Comparing T2 weighted images/diffusion weighted imaging and T2 weighted images/dynamic contrast enhanced MRI for endometrial carcinoma myometrial invasion

Objectives

To evaluate accuracy of combined T2 and diffusion weighted images (DWI) in comparison to combined T2WI and dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) for assessment of the depth of myometrial invasion.

腰椎峡部裂并脊椎滑脱的MRI表现及影像学比较

目的 :探讨MRI在腰椎峡部裂并脊椎滑脱症中的诊断价值。方法 :分析总结 5 3例腰椎峡部裂并脊椎滑脱症的传统X线片、CT、MR扫描表现并进行比较。结果 :传统X线平片表现为腰椎滑脱、峡部裂、局部骨质增生硬化 ;CT表现为峡部裂、局部骨质增生硬化、韧带肥厚、椎管狭窄及矢状径增大 (双管征 )、椎间盘变形 ;MRI表现为峡部骨髓信号连续性中断、局部骨质呈T1、T2 低信号、韧带肥厚、腰椎滑脱、椎间孔变形 (双叶征 )、神经根卡压、节段性椎管扩张和狭窄。结论 :MR扫描对腰椎峡部裂并脊椎滑脱症的诊断具有重要的临床应用价值     

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     

Dumb-bell-type teratoma in the lumbar spine

We report a case of a lumbar teratoma in a 50-year-old woman. The teratoma showed a dumb-bell-type expansion at the level of the left L3/4 foramen with massive erosion of the L3 vertebral body. MRI revealed inhomogeneous signal changes in the tumor, which were histologically compatible with a mixture of bone, muscle, fat, and cyst containing sebaceous material. Complete resection of the tumor and spinal arthrodesis with pedicle screw fixation was necessary to obtain stability of the affected spinal segment. Received: 30 July 1999 Revision requested: 24 August 1999 Revision received: 11 October 1999 Accepted: 12 October 1999     

Magnetic resonance imaging of the lumbar spine with axial loading: a review of 120 cases

Purpose

To evaluate the imaging findings of patients with clinical symptoms of lower back pain who underwent magnetic resonance imaging (MRI) of the lumbar spine with axial loading.

Materials and methods

We examined 120 patients by MRI, before and after axial loading, using a compression device that applied 50% of their body weight for a load time of 5 min. The dural sac cross area (DSCA) was examined by two experienced radiologists before and after axial load, and their findings were compared. Degenerative abnormalities within and adjacent to the spinal canal were also analyzed.

Results

A reduction in DSCA greater than 15 mm² after axial load was defined as significant, and was found in 81 patients (67.5%) and 138 disc spaces (38.3%). Reduction was most frequent at L4-L5 (n = 55). For other disorders, a 9% increase in cases of bulging disc was seen during axial loading, and seven disc spaces showed protrusion/extrusion only after load. Facet joint synovial cysts, foraminal stenosis, and hypertrophy of the flavum ligaments showed almost no differences, pre- and post-load.

Conclusion

For adequate evaluation of lumbar symptoms, examination should be performed with axial loading, especially in cases of suspected spinal stenosis.     

Longitudinal study of vertebral type-1 end-plate changes on MR of the lumbar spine

The purpose of this study was to investigate the temporal evolution of type-1 end-plate changes on MRI in patients with degenerative disease of the lumbar spine and to evaluate whether any correlation exists between such evolution and the change in patients symptoms. Forty-four patients with 48 Modic type-1 end-plate changes (low TI signal and high T2 signal) were studied. All patients had an initial and a follow-up non-contrast lumbar MRI with variable intervals between the studies (12–72 months). Severity of the end-plate changes was assessed by eyeball estimation. Correlation with patients symptoms was studied with the help of the Visual Analogue Score (VAS), Oswestry Questionnaire Score (OQS) and patients subjective assessment. Of the 48 disc levels with type-1 changes, 18 (37.5%) converted fully to type 2 (high T1 signal and intermediate to high T2 signal), 7 (14.6%) partially converted to type 2, 19 (39.6%) became worse (i.e. type 1 changes became more extensive) and 4 (8.3%) showed no change. Higher average VAS (5.7) and OQS (42.3) scores were noted in patients where there was worsening type-1 change and lower scores (3.8 and 27, respectively) were seen in those where there was conversion to type-2 change. These trends, however, did not reach statistical significance (P values 0.16 and 0.09 for VAS and OQS, respectively). The statistical relationship was stronger after exclusion of patients with confounding factors (i.e. changes in lumbar MRI other than end-plate changes that could independently explain the evolution of patients symptoms) with P-values of 0.08 and 0.07 for VAS and OQS, respectively. Type-1 end-plate change represents a dynamic process and in a large majority of cases either converts to type-2 change or becomes more extensive. The evolution of type-1 change relates to change in patients symptoms, but not to a statistically significant level.     

