枕骨髁置钉内固定的影像解剖学测量

目的对国人经枕骨髁进行置钉的相关结构行影像解剖学测量,探讨国人行枕骨髁螺钉内固定应用于枕颈固定融合手术的可行性。方法随机抽取40例患者在门诊就诊并进行颅颈部三维CT数据,男女比例1:1,CT扫描层厚为1 mm。获得的CT数据行枕骨髁的轴面,矢状面和冠状面的重建。测量枕骨髁的长度、宽度、高度,在枕骨髁轴面上测量枕骨髁中轴线与正中矢状面的夹角。结果轴向平面枕骨髁的平均长度为(21.5±2.2)mm,其范围为16.5～26.1 mm;矢状面枕骨髁的平均长度为21.61±2.1 mm,其范围为17.4～26.5 mm;轴向平面上枕骨髁的平均宽度为(11.07±1.09)mm,其范围为9.1～13.6 mm;矢状面上枕骨髁的平均高度为(10.15±1.50)mm,其范围为7～13.9 mm;冠状面上枕骨髁的平均高度为(9.8±1.0)mm,其范围为7.7～11.9 mm;轴向平面上枕骨髁中轴线与正中矢状面的夹角平均为(32.53±3.88)°,其范围为24.3～42.6°。结论国人枕骨髁解剖学特征具备植入螺钉条件,可以轻松容纳直径为3.5 mm的螺钉。     

面神经隐窝入路关键手术剖面多层螺旋CT双斜面多平面重组的研究

目的 探讨双斜面CT MPR重组技术对面神经隐窝进路手术中关键手术剖面涉及到的解剖标志同层显示的可行性及方法.方法 在尸体头颅标本上观察面神经隐窝入路手术中涉及到的关键手术剖面及相关解剖标志,利用双斜面MPR重组技术,对30具(60侧)完整的成年国人尸体头颅标本进行关键手术剖面重组,对比手术剖面主要解剖标志观察结果,对4个不同方位图像(横断面、冠状面、矢状面及双斜矢状面)同层显示主要解剖标志的程度进行分级评价.主要手术解剖标志同层显示为100％者记为4级、显示为90％～99％记为3级、显示为80％～89％记为2级、显示70％～79％记为l级,显示＜70％记为0级.对所得资料行x2检验.结果 面神经隐窝入路手术中涉及到4层关键手术剖面,均为斜矢状面.4层关键手术剖面双斜面MPR重组的旋转中心标志点分为水平半规管、砧骨窝、锥隆起及圆窗后缘;重组水平参考轴线及水平旋转角度分别为砧骨短突及22.15° ±5.22°、砧骨短突及20.15°±5.52°、面神经水平段及32.53°±5.22°、卵圆窗上缘及50.15°±8.02°;重组垂直参考轴线均为面神经垂直段,垂直旋转角度分别为14.35°±4.02°、13.15°±3.33°、15.05° ±4.43°及15.25°±4.12°.对于主要解剖标志同层显示的程度,在第1层关键手术剖面中,双斜矢状面为4级60侧,横断面为2级12侧、3级48侧,冠状面为2级15侧、3级45侧,矢状面为3级10侧、4级50侧;第2层关键手术剖面中,双斜矢状面为4级60侧,横断面为2级11侧、3级49侧,冠状面为2级13侧、3级47侧,矢状面为3级11侧、4级49侧;第3层关键手术剖面中,双斜矢状面为4级60侧,横断面为2级10侧、3级50侧,冠状面为2级11侧、3级49侧,矢状面为3级9侧、4级51侧;第4层关键手术剖面中,双斜矢状面为4级60侧,横断面为2级9侧、3级51侧,冠状面为2级8侧、3级52侧,矢状面为3级5侧、4级55侧;4层关键手术剖面解剖标志同层显示在不同方位图像显示程度差异均有统计学意义(x2值分别为123.3200、121.4231、122.4011、125.4213,P值均＜0.05);4层关键手术剖面解剖标志双斜面同层显示成功率均为100％(60/60侧).结论 双斜面MPR重组技术可清晰同层显示面神经隐窝径路手术剖面相关解剖标志,能为术者提供更有使用价值的影像学信息.     

