BACKGROUND & AIMS: :The oropharyngeal swallow mechanism is comprised of several behaviours that change systematically or occur randomly. The systematic changes are dependent on the bolus characteristics (i.e. volume and viscosity) and voluntary control. An oropharyngeal swallow is rapid (less than 2 s), and videofluoroscopy is required to determine which muscles or nerves are damaged in dysphagic patients. Once the specific problem has been identified, a treatment plan can be designed. Various categories of treatment are available, including behavioural procedures such as changes in head postures, heightening sensory input prior to the swallow, voluntary manoeuvres, exercise programmes, medications and surgical procedures. A swallowing specialist, usually a speech-language pathologist, identifies and assesses optimal treatments and works with the patient to improve swallowing patterns in order to return the patient to safe and efficient oral intake. This chapter describes these approaches.

背景与目标： : 口咽吞咽机制由几种系统变化或随机发生的行为组成。系统的变化取决于推注特性 (即体积和粘度) 和自愿控制。口咽吞咽迅速 (少于2 s)，需要进行视频透视以确定吞咽困难患者的肌肉或神经受损。一旦确定了具体问题，就可以设计治疗方案。可以使用各种类型的治疗方法，包括行为程序，例如头部姿势的变化，吞咽前提高感觉输入，自愿演习，锻炼计划，药物和外科手术。吞咽专家 (通常是言语病理学家) 识别并评估最佳治疗方法，并与患者一起改善吞咽方式，以使患者恢复安全有效的口服摄入。本章介绍了这些方法。

BACKGROUND & AIMS: :The prevalence of swallowing disorders (dysphagia) following a total laryngectomy remains unknown, with estimates varying from 17 to 70%. The primary aim of this study was to investigate the prevalence and nature of self-reported dysphagia following a total laryngectomy across New South Wales (NSW), Australia. A secondary aim was to document the effect of dysphagia on the respondents' social activities and participation. A questionnaire battery, with a prepaid envelope for return, was sent to all laryngectomy members (n = 197) of the Laryngectomy Association of NSW. One hundred twenty questionnaires (61%) were completed and returned. Dysphagia was self-reported by 71.8% of the cohort. In this cohort with dysphagia, the most commonly reported features included an increased time required to swallow, a need for fluids to wash down a bolus, and avoidance of certain food consistencies. Severe distress was reportedly associated with dysphagia for 39.7% of these respondents and prevented 57% of them from participating in social activities, such as eating at friends' houses and/or at restaurants. The prevalence of self-reported dysphagia following total laryngectomy in this Australian study was 72%. Dysphagia can result in laryngectomies making significant changes to their diets and it has a marked impact on their activities and social participation.

背景与目标： : 全喉切除术后吞咽障碍 (吞咽困难) 的患病率仍然未知，估计值从17到70% 不等。这项研究的主要目的是调查澳大利亚新南威尔士州 (NSW) 进行全喉切除术后自我报告的吞咽困难的患病率和性质。第二个目的是记录吞咽困难对受访者的社交活动和参与的影响。将带有预付费信封的问卷电池发送给新南威尔士州喉切除术协会的所有喉切除术成员 (n = 197)。完成并返回了120份问卷 (61%)。该队列的71.8% 自我报告了吞咽困难。在患有吞咽困难的队列中，最常报告的特征包括吞咽所需的时间增加，需要液体来冲洗推注以及避免某些食物的一致性。据报道，对于这些受访者中的39.7% 人来说，严重的痛苦与吞咽困难有关，并阻止他们中的57% 人参加社交活动，例如在朋友家和/或餐馆吃饭。在这项澳大利亚研究中，72% 了全喉切除术后自我报告的吞咽困难的患病率。吞咽困难可导致喉切除术使其饮食发生重大变化，并对其活动和社会参与产生显着影响。