Prediction of transitional lumbosacral anatomy on magnetic resonance imaging of the lumbar spine

AIM:To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra(LSTV) in magnetic resonance imaging(MRI) studies of the spine.METHODS:The lumbar spine MRI studies of 50 subjects with LSTV and 50 subjects with normal lumbosacral anatomy were retrospectively evaluated.In each study,the mid-sagittal T2-weighted image was used to measure the angle formed by a line parallel to the superior surface of the sacrum and a line perpendicular to the axis of the scan table(A-angle),as well as the angle formed by a line parallel to the superior endplate of the L3 vertebra and a line parallel to the superior surface of the sacrum(B-angle).RESULTS:The total study population consisted of 100 subjects(46 males,54 females,51 ± 16 years old).There were no differences in age and sex between the two groups.Both A-angle and B-angle were significantly increased in subjects with LSTV compared to controls(P < 0.05).The optimal cut-off values of A-angle and B-angle for the prediction of LSTV were 39.8°(sensitivity = 80%,specificity = 80%,accuracy = 83%;95% confidence interval = 74%-89%,P = 0.0001) and 35.9°(sensitivity = 80%,specificity = 54%,accuracy = 69%;95% confidence interval = 59%-78%,P = 0.0005),respectively.CONCLUSION:On sagittal MR images of the lumbar spine,an increased A-angle and/or B-angle should alert the radiologist to the presence of LSTV.     

Automatic spinal canal detection in lumbar MR images in the sagittal view using dynamic programming

As there is an increasing need for the computer-aided effective management of pathology in lumbar spine, we have developed a computer-aided diagnosis and characterization framework using lumbar spine MRI that provides radiologists a second opinion. In this paper, we propose a left spinal canal boundary extraction method, based on dynamic programming in lumbar spine MRI. Our method fuses the absolute intensity difference of T1-weighted and T2-weighted sagittal images and the inverted gradient of the difference image into a dynamic programming scheme and works in a fully automatic fashion. The boundaries generated by our method are compared against reference boundaries in terms of the Euclidean distance and the Chebyshev distance. The experimental results from 85 clinical data show that our methods find the boundary with a mean Euclidean distance of 3 mm, achieving a speedup factor of 167 compared with manual landmark extraction. The proposed method successfully extracts landmarks automatically and fits well with our framework for computer-aided diagnosis in lumbar spine.     

Degenerative diseases of the lumbar spine. Comparison of the multiecho data image combination sequence with magnetization transfer saturation pulse versus lumbar myelography/postmyelographic computed tomography

Purpose: To compare a T2* weighted 2D spoiled gradient echo multiecho sequence (MEDIC) with magnetization transfer saturation pulse versus lumbar myelography and postmyelographic computed tomography (pCT). Material and Methods: 84 disk levels in 27 patients were examined. The vertebral bodies, intervertebral disks, neural foramina, cauda equina, ligamentum flavum, and narrowing of the spinal canal were investigated using an evaluation scale. In addition, the pCT and the MEDIC sequence were evaluated for assessing the narrowing of the neural foramina in a phantom study using a cadaver preparation of the lumbar spine. Results: A total of 28 disk herniations, 11 cases of osteophytes narrowing the spinal canal or the neural foramina, and 7 spinal canal stenoses were detected. The pCT was significantly better in visualizing the cauda equina. The MEDIC sequence was significantly superior in visualizing the extension of the ligamentum flavum. No statistical differences between either image modality were found concerning assessment of the narrowing of the neural foramina and the spinal canal, nor regarding evaluation of the vertebral disk and the vertebral body. Measurements of the phantom study showed that the MEDIC sequence did not overestimate narrowing of the neural foramina. Conclusions: The T2* MEDIC sequence has proved to be as accurate as pCT in evaluating osteophytes and narrowing of the neural foramina. In doubtful standard magnetic resonance imaging findings, this means that an additional axial T2* MEDIC sequence may be of value in reaching the same accuracy as pCT.     

