数字化立位全脊柱成像技术的研究

目的　探讨数字化立位全脊柱的成像技术。方法　在数字化X线设备上 ,分次采集全脊柱的影像数据 ,获得 2 2例受检者的正、侧位原图共 88幅 ,经图像工作站合成为 4 4张数字化全脊柱影像。选择同一体位的胸、腰椎片为配对组 ,测量每组图像的水平位移长度 ,分析其对脊柱侧凸角(Cobb角 )的影响。结果　每一配对组的胸、腰椎影像移位差异无显著性意义 (t =0 0 8～ 1 0 1,P >0 0 5 )。椎体移位每递增 1 7cm ,人体倾角 (α)发生± 1°的变化 ,对Cobb角影响极小 ,可以忽略不计。结论　在图像工作站实现数字化全脊柱的成像技术 ,对普及脊柱侧凸检查具有很好的推广应用价值。     

CR全脊柱数字化成像技术的应用与比较

脊柱侧凸的常规检查方法是全脊柱X线正、侧位摄片,来反映脊柱侧凸畸形的状况。脊柱侧凸的X线检查要求每张脊柱正、侧位片,包含上自颈椎和双侧肩部,下至骨盆和髋关节在内的全脊柱,可以反映畸形的真实面貌和平衡情况。一张拼接好的X线片对青少年特发性脊柱侧凸进行手术前评估和脊柱侧凸三维矫形的预测有重要意义[1]。以前多采用超长感绿X线胶片(30 cm×61 cm)一次曝光[2];后采用多块IP板一次曝光,并将图像在计算机内进行拼接,但其拼接密度的均匀性和准确性不太理想。本院引进富士CR超长IP板,进行全脊柱一次曝光摄片。笔者就多块IP板一次…     

Luque技术矫正脊柱侧凸X线摄影分析

本文对15例Luque技术矫正脊柱侧凸进行X线摄影分析,其中包括特发性脊柱侧凸12例,先天性脊柱侧凸3例。男7例,女8例。年龄10～28岁,平均18岁。作者对其X线摄影技术和脊柱侧凸测量及X线观察问题进行了简要讨论。     

骨盆数字化X射线摄影曝光剂量的优化研究

目的研究直接数字化X射线摄影照射剂量与成像质量的关系，确定骨盆X射线摄影的最佳摄影条件。方法以对比度一细节体模CDRAD2．0在不同照射剂量下所获取的影像的图像质量因子IQF，进行ANOVA及SNK统计学分析，确定最佳照射条件。应用X射线摄影模拟人拍摄骨盆X射线影像，按照欧共体（CEC）图像质量标准验证最佳摄影条件与常规摄影条件下照射剂量与成像质量的差别。结果不同照射剂量条件下，对比度一细节体模影像质量因子IQF有显著性差别（P=0．0001），照射剂量大于0．61mGy时，不同剂量组间IQF差异无统计学意义。对以最佳照射条件和常规照射条件所拍摄的X射线摄影模拟人影像按照CEC标准评判，两者影像质量的差异无统计学意义。结论直接数字化X射线摄影时通过增大照射剂量可以提高影像质量，但是当曝光剂量达到足够大时，再增大曝光剂量并不能显著改善图像质量，影像质量与曝光剂量间存在一个优化剂量。标准体模骨盆X射线摄影的优化剂量为0．61mGy。     

全数字化乳腺摄影对乳腺癌的诊断价值

目的探讨全数字化乳腺摄影对乳腺癌,尤其未扪及肿块的乳癌的诊断价值。方法搜集2005年3月至9月门诊、住院及体检作全数字化乳腺摄影检查1290例,从中发现并经手术、病理证实乳腺癌50例,其中,临床扪及肿块42例,未扪及肿块8例。所有病例常规摄双侧乳腺CC位(头尾位)、MLO位(内外斜位),必要时局部点压摄片。对未扪及肿块者,行术前定位。使用医生工作站高分辨竖屏显示器观察图像。结果42例临床扪及肿块的乳癌中,主要X线表现有单纯肿块22例,肿块伴钙化18例,结构紊乱2例;病理类型为浸润性导管癌30例,髓样癌6例,黏液腺癌4例,浸润性小叶癌2例。8例未扪及肿块的乳癌中,分别表现为单纯钙化5例,小结节影伴钙化2例,局部结构紊乱1例;病理类型为导管原位癌3例,导管浸润癌3例,小叶原位癌2例。结论全数字化乳腺摄影能较清晰显示乳腺癌的直接及间接X线征象,对乳腺癌尤其是未扪及肿块的乳癌具有重要的诊断价值。     

