颈髓扩散张量磁共振成像扫描参数的比较

目的 探索颈髓扩散张量磁共振成像(DTI)最佳扫描参数. 资料与方法 对40名成年健康志愿者行颈髓DTI,比较不同b值、扩散敏感梯度方向数、激励次数(NEX)、层厚对图像质量的影响.第1组,b值分别取400 mm2/s、700 mm2/s、1000 mm2/s;第2组,扩散敏感梯度方向数分别取6个、13个、25个;第3组,激励次数分别取2、4、8;第4组,层厚分别取2 mm、3 mm、4 mm. 结果 在四种不同扫描参数的比较中,b值为700 mm2/s的一级图像数较b值为400 mm2/s 和1000 mm2/s的多;方向为25时的一级图像数较方向为6和13的图像质量多;NEX为4的一级图像数较NEX为2和8的多;层厚为4 mm的一级图像质量较层厚2 mm和3 mm的多. 结论 b值为700 mm2/s、扩散敏感梯度方向数为25个、NEX为4和层厚为4 mm是颈髓DTI较好的扫描参数.     

颈髓MR扩散张量成像扫描参数的比较研究

目的 探讨颈髓MR扩散张量成像(DTI)合适的扫描参数.方法 对80名成年健康志愿者行颈髓常规MR及DTI检查,比较不同扫描参数[扩散敏感系数(b)值、扩散敏感梯度方向数、激励次数(NEX)及层厚]对图像质量的影响.第1组,b值分别取400、700、1000 s/mm2;第2组,扩散敏感梯度方向数分别取6、13、25个;第3组,NEX分别取2、4、8次;第4组,层厚分别取2、3、4 mm.并由2名高年资放射科医师采用双盲法对图像质量进行评分,据此对不同图像进行比较.结果 在4种不同扫描参数的比较中,b值为700 s/mm2时图像质量最好[(2.25±0.58)分],与b值为400 s/mm2[(1.86±0.53)分]和1000 s/mm2[(1.48±0.35)分]时比较差异有统计学意义(P＜0.05);扩散敏感梯度方向为25个时图像质量最好[(2.58±0.59)分],与方向为6个[(1.33±0.36)分]和13个[(1.90±0.51)分]时比较,差异有统计学意义(P＜0.05);NEX为4的图像质量[(2.45±0.63)分]最好,与NEX为2[(1.47±0.32)分]和8[(2.29±0.55)分]比较,差异有统计学意义(P＜0.05);层厚为4 mm的图像质量[(2.41±0.55)分]最好,与层厚2 mm[(1.54±0.27)分]和3mm[(1.87±0.48)分]比较,差异有统计学意义(P＜0.05).结论 选择合适的颈髓DTI扫描参数,有利于临床对颈髓细微结构的研究.     

呼吸导航与心电触发对兔肝脏磁共振成像应用比较

目的 比较1.5T磁共振扫描仪(Avanto)在呼吸导航技术和心电触发技术配合下对兔肝脏扫描成像质量的优劣.方法 分别应用呼吸导航技术和心电触发技术配合1.5T磁共振扫描仪对10只新西兰大白兔进行肝脏扫描,在保证图像平均信噪比(SNR)在1±0.1状态下,比较每种检查图像的优劣.扫描序列分别为TSE序列T_1加权、脂肪抑制T_1加权平扫及增强、T_2加权和脂肪抑制质子加权.结果 在心电触发配合下各个序列扫描图像质量均优于在呼吸导航下扫描所得图像,主要表现为前者受运动伪影干扰明显少于后者.结论 在SNR为1±0.1状态下.1.5T磁共振采用心电触发技术扫描兔肝脏所得图像质量优于采用呼吸导航时相同序列扫描所得图像,原因可能和兔的生理特点及2种不同门控方法的敏感度差异有关.     

