双能量减影自动去骨技术在双源CT颈动脉成像中的临床应用

目的探讨双源CT双能量减影中自动去骨技术在颈动脉成像中的临床应用价值。方法对65例临床拟诊颈动脉狭窄的患者,行双源CT颈部血管成像,分析双能量减影自动去骨技术对颈动脉病变的显示,并评价图像质量。结果 65例中3例血管正常变异,33例未见明显病变,血管主干及其分支显示清楚。32例颈动脉粥样硬化,其中4例支架植入术后。双能量CTA对颈根段、颅外段及颅底段血管的满意显示率分别为67.2%、96.2%及66.2%;3个部位血管原始评分比较差异有统计学意义(P=0.000);进一步两两比较,颈根段和颅底段血管的评分差异无统计学意义(P=0.181)。结论双源CT双能量减影成像是一种快速、简便、无创性检查方法,其整体去骨效果较好,血管显示效果最好者是颈动脉颅外段(颈总动脉和颈内动脉颅外段)。     

双源CT双能量去骨技术在头颈部血管成像中的应用

目的：比较双能量去骨与减影去骨对头颈部血管CT成像（CTA）的差异,探讨头颈部双能量CT血管成像（DECTA）的应用价值。方法：50例患者行DECTA检查并行双能量去骨,对照组45例患者使用减影CTA检查并去骨,然后分别比较DECTA和减影CTA的图像质量、去骨所用时间及放射剂量,并观察DECTA上颈总动脉分叉处钙化的显示效果。结果：颅内动脉DECTA和减影CTA的图像质量差异无显著性意义（Z=0.790,P=0.430）,颈内动脉虹吸段和岩段DECTA图像质量优于减影CTA（虹吸段Z=-1.989,P=0.047;岩段Z=-2.014,P=0.044）,而减影CTA显示颈根部动脉优于DECTA（Z=3.900,P〈0.001）。同时DECTA减少约24.0%的放射剂量。DECTA上共有28例发现有血管性病变,所有病变显示清晰,其中10例并与DSA或外科手术对照具有良好的一致性。颈总动脉分叉处36个钙化灶中有8个钙化灶未在DECTA上显示。结论：DECTA显示头颈部血管总体良好,成功率高,且放射剂量明显减少,但对于颈根部动脉显示仍存在一定局限。     

双源CT双能量自动减影去骨技术在颈动脉造影中的临床应用

目的 评价双源CT双能量自动减影去骨去钙化技术在颈动脉造影中的临床应用价值.方法 回顾性分析自2012年11月～2014年2月在本院就诊应用双源CT双能量颈动脉血管成像检查的患者126例,分析全部患者颈动脉双源CT双能量自动去骨去钙化技术对颈动脉的显示,并评价图像质量.其中阳性结果患者中有27例患者接受了头颈部血管造影(DSA)检查,并以DSA图像为金标准对照,评价双源CT双能量自动减影去骨去钙化技术诊断颈动脉狭窄与DSA对照的统计学意义.结果 126例患者颈动脉双能量自动去骨后,对颈总动脉(CCA)血管满意显示率为71.0％,颈内动脉颅外段(ICA-E)血管显示满意率为96.0％,颈内动脉颅内段(ICA-I)血管满意显示率为74.2％,ICA-E血管满意显示率最高,与CCA及ICA-I相比有统计学意义(P＜0.05),全部血管总满意显示率为80.4％.27例阳性患者颈动脉双能量自动去骨后与DSA对照,狭窄吻合率一致性很高(P＞0.05),尤其重度及闭塞吻合率达到95％以上.结论 双源CT双能量自动去骨去钙化技术在颈动脉成像中的应用是一种快速、有效、无创的检查新手段,获得的图像质量好,尤其在ICA-E段血管的显示几乎可以替代DSA检查.     

