Most commonly, FNH shows a homogeneous (without scar) and strong enhancement during the arterial phase, with lesion isointensity or slight hyperintensity during the portal venous phase. Received: 15 May 2001/Revision accepted: 22 August 2001     

恶性脑膜瘤的MRI诊断与鉴别诊断

目的探讨恶性脑膜瘤的MRI表现及鉴别特征。方法对经手术病理证实的23例恶性脑膜瘤的MR图像进行分析。结果肿瘤T1加权像以等、低混杂信号多见,T2加权像呈均匀或混杂高信号;可见囊变及出血信号;增强扫描肿瘤强化不均匀;肿瘤侵犯半球呈磨伞征;边缘不规则或呈锯齿状,硬膜尾征呈粗短不规则形;部分病例向颅内外浸润。结论恶性脑膜瘤MRI表现具有一定特异性,提高识别恶性脑膜瘤的MR表现,有利于临床术前诊断及综合治疗,但须与良性脑膜瘤、胶质母细胞瘤及转移瘤鉴别。     

MRI在多发性肌炎、皮肌炎诊疗中的应用

目的探讨多发性肌炎（PM）、皮肌炎（DM）患行肌肉MRI农现,计价MRI在PM、DM诊断和疗效评估中的价值。材料与方法对临床资料完整的15例PM和21例DM患者的肌肉MR图像进行回顾分忻,所有病例均行治疗前双侧大腿肌肉MRI检查,8例患者进行了治疗后MRI复查。MRI检查序列包括快速门旋回波（TSE）T1WI、T2WI、短时反转恢复序列（STIR）。结果36例PM、DM中31例大腿肌肉MRI上存在异常,异常表现包括肌肉炎性水肿30例、肌筋膜炎7例、皮下软组织水肿14例、肌肉萎缩伴脂肪浸润5例。8例治疗后复AMRI均显示炎性水肿较治疗前明显好转、吸收。结论MRI枪查是一种敏感、无创的检查手段,其在PM、DM诊断、疗效评估中有重要应用价值：肌肉和皮下组织炎性水肿是PM、DM患者最常见的肌肉MRI表现。     

低场强核磁共振在跟腱外伤中的应用

目的:探讨核磁共振成像技术(MRI)在跟腱外伤中的诊断价值。材料与方法:回顾性分析我院于2007年7月至2010年9月期间收治的19例经手术证实的外伤性跟腱损伤患者的临床资料,归纳其MRI表现特征。结果:跟腱完全性损伤的患者8例,其MRI表现特征为跟腱肌腱不完全增粗,形态不规则,肌腱束连续性完全中断,肌腱内T1WI、T2WI上呈混杂性信号。跟腱部分性损伤11例,MRI表现特征为肌腱增粗,肌腱内T1WI、T2WI上呈局限性高信号,肌腱束内毛糙、不规则。手术病理证实9例完全性损伤,10例部分性损伤。结论:MRI能清晰显示跟腱形态及其内部结构,准确判断跟腱损伤的性质、范围,有利于临床诊治。     

骨原发性淋巴瘤的MRI表现

目的:探讨骨原发性淋巴瘤的MRI表现及其诊断价值。方法:对8例经手术病理证实,MRI资料完整的骨原发性淋巴瘤进行回顾性分析。8例均行MRI平扫和增强。结果:7例为单骨发病,1例为多发。7例为B细胞源性,1例为T细胞源性。病变在T1WI多呈等或稍低信号,T2WI多呈等或稍高信号,呈明显均匀或不均匀强化。8例均合并大小不等的软组织肿块影。结论:骨原发性淋巴瘤主要发生于脊柱和骨盆,多侵犯单骨。软组织肿块大、骨膜反应轻、T2WI信号不高,增强扫描多呈明显强化,是其相对特征影像学特点。平扫和增强MRI检查对骨原发性淋巴瘤定性诊断有较高的诊断价值。     