全数字化乳腺摄影与乳腺计算机X线摄影的临床应用对比分析

目的: 比较全数字化乳腺摄影(FFDM)系统与计算机X线摄影(computed radiography,CR)系统在诊断乳腺疾病中的临床应用价值.材料和方法: 回顾2006-01～2007-06 CR检查300例和2007-07～12 FFDM检查300例的临床及影像资料,分析图像质量,统计受检者的照射剂量,比较技术操作、图像质量控制与后处理技术、工作效率等方面的优势.结果: CR和FFDM同时清楚显示皮肤、皮下组织、血管及腺体和导管等结构分别为45.5%(300例)和99.2%(300例);检查时间(包括图像采集及后处理时间),FFDM为5～10min/人,CR为15～20min/人;摄影条件,FFDM为26～30kV,26～60mAs,CR为30～45kV,36～100mAs;FFDM照射剂量(乳房压迫厚度5cm,有滤线栅)为0.5～2.0mGy,CR照射剂量(乳房压迫厚度5cm,有滤线栅)1.0～2.5mGy.FFDM对乳腺癌的诊断敏感性、特异性和准确性分别为83.3%、75%、80%,与CR差异非常显著(P＜0.05).结论: FFDM的图像质量、后处理功能、工作流程能力、患者吸收剂量及FFDM对乳腺癌的诊断敏感性、特异性和准确性均明显优于CR,更有利于乳腺检查.     

乳腺疾病的全数字化乳腺摄影与磁共振检查对比研究

目的:全数字化乳腺摄影与磁共振检查对乳腺疾病的诊断价值。材料和方法:本研究收集了自2003年12月至2006年1月期间行全数字化乳腺摄影并同时行磁共振检查患者共67例,全部经病理证实,其中良性病变38例,恶性病变29例。采用美国GE Senographe2000D全数字化乳腺摄影机及美国GE1.5Tesla MRI扫描仪;采用专门乳腺线圈。全部病例行动态增强扫描和图像后处理。结果:本组显示FFDM对乳腺疾病诊断的敏感性、特异性及准确性分别为74.29%,92.1%,83.36%;MRI对乳腺疾病诊断的敏感性、特异性及准确性分别为94.29%,89.47%,91.78%。结论:对于乳腺癌诊断FFDM的特异性高于MRI,而敏感性较低。     

全数字化乳腺摄影对乳腺疾病的诊断价值

目的 评价全数字化乳腺摄影在临床中对乳腺疾病的诊断价值.方法 回顾215例经手术或活检的术前全数字化乳腺摄影资料,对比影像诊断与最终病理诊断异同.分析不同疾病的误诊原因,初步分析及探讨全数字化乳腺摄影对乳腺疾病的诊断价值.结果 215例经手术或活检的病例中,132例被病理确诊为乳腺癌,83例被诊断为良性病变.在被病理证实为乳腺癌的132例乳腺癌病例中,14例被全数字化乳腺摄影诊断漏诊或误诊.而同时被影像诊断为恶性病变可能的130例(BI-RADS大于4级)的病例中,12例最终病理诊断确定为良性病变.结论 全数字化乳腺摄影是乳腺疾病的重要检查手段,尤其对发现及筛查乳腺癌具有重要价值,但对某些乳腺良性病变,其诊断准确率较低,需要结合其他临床诊断方式.     

全数字化乳腺摄影在乳腺病变中的临床应用价值

目的探讨全数字化乳腺摄影(FFDM)在乳腺病变中的临床应用价值。资料与方法搜集经手术病理证实有完整临床资料的乳腺病变共102例,所有患者均行FFDM,结合病理进行影像学分析。结果 102例乳腺病变中乳腺癌31例,乳腺良性病变71例。临床触及肿块者63例,未触及肿块者39例。影像表现为肿块80例,单纯成簇微小钙化4例,结构紊乱并粗长毛刺2例,结构紊乱并微小钙化1例,局部片状致密影14例,无明显影像表现1例。FFDM对乳腺癌诊断敏感性为90.3%,特异性为94.4%,准确性为93.1%。结论 FFDM能清晰显示乳腺病变的X线征象,尤其能够显示乳腺癌的主要X线征象,为临床早期诊断乳腺病变创造了条件,尤其对临床未触及肿块的早期乳腺癌具有重要的临床价值。     