多层螺旋CT编辑减影去骨技术在颈部血管成像中的应用

目的：探讨编辑减影技术在16层螺旋CT颈部血管成像中的应用价值。方法：30例疑颈部动脉病变患者,行低剂量CT平扫和颈动脉CTA扫描,采用小剂量对比剂预注射技术确定动脉期延迟时间,利用object editor后处理软件进行编辑减影去骨处理,完成颈动脉血管的去骨成像。结果：本组30例颈部动脉CTA共发现梭形动脉瘤4例,动脉局限性狭窄12例,钙化斑块共计71处。按骨骼完全去除、少许残留和残留明显等不同程度对图像进行评分（1～3）,其中3分10例（33%）,2分15例（50%）,1分5例（17%）。结论：16层螺旋CT常规软件objecteditor能够快速、自动的去除颈部动脉CTA中的骨结构,直观、全面显示颈部血管,同时能快速去除充盈致密对比剂的头臂和上腔静脉影的干扰,并可选择性保留或除去血管壁钙化斑块,具有较高的临床应用价值。     

头颈部CTA两种扫描方式及其辐射剂量的比较分析

目的：优化头颈部CT增强扫描血管成像的扫描方式,减少其辐射危害。方法：回顾性地分析86例头颈部CT增强扫描血管成像的病例资料,其中行减影成像法及常规扫描成像法各43例,观察其成像质量,比较其单次扫描的CT剂量加权指数（CTDIvol）及剂量长度乘积（DLP）。结果：在扫描范围、扫描参数（kV、mAs、p、thin等）、对比剂注射流率和注射部位完全相同的情况下,常规扫描成像与减影成像法的图像质量相同,单次扫描CTDIvol相同,但DLP降低约48.26%左右。结论：常规扫描法能有效降低总曝光量和累计剂量长度乘积,可以有效地降低患者的辐射剂量,减少其辐射危害。     

减影去骨技术在头颈CT血管双期成像中的应用

目的：比较减影去骨法与手动去骨法对头颈血管CT成像的差异,探讨减影去骨法的应用价值。方法：51例患者30例行脑动脉CTA（12例行脑静脉CTV）,另外21例行头颈动脉CT成像。先测试颅底动脉达峰时间,平扫后根据达峰时间行动脉期扫描,必要时立即行静脉期扫描;动脉增强、平扫薄层图像同层相减生成动脉期三维图像,少量残余骨质辅以手动去骨,同样方法处理静脉系统。以手动去骨处理血管增强的原始图像得到动脉（和静脉）三维结构图。观察颈根动脉、颈5椎体-颅内动脉以及脑静脉的完整度,观察颅内血管分支、颅底-颈5椎体动脉的清晰度,计算动脉系统成像后处理消耗的时间,与手动去骨成像对比。结果：减影去骨法显示颈5椎体颅内动脉的完整性优于手动去骨（χ^2=27,P=0．008）,前者显示脑静脉的完整度明显好于后者,但两种方法显示颈根部动脉的效果都一般;手动去骨显示颅内动脉分支的清晰度优于减影去骨法（χ^2=9,P=0．01）,显示颅底-颈5椎体动脉的清晰度差异无显著意义（χ^2=5．6,P=0．06）;减影去骨处理动脉系统消耗的时间明显少于手动去骨（t=-11．16,P〈0．001）;总共发现有病变的患者32例,其中减影去骨法对颅底血管狭窄和动脉瘤显示立体效果更好。结论：减影去骨法可显示血管全貌,对病变立体定位更好,但是脑部小血管亮度欠佳,对患者固定要求高。     

炫速CT双能量与常规减影血管成像在诊断颅内血管病变显示的对比研究

目的 对双能量直接去骨减影法(Dual-Energy CTA)与常规减影法(Neuro-DSA)在脑动脉成像的图像质量、患者接受辐射剂量及图像处理效率及检查成功率方面进行比较,探讨两种减影方法的差异.方法 根据投照技师操作习惯不同,将连续120名接受头颅CTA检查的患者随机分为双能量扫描组和常规扫描组,采用SIMENS SOMATOMDefinition Flash CT机分别以双能量模式及常规模式进行扫描.结果 双能量减影法与常规减影法对图像质量无明显影响,辐射剂量明显低于常规减影,降低率为44％,图像处理效率及检查成功率均明显高于对照组,差异具有统计学意义(t=1.66,P＜0.01).结论 双能量直接去骨减影法具有辐射剂量低,图像质量清晰,图像处理快,检查成功率高的优势,具有广阔的应用前景,值得推广应用.     