使用U-Net深度学习网络对腰椎矢状T2WI图像自动分割的可行性研究

目的:研究训练U-Net模型自动分割腰椎矢状面T₂WI图像中各结构的可行性。方法:回顾性搜集腰椎矢状面T2WI图像数据,共获得80个矢状面T₂WI序列。由2位影像医师手工标注矢状面腰椎椎体、椎间盘、椎间孔、椎管/硬膜囊、脊髓及马尾神经。将数据随机分为训练集、调优集和测试集,使用U-Net网络分两步(coarse-to-fine)训练腰椎矢状T₂WI分割模型。模型评价指标包括客观评估(Dice系数)和主观评估。结果:11例测试集数据中U-Net模型预测腰椎5个解剖部位分割的Dice值分别为椎体0.82~0.9(平均0.864)、椎间盘0.86~0.92(平均0.898)、椎管/硬膜囊0.76~0.87(平均0.837)、椎间孔0.6~0.76(平均0.67)、脊髓及马尾神经0.55~0.9(平均0.669)。主观评估各解剖部位分割满意率分别为椎体97.5%、椎间盘97.9%、椎管/硬膜囊86.4%、椎间孔76.7%、脊髓及马尾神经78.6%。结论:基于U-Net深度学习网络对腰椎矢状T₂WI图像的解剖结构进行自动分割是可行的。     

Quantitative T2 evaluation at 3.0T compared to morphological grading of the lumbar intervertebral disc: a standardized evaluation approach in patients with low back pain

Background

The purpose of our investigation was to compare quantitative T2 relaxation time measurement evaluation of lumbar intervertebral discs with morphological grading in young to middle-aged patients with low back pain, using a standardized region-of-interest evaluation approach.

Patients and methods

Three hundred thirty lumbar discs from 66 patients (mean age, 39 years) with low back pain were examined on a 3.0 T MR unit. Sagittal T1-FSE, sagittal, coronal, and axial T2-weighted FSE for morphological MRI, as well as a multi-echo spin-echo sequence for T2 mapping, were performed. Morphologically, all discs were classified according to Pfirrmann et al. Equally sized rectangular regions of interest (ROIs) for the annulus fibrosus were selected anteriorly and posteriorly in the outermost 20% of the disc. The space between was defined as the nucleus pulposus. To assess the reproducibility of this evaluation, inter- and intraobserver statistics were performed.

Results

The Pfirrmann scoring of 330 discs showed the following results: grade I: six discs (1.8%); grade II: 189 (57.3%); grade III: 96 (29.1%); grade IV: 38 (11.5%); and grade V: one (0.3%). The mean T2 values (in milliseconds) for the anterior and the posterior annulus, and the nucleus pulposus for the respective Pfirrmann groups were: I: 57/30/239; II: 44/67/129; III: 42/51/82; and IV: 42/44/56. The nucleus pulposus T2 values showed a stepwise decrease from Pfirrmann grade I to IV. The posterior annulus showed the highest T2 values in Pfirrmann group II, while the anterior annulus showed relatively constant T2 values in all Pfirrmann groups. The inter- and intraobserver analysis yielded intraclass correlation coefficients (ICC) for average measures in a range from 0.82 (anterior annulus) to 0.99 (nucleus).

Conclusions

Our standardized method of region-specific quantitative T2 relaxation time evaluation seems to be able to characterize different degrees of disc degeneration quantitatively. The reproducibility of our ROI measurements is sufficient to encourage the use of this method in future investigations, particularly for longitudinal studies.     

