多层螺旋CT对复杂型先天性心脏病的诊断价值

目的探讨多层螺旋CT（MSCT）对比增强及后处理技术对复杂型先天性心脏病（CCHD）的诊断价值。资料与方法分析35例经手术证实的CCHD的MSCT资料,术前均行经胸心脏二维超声（TTE）检查,其中17例有X线心血管造影（CAG）对照。结果手术证实畸形共136处,MSCT、TTE及CAG总的诊断准确性分别为94.9%、72.1%,95.3%;其中心脏畸形47处,MSCT漏诊4处,TTE漏诊2处,CAG漏诊1处,3种检查的诊断准确性差异无统计学意义（χ^2=0.89,P〉0.05）;心脏大血管连接部及大血管畸形共计89处,MSCT、TTE、CAG诊断准确性分别为96.6%,59.6%,95.1%,MSCT（χ^2=35.76,P〈0.01）及CAG（χ^2=17.17,P〈0.01）诊断准确性明显高于TTE,MSCT与CAG诊断准确性差异无统计学意义（χ^2=0.17,P〉0.05）;MSCT与TTE联合应用可提高诊断准确性达97.8%。结论MSCT能客观清晰地显示CCHD的病理解剖形态,对心脏大血管连接部及大血管畸形的诊断明显优于TTE,在CCHD的无创性检查中具有较高的诊断价值。     

64层螺旋CT诊断复杂先天性心脏病及与超声心动图和手术对照

目的探讨64层螺旋CT对复杂先天性心脏病(简称复杂先心病)的诊断价值。资料与方法对25例复杂先心病患者的心脏CT和超声心动图(TTE)进行回顾性分析,并与手术结果对照。全部病例均经手术证实。结果25例患者中手术证实畸形79处,64层螺旋CT与TTE诊断的准确率分别为96%和73%。其中,心脏部分畸形29处,64层螺旋CT漏误诊2处,TTE漏误诊4处,两种检查的诊断准确率差异无统计学意义。心脏-大血管连接部及大血管部分畸形50处,64层螺旋CT漏误诊1处,TTE漏误诊17处,两种检查的诊断准确率差异有统计学意义。结论64层螺旋CT在复杂先心病诊断中畸形的检出率优于TTE,诊断准确率达96%,特别是对主动脉、肺动脉及肺静脉畸形的显示具有明显优势。     

64层螺旋CT在先天性心脏病诊断中的应用

目的 评价64层螺旋CT(MSCT)在先天性心脏病(CHD)诊断中的应用价值. 方法对57例CHD患者的MSCT资料行回顾性分析,与手术或心血管造影结果对照.所有病例行MSCT增强心脏检查,原始图像在工作站经多平面重组(MPR)、最大密度投影(MIP)和容积再现(VR)法重组.患者平均年龄11.7岁(1～52岁),男36例,女21例.所有病例同期行超声心动图(ECHO)检查,47例行心血管造影(CAG)检查,42例手术治疗.结果以手术或CAG检查为诊断标准,64层MSCT在CHD心外大血管畸形方面诊断符合率为95.9%(47/49),明显优于ECHO(χ2＝14.69,P<0.001);心内畸形诊断符合率91.5%(54/59),与ECHO差异无统计学意义(χ2＝1.58,P>0.05);心脏-大血管连接异常诊断符合率100%(39/39),与ECHO差异无统计学意义(χ2＝3.42,P>0.05).结论 64层MSCT在CHD诊断中是一种准确的无创性方法.     

紫绀型先天性心脏病肺血管成像方法的对比研究

目的 评价超声心动图、64排螺旋CT(MSCT)及电影心血管成像(CAG)对于紫绀型先天性心脏病肺血管成像的临床应用价值.方法 回顾42例紫绀型先天性心脏病患者的超声心动图、MSCT、CAG影像学资料,并和手术结果对比,进行统计学分析.其中男29例,女13例,年龄11 d～28岁,平均7.26岁.结果 本组42例患者经手术证实肺血管共有109处畸形.超声心动图正确诊断93处畸形,符合率85.3%;漏诊误诊16处; MSCT确诊102处畸形,符合率93.6%;漏诊误诊7处畸形;CAG确诊106处畸形,符合率97.2%;漏诊误诊3处畸形.超声心动图和MSCT、CAG对比诊断符合率均有显著性差异. MSCT和CAG对比诊断符合率无显著性差异.结论 MSCT对紫绀型先天性心脏病肺血管成像具有较高的临床应用价值.     