BACKGROUND & AIMS: BACKGROUND & AIMS:Central control of swallowing is regulated by a central pattern generator (CPG) positioned dorsally in the solitary tract nucleus and neighboring medullary reticular formation. The CPG serially activates the cranial nerve motor neurons, including the nucleus ambiguus and vagal dorsal motor nucleus, which then innervate the muscles of deglutition. This case provides insight into the central control of swallowing. METHODS:A 65-year-old man with a right superior lateral medullary syndrome presented with a constellation of symptoms, including dysphagia. The swallow was characterized using videofluoroscopy and esophageal motility and the results were compared with magnetic resonance imaging (MRI) findings. RESULTS:Videofluoroscopy showed intact lingual propulsion and volitional movements of the larynx. Distal pharyngeal peristalsis was absent, and the bolus did not pass the upper esophageal sphincter. Manometry showed proximal pharyngeal contraction and normal peristaltic activity in the lower esophagus (smooth muscle), but motor activity of the upper esophageal sphincter and proximal esophagus (striated muscle) was absent. MRI showed a lesion of the dorsal medulla. CONCLUSIONS:These findings are compatible with a specific lesion of the connections from a programming CPG in the solitary tract nucleus to nucleus ambiguus neurons, which supply the distal pharynx, upper esophageal sphincter, and proximal esophagus. There is functional preservation of the CPG control center in the solitary tract nucleus and of the vagal dorsal motor nucleus neurons innervating the smooth muscle esophagus.

背景与目标：

BACKGROUND & AIMS: :Since April 1997, in Melbourne, Australia, speech pathologists have collaborated to establish a prospective database of functional outcomes of speech, swallowing and voice for patients undergoing head and neck cancer treatments. Staff at eight acute care hospitals, all of which offer speech pathology for head and neck cancer services in Victoria, are contributing data, collated centrally, in an agreed pro forma. Early results are given (after 12 months' data collection). The implications for clinically-based research, and the future potential for benchmarking outcomes--by expansion of the rehabilitation database beyond the current participating sites--is discussed. This paper outlines the rationale of establishing the database is multicentered, and explores some of the complexities involved, including the challenges inherent in long-term accurate data collection in the head and neck cancer patient population. This work represents the development of an appropriate, usable tool for data collection on functional outcomes.

背景与目标： : 自1997年4月以来，在澳大利亚墨尔本，言语病理学家合作建立了一个前瞻性数据库，用于接受头颈癌治疗的患者的言语，吞咽和语音功能结果。八家急诊医院的工作人员正在以商定的形式提供数据，这些医院都为维多利亚州的头颈癌服务提供言语病理学。给出了早期结果 (在12个月的数据收集后)。讨论了基于临床研究的含义以及通过将康复数据库扩展到当前参与站点之外的基准结果的未来潜力。本文概述了建立多中心数据库的基本原理，并探讨了其中的一些复杂性，包括头颈癌患者人群长期准确数据收集所固有的挑战。这项工作代表了开发一种适当的，可用的工具来收集功能结果的数据。

BACKGROUND & AIMS: PURPOSE OF REVIEW:Flexible endoscopic examination of swallowing with and without sensory testing is rapidly becoming a significant tool in the otolaryngologist's armamentarium for diagnosing dysphagia. Patients with swallowing disorders often present to the otolaryngologist, and an understanding of the utility of these techniques is critical. RECENT FINDINGS:Recent studies have confirmed that flexible endoscopic examination of swallowing with and without sensory testing is an exceptionally safe procedure with excellent portability. Flexible endoscopic examination of swallowing is accurate in diagnosing aspiration when compared with videofluoroscopy. Laryngopharyngeal sensory deficits as assessed by flexible endoscopic evaluation of swallowing with sensory testing are associated with cough, reflux disease, penetration, and aspiration. Both techniques have emerged as complementary to videofluoroscopic studies, rather than as replacements for the modified barium swallow. SUMMARY:Flexible endoscopic evaluation of swallowing with and without sensory testing is a safe technique that should be considered in the workup of patients with dysphagia presenting to the otolaryngologist.

背景与目标：

BACKGROUND & AIMS: Dysphagia is a common symptom from the oral cavity, pharynx and esophagus, and its causes may be morphological or functional. A biphasic barium swallow is the best way of evaluating these patients. Using a careful clinical history, and by tailoring the examination to the individual case, the radiologist is usually able to pinpoint the cause of the patient's complaints and suggest further diagnostic procedures and treatment.