MR imaging in intracystic hemorrhage of simple hepatic cysts

Intracystic hemorrhage of simple hepatic cysts is one of the most frequent complications. Ul-trasonography (US) and computed tomography (CT) may show abnormal findings and mimic other diseases. We describe magnetic resonance (MR) imaging in four patients with intracystic hemorrhage confirmed by surgery or percutaneous aspiration. In all cases the lesions were hyperintense on both T1- and T2-weighted sequences. In three of the four cases the signal was heterogeneous on T1-weighted sequences. Two cases of a thickened wall and one case of a fluid-fluid level were also observed. We suggest that MR imaging may be helpful to differentiate intracystic hemorrhage from other cystic lesions by showing high signal on T1- and T2-weighted sequences.     

韧带样型纤维瘤病的CT和MR诊断

目的本文分析韧带样型纤维瘤病CT和MR平扫和增强特征,探讨影像学诊断价值。方法回顾性分析12例经手术病理证实的韧带样型纤维瘤病病例,术前经MR检查9例,CT检查3例。MR检查序列包括SET1WI、FSET2WI、STIR、SPGR平扫和多期的MR动态增强。所有病例影像资料均经3名高年资医师分别阅片,分别确定病变浸润范围、信号特征和强化程度等,并与手术病理对照。结果12例韧带样型纤维瘤病病例中,腹部外7例(颈部2,肩1,四肢4),腹壁型3例(腹壁肌肉),腹内型2例(肠系膜1,腹膜后1)。肿瘤直径3.7～21.8cm,<5cm3例,5～10cm7例,>10cm2例,平均7.2cm。浸润性生长9例,膨胀生长3例。密度或信号相对均匀5例,不均匀7例。9例MR检查病例中,SET1WI呈等信号5例,略高信号4例。所有病例T2WI信号略高于肌肉,STIR为高信号,各序列常见低信号致密胶原纤维成分。无论肿瘤大小,STIR都清楚显示肿瘤边缘和境界。5例MR动态增强病例中,动脉期明显强化4例,显著强化1例;门脉期强化程度与动脉期相仿,强化趋于均匀。3例CT检查病例,肿瘤密度与肌肉相仿,密度均匀,形态不规则,境界欠清楚。1例病灶内可见形态正常的血管影。结论韧带样型纤维瘤病形态多不规则,信号不均匀,境界模糊不清,MRT2WI为略高信号,STIR为高信号,强化显著,病灶内常见致密胶原纤维形成低信号。CT和MR特征明显,多数病变术前可以诊断。     

Magnetic resonance imaging in retropharyngeal tendinitis

Cephalalgia Seven consecutive patients with acute retropharyngeal tendinitis underwent plain X-ray and magnetic resonance imaging (MRI) of the cervical spine. All seven had marked soft tissue swelling anterior to C1 and C2 on plain X-ray, and soft tissue calcification at this level was present in five of them. On MRI, there was markedly increased signal intensity on T₂-weighted images in the acute phase and intermediate signal intensity on T₁-weighted images, anterior to the level of C1 and C2, often extending as far down as C6. These changes correlated well with the soft tissue swelling seen on conventional X-ray of the cervical spine. The maximum mid-sagittal thickness of the soft tissues was significantly greater in the tendinitis patients ( p < 0.001) than in 12 control subjects free of symptoms from the pharynx or the cervical spine. Treatment with non-steroidal anti-inflammatory drugs rapidly alleviated symptoms, and at follow-up MRI showed regression or complete restitution of the changes. In conclusion, MRI can visualize the edematous changes in the longus colli muscle and adds useful diagnostic information in suspected cases of acute retropharyngeal tendinitis.     