多层螺旋CT在右室双出口诊断中的应用价值

目的：探讨多层螺旋CT（MSCT）在右室双出口诊断中的应用价值。方法：75例经临床、X线片、心脏超声（UCG）拟诊为右室双出口的再行MSCT检查,采用心脏节段分析法分析内脏心房位、心室袢、大动脉关系,另外,观察室间隔缺损部位、有无肺动脉狭窄、主动脉异常及其它并发畸形,并将CT结果与手术结果进行对照。结果：75例手术证实右室双出口中,MSCT定性诊断正确73例,误诊2例。75例均有室间隔缺损。肺动脉高压10例,肺动脉狭窄53例,心脏大血管连接部分及心外并发畸形共72处,小房间隔缺损或卵圆孔未闭漏诊4处。结论：MSCT对右室双出口的解剖诊断及分型具有重要价值。观察心脏大血管连接部分及心外大血管畸形有明显优势,能显示冠状动脉情况。     

64层螺旋CT诊断复杂先天性心脏病的临床价值

目的 探讨64层螺旋CT(64SCT)对比增强及后处理技术对复杂先天性心脏病(CCHD)的诊断价值.方法 39例CCHD手术前均行经胸心脏二维超声(TTE)检查和648CT对比增强扫描检查,其中CT扫描时有8例采用心电门控技术.手术后按心内畸形、心脏大血管连接部畸形及大血管部分畸形分别统计CT及TTE 2种检查方法及有否使用心电门控技术的诊断正确率,并使用SPSS13.0版软件包对结果行χ~2检验.结果 手术证实畸形共102处,其中心脏部分畸形47处,CT和TTE的诊断准确率分别为85.1%和95.7%,2种检查的诊断正确性差异无显著性意义(χ~2=2.68,P>0.05);心脏大血管连接部分及大血管部分畸形共计55处,CT和TTE的诊断准确率分别为98.2%和78.2%,64SCT诊断正确率明显高于TTE(χ~2=14.64,P<0.01).未使用和使用心电门控在定性诊断准确性差异上无显著意义(χ~2=1.84,P>0.05),但采用心电门控技术CT扫描图像更清晰.结论 64CT对CCHD的检查具有较高的诊断价值.扫描时是否采用心电门控技术对CCHD的定性诊断无明显统计学差别.     

多层螺旋CT在小儿复杂先天性心脏病诊断中的应用

目的　探讨多层螺旋CT(MSCT)对小儿复杂先天性心脏病 (简称先心病 )的诊断价值。方法　MSCT对比增强心脏检查 4 8例 ,原始图像在工作站经多平面 (MPR)、最大密度投影 (MIP)、容积再现 (VR)及表面阴影成像 (SSD)法重建。 4 8例作心脏超声 (US)对照 ,2 1例作X线心血管造影 (CAG)对照。所有病例均经手术证实。结果　手术证实畸形共 174处 ,MSCT总的诊断敏感度 97 1%、特异度 99 4 %、准确度 95 9%。其中 ,心脏部分畸形 5 7处 ,MSCT漏诊 4处 ,US误诊 2处 ,CAG漏诊 1处 ,3种检查的诊断准确率差异无显著性意义 (χ2 =0 86 ,P >0 0 5 )。心脏大血管连接部分及大血管部分畸形共计 117处 ,MSCT、US、CAG诊断准确率分别为 97 4 %、76 9%、92 7% ,MSCT(χ2 =2 2 0 2 ,P <0 0 1)及CAG(χ2 =4 90 ,P <0 0 5 )诊断准确率明显高于US ,MSCT与CAG诊断准确率差异无显著性意义 (χ2 =0 80 ,P >0 0 5 )。MSCT与US联合可提高诊断准确率至 99 4 %。结论MSCT对小儿复杂先心病畸形的检出优于US ,MSCT与US联合可提高对小儿先心病诊断的准确率。MSCT可作为CAG的补充 ,有时甚至可取代CAG。     