背景与目标： 吞咽困难是口腔，咽部和食道的常见症状，其原因可能是形态学或功能性。双相钡吞咽是评估这些患者的最佳方法。放射科医生通过仔细的临床病史，并根据个别病例进行调整，通常能够查明患者主诉的原因，并提出进一步的诊断程序和治疗建议。

BACKGROUND & AIMS: OBJECTIVE:A videofluoroscopic swallowing study (VFSS) is generally used to assess dysphagia and aspiration, although false-negative results may be obtained. Saliva aspiration may cause false-negative VFSS findings in elderly people. A radionuclide salivagram can be useful in detecting saliva aspiration. We therefore compared these two methods for the evaluation of patients with aspiration pneumonia. METHODS:We prospectively enrolled 50 patients with aspiration pneumonia into this study. All patients underwent VFSS, and were evaluated on the Penetration-Aspiration Scale. A salivagram was performed on the day after VFSS and each patient received 1 mL Tc-99 m DTPA sublingually. Both dynamic and delayed images were obtained. RESULTS:Aspiration was observed in 34% of patients by salivagram and in 42% by VFSS. The frequency of tests that were positive for aspiration pneumonia using a combination of the two methods was 52%. Five patients with positive aspiration findings on salivagram were negative on VFSS. The association between VFSS and salivagram findings was significant but the total agreement was 72%. The frequency of aspiration pneumonia was significantly associated with an abnormal salivagram finding. CONCLUSIONS:A salivagram may be a useful method for the evaluation of aspiration in elderly people, and a combination of the VFSS and salivagram methods could enable a more effective investigation of aspiration pneumonia.

背景与目标：

BACKGROUND & AIMS: BACKGROUND AND PURPOSE:Prospective assessment of dysphagia and trismus in chemo-IMRT head and neck cancer patients in relation to dose-parameters of structures involved in swallowing and mastication. MATERIAL AND METHODS:Assessment of 55 patients before, 10-weeks (N=49) and 1-year post-treatment (N=37). Calculation of dose-volume parameters for swallowing (inferior (IC), middle (MC), and superior constrictors (SC)), and mastication structures (e.g. masseter). Investigation of relationships between dose-parameters and endpoints for swallowing problems (videofluoroscopy-based laryngeal Penetration-Aspiration Scale (PAS), and study-specific structured questionnaire) and limited mouth-opening (measurements and questionnaire), taking into account baseline scores. RESULTS:At 10-weeks, volume of IC receiving ≥60 Gy (V60) and mean dose IC were significant predictors for PAS. One-year post-treatment, reported problems with swallowing solids were significantly related to masseter dose-parameters (mean, V20, V40 and V60) and an inverse relationship (lower dose related to a higher probability) was observed for V60 of the IC. Dose-parameters of masseter and pterygoid muscles were significant predictors of trismus at 10-weeks (mean, V20, and V40). At 1-year, dose-parameters of all mastication structures were strong predictors for subjective mouth-opening problems (mean, max, V20, V40, and V60). CONCLUSIONS:Dose-effect relationships exist for dysphagia and trismus. Therefore treatment plans should be optimized to avoid these side effects.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Little is known about what factors affect patient-reported swallowing outcome after total laryngectomy. We explored whether patient demographics, surgical variables, use of adjuvant treatment, and time since surgery were associated with patient-reported swallowing outcome. METHODS:Cross-sectional study of laryngectomees in eight UK hospitals. Demographic, treatment, and surgical variables were drawn from medical notes. The swallowing outcomes after laryngectomy (SOAL) questionnaire captured perceived swallowing outcome. RESULTS:Two hundred and twenty one participants had complete data on treatment-related variables. In regression analysis, having a free jejunum flap repair and requiring chemoradiation were the only two variables that added significantly to the model of worse self-reported swallowing outcome (R2 adjusted = .23, P < .001). CONCLUSION:The SOAL is a sensitive measure of self-reported swallowing outcome after laryngectomy. Type of surgical closure and the type of additional treatment influenced the swallowing outcome reported by patients. Changes in perceived swallowing function need to be routinely evaluated to inform clinical decision-making and intervention.

