Combined diffusion-weighted and dynamic contrast-enhanced imaging of patients with acute osteoporotic vertebral fractures

Objectives

To evaluate the potential and to analyze parameter correlations of combined quantitative diffusion-weighted MRI (DWI) and high-temporal-resolution dynamic contrast-enhanced MRI (DCE-MRI) in vertebral bone marrow (vBM) of patients with osteoporosis and acute vertebral compression fractures, providing additional information for a better understanding of the physiological background of parameter changes.

Materials and methods

20 patients with acute osteoporotic fractures were examined with DWI and DCE-MRI at 1.5 T. DCE-MRI was performed with a 2D saturation-recovery turbo-FLASH sequence, acquiring 300 dynamics with a temporal resolution of 1 s. For DWI measurements, a DW HASTE sequence with b-values from 100 to 600 s/mm² was applied. In each patient, ROIs were drawn manually in the fractures and in normal appearing vertebrae. For DCE-MRI, the concentration-time curves of these ROIs were analyzed using a two-compartment tracer-kinetic model in the lesions, providing separate estimates of perfusion and permeability, and a one-compartment model in normal vBM, providing only a mixed representation of perfusion and permeability in terms of a mixed flow parameter K^trans and the extracellular volume (ECV). In the case of DWI, attenuation curves were fitted to a monoexponential decay model to determine the apparent diffusion coefficient (ADC).

Results

Mean perfusion parameters and ADCs were significantly (p < 0.001) different in the fractures compared to adjacent normal appearing vertebrae (K^trans: 7.81 mL/100 mL/min vs. 14.61 mL/100 mL/min, ECV: 52.84 mL/100 mL vs. 4.61 mL/100 mL, ADC: 1.71 × 10^-3 mm²/s vs. 0.57 × 10^-3 mm²/s). ADCs showed a significant correlation with the ECV.

Conclusion

The quantitative analysis of DWI and DCE-MRI could distinguish osteoporotic fractures from normal appearing vertebrae. A significant correlation found between ECV and ADCs might be able to explain the cause for the increased diffusivity in osteoporotic fractures. Since the other perfusion parameters do not correlate with the ADC, they provide additional pathophysiological information not accessible with DWI.     

Sky骨膨胀复位器椎体后凸成形术治疗骨质疏松性椎体压缩性骨折

目的 探讨使用Sky骨膨胀复位器行椎体后凸成形术治疗老年骨质疏松椎体压缩性骨折。方法 自2004年8月至2005年11月，应用Sky骨膨胀复位器椎体后凸成形术治疗老年骨质疏松性椎体压缩骨折18例。术中采用局部注射浸润麻醉，选择从椎体病变严重侧单侧穿刺，经椎弓根入路，使用Sky骨膨胀复位器将压缩椎体复位，注射骨水泥量3．5—5ml。结果 术后随访3～11个月，平均4．5个月。术后患者背部疼痛均明显缓解或消失，无并发症发生。结论 Sky骨膨胀器椎体后凸成形术操作简单，创伤小，手术安全性高，能有效复位并快速有效控制背痛，近期疗效满意。     

椎体成形术治疗骨质疏松性椎体压缩骨折的生命质量评价

目的 评价经皮椎体成形术(PVP)治疗骨质疏松性椎体压缩骨折的长期生活质量.方法 随访PVP治疗骨质疏松性椎体压缩骨折患者183例,获得完整随访资料25例,用形象类比(VAS)评价术前、术后不同时期的疼痛程度,用日常生活自理能力(ADL)和下腰部功能活动障碍(OLBPDQ)量表分别观察患者术前、术后大于1年的生活质量,并观察骨水泥渗漏对生命质量的影响.结果 术后末次随访平均36.5个月(13～42个月).术前、术后1 d、3、6个月及1年以上随访时VAS疼痛分值分别为8.96±1.11、4.58±2.56、3.16±2.28、2.11±0.27、1.63±0.21;ADL量表(Barthel指数)术前、术后分别为54.34±13.21、84.28±18.30,较术前提高了55%;OLBPDQ量表(ODI指数)术前、术后分别为25.64±13.84、17.52±10.71,较术前下降了32%.两组间P值均＜0.05.术后CT证实少量骨水泥渗漏5例,平均随访32个月均无临床症状.结论 PVP术治疗骨质疏松性椎体压缩骨折不仅可迅速缓解患者疼痛,而且可长期提高患者生活质量;少量无症状的骨水泥渗漏对患者长期生命质量无明显影响.     