全数字化乳腺摄影技术在乳腺癌诊断中的应用价值

目的 探讨全数字化乳腺摄影技术(FFDM)在乳腺癌诊断中的应用价值.方法 搜集本院2006-04-2007-11门诊病例及健康体检者行FFDM检查者2900例,其中经手术病理证实的乳腺癌53例,分析其年龄分布特征,病理类型及X线表现特征.结果 53例乳腺癌的发病年龄为36～8l岁,其中40～59年龄段者占到总病例的66%.X线表现为单纯肿块者24例(45.3%).肿块合并钙化者17例(32.1%),单纯钙化者4例(7.6%).结构紊乱者5例(9.4%),结构紊乱并钙化者3例(5.6%).病理结果:浸润性导管癌43例,黏液腺癌4例,乳腺小叶癌2例,Paget病4例.结论 FFDM可以更清晰的显示乳腺病变的特征,对乳腺癌的早期诊断具有重要价值.     

床旁DR与CR胸部摄影质量的对比研究

目的通过床旁数字化X线摄影(digitalradiography,DR)系统与计算机X线摄影(computedradiography,CR)系统胸部摄影图像质量的对比分析,探讨床旁DR摄影的优势。方法随机抽取2010年拍摄的DR床旁X线胸片1000份和既往CR床旁X线胸片1000份进行对比分析。结果床旁DR摄影的应用提供了更加优良的图像质量,明显减少了放射技师的工作量,同时还降低了患者接受的辐射剂量。结论床旁DR胸部摄影比CR胸部摄影有着明显的优势,对手术患者和危重患者的诊治起到了积极作用。     

数字摄影受检者辐射剂量调查

目的 了解数字摄影（DR）检查中受检者的辐射剂量水平,为数字放射摄影受检者指导水平的制定提供基础数据。方法 使用热释光剂量计TLD测量受检者不同部位、不同投照方向的入射体表剂量（ESD）;使用剂量面积乘积仪测量受检者不同部位、不同投照方向的剂量面积乘积（DAP）,并利用测量的DAP值,估算出有效剂量（E）。结果 同类检查中,kV和mAs的变化范围较大,不同部位DR检查中ESD、DAP和E的差别均具有统计学意义（F=33.47、24.68、43.19,P<0.05）。其中,ESD和DAP均以腰椎（LAT）最高,均数为4.62mGy/次和2.26Gy·cm²/次;E以腹部（AP）最高,均数为0.59mSv,高于腰椎（LAT）的0.31mSv。结论 DR在加强受检者放射防护最优化方面很有潜力,应尽快建立适合我国国民体质特征的数字放射摄影受检者辐射剂量的指导水平。     

Flexion-extension cervical spine radiography in blunt trauma: A survey of emergency physicians

A survey investigating the use of flexion-extension cervical spine radiography (FE CSR) was distributed to emergency medicine physicians (EMPs). A 20-point survey was mailed to EMPs (N=250) randomly chosen from the membership of the American College of Emergency Physicians in the United States and Canada. One hundred forty-four surveys (58%) were returned. Sixty-six percent of the EMPs were emergency medicine residency-trained, and 38% of the respondents had less than 5 years of clinical experience. Practice settings included emergency departments with an annual volume of >40,000 patients (50%), community-based hospitals (66%), and level I trauma centers (41%). Eighty-seven percent of EMPs obtained FE CSR in 20% of blunt trauma patients with neck complaints. Indications for FE CSR were minimal disruption of cervical contour lines (68%), posterior element interval widening (53%), tenderness (49%), pain (45%), soft tissue swelling (38%), and mechanism of injury (34%). Contraindications to FE CSR were altered mentation (91%), focal neurologic issue (88%), distracting injury (71%), non-English speaker (50%), and young age (defined as <6 years) (29%). With normal FE CSR, 27% would use additional studies: computed tomography (CT) (56%), oblique view (19%); and magnetic resonance imaging (MRI) (7%). EMPs reported that they did not accompany the patient in 52% of cases. The consultant physician recommended FE CSR in 71% (radiology consultation) and 41% (orthopedic or neurosurgical consultation) of cases, respectively. EMPs used FE CSR in a significant minority of blunt trauma patients along with other radiographic imaging modalities. Reasons for ordering FE CSR more often included radiographic abnormalities rather than historical or examination findings. Consultants frequently recommended their use. FE CSRs were performed most often without physician supervision. Presented in part at the Society for Academic Emergency Medicine, New England Regional Meeting, Providence, RI, April 1997; the American College of Emergency Physicians Research Forum, San Francisco, CA, October 1997; and Trauma Tactics, Orlando, FL, April 1998.     