16层螺旋CT颈部血管成像中Neuro DSA去骨软件的应用探讨

目的 通过与常规Subtraction软件比较,探讨Neuro DSA软件在16层螺旋cr颈动脉减影去骨成像中的应用价值.资料与方法 21例疑颈部动脉病变患者,小剂量测试后确定动脉期延迟时间,行相同范围低剂量平扫与颈动脉CTA,分别进行Subtraction减影去骨及Neuro DSA减影去骨成像,比较两种去骨方法的成像时间及手工辅助去骨前后的图像质量.结果 21例颈动脉平均强化值为(396.58±97.71)HU;颈动脉与颈静脉平均强化差值为(231.33±94.85)HU;颈静脉干扰轻微,1例静脉返流严重,1例位置移动过大不能进行减影去骨血管成像.其余19例均可进行减影去骨处理,Subtraction软件直接减影的平均时间及手工辅助去骨平均时间分别是(4.05±1.28)min、(20.95±6.73)min,Neuro DSA减影的平均时间及手工辅助去骨平均时间分别是(2.35±1.05)min、(8.39±4.03)min.两者差异有统计学意义(P<0.001).Subtraction软件直接去骨及手工辅助去骨后图像评分分别为1.08±0.28、2.15±0.69.Neuro DSA软件直接去骨及手工辅助去骨后图像评分分别为2.46±0.78,2.85±0.38.两者差异有统计学意义(P<0.05).21例共发现动脉瘤3例,动脉狭窄12例.两者均能清晰显示所有病变.结论 Neuro DSA软件较常规Subtraction软件能更快速、自动去除颈动脉CTA中的骨结构,更清晰、全面显示颈动脉血管,具有较高的应用价值.     

双能量CT脑血管成像的初步临床应用

目的 探讨双能量CT脑血管成像的临床应用价值.方法 对30例临床怀疑颅内血管性病变患者进行双能量CT血管成像检查,扫描采用双能量程序,一次性扫描采集2个不同能量的数据.所得原始数据的后处理采用80 kV及140 kV 2个不同能量的数据进行直接去骨减影(即双能量减影),并保存减影后数据.所有病例均完成容积显示(VR)和最大密度投影(MIP).全部病变结果均经手术或介入栓塞证实.结果 30例病人双能量减影均清晰显示颈内动脉颅内主干及主要分支,Willis环显示清楚.其中19例动脉瘤病例均清晰显示动脉瘤大小、形态,与载瘤动脉关系,瘤颈及瘤轴指向,及其动脉瘤与邻近血管分支的空间关系,其中17例为单个动脉瘤,2例为2个动脉瘤,动脉瘤直径2～ 35 mm,平均约4.7 mm.4例血管畸形病例均清晰显示异常血管团形态和范围.结论 双能量CT血管造影能够清晰显示正常颅内血管及血管性病变,是一种具有发展潜力的检查方法.     

低剂量双期扫描在颅脑CTA中的应用价值

目的:探讨MSCT低剂量双期扫描在脑血管病变的成像质量与诊断价值。方法:41例临床怀疑有脑血管病变的患者行低剂量双期CT动脉及静脉成像检查,另收集41例对照组患者行常规减影CTA;评价2种方法在脑血管的成像质量,测量X线辐射剂量,并从脑血管显示率、病变检出、病变来源、病变定性及与周围组织毗邻情况方面评价低剂量双期CT动脉及静脉成像对脑血管病变的诊断意义。结果:低剂量双期CT动脉及静脉成像的辐射剂量明显低于常规减影CTA,图像质量无明显差异(P=0.975)。低剂量双期CT动脉及静脉成像与常规减影CTA对病变检出质量的比较,5分的病变分别占95.12%,26.83%,低剂量双期CT动脉及静脉成像质量明显高于常规减影CTA(P=0.000)。结论:低剂量双期CT动脉及静脉成像的图像质量无明显下降,辐射剂量明显降低,且能够清晰显示病变来源及与周围组织毗邻情况,病变检出率、病变定性水平均有提高;对脑血管病变有较高的诊断价值。     

Bone-subtraction CT angiography for the evaluation of intracranial aneurysms

PURPOSE: CT angiography (CTA) has been established for detection and therapy planning of intracranial aneurysms. The analysis of aneurysms at the level of the skull base, however, remains difficult because bone prevents a free view. We report initial clinical results of an approach for automatic bone elimination from CTA data. MATERIAL AND METHODS: Before the bone-removal process 2 datasets are acquired: nonenhanced spiral CT with reduced dose and contrast-enhanced CTA. The software automatically registers the nonenhanced data onto the CTA data and selectively removes bone. Vascular structures, as well as brain tissue, remain visible. In this study, we investigated 27 patients with 29 aneurysms, 13 of which were located at the skull base. 3D volume-rendered images with and without bone removal were reviewed and compared with digital subtraction angiography by 2 radiologists in consensus. RESULTS: All supraclinoidal aneurysms were detected on 3D volume-rendered images of both CTA and bone-subtraction CT angiography (BSCTA). Four intracavernous and 3 paraclinoid aneurysms of the internal carotid artery were not visible or were only partially visible on conventional 3D CTA, whereas they could be optimally visualized with BSCTA. Bone removal was successful in all patients; the average additional time for postprocessing was 6.2 minutes. In 7 patients (26%), perfect bone removal without any artifacts was achieved. In most patients, some bone remnants were still present, though it did not disturb the 3D visualization of vascular structures. CONCLUSION: BSCTA allows robust and fast selective elimination of bony structures, thus ascertaining a better analysis of arteries at the level of the skull base. This is useful for both detection and therapy planning of intracranial aneurysms.     