椎体压缩性骨折的影像学诊断

目的探讨MR扫描对椎体原发性骨质疏松压缩性骨折及转移瘤所致的压缩性骨折的诊断及鉴别诊断的价值及表现。材料与方法对30例椎体原发性骨质疏松压缩性骨折和30例转移瘤压缩性骨折进行回顾性分析。结果椎体原发性骨质疏松性压缩骨折的特点椎体变形可分为楔形变、双凹形、扁平形,椎体后上角后突入椎管具有特异性;椎体信号特点椎体终板下或椎体中央带状T1WI低信号或椎体后部等信号外,椎体前部低信号,增强扫描后椎体信号强度与相邻正常椎体相同。转移瘤所致压缩性骨折的特点椎体后部皮质后突,T1WI上椎体内及椎弓根弥漫性低信号,增强扫描呈明显不均匀强化。结论增强扫描和非增强扫描的MR检查对椎体良恶性压缩骨折的鉴别有一定的价值。     

Radiological assessment of necrosis in glioblastoma: variability and prognostic value

In a previous study, we found that the extent of necrosis was the only radiological feature which correlated significantly with survival in patients with glioblastoma. The aim of this paper was to evaluate the variability and prognostic value of the extent of the necrotic area as seen on contrast-enhanced MRI and CT in a larger series. We studied 72 patients who underwent surgical removal of supratentorial glioblastomas and had CT and/or MRI with contrast medium before surgery; 38, all undergoing the same treatment (surgery plus radiotherapy), were followed clinically. Necrosis within the tumour varied greatly, ranging from none (only 1 case) to involvement of 76 % of the tumour. Survival data in the subgroup suggested that only patients with a small area of necrosis (less than 35 % of the tumour) had a significantly longer survival time. When necrosis involved more than 35 % of the mass, patients had a shorter survival time, without any further correlation with the extent of necrosis.     

脊柱原发性骨质疏松椎体压缩的MRI表现

目的探讨脊柱原发性骨质疏松椎体压缩的ＭＲＩ表现。方法对３年间Ｘ线诊断、临床证实的６０例脊柱原发性骨质疏松的ＭＲＩ表现进行回顾分析，并与对照组比较。结果１６２个椎体表现为压缩变形，其中凹陷形９８个，楔形５１个，扁平形１３个。压缩椎体邻近椎间盘常膨突到椎体凹陷区内；矢状位Ｔ１ＷＩ４７个椎体表现为椎体内不同范围、不同类型的低信号。结论压缩椎体后上角突入椎管内，Ｔ１ＷＩ椎体终板下呈带状低信号和除椎体后角外全椎体呈低信号，为原发性骨质疏松椎体压缩ＭＲＩ比较典型的表现。     

Acrylic vertebroplasty in symptomatic cervical vertebral haemangiomas: report of 2 cases

We report two cases of acrylic vertebroplasty in symptomatic cervical vertebral haemangiomas. In both cases significant improvement of symptoms was rapid. One patient was able to return to work.     

经皮椎体成形术治疗骨质疏松性椎体骨折疗效观察

目的探讨经皮椎体成形术治疗骨质疏松性椎体压缩性骨折的临床疗效及应用价值。方法36例骨质疏松性压缩性骨折患者45个椎体，在C型臂X线透视下，取俯卧位，经皮穿刺，在病椎注入聚甲基丙烯酸甲酯。术前及术后3d进行疼痛视觉类比评分（VAS评分），并进行统计学分析。结果治疗后36例患者疼痛较治疗前有明显好转，VAS评分差异有统计学意义（P〈0．001）；活动能力也有不同程度改善；部分椎体的前缘和椎体中部高度有一定恢复。结论经皮椎体成形术治疗骨质疏松性椎体压缩骨折止痛效果明显，能很快改善患者的活动能力，早期下床活动。该手术属微创手术，在骨科临床有一定的应用前景。     

Prevalence of thoracolumbar vertebral fractures on multidetector CT: underreporting by radiologists

Objective

To evaluate the prevalence of osteoporotic vertebral fractures in patients undergoing multidetector computed tomography (MDCT) of the chest and/or abdomen.