3.0T磁共振乳腺成像扫描参数的优化

目的 探讨不同参数对乳腺MRI图像质量及扫描时间的影响.方法 (1)采用GE Signa Excite 3.0T MR成像系统和8通道乳腺线圈,对3个新鲜手术乳腺标本进行多序列、多参数扫描,根据图像质量及扫描时间选择适合乳腺MR成像的扫描序列和参数.(2)对10名健康志愿者采用FSE-IR、抑脂和非抑脂 FSE-XL T1WI和抑脂FSE-XL T2WI序列及不同参数进行乳腺MR成像,测量比较不同参数图像的信噪比.结果 其它参数相同时,采用以下序列和参数进行乳腺MR成像可在较短的扫描时间内获得较高的图像质量,包括FSE-IR序列:TR 6000 ms、TI 190 ms、TE 42 ms、带宽62.50 kHz、NEX 1、扫描层数18;FSE-XL T1WI序列:TR 500 ms、TE 11.5 ms、带宽50 kHz、NEX 2、扫描层数18;FSE-XL T2WI序列:TR 4200 ms、TE 80 ms、带宽41.67 kHz、NEX 1、扫描层数18.结论 3.0T MR乳腺成像,通过扫描参数的优化可节约扫描时间、提高图像质量.     

压缩感知不同加速因子对肝脏3D-mDixon序列成像质量的影响

【摘要】目的：探讨压缩感知技术（CS）的不同加速因子（AF）对肝脏3D-mDixon序列图像质量的影响。方法：招募10例健康志愿者采用3.0T MR仪行肝脏3D-mDixon序列扫描,设计6组扫描方案： SENSE2及AF为2~6的CS技术（CS2~CS6组）,扫描时间分别为20.5、18.7、12.9、10.0、8.5和7.1s,6组的其它扫描参数保持一致。由两位观察者分别在第一肝门水平的肝左外叶、左内叶、右前叶、右后叶及右侧竖脊肌处放置勾画ROI,分别测量各ROI的信号强度及其标准差,并计算相应的信噪比（SNR）和对比噪声比（CNR）。两位观察者分别对6组的图像质量进行5分制主观评分。对6组图像质量的主观评分和客观评价指标进行统计学分析。结果：两位观察者对图像质量的客观评价指标的测量结果及主观评分的一致性均达到了良好（ICC>0.75）。6组间SNR和CNR的差异有统计学意义（P＜0.05）。 SENSE2组及CS2~CS4组：4组的SNR分别为44.1±3.6、47.9±6.8、47.6±6.2和48.0±6.7,CNR分别为16.0±1.8、16.9±4.0、17.0±4.4和17.4±4.4,4组间SNR和CNR的差异均无统计学意义（P＞0.05）。CS5和CS6组图像的SNR分别为40.5±3.9和40.7±4.6,CNR分别为12.3±3.2和13.4±2.4,均显著低于CS2~CS4组,组间差异均有统计学意义（P＜0.05）。SENSE2组和CS2~CS4组的图像质量评分均高于CS5和CS6组,组间差异均有统计学意义（P＜0.05）。结论：基于压缩感知技术的3D-mDixon序列肝脏扫描,随着加速因子的增加,扫描时间缩短,但肝脏的SNR及图像质量下降,加速因子为4时能在确保图像质量的前提下使扫描时间降低约50％,可作为肝脏检查的最佳扫描方案。     

压缩感知技术的不同加速因子在耳蜗3D-DRIVE水成像中的应用

目的 探讨压缩感知技术中不同加速因子在耳蜗3D-DRIVE水成像中的应用价值.方法 采用MRI的3D-DRIVE序列对30例健康志愿者耳蜗进行扫描,分别使用SENSE技术及压缩感知技术(CS)的5种不同的加速因子:SENSE、3.5、4.0、4.5、5.0及5.5,扫描时间分别为237 s、212 s、185 s、16...     

基于压缩感知技术3.0 T MR无对比剂冠状动脉血管成像的临床应用可行性

目的探讨压缩感知(CS)技术在无对比剂MR冠状动脉血管成像(NMRCA)中应用的最佳加速因子及其可行性。方法 2021年8至11月, 前瞻性收集阜阳市人民医院31例疑似冠心病, 同时完成冠状动脉CT血管成像和3.0 T NMRCA序列扫描的患者的影像学资料。NMRCA扫描序列包括常规灵敏度编码(SENSE)序列(加速因子为2)和基于SENSE的CS序列(加速因子分别为4、5、6)。采用Friedman检验和Wilcoxon秩和检验比较4组序列之间的图像质量主观评分及冠状动脉和心肌之间的信号对比度(CMCR)的差异。结果 CS序列CS4、CS5和CS6的扫描时间分别为(269±36)、(214±29)、(178±26)s, 较常规SENSE2[(343±46)s]分别缩短21.5%、37.5%和48.0%。4组图像的主观评分具有良好的一致性(Kappa=0.769, 95%CI为0.738～0.800)。CS4组主观评分及CMCR值与SENSE2组差异无统计学意义(P>0.05), CS5组部分冠状动脉节段及CS6组各冠状动脉节段均与SENSE2组差异具有统计学意义(P<0....     