四肢侵袭性纤维瘤病的MRI表现

目的探讨四肢侵袭性纤维瘤病（AF）的磁共振成像（MRI）表现。方法回顾分析11例经手术病理证实的四肢AF的MRI表现,其中7例加做增强扫描。结果肿瘤在T1WI呈等信号11例;脂肪抑制FSET2WI高信号10例,1例为混杂信号;7例静脉注射GdDTPA后脂肪抑制SE T1WI明显强化。10例在所有序列均见到低信号带。8例边界不清,1例部分边界清楚,2例边界清楚,并可见完整的包膜。3例侵犯相邻骨质,其中1例累及髓腔;3例侵犯皮下脂肪。所有病变均未见坏死出血和囊变,瘤周未见水肿。结论四肢AF有不同于其他身体部位AF的MRI特征,MRI对四肢AF的诊断、术前规划和术后监测有重要意义。     

Value of endorectal coil versus body coil MRI for diagnosis of recurrent pelvic malignancies

Background: To compare endorectal coil magnetic resonance imaging (MRI) with body coil MRI in detecting local recurrence of gynecologic tumors and prostate and rectal cancers. Methods: Forty-six patients with suspected recurrent pelvic malignancies (13 gynecologic, 15 prostatic, and 18 anorectal primaries) were enrolled in the study. Axial T1- and T2-weighted body coil images and T2- and contrast-enhanced T1-weighted axial endorectal coil images were obtained on a 1.5 T system. Results of the MR examinations were compared with histogical findings and follow-up examinations with respect to the diagnostic accuracy and diagnostic confidence for assessment or exclusion of local recurrence. Results: Recurrent disease was histologically confirmed in eight patients with primary gynecologic malignancies, seven with suspected prostatic recurrence, and seven with suspected anorectal recurrence. Overall, accuracy of body coil MRI was 67% for gynecologic tumors, 36% for prostatic recurrences, and 59% for rectal recurrences. T2- and contrast-enhanced T1-weighted endorectal sequences yielded similar results, with an accuracy of 73% for depiction of gynecologic recurrence, 77% for prostatic recurrence, and 77% for rectal recurrence. The difference in accuracy between body coil and endorectal coil examinations was statistically significant (p < 0.05) only for prostatic cancer. Diagnostic confidence was, however, significantly improved (p < 0.05) in all tumors (T2-weighted endorectal coil examination was superior to T2-weighted body coil images in 71% of cases). Conclusion: Although the results of endorectal coil MRI are only slightly superior to those of body coil MRI for the detection of recurrent gynecologic and anorectal tumors, diagnosis can be made with greater diagnostic confidence in many cases. For detection of prostatic recurrence, endorectal MRI is highly recommended. Received: 27 April 1995/Accepted: 17 June 1995     

色素沉着绒毛结节性滑膜炎的MRI表现

目的：探讨色素沉着绒毛结节性滑膜炎的MRI表现特点。方法：分析38例病人行MRI检查并经术后病理证实病例的临床资料。结果：弥漫性32例，其中28例表现为关节内滑膜弥漫性增厚，在T1WI上23例呈中等信号，5例呈多发的结节状低信号，在T2WI上12例呈中等信号，11例呈低信号，5例呈多发的结节状低信号；其余4例表现为关节内局限性肿块形成，在T1WI上均呈中等信号，在T2WI上2例呈中等信号，2例呈低信号。局灶性6例，表现为软组织内的肿块形成，在T1WI、T2WI上5例呈中等信号，1例呈低信号。结论：色素沉着绒毛结节性滑膜炎病人的MRI可表现为滑膜的弥漫性增厚和局限性肿块形成2种，其典型的表现是在T1WI和T2WI上均为低信号。     

Voxel-based iterative sensitivity (VBIS) analysis: methods and a validation of intensity scaling for T2-weighted imaging of hippocampal sclerosis