Materials and methods

323 consecutive patients (196 males, 127 females) with a mean age of 62.6 years (range 20–88) who had undergone chest and/or abdominal MDCT were evaluated. Sagittal reformats of the spine obtained from thin section datasets were reviewed by two radiologists and assessed for vertebral fractures. Morphometric analysis using electronic calipers was performed on vertebral bodies which appeared abnormal upon visual inspection. A vertebral body height loss of 15% or more was considered a fracture and graded as mild (15–24%), moderate (25–49%) or severe (more than 50%). Official radiology reports were reviewed and whether the vertebral fractures had been reported or not was noted.

Results

31 out of 323 patients (9.5%) had at least 1 vertebral fracture and 7 of those patients had multiple fractures for a total of 41 fractures. Morphometric grading revealed 10 mild, 16 moderate and 15 severe fractures. Prevalence was higher in women (14.1%) than men (6.6%) and increased with patients age with a 17.1% prevalence in post-menopausal women. Only 6 out 41 vertebral fractures (14.6%) had been noted in the radiology final report while the remaining 35 (85.45) had not.

Conclusion

although vertebral fractures represent frequent incidental findings on multidetector CT studies and may be easily identified on sagittal reformats, they are often underreported by radiologists, most likely because of unawareness of their clinical importance.     

Percutaneous vertebroplasty in the management of vertebral osteoporotic fractures. Short-term,mid-term and long-term follow-up of 285 patients

Objectives  To evaluate the short-term, mid-term and long-term follow-up of 285 patients who had undergone percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (VCF) in our department from 2003 to 2006, and, particularly, to analyse our data on the safety and the usefulness of PVP for durable pain reduction, mobility improvement and the need for analgesic drugs. Materials and methods  Follow-up analysis was made through a questionnaire completed by the patients before and after PVP (1 week, 1 year and 3 years). The results are reported by subdivision of patients into groups (by gender, age and number of treated vertebrae), with special reference to pain management, drug administration and quality of life. Results  All patients (285) were followed up for 1 week, 186 for 12 months, and 68 patients were followed up for 3 years. One week after PVP all patients reported normal ambulation (with or without pain), and more than 95% were able to perform activities of daily living (ADL) either without pain or with mild pain. There was no difference in pain relief between the genders after 1 week’s follow up, but after 3 years better analgesia results were observed in women. There was no statistically significant difference in the visual analogue scale (VAS) values before PVP between age groups (P = 0.7) and gender (P = 0.4); Patients younger than 75 years had better outcomes than did older ones (>75 years) at 1 week and 1 year follow up. Patients also reported significant reduction in drug therapy for pain. Conclusions  PVP is a safe and useful procedure for the treatment of vertebral osteoporotic fractures. It produces enduring pain reduction, improves patients’ mobility and decreases the need for analgesic drugs.     

Incidental vertebral compression fractures in imaging studies: Lessons not learned by radiologists

AIM: To assess radiologists reporting rates of incidental vertebral compression fractures in imaging studies.METHODS: We performed a review of the current literature on the prevalence and reporting rates of incidental vertebral compression fractures in radiologic examinations.RESULTS: The bibliographic search revealed 12 studies: 7 studies using conventional radiology and 5 using multidetector computed tomography (MDCT). The loss of height cut-off to define a vertebral fracture varied from 15% to 25%. Fracture prevalence was high (mean 21.1%; range 9.5%-35%) in both radiographic and MDCT studies (mean 21.6% and 20.2%, respectively). Reporting rates were low with a mean value of 27.4% (range 0%-66.3%) and were significantly lower in MDCT than in radiographic studies (mean 8.1% vs 41.1%). Notably, recent studies showed lower reporting rates than older studies.CONCLUSION: Many scientific studies have confirmed a high prevalence of vertebral compression fractures as incidental findings on imaging studies. However, the underreporting of these fractures, as determined in our study, may negatively affect patient care.     