背景与目标：

BACKGROUND & AIMS: INTRODUCTION:Premature baby's oral feeding is not possible until the reflex of sucking-swallowing-breathing adquisition. Its delay extends hospital stay and increases the incidence of oral motor disorders in early childhood. AIMS:To analyze the transition from enteral to oral nutrition, the comorbidity associated with its delay and the impact of an early suction stimulation in a cohort of premature babies. PATIENTS AND METHODS:Retrospective checking of 95 infants less than 32 gestation weeks (GW) admitted to a neonatal ICU in the last 4 years. It was revised the gestational age, anthropometric at birth and discharge, comorbidity, duration of mechanical ventilation, oxygen requirements, time of beginning and end of enteral/oral nutrition, beginning of Kangaroo method and the suction stimulation and the daily weight gain average. RESULTS:Suction stimulation began between weeks 29 and 40 GW (average and median 32 GW). Oral nutrition was initiated between 31-40 GW (average and median 33 GW) and completed between 33-44 GW (average and median 35 GW). Oral nutrition was delayed in patients who required longer mechanical ventilation and oxygen therapy. There was a positive correlation between the beginning of suction stimulation and the time of acquisition of a complete oral nutrition (84% Spearman correlation test) and length of hospital stay (80% Spearman correlation test). CONCLUSIONS:[corrected] Early suction stimulation in a preterm patient seems to facilitate full oral nutrition at an early stage and it is associated with a hospital stay decrease and the improvement in the daily weight gain average.

背景与目标：

BACKGROUND & AIMS: :Purpose: Dysphagia is common in critically ill neurological patients and is associated with a high mortality and morbidity. Data on the usefulness of flexible endoscopic examination of swallowing (FEES) in neurological intensive care unit (ICU) patients are lacking, raising the need for evaluation.Method: FEES was performed in neurological intensive care patients suspected of dysphagia. We correlated findings with baseline data, disability status, pneumonia and duration of hospitalisation, as well as a need for mechanical ventilation or tracheotomy.Result: This analysis consisted of 125 patients with suspected dysphagia. Most of the patients (81; 64,8%) suffered from acute stroke. Dysphagia was diagnosed using FEES in 90 patients (72%). FEES results led to dietary modifications in 80 patients (64%). The outcome at discharge was worse in dysphagic stroke patients diagnosed by FEES as compared to non-dysphagic stroke patients (p = 0.009). Patients without oral diet had higher need for intubation (p = 0.007), tracheotomy (p = 0.032) and higher mortality (p < 0.001) in comparison to patients with at least small amounts of oral intake.Conclusion: As the clinical assessment of the patients often classified the dysphagia incorrectly, the broad use of FEES in ICU patients might help to adequately adjust patients' oral diet. This knowledge might contribute to lower mortality and morbidity.

背景与目标： 目的: 吞咽困难在重症神经系统患者中很常见，并且具有很高的死亡率和发病率。缺乏神经重症监护病房 (ICU) 患者吞咽灵活内窥镜检查 (收费) 的有用性数据，这增加了评估的需求。方法: 对怀疑吞咽困难的神经重症监护患者进行收费。我们将结果与基线数据、残疾状况、肺炎和住院时间以及机械通气或气管切开的需求相关联。结果: 该分析包括125例疑似吞咽困难的患者。大多数患者 (81; 64，8%) 患有急性中风。在90例患者 (72%) 中使用费用诊断吞咽困难。收费结果导致80名患者 (64%) 的饮食改变。与非吞咽障碍卒中患者相比，经收费诊断的吞咽障碍卒中患者出院时的结局更差 (p   =   0.009)。与至少少量口服摄入的患者相比，没有口服饮食的患者对插管 (p   =   0.007)，气管切开 (p   =   0.032) 的需求更高，死亡率更高 (p  <  0.001)。结论: 由于患者的临床评估经常错误地对吞咽困难进行分类，在ICU患者中广泛使用费用可能有助于充分调整患者的口服饮食。这些知识可能有助于降低死亡率和发病率。

BACKGROUND & AIMS: OBJECTIVE:To define the effects of Lee Silverman Voice Treatment (LSVT on swallowing and voice in eight patients with idiopathic Parkinson's disease.

METHODS:Each patient received a modified barium swallow (MBS) in addition to voice recording before and after 1 month of LSVT. Swallowing motility disorders were defined and temporal measures of the swallow were completed from the MBS. Voice evaluation included measures of vocal intensity, fundamental frequency, and the patient's perception of speech change.