先天性心脏病复杂畸形的影像学诊断

目的：探讨多层螺旋CT、超声心动图以及心血管造影三种影像学方法在先天性心脏病复杂畸形诊断中的优选应用。方法：对50例患有先天性心脏病复杂畸形的患者术前均行多层螺旋CT、超声心动图以及心血管造影检查,检查后行心脏外科手术治疗,以手术后所得到的诊断结果为对照,并计算其诊断的准确率。将三种检查方法所得到的诊断准确率分别进行统计学分析。结果：手术证实畸形共149处,其中心内畸形66处,心外畸形83处。多层螺旋CT（MSCT）、超声心动图（UCG）和心血管造影（CAG）对心内畸形诊断的准确率分别为97.0%、100%和98.5%,三者诊断准确率差异无显著性意义（χ^2.098,P〉0.05）;MSCT、UCG和CAG对心外畸形诊断准确率分别为92.8%、78.3%和97.6%,MSCT和CAG诊断准确率明显高于UCG（χ^21.58,P〈0.01和χ^2.08,P〈0.05）,MSCT与CAG之间诊断率差异无显著性意义（χ^2.37,P〉0.05）。MSCT与UCG联合可提高诊断准确率至98.7%。结论：MSCT在心外血管结构的显示上较UCG有优势,而UCG对心内结构的评价更准确;MSCT与UCG的联合应用可提高小儿先天性心脏病诊断准确率;但对显示体-肺侧支,肺血管特别是外围血管的发育,测量心脏及大动脉内压力等,目前仍需依靠有创性的心血管造影。     

多层螺旋CT在小儿先天性心血管畸形中的应用

目的 探讨多层螺旋CT (MSCT)对小儿先天性心血管畸形的应用价值.资料与方法 对22例临床诊断为心血管畸形的患者进行胸部CT扫描.结果 在手术证实的39处心腔外大血管畸形中, MSCT与手术的符合率为94.8%,经胸超声心动图的诊断符合率为82.1%;对手术证实的28处心腔内畸形,MSCT的诊断符合率89.3% ,超声心动图的诊断符合率为100%.MSCT与经胸心动超声图在诊断心腔外大血管畸形时有显著性差异(P<0.05),而在诊断心腔内畸形时差异无显著性意义(P>0.05).结论 MSCT能直观地显示主动脉、肺动脉等大血管及其分支的走行、形态,为心外大血管畸形的诊断提供了客观依据,MSCT结合经胸超声心动诊断先天性心血管畸形已基本取代心血管造影.     

320排CT在先天性心脏病诊断中的应用

目的:探讨320排CT对先天性心脏病的临床诊断价值。方法:回顾性分析15例先天性心脏病患者的320排CT扫描资料,并与经胸超声心动图(TTE)及手术结果进行对照研究。结果:15例经手术证实的心内外结构异常共72个,其中心内结构异常27个,心外结构异常45个。320排CT、TTE对心内畸形的诊断符合率分别为96.3%(26/27)和92.6%(25/27),差异无显著性意义(χ2=2.982,P>0.05)。320排CT对心脏大血管连接部位畸形及心外大血管畸形的诊断符合率[100%(45/45)]明显高于TTE[53.3%(24/45)],差异有显著性意义(χ2=31.28,P<0.05)。320排CT及TTE对先心病总的诊断符合率分别为98.6%和68.0%,差异有显著性意义(χ2=28.09,P<0.05)。结论:320排CT对心外大血管结构异常的检出显著优于TTE,对心内结构异常的检出也有良好的效果,320排CT结合TTE可显著提高对小儿先心病的诊断准确性。     

胃癌螺旋CT术前评估及与手术病理分期对照研究

目的:应用螺旋CT行胃癌术前评估,并将CT分期与手术病理分期进行比较。方法:98例胃癌患者术前行腹部螺旋CT检查,并实施手术分期和病理分期。结果:所有患者行手术治疗,其中16例(16%)无法切除,82例(84%)手术切除。CT扫描中胃壁的厚度和浆膜的累及有相关性(P<0.001)。CT和手术预测病理分期的符合率分别为68%和52%。CT过度分期只有17%。结论:螺旋CT是胃癌患者术前检查的一种有效的方法,可预测胃癌病灶的可切除性,从而避免某些不必要的剖腹手术或使手术方案更加合理。CT过度分期的概率较低,其分期的准确率高于手术。     

Congenital anomalies of coronary arteries in complex congenital heart disease: Diagnosis and analysis with dual-source CT