Osteoblastoma in a lumbar vertebral body

We report a young man with low back pain suspected to have a disc protrusion. Imaging suggested a tumour of the dorsal portion of the fifth lumbar vertebral body. Operation suggested a giant-cell tumour and subsequent histology showed an osteoblastoma. All typical imaging features of osteoblastoma are demonstrated in this rather uncommon location. Contrast-enhancing bone-marrow oedema on MRI, with mild enhancement of the tumour, together with the CT appearances were the clues to the diagnosis. Received: 11 December 1997 Accepted: 3 September 1998     

Under-reporting of osteoporotic vertebral fractures on computed tomography

Purpose

Osteoporotic vertebral fractures are frequently asymptomatic. They are often not diagnosed clinically or radiologically. Despite this, prevalent osteoporotic vertebral fractures predict future osteoporotic fractures and are associated with increased mortality and morbidity. Appropriate management of osteoporosis can reduce future fracture risk. Fractures on lateral chest radiographs taken for other conditions are frequently overlooked by radiologists. Our aim was to assess the value of computed tomography (CT) in the diagnosis of vertebral fracture and identify the frequency with which significant fractures are missed.

Materials and methods

The thoracic CT scans of 100 consecutive male and 100 consecutive female patients over 55 years were reviewed. CT images were acquired on General Electric Lightspeed multi-detector (MD) CT scanners (16 or 32 row) using 1.25 mm slice thickness. Midline sagittal images were reconstructed from the 3D volume images. The presence of moderate (25–40% height loss) or severe (>40% height loss) vertebral fractures between T1 and L1 was determined using an established semi-quantitative method and confirmed by morphological measurement. Results were compared with the formal CT report.

Results

Scans of 192 patients were analysed (95 female; 97 male); mean age 70.1 years. Thirty-eight (19.8%) patients had one or more moderate to severe vertebral fractures. Only 5 (13%) were correctly reported as having osteoporotic fractures in the official report. The sensitivity of axial CT images to vertebral fracture was 0.35.

Conclusion

Incidental osteoporotic vertebral fractures are under-reported on CT. The sensitivity of axial images in detecting these fractures is poor. Sagittal reformations are strongly recommended to improve the detection rate.     

Nasopharyngeal carcinoma: MRI and CT assessment

Precise assessment of the extent of nasopharyngeal carcinoma (NPC) represents the basic step towards optimal treatment. We compared the capacity of CT and MRI in assessing the extent of NPC in 67 patients. MRI was superior to CT in demonstrating lesions in the retropharyngeal node, skull base, intracranial area, carotid space, longus colli muscle and levator palatini muscle. Of 25 cases in which retropharyngeal adenopathy was recognised only on MRI, seven had been reported as showing oropharyngeal involvement and 18 as primary extension to the carotid space on CT. MRI showed skull-base involvement in 40 patients compared with 27 on CT and intracranial involvement in 38 patients versus 24 on CT. There was not a single case in which skull base invasion was seen on CT but not on MRI. MRI enabled improved recognition of tumour infiltration of longus colli muscles (34 cases compared with 15 on CT). It allowed us to clarify 12 questionable sinonasal opacities on CT. Overall, T-staging was changed in 18 of 67 patients (26.9 %), including upstaging in 15 cases and downstaging in 3 cases, after comparing CT with MRI. The nodel status was changed from negative on CT to positive on MRI in 4 of 67 patients (6 %). We believe that MRI allows more accurate evaluation of the extent of NPC than CT and should be the primary mode of investigation. Received: 18 November 1996 Accepted: 22 January 1997     

CT-guided vertebroplasty in osteoprotic vertebral fractures: incidence of secondary fractures and impact of intradiscal cement leakages during follow-up