冠状窦及其与左心房肌连接的双源CT冠状动脉成像表现

目的 探讨冠状窦-左心房肌连接的双源CT冠状动脉成像(DSCTCA)形态特征,并评价冠状窦的功能和解剖特点.方法 分析144例受检者(对照组96例,房颤组48例)的DSCTCA影像,通过测量收缩期、舒张期冠状窦横截面积的改变,间接评价冠状窦-右心房肌连接的存在,对冠状窦-左心房肌连接的数量、位置、长度及其与冠状窦形态特点的关系进行研究.连续变量使用t检验,类别变量采用联表的x2检验.结果 (1)冠状窦与二尖瓣环呈平直、轻度弯曲、高位在对照组分别为62、16、18例,在房颤组分别为10、8、30例,2组比较差异无统计学意义(x2=0.093,P=0.954).(2)对照组、房颤组冠状窦长度分别为(34.1±9.1)mm、(33.8±8.9)mm,2组比较差异无统计学意义(t=-0.486,P=0.628).(3)131例(91.0％)可见冠状窦-左心房肌连接,单连接103例,长度为(22.6±12.7)mm,到冠状窦口的距离为(6.3±5.8)mm;双连接28例,近端连接长度为(11.1±3.6) mm,到冠状窦口的距离为(2.1±1.9) mm,远端连接长度为(13.2±6.2) mm,到冠状窦口的距离为(16.7±6.8) mm.对照组、房颤组冠状窦-左心房肌连接的数量、长度差异无统计学意义(P＞0.05).(4)对照组冠状窦从心房舒张期到收缩期,横截面积缩窄约22.4％ (44.5/198.8;t=-21.076,P＜0.01),而房颤组冠状窦从心房舒张期到心房收缩期未见明显收缩(t=0.374,P＞0.05);舒张期房颤组冠状窦横截面积[( 230.4±77.0)mm2]明显大于对照组[(198.8±65.4) mm2;t=-2.579,P＜0.05].对照组9例未显示冠状窦-左心房肌连接患者,均于心房收缩期显示冠状窦收缩,提示冠状窦-左心房肌连接不是冠状窦收缩的主要原因.结论 DSCTCA能清楚显示冠状窦解剖特点,可以了解冠状窦-左心房肌连接的长度、数量和位置.     

CT检查在跟骨关节内移位骨折诊断中的应用

目的 通过CT测量跟骨关节内移位骨折的关节外变化指标,评价CT对该类损伤的诊断价值.方法对40个成人跟骨标本、20个正常健康成人及20个跟骨关节内骨折足的CT图像进行测量获得跟骨高度、跟骨宽度、距跟角及跟骰角,对以上获得值进行t检验或单向方差分析.结果 (1)跟骨高度的测量:正常成人跟骨标本后关节面最高点处高度为(43.07±2.85)mm,跟骨结节最高点处高度为(44.69±3.67)mm;正常成人健康足CT冠状面图像的结果分别为(42.84±1.66)mm、(43.40±3.01)mm,对以上两组数据进行比较,相互之间差异无统计学意义(P＞0.001).骨折足CT冠状面图像的结果分别为(34.76±3.24)mm、(40.41±3.69)mm,与前两组数据之间比较,差异有统计学意义(P值均＜0.001.(2)跟骨宽度测量:正常成人跟骨标本载距突后缘处跟骨宽度为(30.53±2.06)mm,跟骨结节最宽处的宽度为(33.57±2.17)mm;正常成人健康足CT冠状面图像的测量结果分别为(30.47±2.33)mm、(32.69±2.00)mm,对以上两组数据进行比较,相互之间差异无统计学意义(P＞0.001).骨折足CT冠状面图像的结果分别为(45.99±4.79)mm、(36.28±2.08)mm,与前两组数据之间比较,差异均有统计学意义(P值均＜0.001).(3)跟骨内翻角测量:正常成人健康足CT轴面图像的跟骰角为25.56°±0.95°,冠状面图像测得的距跟角为13.33°±0.75°;而对发生跟骨骨折的足进行CT扫描,其测得的结果分别为30.15°±1.62°、22.51°±1.34°.两组相对应的数据之间进行比较,差异均有统计学意义(P值均＜0.001).结论 CT检查是评价跟骨关节内移位骨折病例的关节外变化的有效手段.     