BackgroundCongenital heart diseases (CHDs) are sometimes associated with coronary artery anomalies (CAAs). Accurate preoperative evaluation of coronary artery anatomy is essential for successful surgical repair of complex CHD.ObjectiveThe aim of this study was to evaluate the incidence of congenital CAAs in patients with complex CHD at dual-source CT.MethodsFour hundred seventeen consecutive patients with complex CHD underwent contrast-enhanced cardiac CT angiography. The results were retrospectively analyzed, including the types and incidences of CAAs in various forms of complex CHD. Each patient was analyzed independently by 2 experienced cardiovascular radiologists. Image quality of coronary arteries was assessed on a 5-point scale with 2 or less being nondiagnostic.ResultsThirty-five of 417 studies were nondiagnostic (8.39%). Sixty-three cases of CAA (15.11%) were detected by anomalous ostia and coronary arteries. CAA was involved in 6 of 108 patients with tetralogy of Fallot (5.56%), 18 of 84 patients with double outlet right ventricle (21.43%), 11 of 97 patients with pulmonary artery atresia (11.34%), 7 of 36 patients with transposition of the great arteries (22.22%), 15 of 41 patients with single ventricle (36.59%), 4 of 12 patients with truncus arteriosus/aortopulmonary window (33.33%), and 2 of 39 patients with interruption of the aortic arch/coarctation of the aorta (5.13%). Twenty of these were accompanied with an anomalous coronary course (31.74%).ConclusionPatients with complex CHD have a higher prevalence of CAAs, which should be considered before surgery. Dual-source CT is an effective technique to visualize and evaluate complex CHD.     

Introduction to cardiac imaging in infants and children: techniques, potential, and role in the imaging work-up of various cardiac malformations and other pediatric heart conditions

The increasing prevalence of congenital heart disease (CHD) can be attributed to major improvements in diagnosis and treatment. Although echocardiography is the most commonly used imaging modality for diagnosis and follow-up of subjects with CHD, the evolution of cardiovascular magnetic resonance (MR) imaging and increasingly computed tomography (CT) does offer new ways to visualize the heart and the great vessels. The development of cardiovascular MR techniques allows for a comprehensive assessment of cardiac anatomy and function. This provides information about the long-term sequlae of the underlying complex anatomy, hemodynamic assessment of residual post-operative lesions and complications of surgery. As much of the functional data in CHD patients is usually acquired with invasive X-ray angiography, non-invasive alternatives such as cardiovascular MR (and CT) are desirable. This review evaluates the role of MR imaging in the management of subjects with CHD, particularly detailing recent developments in imaging techniques as they relate to the various CHD diagnoses we commonly encounter in our practice.     

Nonsurgical management of blunt splenic injury: use of CT criteria to select patients for splenic arteriography and potential endovascular therapy

PURPOSE: To determine if contrast material-enhanced spiral computed tomography (CT) can be used to select patients with blunt splenic injuries to undergo arteriographic embolization. MATERIALS AND METHODS: During a 15-month period, 78 patients who were hemodynamically stable and required no immediate surgery underwent contrast-enhanced spiral CT followed by splenic arteriography. CT scans were assessed for splenic vascular contrast material extravasation or posttraumatic splenic vascular lesions. Medical records were reviewed for splenic arteriographic results and clinical outcome. RESULTS: There were 25 grade I, 12 grade II, 27 grade III, 12 grade IV, and two grade V splenic injuries. CT showed active contrast material extravasation in seven patients and splenic vascular lesions in 19 patients. At CT, splenic vascular contrast material extravasation was 100% (seven of seven patients) and a posttraumatic splenic vascular lesion was 83% (10 of 12 patients) sensitive on the basis of arteriographic or surgical outcome in predicting the need for transcatheter embolization or splenic surgery. Overall, CT had a sensitivity of 81% (17 of 21 patients), a specificity of 84% (48 of 57 patients), negative and positive predictive values of 92% (48 of 52 patients) and 65% (17 of 26 patients), respectively, and an accuracy of 83% (65 of 78 patients) in predicting the need for splenic injury treatment. CONCLUSION: Contrast-enhanced spiral CT plays a valuable role in selecting hemodynamically stable patients with splenic vascular injury who may be treated with transcatheter therapy and potentially improves the success rate of nonsurgical management.     