The purpose of this study was to analyse the number and types of secondary fractures, and to investigate the impact of intradiscal cement leaks for adjacent vertebral fractures. Patients with osteoporotic vertebral fractures were treated with vertebroplasty. Results were documented and prospectively followed by means of computed tomography (CT) and magnetic resonance imaging. The frequency and the types of cement leakages were analysed from multiplanar CT images and secondary fractures were characterised as follows: (1) adjacent fracture in the immediate vicinity of an augmented vertebra; (2) sandwich fracture, fracture of an untreated vertebra between two vertebrae that had been previously augmented, and (3) distant fractures not in the vicinity of augmented vertebrae. A total of 385 osteoporotic vertebral fractures were treated in 191 patients (61 men, 130 women, age 70.7 ± 9.7 years). The overall rate of cement leaks was 55.6%, including all leaks detectable by CT. Intradiscal leaks through the upper, the lower, and both endplates occurred in 18.2%, 6.8%, and 2.6%, respectively. In 39 patients (20.4%), a total of 72 secondary fractures occurred: 30 adjacent fractures in 23 patients (12.0%) with a time to fracture of 2 months [median; 1.0/4.0 months, first/third quartile (Q1/Q3)]; 11 secondary sandwich fractures in 11 patients (5.8%) after 1.5 months (median; 0.25/7.5 months, Q1/Q3); and 31 distant fractures in 20 patients (10.5%) after 5 months (median; 2.0/8.0 months, Q1/Q3). Ten of 30 adjacent fractures occurred in the presence of pre-existing intradiscal cement leaks and 20 where there was no leakage. Six of 11 sandwich fractures occurred in the presence of intradiscal leaks (five leaks in both adjacent disc spaces, one leak in the lower disc space) and five where there was no leakage. The rate of secondary adjacent and non-adjacent fractures is quite similar and there is no specific impact of intradiscal leakages on the occurrence of adjacent secondary fractures. Adjacent fractures occur sooner than distant secondary fractures. Sandwich fractures are associated with specific biomechanical conditions, with a 37.9% fracture rate in sandwich constellations.     

椎体成形术和传统法治疗骨质疏松性椎体压缩骨折疗效的对比研究

目的研究并比较椎体成形术(PVP)和保守疗法治疗骨质疏松性椎体压缩骨折的临床疗效。方法骨质疏松性椎体新鲜压缩骨折83例共104节,非随机分为2组,组1共44例58节用PVP治疗,组2共39例46节用保守治疗,比较两组治疗后随访期内疗效及椎体高度变化。结果组1患者44例PVP后1周疼痛均得到缓解,视觉疼痛评分(VAS)平均分值从术前8.5下降至2.6(平均下降5.9)。组2患者39例保守治疗后1周VAS分值无变化,在治疗后1周、1和3个月时。组1的VAS分值明显低于组2(P<0.01),6个月时两组差异无统计学意义(P>0.05)。平均随访8.9个月,组1有新发骨折3例3节,组2有2例2节,两组比较无显著差异无统计学意义(P>0.05)。PVP后1周椎体高度恢复平均为前缘2.2mm,中央2.3mm,后缘高度无变化,随访3、6个月椎体前缘、中央高度与PVP后1周时无差异(P<0.01)。保守治疗后1周椎体前缘、中央及后缘高度与治疗前比较无显著改变,3个月时椎体高度丢失平均为前缘1.9mm,中央2.1mm,6个月时与3个月无差异。在治疗3个月后,组1椎体高度明显高于组2(P<0.01)。结论PVP可迅速缓解疼痛,明显缩短病程,但6个月后两组疗效无显著差异;PVP可使新鲜压缩椎体的前缘和中央高度得到部分恢复,可显著预防椎体进一步塌陷;保守治疗在3个月内椎体高度可进一步丢失;PVP后新发骨折可能是骨质疏松症的自然发病过程。     

Stress fractures in the lower extremity. The importance of increasing awareness amongst radiologists