前庭导水管的冠状面CT研究

目的　评价冠状面CT图像上正常前庭导水管 (VA)的特征 ,为不明原因感音神经性耳聋的诊断进一步提供依据。资料与方法　对 5 2名 10 4只正常耳作螺旋CT横断位及冠状位扫描 ,分别测量VA的宽度、长度 ,并在冠状面上测量VA长轴与水平线的夹角。然后对数据进行统计分析。结果　冠状面上VA峡部的显示率、可测率均为 10 0 % ;横断面上VA峡部的显示率为 10 0 % ,其可测率仅为 88.5 %。VA后部的显示率和可测率均为 6 1.5 %。冠状面VA峡部的宽度为 (0 .87± 0 .5 7)mm ,长度为 (3.0 7± 1.34)mm ;VA后部的宽度为 (1.2 3± 0 .5 1)mm ,长度为(4 .89± 1.6 1)mm。正常VA峡部的上限值为 4 .4mm× 1.5mm(长×宽 )。结论　冠状面上可清楚地观察VA的走行并对峡部进行测量 ,提出了冠状面上正常VA峡部的范围。冠状面结合横断面图像可提高VA扩大的诊断准确性 ,从而提高感音神经性耳聋患者的病因检出率。     

成人下腔静脉的CT测量及其在介入治疗中的意义

目的:了解肾静脉以上段下腔静脉左右径、前后径及其与冠状面成角、肝后段下腔静脉长度.方法:利用100例患者腹部CT增强图像,分别测量下腔静脉右心房入口处的左右径和前后径、第一肝门平面及肾盂平面的左右径、前后径及它们与冠状面所成角度,肝后段下腔静脉长度.患者年龄19～81岁,平均年龄为50.9岁.结果:第一肝门平面左右径和前后径与冠状面所成角度分别为(43.4±12.0)°、(46.8±11.8)°;肾盂平面左右径和前后径与冠状面所成角度分别为(37.8±9.8)°、(50.6±10.9)°.以上两个平面左右径与冠状面所成角度差异具有显著性意义(t=3.8,P=0.000),以上两个平面前后径与冠状面所成角度差异也具有显著性意义(t=-2.36,P=0.019).右心房入口处的左右径和前后径分别为(28.4±4.2) mm、(19.8±3.5) mm;第一肝门平面左右径和前后径分别为(25.6±3.7) mm、(18.2±3.6) mm;肾盂平面的左右径和前后径分别为(25.7±4.6) mm、(15.4±3.2) mm.单因素方差分析表明3个不同平面的下腔静脉左右径之间差异存在显著性意义(F=15.0,P=0.000);3个不同平面的下腔静脉前后径之间差异也存在显著性意义(F=40.9,P=0.000).肝后段下腔静脉长度为(58.9±10.0) mm.结论:对肾静脉以上段不同平面下腔静脉径线及其与冠状面成角、肝后段下腔静脉长度的测量结果,为下腔静脉有关的介入诊疗提供参考数据.     

多层螺旋CT面神经管曲面重建与解剖对照研究

目的探讨螺旋CT面神经管曲面重建(curved p lanar reform ation,CPR)的方法并研究其解剖学的可靠性。方法20具(40侧颞骨)成人尸头标本行高分辨CT扫描及面神经管轴位、冠状位和矢状位曲面重建并测量各段长度、直径和2个弯曲的角度,观察重建图像上面神经管各段的形态及走行;对40侧颞骨标本的面神经管进行解剖,测量相应各段长度、直径和2个弯曲角度,并观察面神经管形态及走行。结果①3个方向CPR图均能将面神经管全程直观地显示在1幅图像上,可清楚的显示面神经管在颞骨内的走行、形态和管壁等情况;②重建图像均可准确测得各段长度、直径及锥曲角度,冠状位和矢状位能准确测量膝状神经节角度,与解剖测量结果一致(P>0.05);③迷路段和膝状神经节的形态与走行方向在冠状位CPR显示好,水平段、锥曲及垂直段形态和走行在轴位CPR显示好,与解剖具有很好的对应性。结论面神经管高分辨率CT图像的CPR为研究面神经管影像解剖良好的、可靠的方法,可代替解剖测量与观察。     