Supratentorial Low-Grade Glioma: Results and Prognostic Factors Following Postoperative Radiotherapy

BACKGROUND AND PURPOSE: To assess treatment outcome and prognostic factors following postoperative external radiotherapy in 77 patients with low-grade glioma. PATIENTS AND METHODS: Between 1977 and 1996, 45 patients with astrocytoma, 14 with oligodendroglioma and 18 with mixed glioma received postoperative radiotherapy with a median total dose of 52 Gy (range, 45 to 61 Gy). Sixty-seven patients were treated immediately following surgery, 10 patients with tumor progression. The influence of various factors including histology, gender, age, seizures, duration of symptoms (< or = 6 weeks vs > 6 weeks), CT pattern (enhancement vs no enhancement), type of surgery, total radiotherapy dose and timing of radiotherapy on relapse-free survival and overall survival was investigated. RESULTS: The median overall survival time was 81 months, the 5- and 10-year survival rates were 54% and 31%, respectively. The median time to progression was 56 months, while the 5- and 10-year progression-free survival rates were 45% and 24%. Univariate analyses identified the total radiotherapy dose (p = 0.01), duration of symptoms (p = 0.05), the presence of seizures (p = 0.04), and the CT pattern following intravenous contrast (p = 0.005) as significant prognostic factors for overall survival. Progression-free survival rates were influenced by the total dose (p = 0.04), the duration of symptoms (p = 0.01) and CT pattern (p = 0.006). On multivariate analysis, only the CT pattern (enhancement vs no enhancement) remained as independent prognostic factors for both progression-free survival and overall survival. CONCLUSIONS: A minimum total dose of 52 Gy is recommended for the postoperative radiotherapy in low-grade glioma. Tumors with CT enhancement seem to need further intensification of treatment.     

结节性甲状腺肿的CT诊断

目的:观察结节性甲状腺肿CT表现,探讨结节性甲状腺肿的CT特征.材料和方法:回顾性分析了52例经手术病理证实的结节性甲状腺肿的CT表现,并与病理所见作对照研究.结果:根据52例结节性甲状腺肿的CT表现,将其分为弥漫型和局限型两种类型,弥漫型38例(双侧16例,单侧22例),局限型14例(多发8例,单发6例).15例弥漫型病变伴大范围囊变者,囊壁环状强化,厚薄不均,壁结节强化,囊内呈岛状强化,是结节性甲状腺肿的特征性表现,而病灶密度、钙化、延伸范围、对气管血管压迫情况只可作为诊断的参考依据.结论:CT扫描特别是增强及薄层扫描对诊断结节性甲状腺肿具有重要价值,并能评价其与周围结构的关系.     

Hereditary hemorrhagic telangiectasia: multi-detector row helical CT assessment of hepatic involvement

PURPOSE: To describe findings obtained with multi-detector row helical computed tomography (CT) of the liver in patients with hereditary hemorrhagic telangiectasia. MATERIALS AND METHODS: Multiphasic multi-detector row helical CT was performed in 70 consecutive patients (29 females and 41 males; mean age, 48.5 years; age range, 15-75 years): 64 considered to have hereditary hemorrhagic telangiectasia and six suspected of having the disease. Scanning delay was achieved by using a test bolus of contrast medium to obtain early arterial phase, late arterial phase, and portal venous phase images. Multiplanar and angiographic reconstructions were then generated. The presence of shunts, hepatic perfusion disorders, telangiectases, other vascular lesions, indirect signs of portal hypertension, and vascular anatomic variants were evaluated by two radiologists in consensus. RESULTS: Fifty-two of 70 (74%) patients had hepatic vascular abnormalities. Only four of 52 (8%) patients were symptomatic. Arterioportal shunts were present in 27 of 52 (52%) patients, arteriosystemic shunts in eight of 52 (15%), and both shunt types in 17 of 52 (33%). In 34 of 52 (65%) patients, parenchymal perfusion disorders were detected. Telangiectases were found in 33 of 52 (63%) patients. Large confluent vascular masses were identified in 13 of 52 (25%) patients. In 31 of 52 (60%) patients, indirect CT signs of portal hypertension were detected, but only one had clinical signs of this condition. Vascular anatomic variants were detected in seven patients (13%). CONCLUSION: Multi-detector row helical CT and reconstructions depict the complex hepatic vascular alterations typical of hereditary hemorrhagic telangiectasia.     