Abnormalities in the brain generally manifest on MRI as changes in shape (morphometry) or changes in the nature of the tissue (signal intensity). Voxel Based Morphometry (VBM) is a whole brain quantitative way of assessing morphometric changes. Voxel Based Relaxometry (VBR) directly assesses signal intensity changes in quantitative maps of T2 relaxation time, but this requires specialised multiple-echo acquisition sequences that are not usually available at clinical sites. This paper introduces and assesses an objective voxel-based statistical method for evaluation of signal intensity in groups of routinely acquired qualitative images. We call the method Voxel-Based Iterative Sensitivity (VBIS) analysis. It adaptively optimises the relative global scaling of images to maximise sensitivity to regional effects. We apply and validate the method of analysis for T2-weighted images of the human brain. To validate the method, it was directly compared with VBR by extracting T2-weighted images of a single echo from multi-echo T2 relaxometry acquisitions from a group of 24 patients with left hemisphere hippocampal sclerosis and 97 healthy controls. Expected signal abnormalities in the patients were detectable with VBIS-T2, confirming the feasibility of the technique. This opens the door to the use of a voxel-based analysis approach on the vast amount of T2-weighted image data that has been and is being acquired on MRI scanners. When a quantitative modality is not available, VBIS can be an effective way to quantify differences between groups. We expect the method could also assist quantitative analysis of other qualitative modalities such as T1-weighted MRI, SPECT and CT.     

膝关节周围骨梗死的低场MRI表现

目的探讨膝关节周围骨梗死的低场MRI表现特征。方法回顾性分析11例临床证实的膝关节周围骨梗死的临床及影像资料。结果 11例膝关节周围骨梗死累及20个骨(股骨11个,胫骨9个),同期X线检查中9例阴性。本组均具有典型MRI改变:病变中心呈短T1WI类似骨髓信号,周边环绕花边状混杂信号,T2WI可见双环靶征、三环靶征。结论低场MRI较X线平片能早期诊断骨梗死,值得应用。     

Magnetic resonance tomography pattern of a normal hip joint in a child and the respective pattern following trophic disturbances which resulted from treatment of developmental dislocation

MRI gives unique opportunities to visualize all structures of pediatric hip both in normal and pathologic conditions. As such it is a valuable supplement to other methods used so far in hip imaging, e.g., conventional radiography and ultrasonography. The aim of this study was to show MR pictures of normal pediatric hip and following avascular necrosis in developmental hip dislocation. The value of MRI and these conventional radiography were also compared. Magnetic resonance imaging appeared to be superior to radiography in assessment of subcapital growth plate and its damage in most of the hips. The most common presentation of the area of subcapital growth plate of the proximal femur on MR images was that of hypointense band on T1-weighted images and hyperintense band on sequences using fat saturation. T1-weighted images were best for visualization of bony bridges containing yellow marrow crossing the growth plate. The sequences using fat saturation were good for visualization af any damage to the growth plate without possibility to distinguish fibrous or osseous changes. T1-weighted images together with FLASH 3D FAT SAT seem to be sufficient for the analysis of the growth plate and its damage.     

髓母细胞瘤mri诊断(附19例分析)

目的:探讨髓母细胞瘤的MRI特征.材料与方法:对19例髓母细胞瘤的临床及MRI影像表现加以分析.结果:髓母细胞瘤MRI表现为:18例位于小脑蚓部,1例位于小脑半球.MRI平扫T1WI低信号16例,等信号3例;T2WI表现为略高信号.19例中16例还有增强MRI,增强MRI显示肿块有明显强化,且较均匀(15/16).结论:MRI对于髓母细胞瘤的诊断及鉴别诊断价值较大.     