Bone-subtraction CT angiography: evaluation of two different fully automated image-registration procedures for interscan motion compensation

BACKGROUND AND PURPOSE: Bone-subtraction techniques have been shown to enhance CT angiography (CTA) interpretation, but motion can lead to incomplete bone removal. The aim of this study was to evaluate 2 novel registration techniques to compensate for patient motion. MATERIALS AND METHODS: Fifty-four patients underwent bone-subtraction CTA (BSCTA) for the evaluation of the neck vessels with 64-section CT. We tested 3 different registration procedures: pure rigid registration (BSCTA), slab-based registration (SB-BSCTA), and a partially rigid registration (PR-BSCTA) approach. Subtraction quality for the assessment of different vascular segments was evaluated by 2 examiners in a blinded fashion. The Cohen kappa test was applied for interobserver variability, and the Wilcoxon signed rank test, for differences between the procedures. Motion between the corresponding datasets was measured and plotted against image-quality scores. RESULTS: Algorithms with motion compensation revealed higher image-quality scores (SB-BSCTA, mean 4.31; PR-BSCTA, mean 4.43) than pure rigid registration (BSCTA, mean 3.88). PR-BSCTA was rated superior to SB-BSCTA for the evaluation of the cervical internal and external carotid arteries (P<.001), whereas there was no significant difference for the other vessels (P=.157-.655). Both algorithms were clearly superior to pure rigid registration for all vessels except the basilar and ophthalmic artery. Interobserver agreement was high (kappa=0.46-0.98). CONCLUSION: Bone-subtraction algorithms with motion compensation provided higher image-quality scores than pure rigid registration methods, especially in cases with complex motion. PR-BSCTA was rated superior to SB-BSCTA in the visualization of the internal and external carotid arteries.     

双能量CT头颅血管成像的影像质量、辐射剂量及初步临床应用

目的 探讨双源CT(DSCT)双能量技术头颅血管成像的初步临床应用价值.方法 选择41例临床怀疑有脑血管病变患者行双能量CTA(DECTA),另选择对照组41例患者行常规减影CTA.2名医师共同进行分析协商,评价两种方法颅底及颅内血管影像质量,计算辐射剂量,分析DECTA对41例患者的检查情况,选取经DSA证实的9例12个动脉瘤,测量动脉瘤的大小、瘤颈,并与DSA进行比较.DECTA和常规减影CTA血管影像质量的比较采用独立样本的非参数等级检验,辐射剂量的比较采用两个独立样本的t检验,DECTA和DSA显示动脉瘤的大小、瘤颈的比较采用配对t检验,DECTA和DSA测量动脉瘤颈、瘤长轴及瘤短轴的相关性采用Spearman相关分析.结果 颅内血管DECTA和常规减影CTA影像质量5分的病例分别占70.7%(29/41)、75.6%(31/41),差异无统计学意义(Z=-0.455,P=0.650),而颅底血管常规减影CTA总的影像质量优于DECTA(Z=-4.087,P=0.000),主要是岩段和虹吸段的影像质量较差;DECTA和常规CTA总辐射剂量分别为(396.54±17.43)、(1090.95±114.29)mGy·cm;DECTA所用总辐射剂量较常规减影CTA总辐射剂量降低了64%,差异有统计学意义(t=-38.52,P=0.000).41例临床怀疑有脑血管病变患者,DECTA检出19例患者有动脉瘤,2例动静脉畸形,3例烟雾病,17例阴性患者.9例动脉瘤患者(12个动脉瘤)、2例脑动静脉畸形、3例烟雾病和2例阴性患者行DSA或手术证实,诊断符合率达100%.DECTA检测动脉瘤颈、瘤长轴及瘤短轴分别为(2.90±1.61)、(5.23±1.68)及(3.83±1.69)mm,DSA检测动脉瘤颈、瘤长轴及瘤短轴分别为(2.95±1.71)、(5.10±1.60)及(3.83±1.65)mm.两者在动脉瘤大小、瘤径测量方面的差别无统计学意义(瘤颈、瘤长轴及短轴所对应的t值分别为-0.734、1.936及0.125,P值分别0.482、0.085及0.903);且两者测量之间有很好的相关性(瘤颈、瘤长轴及短轴的r值分别为0.964、0.976、0.973,P值均为0.000).结论 相对于常规减影CTA,颅内血管DECTA的图像质量没有明显下降,而颅底血管,尤其是岩段和虹吸段的影像质量较差.双源CT双能量CTA明显减少患者辐射剂量,有很高的诊断准确性,是一种较好的影像学检查手段.     