小肝癌螺旋CT多期扫描不强化的病理基础探讨

目的:分析螺旋CT多期扫描诊断小肝癌的价值,从而探讨少数小肝癌不强化的病理基础。方法:52例小肝癌(SHCC)患者行螺旋CT平扫和多期增强扫描,平扫后分别行动脉期、门脉期和延迟期增强扫描,观察病灶的强化形式。手术病理记录肝脏有无肝硬化、坏死囊变、透明细胞变及脂肪变性等。结果:52例患者共发现病灶72个,CT动脉期扫描有48个病灶有明显强化。SHCC在CT动脉期-门脉期-延迟期扫描中的典型方式为高-低-低密度等高-等-低密度;不典型方式为低-低-低密度和高-等-等密度。术中见肝硬化者占79.2%,18.1%的病灶内见出血坏死,16.7%的病灶出现透明细胞变或全灶为透明细胞癌。结论:大部分小肝癌在动脉期出现强化,多期扫描不强化的占11.1%,不强化主要是坏死造成,脂肪变性和透明细胞变性也是主要原因之一。     

PET/CT using 18F-FDG in suspected lung cancer recurrence: diagnostic value and impact on patient management.

The goal of this study was to assess the value of hybrid imaging using a combined PET/CT device with 18F-FDG in the diagnosis and clinical management of suspected recurrent lung cancer. METHODS: Forty-two patients with non-small cell lung cancer (NSCLC) with suspected recurrence due to new clinical, biochemical, and radiologic findings were prospectively evaluated. PET/CT results were compared with PET interpreted with side-by-side CT data. A final diagnosis of recurrence was confirmed by histologic tissue sampling during surgery or biopsy or by further clinical and radiologic work-up. The impact of PET/CT on patient management was assessed. RESULTS: Twenty-four of 27 positive PET/CT studies (89%) were proven to have recurrent disease. Fourteen of 15 negative PET/CT studies (93%) had no evidence of disease. The sensitivity, specificity, and positive and negative predictive values of PET/CT for diagnosis of recurrence were 96%, 82%, 89%, and 93% compared with 96%, 53%, 75%, and 90%, respectively, for PET. PET/CT changed the PET lesion classification in 22 patients (52%), by determining the precise localization of sites of increased 18F-FDG uptake. PET/CT changed the management of 12 patients (29%) by eliminating previously planned diagnostic procedures (5 patients), by initiating a previously unplanned treatment option (4 patients), or by inducing a change in the planned therapeutic approach (3 patients). CONCLUSION: In patients with a suspected recurrence of NSCLC, PET/CT provides a better anatomic localization of suspicious lesions compared with PET interpreted with side-by-side CT data. This improved diagnostic performance of PET/CT has a further impact on the clinical management and treatment planning of the patients.     

Computed tomography in blunt abdominal trauma: an analysis of clinical management and radiological findings.

We have retrospectively assessed the computed tomography (CT) findings in 92 patients suffering severe blunt abdominal trauma. Surgical findings and clinical follow-up were correlated with the CT findings. In nine patients CT was first used after emergency surgery and provided baseline data which was useful for further management. In two patients CT did not demonstrate small hepatic lacerations seen during previous surgery. No deaths were recorded. In 16 patients surgery followed CT within 24 h; there was good correlation between the CT and operative findings in 10 patients. However, CT failed to detect significant solid organ injury in five patients and was misleading (false positive) in another patient. There were two deaths amongst these 16 patients. Sixty-seven haemodynamically stable patients were initially managed non-operatively. Fifteen of these 67 patients had normal CT examinations; only one had subsequent laparotomy (for reasons unconnected with the trauma) where no injury was detected; there were no deaths. Of the 52 patients with an abnormal CT examination, 43 were successfully managed non-operatively. There were three deaths, including one where an injury missed at CT contributed to the demise of the patient. After an initial trial of non-operative management, the remaining six patients went to surgery where there was good concordance with the CT findings except for one missed renal injury. Active non-operative management of blunt abdominal trauma is widely accepted in haemodynamically stable patients and this report shows how CT supports this policy of surgical restraint in such cases. However, on review CT missed 13 injuries in nine patients overall; stricter attention to technique and better equipment may lead to improved results in the future.