RESULTS:before LSVT, the most prevalent swallowing motility disorders were oral phase problems including reduced tongue control and strength. Reduced tongue base retraction resulting in residue in the vallecula was the most common disorder in the pharyngeal stage of the swallow. Oral transit time (OTT) and pharyngeal transit time (PTT) were prolonged. After LSVT, there was an overall 51% reduction in the number of swallowing motility disorders. Some temporal measures of swallowing were also significantly reduced as was the approximate amount of oral residue after 3 ml and 5 ml liquid swallows. Voice changes after LSVT included a significant increase in vocal intensity during sustained vowel phonation as well as during reading.

CONCLUSIONS:LSVT seemingly improved neuromuscular control of the entire upper aerodigestive tract, improving oral tongue and tongue base function during the oral and pharyngeal phases of swallowing as well as improving vocal intensity.

背景与目标： 目的 : 定义Lee Silverman语音治疗 (LSVT对8例特发性帕金森氏病患者的吞咽和语音的影响。
方法 : 除了在LSVT前后1个月的语音记录外，每位患者还接受了改良的钡吞咽 (MBS)。定义了吞咽运动障碍，并从MBS中完成了吞咽的时间测量。语音评估包括声音强度，基本频率，以及患者对言语的感知变化。
结果 : 在LSVT之前，最普遍的吞咽运动障碍是口腔阶段的问题，包括减少的舌头控制和力量。减少的舌根回缩导致的山谷中残留是吞咽阶段最常见的疾病。口腔通过时间 (OTT) 和咽通过时间 (PTT) 延长。LSVT后，吞咽运动障碍的数量总体51% 减少。吞咽的一些时间测量也显着减少，3毫升和5毫升液体吞咽后的口腔残留物的大致数量也显着减少。LSVT后的声音变化包括在持续元音发声以及阅读期间发声强度的显着增加。<
结论 :LSVT似乎改善了整个上消化道的神经肌肉控制，改善了吞咽的口腔和咽阶段的口腔舌和舌根功能，并改善了声音强度。

BACKGROUND & AIMS: :Impairment of swallowing is a common symptom in advanced stage of Parkinson's disease and severe defect of this function may cause aspiration pneumonia, problems with food intake and cachexy. The aim of this study was to assess the reflex and oral, pharyngeal, oesophageal phase of swallowing. Eleven patients with Parkinson's disease and 9 healthy subjects were investigated by electromyography (EMG) and oesophageal scintigraphy. The study demonstrates delayed triggering of swallowing reflex (543 +/- 84 ms in patients with PD vs. 230 +/- 66 ms in controls, p < 0.05) and prolongation of laryngeal movement (1880 +/- 140 ms vs. 1349 +/- 154 ms, p < 0.05). The prolongation of the oesophageal phase of swallowing with predilection to retention of water in lower one/third part of esophagus (12.45 +/- 2.45 s vs. 6.45 +/- 1.18 s, p < 0.001) was observed. The dysphagia limit, that is the maximum amount of water swallowed at once, was also evaluated (all normal subjects are able to swallow 20 ml water or more at once). In the studied patients with Parkinson's disease it was 4.5 +/- 0.86 ml. These results evidently and objectively indicate the presence of swallowing disorders in Parkinson's disease. Dysphagia was observed in all studied patients, although only 8 of them complained about it. In other 3 cases the impairment of swallowing was subclinical and it was connected with prolongation of oesophageal phase.

背景与目标： : 吞咽障碍是帕金森氏病晚期的常见症状，这种功能的严重缺陷可能会导致吸入肺炎，食物摄入问题和恶病痛。这项研究的目的是评估吞咽的反射和口腔，咽，食道阶段。通过肌电图 (EMG) 和食管闪烁显像检查了11例帕金森氏病患者和9例健康受试者。该研究表明吞咽反射的延迟触发 (PD患者为543/- 84 ms，对照组为230/- 66 ms，p <0.05) 和喉运动的延长 (1880/- 140 ms与1349/- 154 ms，p <0.05)。观察到食管下半部分吞咽阶段的延长，并倾向于保留水 (12.45/- 2.45 s vs. 6.45/- 1.18 s，p <0.001)。还评估了吞咽困难的极限，即一次吞咽的最大水量 (所有正常受试者都能够一次吞咽20毫升或更多的水)。在研究的帕金森氏病患者中，4.5为/-0.86毫升。这些结果明显且客观地表明帕金森氏病中存在吞咽障碍。在所有研究的患者中均观察到吞咽困难，尽管其中只有8人抱怨吞咽困难。在其他3例中，吞咽障碍是亚临床的，并且与食管期的延长有关。