兔肝脏3.OT MR多模态定量成像扫描技术探讨

目的 探讨3.0T MR在兔肝脏多模态定量扫描时的技术要求.方法 选择新西兰大白兔8只,应用3.0T MR成像系统,行肝脏T1 mapping、T2 mapping、MT序列及Gd-EOB-DTPA(0.025 mmol/kg)动态增强扫描,后者采用不同的速率(1.5 mL/s和2 mL/s)和生理盐水用量(6 mL和8 mL)进行匹配.判断各种技术的图像质量是否符合要求.结果 全部扫描时间约为20～25 min.T1mapping、T2 mapping、MT序列均获得满意的扫描图像.Gd-EOB-DTPA动态增强扫描时,各组间图像质量无明显差异(P＞0.05),但采用2 mL/s和8 mL的条件时,2只动物死亡.结论 选取合适的扫描参数时,可以成功进行3.0T MR多模态兔肝脏定量成像.     

肺恶性肿瘤和实性良性病变扩散加权成像技术初探

目的 探讨相控阵线圈联合并行采集空间敏感度编码技术(ASSET) 扩散加权成像(DWI)用于检查肺内恶性肿瘤和实性良性病变的可行性,并优化DWI检查扫描参数.方法 12例肺良性病变和50例肺恶性肿瘤(共66个病灶)被纳入研究,其中最初就诊的12例构成不同DWI方案实验组(组1),全部62例病例构成b值实验组(组2).组1采用4种不同DWI扫描方案:A,ASSET+自由呼吸+4NEX;B,ASSET+自由呼吸+1NEX;C,ASSET+屏气+1NEX;D,常规DWI+屏气+1NEX;比较各方案的信噪比(SNR)和对比噪声比(CNR),从中选出最佳扫描方案.组2应用筛选出的最佳扫描方案行不同b值(200、300、500、700和1 000 s/mm2)DWI检查,比较各b值组的SNR、CNR、ADC值以及ADC值对肺良恶性病变的鉴别诊断效能,从中选出最佳b值.结果 组1内4种扫描方案SNR和CNR差异均有统计学意义(P均为0.000),且方案A最大.组2中,不同b值组间SNR差异有统计学意义(P=0.000),而CNR差异无统计学意义(P>0.05);良性病变组和恶性病变组ADC值均随b值增加而逐渐变小,差异有统计学意义(P=0.039,P=0.000);从200～1 000 s/mm2不同b值的4组的ROC曲线下面积(Az)分别为0.608、0.537、0.785、0.583、0.576,均有诊断意义(Az>0.5),b取500 s/mm2时获得的ADC值的诊断效能最大,此时ADC值鉴别良恶性病变的最佳阈值为1.400×10-3 mm2/s,敏感度和特异度分别为83.3%和74.1%.结论 在1.5 T MR设备上,采用相控阵线圈和ASSET技术对肺恶性肿瘤和良性实性病变行DWI检查切实可行;在自由呼吸状态下采用b值为500 s/mm2、激励次数(NEX)为4时能够获得满意的胸部DWI影像.     

SENSE心脏阵列线圈在前列腺MRI检查中的初步应用研究

目的 对灵敏度编码(SENSE)心脏阵列线圈和直肠腔内线圈在前列腺MRI检查中的图像质量进行对比研究,初步评价SENSE心脏阵列线圈在前列腺MRI检查中的价值.资料与方法 选取前列腺病变患者50例.在相同扫描参数下,均使用SENSE心脏阵列线圈和直肠腔内线圈进行前列腺MRI常规检查,对使用两种线圈所分别获得的前列腺轴位(TRA)小视野、薄层T2WI图像的均匀度、对比信噪比(CNR)进行对比分析.结果 采用SENSE心脏阵列线圈所获得的图像均匀度优于采用直肠腔内线圈者(配对t检验,P＜0.05);采用SENSE心脏阵列线圈所获得的图像CNR亦优于采用直肠腔内线圈者(配对t检验,P＜0.05).结论 SENSE心脏阵列线圈在图像均匀度和CNR这两个图像评价指标方面都取得了较好的成像效果,在一定程度上可以替代直肠腔内线圈进行前列腺小视野、薄层、高分辨率T2W成像.     