磁共振成像对腰肌劳损腰痛的诊断价值

目的探讨腰肌劳损MRI检查方法与影像学表现。方法症状性慢性腰肌劳损患者30例,对照组为无症状健康志愿者35例,两组间性别及年龄构成比差异均无统计学意义(前者P=0.084,后者P=0.850)。MRI检查方法包括:常规梯度回波小角度激发T1加权横断面成像(GRET1WI)、快速自旋回波T2加权横断面成像(TSET2WI)和短时反转恢复T2加权横断面成像+脂肪抑制(T2-STIR-FS)、快速反转恢复T2加权横断面成像+脂肪抑制(T2-TIRM-FS)、快速自旋双回波T2加权横断面成像+脂肪抑制(T2+T2-TSE-FS)、弥散加权横断面成像(DWI)。评价征象包括:(1)腰骶背肌-肌间隙改变;(2)腰骶背肌-骨间隙改变;(3)多裂肌厚度改变;(4)多裂肌内脂肪浸润程度。结果腰骶背肌间隙不规则扭曲、积液,棘突旁间隙积液,横突窝积液和小关节突窝积液,髂骨-髂周肌间隙积液这些征象在症状组的发生率显著高于对照组(P<0.05)。多裂肌厚度和脂肪浸润程度在两组间差异无统计学意义(P>0.05)。各种征象中,诊断试验真实性最好的是棘突旁间隙积液征象(YI=0.73)。联合多种MRI征象诊断症状性腰肌劳损的准确性较依靠某一种征象的高,以联合2种MRI征象诊断腰肌劳损的真实性最好(YI=0.79)。检查方法STIR-FS、DWI、TIRM-FS和T2+T2-TSE-FS可以敏感地显示积液征象,显示敏感性基本相同(P>0.05)。结论合理地选择应用MRI常规T1WI和T2WI序列和特殊成像序列STIR-FS、DWI、TIRM-FS或T2+T2-TSE-FS可以很好地显示慢性腰肌劳损的病理生理改变,包括肌-肌间隙改变,肌-骨间隙改变,腰背肌形态结构改变。     

短时翻转恢复序列在皮肌炎、多发性肌炎中的应用价值

目的探讨短时翻转恢复(short-tau inversion recovery,STIR)序列在皮肌炎、多发性肌炎中的应用价值。材料与方法回顾分析我院12例经临床确诊和(或)穿刺活检病理证实的皮肌炎/多发性肌炎患者资料。选择双侧大腿肌肉作为感兴趣区,采用常规T1WI、T2WI及STIR序列进行扫描,观察STIR序列与T1WI、T2WI在病变检出能力上的差异。结果 (1)本组12例患者于MRI上发现双侧大腿有不同程度异常信号表现,其中提示为肌炎11例、肌筋膜炎8例、皮下结缔组织炎9例、肌肉萎缩伴脂肪浸润1例。(2)在STIR序列上,12例患者均被发现双侧大腿有异常信号;T1WI仅发现5例皮下结缔组织炎,1例肌肉萎缩,未发现肌炎、肌筋膜炎;T2WI发现6例肌炎,1例肌肉萎缩及2例皮下结缔组织炎,未发现肌筋膜炎。(3)在STIR序列上,发现有7例患者的双侧大腿后、内侧肌群信号较其他受累肌群信号高,经病理证实该处肌肉损伤程度较重。结论 STIR序列具有高软组织分辨率和高灵敏性,可明显提高软组织炎性病变的检出率,其信号强度可主观反映肌肉的损伤程度,在临床上具有重要应用价值。     

肝细胞癌的MRI诊断

目的：提高MRI对肝细胞癌的诊断与鉴别诊断能力。通过分析MRI征象，建立肝细胞癌的MRI信号变化模式。材料与方法：28例肝细胞癌患者均接受MRI检查。男24例，女4例，年龄32～80岁，平均52岁。检查使用0．5T超导型MR成像系统。常规SE序列T1W成像．TSE序列T2W双回波成像。采用双盲法作前瞻性回顾分析。结果：MRI能清楚显示肝细胞癌的部位，大小、形态、数目，与周围组织关系及继发改变。其MR信号变化具有一定特征性，即T1WI多呈低信号强度，T2WI第一回波（PDWI）呈稍高信号强度或等信号强度，T2WI第二回波多呈不均质性稍高信号强度。结论：根据MRI表现，尤其是信号变化特征，对肝细胞癌能作出定性诊断。并建议把SE序列T1WI，TSE序列T2WI双回波成像技术作为肝细胞癌的常规和首选检查方法。