三维螺旋CT对骨性椎间孔解剖测量分析

目的 探讨腰椎间盘突出症(lumbar disc herniation, LDH)患者与正常人群椎间孔三维CT数据，为临床椎间孔镜手术减压范围提供解剖依据。方法 选取我院行腰椎三维CT检查的LDH患者60例(为突出组)与同期60例体检腰椎正常者(为正常组)的CT影像资料，在腰椎三维CT图像定位二维矢状面图像对L4-5节段椎间隙高度、两侧腰椎间孔高度、椎间孔宽度、椎间孔面积进行测量。结果 L4-5突出组腰椎椎间隙高度(6.992±1.889) mm,两侧平均椎间孔高度(18.664±2.309) mm,椎间孔宽度(8.327±1.026) mm,椎间孔面积(116.445±19.414) mm²;L4-5正常组腰椎椎间隙高度、两侧平均椎间孔高度、宽度、面积分别为(9.628±1.745) mm、(20.069±2.017) mm,(9.070±1.255) mm,(161.083±25.545) mm²,L4-5节段突出组与正常组椎间孔三维参数相比明显变小，差异有统计学意义(P<0.05)。结论 L4-5节段突出症患者骨性椎间孔高度、宽度...     

Cine-MRI测量健康成年人肾脏运动幅度

目的 通过电影磁共振成像(Cine-MRI)技术观察健康成年人平静规律呼吸状态下双肾运动幅度.资料与方法 选取57名健康成年志愿者(男28名,女29名),于平静规律呼吸状态下进行与双肾长轴平行的斜冠状面Cine-MRI检查,测量一次完整呼吸过程中双肾下极运动幅度,比较双侧肾脏及不同性别间肾脏运动幅度的差异.结果 Cine-MRI测得健康成年人平静规律呼吸状态下右肾运动幅度为5.6～16.5 mm,平均(9.5±2.1) mm;左肾运动幅度为4.5～13.9 mm,平均(8.1±2.0) mm;双侧肾脏运动幅度比较,差异有统计学意义(t=9.30,P＜0.05);男性左、右侧肾脏运动幅度分别为(8.7±2.0) mm和(10.3±2.2) mm,均大于女性对应侧肾脏运动幅度[分别为(7.5±1.8) mm和(8.8±1.7) mm],差异有统计学意义(t=2.82、4.41,P＜0.05).结论 平静规律呼吸状态下斜冠状面上右肾运动幅度大于左肾,在进行功能磁共振成像时宜选用左肾数据作为参照标准,尤其是当受检者为男性时.     

股骨头颈直径比的MSCT测量

目的:应用CT多平面重组图像测量股骨头颈直径比的正常值,比较两种测量方法(利用平行于股骨颈的斜正中矢状面和利用髋关节标准冠状面图像)的差异。方法:筛选行骨盆或下腹CT检查而无任何髋部症状的101例成人的202个髋关节的容积CT数据进行MPR后处理,其中男性髋112个、女性髋90个。选取平行于股骨颈斜正中矢状面和标准冠状面MPR图像,通过Digmizer V3.1软件分别进行股骨头、颈的直径测量并计算两者的比值。结果:利用斜正中矢状面MPR图像测量股骨头颈直径比为1.12～2.17,平均值为1.78±0.14;男性平均值为1.77±0.14,女性平均值为1.80±0.14,性别差异无统计学意义(t=-1.490,P>0.05);右侧平均值为1.81±0.12,左侧为1.75±0.15。利用冠状面MPR图像测量股骨头颈直径比为1.07～1.83,平均值为1.46±0.10;男性平均值为1.45±0.12,女性平均值为1.48±0.09;右侧平均值为1.46±0.11,左侧为1.46±0.10,左右侧的差异无统计学意义(t=0.008,P>0.05)。两种测量方法所得的202个股骨头颈直径比的平均值的差异有统计学意义(F=656.102,P<0.001)。结论:利用平行于股骨颈的斜正中矢状面MPR图像测量股骨头颈直径比较利用冠状面MPR图像测量方法能更真实地反映股骨头颈交界处的凹陷程度,可为诊断凸轮型撞击综合征提供一定的参考依据。     

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.     