Effects of MR Parameter Changes on the Quantification of Diffusion Anisotropy and Apparent Diffusion Coefficient in Diffusion Tensor Imaging: Evaluation Using a Diffusional Anisotropic Phantom

Objective

To validate the usefulness of a diffusional anisotropic capillary array phantom and to investigate the effects of diffusion tensor imaging (DTI) parameter changes on diffusion fractional anisotropy (FA) and apparent diffusion coefficient (ADC) using the phantom.

Materials and Methods

Diffusion tensor imaging of a capillary array phantom was performed with imaging parameter changes, including voxel size, number of sensitivity encoding (SENSE) factor, echo time (TE), number of signal acquisitions, b-value, and number of diffusion gradient directions (NDGD), one-at-a-time in a stepwise-incremental fashion. We repeated the entire series of DTI scans thrice. The coefficients of variation (CoV) were evaluated for FA and ADC, and the correlation between each MR imaging parameter and the corresponding FA and ADC was evaluated using Spearman''s correlation analysis.

Results

The capillary array phantom CoVs of FA and ADC were 7.1% and 2.4%, respectively. There were significant correlations between FA and SENSE factor, TE, b-value, and NDGD, as well as significant correlations between ADC and SENSE factor, TE, and b-value.

Conclusion

A capillary array phantom enables repeated measurements of FA and ADC. Both FA and ADC can vary when certain parameters are changed during diffusion experiments. We suggest that the capillary array phantom can be used for quality control in longitudinal or multicenter clinical studies.     

Sensitivity encoding (SENSE) for contrast-enhanced 3D MR angiography of the abdominal arteries

PURPOSE: To assess sensitivity encoding (SENSE) for contrast-enhanced MR angiography (CE-MRA) of the abdominal arteries in comparison with standard MRA protocols. MATERIALS AND METHODS: In 22 patients MRA of the abdominal arteries was performed twice (once using a standard protocol, and once with the additional use of SENSE). In 10 patients all examination parameters were kept constant (TR/TE/FA = 3.8 msec/1.3 msec/30 degrees ), and a reduction in scan time from 22 to 11 seconds was realized with the use of SENSE. In 12 patients, using SENSE the acquisition matrix was increased from 208 to 416, keeping the scan time constant. Image quality was scored on a five-point scale by three radiologists. Additionally, ROI-based measurements of CNR were performed. RESULTS: For both protocols, image quality was significantly improved using SENSE. The time-reducing SENSE protocol yielded an average score of 4.2 points vs. 3.1 for the standard protocol. Using SENSE to increase the acquisition matrix, an average score of 4.3 was reached vs. 3.2 for the standard protocol (P < 0.05). The number of depictable small vessels and their bifurcations was significantly increased by either of the two SENSE protocols as compared to the standard imaging procedure. CONCLUSION: SENSE for MRA of the abdominal arteries significantly increases image quality and permits a substantial reduction in breath-hold time or a significantly improved spatial resolution.     

Can a single‐shot black‐blood T2‐weighted spin‐echo echo‐planar imaging sequence with sensitivity encoding replace the respiratory‐triggered turbo spin‐echo sequence for the liver? an optimization and feasibility study

PURPOSE: To optimize and assess the feasibility of a single-shot black-blood T2-weighted spin-echo echo-planar imaging (SSBB-EPI) sequence for MRI of the liver using sensitivity encoding (SENSE), and compare the results with those obtained with a T2-weighted turbo spin-echo (TSE) sequence. MATERIALS AND METHODS: Six volunteers and 16 patients were scanned at 1.5T (Philips Intera). In the volunteer study, we optimized the SSBB-EPI sequence by interactively changing the parameters (i.e., the resolution, echo time (TE), diffusion weighting with low b-values, and polarity of the phase-encoding gradient) with regard to distortion, suppression of the blood signal, and sensitivity to motion. The influence of each change was assessed. The optimized SSBB-EPI sequence was applied in patients (N = 16). A number of items, including the overall image quality (on a scale of 1-5), were used for graded evaluation. In addition, the signal-to-noise ratio (SNR) of the liver was calculated. Statistical analysis was carried out with the use of Wilcoxon's signed rank test for comparison of the SSBB-EPI and TSE sequences, with P = 0.05 considered the limit for significance. RESULTS: The SSBB-EPI sequence was improved by the following steps: 1) less frequency points than phase-encoding steps, 2) a b-factor of 20, and 3) a reversed polarity of the phase-encoding gradient. In patients, the mean overall image quality score for the optimized SSBB-EPI (3.5 (range: 1-4)) and TSE (3.6 (range: 3-4)), and the SNR of the liver on SSBB-EPI (mean +/- SD = 7.6 +/- 4.0) and TSE (8.9 +/- 4.6) were not significantly different (P > .05). CONCLUSION: Optimized SSBB-EPI with SENSE proved to be feasible in patients, and the overall image quality and SNR of the liver were comparable to those achieved with the standard respiratory-triggered T2-weighted TSE sequence.     