MRI of degenerative lumbar spine disease: comparison of non-accelerated and parallel imaging

Introduction Parallel imaging techniques such as GRAPPA have been introduced to optimize image quality and acquisition time. For spinal imaging in a clinical setting no data exist on the equivalency of conventional and parallel imaging techniques. The purpose of this study was to determine whether T1- and T2-weighted GRAPPA sequences are equivalent to conventional sequences for the evaluation of degenerative lumbar spine disease in terms of image quality and artefacts. Methods In patients with clinically suspected degenerative lumbar spine disease two neuroradiologists independently compared sagittal GRAPPA (acceleration factor 2, time reduction approximately 50%) and non-GRAPPA images (25 patients) and transverse GRAPPA (acceleration factor 2, time reduction approximately 50%) and non-GRAPPA images (23 lumbar segments in six patients). Comparative analyses included the minimal diameter of the spinal canal, disc abnormalities, foraminal stenosis, facet joint degeneration, lateral recess, nerve root compression and osteochondrotic vertebral and endplate changes. Image inhomogeneity was evaluated by comparing the nonuniformity in the two techniques. Image quality was assessed by grading the delineation of pathoanatomical structures. Motion and aliasing artefacts were classified from grade 1 (severe) to grade 5 (absent). Results There was no significant difference between GRAPPA and non-accelerated MRI in the evaluation of degenerative lumbar spine disease (P > 0.05), and there was no difference in the delineation of pathoanatomical structures. For inhomogeneity there was a trend in favour of the conventional sequences. No significant artefacts were observed with either technique. Conclusion The GRAPPA technique can be used effectively to reduce scanning time in patients with degenerative lumbar spine disease while preserving image quality.     

Contrast on T2-weighted images of the lumbar spine using fast spin-echo and gated conventional spin-echo sequences

A prospective study in 31 patients was designed to compare contrast quantitatively using axial conventional, gated spin-echo T2-weighted (T2W) (SE) (asymmetrical echo TE 30 and 80 ms) and axial dual-echo fast spin-echo (FSE) sequences (TE_eff20 and 120 ms) to image lumbar discs, nerve roots, and cerebrospinal fluid CSF. We used two quantitative measures, percent (%) contrast and contrast-to-noise ratio (CNR), to compare the sequences. The FSE sequence had greater % contrast and CNR on the first and second echo images for both disc and nerve root detection using these scan parameters. An axial FSE sequence, therefore, provided contrast characteristics similar to those of gated axial T2W SE sequence in the lumbar spine, with a 60% saving in acquisition time. The FSE sequence is now our standard axial T2W study for the lumbar spine.     

Degenerative disc disease in the lumbar spine: another cause for focally reduced activity on marrow scintigraphy

A patient is presented in whom a focal reduction in marrow activity in the lumbar spine on both leucocyte and nanocolloid marrow scintigraphy was subsequently shown to be due to fatty infiltration of marrow in association with disc degeneration. Degenerative disease in the lumbar spine has not been previously described as a cause of abnormal bone marrow distribution by such means and needs to distinguished from a more serious pathology, such as malignant infiltration and vertebral infection, which it may mimic. In a retrospective review of 33 nanocolloid bone marrow and 117 leucocyte scintigrams, 8 showed a degree of reduced marrow activity in the lumbar spine consistent with that caused by degenerative changes.     

轴向负荷对腰椎间盘MR扩散特点的影响

目的 探讨轴向负荷对受检者椎间盘ADC值、各项异性(FA)值的影响.方法 腰腿痛患者45例,年龄范围25～54岁.进行常规T2WI、T1WI及轴向负荷前后DTI,负荷重量为体质量的40%～50%,负荷时间为10 min.DTI参数:TR 2500 ms,TE 89 ms,扩散方向为6个方向,b值设为400 s/m2,扫描时间4 min 10 s.利用DTI原始数据重组ADC图、FA图、b0图,测定其负荷前后椎间盘的ADC值、FA值,分析短时轴向负荷后ADC值、FA值的变化规律.椎间盘负荷前后ADC值、FA值的差异性比较,采用配对资料t检验或秩和检验.结果 45例225个椎间盘,223个纳入研究,Pfirrmann分级结果:Ⅱ级100个,Ⅲ级48个,Ⅳ级59个,Ⅴ级16个,2个椎间盘钙化未纳入研究,223个椎间盘负荷前、后椎间盘的ADC值分别是为(1666±252)×10-3、(1662±253)×10-3 mm2/s,负荷后平均ADC值减低,但差异无统计学意义(Z=-1.363,P＞0.05),负荷前、后223个椎间盘的FA值分别是(301±104)×10-3、(316±112)×10-3,负荷后平均FA值升高(Z=-2.794,P＜0.05).Pfirrmann Ⅲ级椎间盘,短时轴向负荷后ADC值减低、FA值升高,Ⅳ级椎间盘FA值升高,负荷前、后Ⅲ级椎间盘的ADC值分别是为(1685±190)×10-3、(1624±180)×10-3mm2/s,FA值分别是(300±87)×10-3、(326±87)×10-3,Ⅳ级椎间盘FA值分别是(348±67)×10-3、(351±71)×10-3,差异均有统计学意义(t值分别为3.513、-2.210、-2.006,P值均＜0.05);Pfirrmann Ⅱ级、Ⅳ级和Ⅴ级椎间盘负荷前后ADC值差异无统计学意义(P值均＞0.05);Ⅱ级、Ⅴ级椎间盘FA值负荷前后差异亦无统计学意义(P＞0.05).结论 短时轴向负荷可引起轻度退变椎间盘(Pfirrmann Ⅲ级)ADC值下降、椎间盘扩散能力降低;在正常(Pfirrmann Ⅱ级)和重度退变椎间盘(Pfirrmann Ⅳ级和Ⅴ级),短时轴向负荷前后椎间盘ADC值无明显变化,对椎间盘扩散能力影响不明显.     