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.     

MR imaging of disorders of the brachial plexus

The authors evaluated 64 consecutive patients with suspected brachial plexus (BP) abnormalities of diverse cause with magnetic resonance (MR) imaging, using the body coil and a standardized protocol. Of the 43 patients for whom follow-up was available, 25 were suspected of having neoplastic involvement of the BP, nine had sustained injuries, and nine presented with BP symptoms of uncertain cause. MR imaging was 63% sensitive, 100% specific, and 77% accurate in demonstrating the abnormality in this diverse patient population. When patients with neoplastic and traumatic disorders were considered separately, sensitivity increased to 81%, accuracy to 88%, and specificity remained unchanged. In the patients with a clinical diagnosis of idiopathic or viral plexitis, the MR imaging findings were normal, serving to exclude other structural abnormalities. It is concluded that MR imaging is valuable in the assessment of a wide range of BP disorders.     

MR imaging characteristics of noncancerous lesions of the prostate.

Radical prostatectomy specimens from 53 men with clinical stage A or B prostate cancer were retrospectively reviewed and compared with correlative axial T2-weighted magnetic resonance (MR) images obtained just before surgery. Non-cancerous lesions were evaluated for signal intensity and location. Focal high-signal-intensity areas (n = 72) were present in 81% of patients. The 26% of lesions seen in the central gland all correlated with cystic atrophy. Of the 53 lesions seen in the peripheral prostate, 47 (89%) were cystic atrophy without associated cancer, four (7.5%) cystic atrophy with cancer, and two (3.8%) focal inflammation. Focal low-signal-intensity areas (n = 42) were present in 60% of patients. Of the 31% of lesions in the central prostate, one-fifth correlated with benign prostatic hyperplasia (BPH) and four-fifths with fibrous tissue. Of the 69% of peripheral lesions, 83% corresponded to fibrous tissue, 10% to BPH, and 7% to normal tissue. Mixed lesions (n = 42) were present in 64% of patients; 86% of these were located centrally and 14% peripherally. All mixed central lesions were BPH; the peripheral lesions were areas of combined cystic atrophy and fibrosis. BPH of low or mixed signal intensity can extend into the peripheral prostate and mimic cancer. High-intensity cystic atrophy associated with cancer can mimic normal tissue.     

肾细胞癌的MRI研究进展

肾细胞癌是最常见的成人肾脏恶性肿瘤。近年来，多种功能MRI成像技术（如扩散加权成像、灌注加权成像等）、多参数MRI联合分析以及影像组学等新兴影像处理技术被证实在肾细胞癌的诊断中具有较大的价值。目前，研究热点多集中于良恶性肿瘤的鉴别、组织学亚型的区分、肿瘤分期、预测核分级及判断预后。就MRI新技术及图像处理技术在肾细胞癌中的研究进展予以综述。     

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.     

Influence of in vivo copper on MR images of the liver in rats

To investigate the effects of in vivo copper on magnetic resonance (MR) images, the authors studied Long-Evans cinnamon rats, which develop hepatitis and hepatocellular carcinoma as a result of abnormal copper metabolism. The livers of the rats were imaged before hepatitis developed; the absence of hepatic disease was confirmed histopathologically. The copper that accumulated in the liver of the rats was thought to exist in the form of divalent ions, which were suspected of reducing the T1 and T2 of neighboring protons. However, the signal intensities of the liver on T1- and T2*-weighted images did not change, suggesting that in vivo copper, even when accumulated abnormally, does not influence the signal intensity of MR images.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.     

Dynamic MRI of the gallbladder lesions: Differentiation of benign from malignant

Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.