敏感性编码技术和弥散敏感系数（b值）在兔肝VX2瘤扩散加权成像中的应用

目的探索敏感性编码（SENSE）技术和弥散敏感系数（b值）在兔肝VX2瘤快速MRI扩散加权成像实验中的应用。方法新西兰大白兔24只，于VX2瘤种植后2～3周行快速扩散加权成像（DWI）扫描。成像参数的缩减因子（reduction factor）取值为1，2，观察使用SENSE后扫描时间的缩短情况以及图像的信噪比变化情况。b值取100～600s／mm^2共6个。测量不同b值的兔肝VX2瘤与正常肝组织的信噪比以及相应的表面扩散系数（ADC），进行统计学分析。结果DWI中应用SENSE成像缩减因子为2时扫描时间缩短约13．3％，而图像的信噪比没差别（P≥0．05）。b值400s／mm^2时VX2瘤具有最高信噪比为115．5±71．6；ADC值为1．575±0．218×10^-3mm^2／s（P〈0．05）。结论 合理应用SENSE技术能缩短扫描时间而图像信噪比没有差别，弥散敏感系数（b值）为400s／mm^2是最优b值，兔肝VX2瘤与正常肝组织的信噪比最高，其ADC值最准确。     

Dynamic contrast-enhanced myocardial perfusion MRI accelerated with k-t sense.

In the k-t sensitivity encoding (k-t SENSE) method spatiotemporal data correlations are exploited to accelerate data acquisition in dynamic MRI studies. The present study demonstrates the feasibility of applying k-t SENSE to contrast-enhanced myocardial perfusion MRI and using the speed-up to increase spatial resolution. At a net acceleration factor of 3.9 (k-t factor of 5 with 11 training profiles) accurate representations of dynamic signal intensity (SI) changes were achieved in computer simulations. In vivo, 5x k-t SENSE was compared with 2x SENSE (identical acquisition parameters except for in-plane spatial resolution = 1.48 x 1.48 mm(2) vs. 2.64 x 2.64 mm(2), respectively). In 10 volunteers no differences in myocardial SI profiles were found (relative peak enhancement = 151% vs. 149.7%, maximal upslope = 12.9%/s vs. 13.3%/s for 2x SENSE and 5x k-t SENSE, respectively, all P > 0.05). Overall image quality was similar, but endocardial dark rim artifacts were reduced with k-t SENSE. Signal-to-noise ratio (SNR) in the myocardium was greater with 5x k-t SENSE by a factor of 1.36 +/- 0.23 at peak contrast enhancement with the relative yield decreasing with increasing dynamics in the object in accordance to theory. Higher nominal acceleration factors of up to 10-fold were shown to be feasible in computer simulations and in vivo.     

联合SWI与DWI在急性脑弥漫性轴索损伤中的应用价值

目的：评价联合磁敏感成像（SWI）与扩散加权成像（DWI）在急性期脑弥漫性轴索损伤中的应用价值。方法：32例脑弥漫性轴索损伤急性期患者,所有患者行常规MRI序列、DWI及SWI序列全脑扫描。结果：共检出病灶313个,T1WI 78个,T2WI 207个,FLAIR 292个,DWI 286个,SWI 297个。SWI显示245个病灶内分布斑片状、点状出血灶,其它序列共显示43个内分布出血灶。SWI、DWI病灶检出率高于常规T2WI（χ2=82.465,χ2=59.584;P〈0.01）,SWI、FLAIR及DWI病灶检出率无明显差异（χ2=3.052;P〉0.05）。结论：联合SWI与DWI有利于提高急性脑弥漫性轴索损伤的检出率,有助于准确评价病变的严重程度,SWI与DWI应作为急性脑弥漫性轴索损伤的常规扫描序列组合。     

Double arterial phase dynamic MRI with sensitivity encoding (SENSE) for hypervascular hepatocellular carcinomas