放射防护最优化对数字X射线摄影中受检者辐射剂量降低的价值

目的 通过评价辐射防护最优化前后患者剂量和废弃影像的差异,探讨在应用数字X射线摄影(DR)系统进行日常摄影中实施最优化的必要性.方法 200名近标准体格患者纳入研究,制定DR摄影防护最优化程序,100例执行最优化前方案摄影,100例执行最优化方案摄影.测量最优化前后患者剂量-面积乘积(DAP)和体表入射剂量(ESD).同时统计最优化前后各2个月内的废弃影像,并按废弃原因分类.比较最优化前后患者辐射剂量和影像废弃率的差异.结果 最优化后的ESD和DAP显著低于最优化前(z=9.31、16.22,P＜0.05),影像废弃率明显低于最优化前(x2=36.5,P＜0.05).结论 使用最优化程序的DR摄影可以有效降低患者辐射剂量并减小影像废弃率.     

Towards image quality, beam energy and effective dose optimisation in digital thoracic radiography

This paper outlines how objective measurements of both image quality, in terms of signal-to-noise ratio, and effective dose may be used as tools to find the optimum kVp range for a digital chest radiography system. Measurements were made with Thoravision, an amorphous selenium-based digital chest X-ray system. The entrance surface dose and the effective dose to an anthropomorphic chest phantom were determined demonstrating how effective dose is related to beam quality. The image quality was measured using detective quantum efficiency, threshold contrast and a radiologist preference trial involving 100 patients. The results show that, despite the fact that the entrance surface dose decreases as the kVp increases, the effective dose, a better measure of the risk, reaches a minimum value between 90 and 110 kVp; however, the image quality decreases as the kVp increases. In this study the optimum kVp for chest radiography, using a selenium-based radiography system, is in the range 90–110 kVp. This is contrary to the 120- to 150-kVp range that is commonly used. Also, this study shows how objective measurements can be used to optimise radiographic technique without prolonged patient trials. Received: 4 November 1999 Revised: 10 May 2000 Accepted: 11 May 2000     

Adequacy of plain radiography in the diagnosis of cervical spine injuries

Our hypotheses were (1) that plain radiography of the cervical spine in the evaluation of low risk patients with minor blunt trauma is accurate and (2) that computed tomography (CT) of the cervical spine in the evaluation of low risk patients is unnecessary. This study evaluates those hypotheses. We prospectively recorded findings of all patients with blunt trauma who underwent imaging over a period of 70 days. Injury status was determined by review of all radiographic studies obtained on each patient. Chart reviews were performed to determine mechanism of injury and neurological status. Patients were divided into three groups: very low risk, low risk, and high risk. Study end point was fracture. The study included 219 patients. The very low risk group had 107 patients, none of whom had fractures found on CT (projected specificity of plain radiography: 100%). The low risk group contained 78 patients who had no fractures seen on plain radiography or CT (specificity of plain radiography and CT: 100%). The high risk group consisted of 34 patients; 15 had fractures demonstrated on CT. Plain radiography missed one fracture out of 15. In low risk patients, plain radiography is an efficient diagnostic exam with a specificity of 100%. In high risk patients, plain radiography is a good adjunctive screening exam in conjunction with CT scan, with a sensitivity of 93.3% and specificity of 95%.     

Radiation dose reduction in direct digital panoramic radiography

Objectives

(a) To measure the absorbed radiation doses at 16 anatomical sites of a Rando phantom and (b) to calculate the effective doses including and excluding the salivary gland doses in panoramic radiography using a conventional and a digital panoramic device.