探测器宽度对头颈CTA图像质量及辐射剂量影响的对比研究

目的探讨探测器宽度对头颈CTA图像质量及辐射剂量的影响。方法将120例行头颈CTA检查的患者分为A、B两组,每组60例。A组采用40 mm探测器;B组采用80 mm探测器,其他扫描参数及对比剂注入方式保持一致。测量主动脉弓、右侧颈内动脉甲状软骨平面及右侧大脑中动脉M2段CT值(HU)和客观噪声(SD),记录剂量长度乘积,计算信噪比及有效剂量;对所有采集及后处理图像进行主观及客观评分。结果A、B两组患者辐射剂量分别为(0.56±0.06)mSv和(0.64±0.08)mSv,A组低于B组12.5%(P<0.05);且细支动脉血管对比剂充盈A组优于B组(P<0.05),颅内血管清晰度两组差异无统计学意义(P>0.05)。结论在头颈CTA检查时,采用40 mm探测器宽度可保证较低辐射剂量,同时获得能够满足诊断要求的图像质量。     

Dual-energy direct bone removal CT angiography for evaluation of intracranial aneurysm or stenosis: comparison with conventional digital subtraction angiography

Dual-energy CT can be applied for bone elimination in cerebral CT angiography (CTA). The aim of this study was to compare the results of dual-energy direct bone removal CTA (DE-BR-CTA) with those of digital subtraction angiography (DSA). Twelve patients with intracranial aneurysms and/or ICA stenosis underwent a dual-source CT in dual-energy mode. Post-processing software selectively removed bone structures using the two energy data sets. Three-dimensional images with and without bone removal were reviewed and compared to DSA. Dual-energy bone removal was successful in all patients. For 10 patients, bone removal was good and CTA maximum-intensity projection (MIP) images could be used for vessel evaluation. For two patients, bone removal was moderate with some bone remnants, but this did not inhibit the three-dimensional visualization. Three aneurysms adjacent to the skull base were only partially visible in conventional CTA but were fully visible in DE-BR-CTA. In five patients with ICA stenosis, DE-BR-CTA revealed the stenotic lesions on the MIP images. The correlation between DSA and DE-BR-CTA was good (R ²=0.822), but DE-BR-CTA led to an overestimation of stenosis. DE-BR-CTA was able to eliminate bone structure using only a single CT data acquisition and is useful to evaluate intracranial aneurysms and stenosis.     

Dual energy CT of peripheral arteries: effect of automatic bone and plaque removal on image quality and grading of stenoses

Purpose

To evaluate the effect of automatic bone and plaque removal on image quality and grading of steno-occlusive lesions in patients undergoing dual energy CT angiography (CTA) of lower extremity.

Materials and methods

Dual energy (DE) runoff CTA was performed in 50 patients using the following parameters: collimation 2 × 32 × 0.6; tube potentials, 80 kV and 140 kV; reconstructed slice thickness 1 mm. 100 mL iomeprol 400 and 50 mL saline were injected at 4 mL/s. Separate datasets were calculated for each of the two tubes and used to generate automatically bone-subtracted images (ABS) as well as bone and plaque subtracted images (ABPS). Residual bone in the ABS dataset was removed manually (=ABS-B dataset). In addition, a weighted average dataset from both dual energy acquisitions resembling a routine 120 kV CT acquisition was used for standard manual bone subtraction (MBS). Operator time for bone removal was measured. Effectiveness of bone subtraction and presence of vessel erosions was assessed by two readers in consensus. Stenosis grading in plaque subtracted and unsubtracted images was assessed and correlated.