Stress fractures are fatigue injuries of bone usually caused by changes in training regimen in the population of military recruits and both professional and recreational athletes. Raised levels of sporting activity in today's population and refined imaging technologies have caused a rise in reported incidence of stress fractures in the past decades, now making up more than 10% of cases in a typical sports medicine practice. Background information (including etiology, epidemiology, clinical presentation and treatment and prevention) as well as state of the art imaging of stress fractures will be discussed to increase awareness amongst radiologists, providing the tools to play an important role in diagnosis and prognosis of stress fractures. Specific fracture sites in the lower extremity will be addressed, covering the far majority of stress fracture incidence. Proper communication between treating physician, physical therapist and radiologist is needed to obtain a high index of suspicion for this easily overlooked entity. Radiographs are not reliable for detection of stress fractures and radiologists should not falsely be comforted by them, which could result in delayed diagnosis and possibly permanent consequences for the patient. Although radiographs are mandatory to rule out differentials, they should be followed through when negative, preferably by magnetic resonance imaging (MRI), as this technique has proven to be superior to bone scintigraphy. CT can be beneficial in a limited number of patients, but should not be used routinely.     

Height gain of vertebral bodies and stabilization of vertebral geometry over one year after vertebroplasty of osteoporotic vertebral fractures

The height gain of vertebral bodies after vertebroplasty and geometrical stability was evaluated over a one-year period. Osteoporotic fractures were treated with vertebroplasty. The vertebral geometry and disc spaces were analysed using reformatted computed tomography (CT) images: heights of the anterior, posterior, and lateral vertebral walls, disc spaces, endplate angles, and minimal endplate distances. Vertebrae were assigned to group I [severe compression (anterior height/posterior height) <0.75] and group II (moderate compression index >0.75). A total of 102 vertebral bodies in 40 patients (12 men, 28 women, age 70.3 ± 9.5) were treated with vertebroplasty and prospectively followed for 12 months. Group I showed a greater benefit compared with group II with respect to anterior height gain (+2.1 ± 1.9 vs +0.7 ± 1.6 mm, P < 0.001), reduction of endplate angle (−3.6 ± 4.2 vs −0.8 ± 2.3°, P < 0.001), and compression index (+0.09 ± 0.11 vs +0.01 ± 0.06, P < 0.001). At one-year follow-up, group I demonstrated preserved anterior height gain (+1.5 ± 2.8 mm, P < 0.015) and improved endplate angle (−3.4 ± 4.9°, P < 0.001). In group II, the vertebral heights returned to and were fixed at the pre-interventional levels. Vertebroplasty provided vertebral height gain over one year, particularly in cases with severe compression. Vertebrae with moderate compression were fixed and stabilized at the pre-treatment level over one year.     

应用国产药械行经皮椎体成形术治疗骨质疏松性椎体压缩骨折

目的：应用国产器械行椎体成形术治疗骨质疏松性椎体压缩骨折。观察其疗效。探讨椎体成形术操作技术和并发症的预防。方法：17例骨质疏松性椎体压缩骨折患者25个椎体应用国产器械经双侧椎弓根入路行椎体成形术。国产PMMA的粉、液及对比剂比例为3：2：1。操作在X线监测下进行。PMMA在浆糊期向椎体内注射。手术前后CT检查对照。随访患者5～24个月，观察临床疗效。结果：穿刺成功率100％，术后CT检查显示PMMA填充病灶均在50％以上。术后3d内患者的治疗效果为：CR15例，PR2例，临床治疗有效率达100％。17例患者随访5—24个月。未发现注射PMMA的椎体有新压缩出现，未发生由于PMMA外溢出现临床症状的并发症。结论：应用国产器械行椎体成形术治疗骨质疏松性椎体压缩骨折疗效良好，在浆糊期注射是预防PMMA外溢的重要措施。     

CT and MRI: prognostic tools in patients with AIDS and neurological deficits

Summary To determine the prognostic value of CT and MRI in AIDS we studied the survival of patients with neurological involvement, in relation to the initial imaging results. Twenty-six initial CT and 15 MRI examinations of 41 patients were reviewed for the presence of cerebral atrophy and/or focal lesions. The mean survival time of patients with initially normal imaging was longer (700±89 days) than that of patients with isolated cerebral atrophy (326±65) or isolated focal lesions (202±97). The shortest survival (78±44 days) was found in patients with both cerebral atrophy and focal lesions. The risk of death in patients with focal lesions alone 6.4 times higher, and in patients with both changes 19.3 times higher than in patients with initially normal imaging. Cerebral imaging with CT and/or MRI thus allows identification of AIDS-related cerebral changes and may contribute to assessment of prognosis.