Study design

Thermoluminescent dosimeters (TLD-100) were placed at 16 sites in a Rando phantom, using a conventional, Planmeca Promax and a digital, Planmeca PM2002CC Proline 2000 (Planmeca Oy, 00880 Helsinki, Finland) panoramic device for panoramic radiography. During conventional radiography the selected exposure settings were 66 kVp, 6 mA and 16 s, while during digital radiography two combinations were selected 60 kVp, 4 mA, 18 s and 66 kVp, 8 mA, 18 s with and without image processing function. The dosimeters were annealed in a PTW-TLDO Harshaw oven. TLD energy response was studied using RQN beam narrow series at GAEC's Secondary Standard Calibration Laboratory. The reader used was a Harshaw, 4500. Effective dose was estimated according to ICRP₆₀ report (E_ICRP60). An additional estimation of the effective dose was accomplished including the doses of the salivary glands (E_SAL). A Wilcoxon signed ranks test was used for statistical analysis.

Results

The effective dose, according to ICRP report (E_ICRP60) in conventional panoramic radiography was 17 μSv and E_SAL was 26 μSv. The respective values in digital panoramic radiography were E_ICRP60 = 23 μSv and E_SAL = 38 μSv; while using the lowest possible radiographic settings E_ICRP60 was 8 μSv and E_SAL was 12 μSv.

Conclusions

The effective dose reduction in digital panoramic radiography can be achieved, if the lowest possible radiographic settings are used.     

Specificity of cervical spine radiography: Importance of clinical scenario

Knowledge of the sensitivity and specificity of relevant imaging studies is critical to the design of cost-effective clinical algorithms. In developing a cost-effectiveness analysis for cervical spine injuries, we encountered a paucity of data on the specificity of plain radiographs for the detection of cervical spine fracture. Therefore, we measured the specificity of cervical spine radiography in trauma patients at various levels of risk for fracture. A random sample of trauma patients who underwent cervical spine radiography were selected for each of several clinical scenarios. The numbers of false-positive and true-negative studies were determined from radiology records, and specificity was calculated. Specificity ranged from a low of 72% in patients who sustained a pelvic fracture from a fall to a high of 96% in all patients who sustained nonpenetrating trauma. In patients at high risk for cervical spine fracture, the specificity of radiography was relatively low. Understanding of radiographic specificity can aid in the development of imaging guidelines.Presented at the 8th Annual Meeting of the American Society of Emergency Radiology, New Orleans, March 22, 1997. Recipient of the John H. Harris, Jr. Award for Best Paper Presentation by a Resident or Fellow.The opinions, views, and conclusions expressed in this article are those of the authors and not necessarily those of the Robert Wood Johnson Foundation.     

A comparison of effective dose and risk for different collimation options used in AP shoulder radiography

IntroductionRadiography forms the cornerstone of the evaluation of shoulder disorders. While the benefits of radiography exceed the risks, there continues to be a compelling case for reduction of radiation exposure from diagnostic radiography. The aim of this project was to evaluate the radiation dose and risk for a variety of collimation settings used during anteroposterior (AP) shoulder radiography.MethodsThis was a phantom based study where an ATOM adult dosimetry phantom was loaded with 272 thermoluminescent dosimeters (TLDs). Following loading, the phantom was setup for an AP shoulder X-ray projection with standard 25 × 30 cm rectangular collimation. The phantom was exposed three times and then the TLDs were removed and read. The experiment was repeated using a diamond shaped collimation and rectangular collimation with a minimum field of view to portray only relevant anatomy. Using the TLD dose measurements the effective doses and radiation risks were determined and compared.ResultsAs expected, organs neighbouring the shoulder experienced the highest absorbed doses (greater than 0.01 mGy); these organs included breast, lung and thyroid gland. The effective doses for standard rectangular, small rectangular and diamond collimation were 0.011, 0.008 and 0.016 mSv, respectively. When compared to standard collimation, a small field of view reduced effective dose by 27.3% and when moving to a diamond shape there was a 45.5% increase. The differences are likely driven by differences in the coverage of the radiosensitive lung and breast tissue.ConclusionBy utilising a variety of different collimation settings, effective dose can be reduced. Reducing the radiation dose is both financially beneficial and results in a lower stochastic risk for patients. Image quality must also be considered when choosing different collimation settings. It stands to reason that by reducing the field size, dose will be reduced, and our study has served to quantify the effects in a practical situation.Implications for practiceThe utilisation of smaller/tight collimation is recommended as it offers the lowest dose when compared with other types of collimations. Although well-known this study serves to remind practitioners of the practical importance of collimation and is associated effect on effective dose and risk.