Results

Residual bone fragments (ribs: 46%, patella: 25%, spine: 4%, pelvis: 2%, tibia 2% of patients) were only observed with ABS. The time needed to manually remove these residual bones was 2.1 ± 1.1 min and was significantly lower than the duration of manual bone removal (6.8 ± 2.0 min, p < 0.0001, paired t-test). A total of 1159 arteries were analyzed. Compromising vessel erosions were observed less frequently in the ABS-B dataset (10.6%) than in the MBS dataset (15.2%, p < 0.001, wilcoxon’s signed rank test). A total of 817 steno-occlusive lesions were assessed. While the agreement of grading of steno-occlusive lesions was good at the levels of the aorta and the pelvic arteries (κ = 0.70 in both, Cohen’s kappa statistics), it was moderate at the level of the thigh arteries (κ = 0.57) and poor at the level of the calf (κ = 0.16).

Conclusion

DE CTA has substantial advantages over conventional CTA. Automatic bone subtraction is more time efficient and reliable. Automatic plaque subtraction for the first time provides a true CTA-luminogram which is easy to interpret and reduces the need for further post-processing. DE CTA provides best results in arteries of the thigh; below the knee, plaque subtraction is less accurate.     

Automatic bone and plaque removal using dual energy CT for head and neck angiography: Feasibility and initial performance evaluation

Purpose

We sought to evaluate the feasibility and efficiency of dual energy (DE) bone and plaque removal in head and neck CT angiography.

Materials and methods

20 patients with suspected carotid stenoses received head and neck DE-CTA as part of their pre-interventional workup. Visual grading using multiplanar reformations (MPR), thick slab maximum intensity projections (MIP) and quantitative vessel analysis (QVA) of stenoses was performed prior and after DE bone removal. Results were evaluated for the detection of relevant stenoses (vessel area reduction >70%). Vessel segmentation errors were analyzed.

Results

Segmentation errors occurred in 19% of all vessel segments. Nevertheless, most post-bone removal artifacts could be recognized using the MPR technique for reading. Compared to MPR reading prior to bone removal, sensitivity, specificity, positive and negative predictive values after bone removal were 100%, 98%, 88% and 100% for MPR reading and 100%, 91%, 63% and 100% for exclusive MIP reading, respectively. There was a good agreement between the QVA results prior and post-DE plaque removal (r² = 0.8858).

Conclusion

DE bone and plaque removal for head and neck angiography is feasible and offers a rapid and highly sensitive overview over vascular head and neck studies. Due to a slightly limited specificity of the MIP technique due to segmentation errors, possible stenoses should be verified and graded using MPR techniques.     

Bone mineral density and muscle strength in female ice hockey players

The purpose of this study was to investigate bone mineral density (BMD) at different sites in female ice hockey players as well as to study the relationship between BMD, muscle strength, and body composition parameters. The study group consisted of 14 female ice hockey players (age 22.2 +/- 4.3 years) which was compared with 14 inactive females (age 21.5 +/- 3.8 years). The two groups were matched for age and weight. Areal bone mineral density was measured in total body, head, lumbar spine, femoral neck, Ward's triangle and the trochanter, using dual energy X-ray absorptiometry. Body composition parameters were derived from the total body scan. Isokinetic concentric peak torque of the left quadriceps and hamstrings muscles was measured using an isokinetic dynamometer. Compared to the inactive group, the ice hockey players had significantly higher BMD of all of the bone sites measured, except for the head, (total body 6.9%, head -2.6%, lumbar spine 8.9%, femoral neck 17.6%, Ward's triangle 20.4%, and trochanter 21.7%). The hockey players also had significantly higher peak torque in the quadriceps and hamstrings muscles. In the ice hockey group, a significant positive correlation was found between BMD of the femoral neck and hamstrings peak torque at 225 degreesisecond (r = 0.67, P < 0.01). In the inactive group, significant positive correlations were found between BMD and peak torque in the hamstrings muscles (90 degrees/second: r = 0.6-0.8, P<0.05 (total body, trochanter) and P<0.01 (spine, neck), 225 degrees/second: r = 0.5-0.8, P<0.05 (total body, Ward's triangle, trochanter) and P< 0,01 (spine, neck)). In the inactive group significant positive correlations was also found between lean body mass and BMD of the trochanter (r = 0.58, P < 0.05). In young females it appears that training and playing ice hockey might influence BMD and muscle strength in a positive direction. The correlation between BMD and muscle strength seems to weaken with increased exercise level.