PURPOSE: To investigate the efficacy of SENSE MRI, including the double arterial phase dynamic study, to detect hypervascular hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: MRI of the liver was performed in 40 consecutive patients (20 by conventional MRI and 20 by SENSE MRI). The SENSE technique was used to obtain breath-hold T1-weighted FSE images (TR/TE = 556/12 msec), respiratory-triggered T2-weighted FSE images (TR/TE = 1800/90 msec) with and without fat suppression, and dynamic MR images (TR/TE/FA = 160-168/4.6 msec/70 degrees ). In each arterial dominant phase and portal dominant phase, two scans were consecutively performed with one breath-hold, leading to the double arterial phase and double portal phase images with SENSE. RESULTS: The sensitivity of SENSE MRI for HCCs diagnosed from all MR images, including dynamic study, T1-weighted images, and T2-weighted images, was 91.7%, while that of conventional MRI was 76.3%. The positive predictive value of SENSE MRI for HCCs was 91.7%, while that of conventional MRI was 87.9%. In terms of HCCs < or = 10 mm, the sensitivity and positive predictive values of SENSE MRI were 78.6% and 78.6%, respectively, while those of conventional MRI were 27.3% and 60.0%, respectively. The number of detected HCCs < or = 10 mm was significantly larger in SENSE MRI than in conventional MRI (P < 0.05). The cause of false-positive lesions on SENSE MR images was an arterioportal shunt. CONCLUSION: SENSE MRI with double arterial phase dynamic study showed higher sensitivity compared to the conventional technique. Therefore, SENSE MRI is a promising method for the detection of HCC.     

Comparison of k‐t SENSE/k‐t BLAST with conventional SENSE applied to BOLD fMRI

Purpose:

To compare k‐t BLAST (broad‐use linear‐acquisition speedup technique)/k‐t SENSE (sensitivity encoding) with conventional SENSE applied to a simple fMRI paradigm.

Materials and Methods:

Blood oxygen level‐dependent (BOLD) functional magnetic resonance imaging (fMRI) was performed at 3 T using a displaced ultra‐fast low‐angle refocused echo (UFLARE) pulse sequence with a visual stimulus in a block paradigm. Conventional SENSE and k‐t BLAST/k‐t SENSE data were acquired. Also, k‐t BLAST/k‐t SENSE was simulated at different undersampling factors from fully sampled data after removal of lines of k‐space data. Analysis was performed using SPM5.

Results:

Sensitivity to the BOLD response in k‐t BLAST/k‐t SENSE was comparable with that of SENSE in images acquired at an undersampling factor of 2.3. Simulated k‐t BLAST/k‐t SENSE yielded reliable detection of activation‐induced BOLD contrast at undersampling factors of 5 or less. Sensitivity increased significantly when training data were included in k‐space before Fourier transformation (known as “plug‐in”).

Conclusion:

k‐t BLAST/k‐t SENSE performs at least as well as conventional SENSE for BOLD fMRI at a modest undersampling factor. Results suggest that sufficient sensitivity to BOLD contrast may be achievable at higher undersampling factors with k‐t BLAST/k‐t SENSE than with conventional parallel imaging approaches, offering particular advantages at the highest magnetic field strengths. J. Magn. Reson. Imaging 2010;32:235–241. © 2010 Wiley‐Liss, Inc.     

The SENSE ghost: field-of-view restrictions for SENSE imaging

PURPOSE: To describe a known (but undocumented) limitation in parallel imaging using simulation and experiment. This limitation consists of an artifact that appears when the imaging field of view (FOV) is less than the object size. This study demonstrates this artifact in the phase- and partition-encoding dimensions. MATERIALS AND METHODS: One-dimensional simulations as well as in vivo experiments were performed with FOVs greater and less than the object being imaged. Full-FOV, reduced-FOV, and SENSE reconstructions were visually compared. RESULTS: Image artifacts occurred when the final SENSE FOV was smaller than the object being imaged. This artifact, termed the SENSE ghost, was a residual fold-over/aliasing artifact. Its location was in the central portion of the image rather than at the edges of the image. CONCLUSION: This image artifact results from an FOV being smaller than the imaged object. The SENSE reconstruction cannot unfold this additional fold-over, and will place it in a predictable image location based on the SENSE reduction factor. Knowledge of this artifact is necessary when prescribing SENSE acquisitions and interpreting the resulting images.