Comparison of T1 and T2 weighted images of the lumbar spine

In order to develop an optimal routine magnetic resonance (MR) spine scanning protocol, we have compared the relative efficacy of performing T1- and T2-weighted images in patients with various disorders of the lumbar region. Forty cases were randomly selected from studies performed from 1984 to 1987 and the T1- and T2-weighted images of each case were separated and interpreted blindly and independently by two neuroradiologists. Our results indicate no significant difference between T1- and T2-weighted images in the depiction of disc protrusion. The T2-weighted images were superior in depicting disc dessication, but the clinical significance of identifying a dessication disc remains uncertain. No significant difference in the depiction of osteophytes was seen between T1- and T2-weighted images. Cases of tethered cord, metastatic disease, and arachnoiditis were better delineated with T1-weighted images. The increase in signal of cerebrospinal fluid (CSF) with T2-weighting often obscured lesions within the spinal canal. In a signal case of postoperative discitis, the T2-weighted images disclosed disc space abnormalities and epidural fluid collections not appreciated on T1-weighted images. The T1-weighted images, however, did show thecal sac and adjacent epidural extension more clearly. In cases of metastatic disease, increase in the signal of metastases with T2 weighting often rendered them isointense to surrounding medullary bone. Given the lack of superiority of T2-weighted images over T1-weighted images in evaluating intervertebral disc protrusions and the superiority of T1-weighted images in depicting nearly all other abnormalities observed in this series, we no longer acquire T2-weighted images of the lumbar spine on a routine basis.(ABSTRACT TRUNCATED AT 250 WORDS)     

腰椎间盘高度的影像学测量

腰椎间盘高度的影像学测量,由于容易受到投照及体位等因素的影响,多年以来一直存在争议。本文对历年来几种主要的影像学测量技术手段及方法做一回顾性分析,并着重介绍了最新的测量方法。     

颅骨与腰椎骨髓转化的MR定量研究及临床应用

目的 :从定量角度探讨MRI上颅骨与腰椎骨髓转化特点并评估骨髓相对信号强度 (RSI)的诊断价值。方法 :正常组 2 5 7例 ,其中颅骨 10 1例 ,腰椎 15 6例 ;异常组 6例 ,白血病 5例 ,多发性骨髓瘤 1例。MR扫描仪为 0 .5TPhilipsGyroscan。成像序列为TSET1 WI ,测定颅骨和腰椎骨髓的RSI并进行F检验、相关分析及动态分析。结果 :腰椎和颅骨骨髓RSI与年龄呈明显正相关 (P <0 .0 1)。颅骨骨髓RSI的净增量及平均增长速度大于腰椎。正常组颅骨骨髓与腰椎骨髓RSI在不同年龄段之间差异有显著性意义。异常组骨髓RSI值明显低于相应年龄段正常均值。结论 :骨髓RSI在不同年龄段间存在显著性差异 ,颅骨骨髓转化程度、速度均较腰椎显著。RSI对弥漫性骨髓浸润性疾病有较高的敏感性 ,但缺乏特异性。