BACKGROUND & AIMS: :Purpose: To investigate the amount of laryngeal lift during the pitch glide speech task and during a bolus swallow.Method: Modified Barium Swallows (MBS) videos captured speech tasks and bolus trials. Using SwallowTail®, laryngeal elevation was measured by the amount of laryngeal lift from rest to its maximum excursion during each subject's pitch glide and 5 mL thin liquid, 20 mL thin liquid, and 15 mL puree trials. Paired t-tests, with Bonferroni correction, determined if there was a difference in laryngeal lift between the pitch glide and the bolus trials. Two methods were used to compare the methodology of measuring laryngeal lift.Result: Each subject's pitch glide was compared to their swallows. Laryngeal lift during the bolus swallow was greater than the lift during the pitch glide by an average of 1.10 cm, 1.38 cm, and 1.34 cm for 5 mL thin liquid, 20 mL thin liquid, and 15 mL puree, respectively. There was a significant difference in laryngeal lift between the pitch glide task and the 20 mL thin liquid, 5 mL thin liquid, and 15 mL puree swallows. Measurement tracking the posterior cricoid detected greater differences than the previous methodology using the hyoid.Conclusion: In this group of dysphagic patients, the larynx lifted significantly less during a pitch glide than during bolus swallows.

背景与目标： 目的: 研究俯仰滑行语音任务和推注吞咽过程中喉部提升的量。方法: 改良的钡燕子 (MBS) 视频捕获语音任务和推注试验。使用燕尾®,通过在每个受试者的俯仰滑行和5  mL稀液体，20  mL稀液体和15  mL原浆试验中从静止到最大偏移的喉部提升量来测量喉部升高。配对t检验，Bonferroni校正，确定了俯仰滑行和推注试验之间的喉升度是否存在差异。使用两种方法比较测量喉升度的方法。结果: 将每个受试者的俯仰滑行与其燕子进行比较。对于5  mL稀液体、20  mL稀液体和15  mL浓汤，推吞过程中的喉部升力分别大于俯仰滑行过程中的升力，平均分别为1.10  cm、1.38 cm cm和1.34  cm。俯仰滑翔任务与20  mL稀液、5  mL稀液、15  mL原浆燕子的喉部升力有显著性差异。与以前使用舌骨的方法相比，后环状肌的测量跟踪检测到更大的差异。结论: 在这组吞咽困难的患者中，在俯仰滑行期间的喉部抬起明显少于推注吞咽期间。

BACKGROUND & AIMS: OBJECTIVES:Dysphagia can be caused by a myriad of disease processes, and it has significant impacts on patients' quality of life, life expectancy, and economic burden. To date, the most common causes of dysphagia in outpatient tertiary-care swallowing centers are unknown. We undertook this study to determine these prevalences. We also describe the diagnostic techniques utilized to establish the diagnosis. METHODS:The electronic charts of 100 consecutive patients who presented to an outpatient tertiary-care university swallowing center between January 2010 and April 2011 were retrospectively reviewed. Information regarding patient demographics, validated symptom surveys, diagnostic workups, and ultimate diagnoses was abstracted and tabulated into a central database. Descriptive statistics were used to evaluate the association between patient symptoms and diagnoses. RESULTS:The mean age of the entire cohort was 62 +/- 13.5 years, and 58% of the cohort was male. The most common identified causes of dysphagia were reflux (27%), postirradiation dysphagia (14%), and cricopharyngeus muscle dysfunction (11%). In 13% of cases, the cause of dysphagia was undetermined. The diagnostic tests utilized included flexible laryngoscopy (71%; 17% with endoscopic swallow evaluation), modified barium swallow study (45%), esophagoscopy (35%), barium esophagography (21%), manometry (10%), and ambulatory pH testing (2%). CONCLUSIONS:The most common causes of dysphagia in a tertiary-care swallowing center are reflux, postirradiation dysphagia, and cricopharyngeus muscle dysfunction. A precise cause for the symptom could not be identified in 13% of our cohort. Endoscopic visualization (laryngoscopy, flexible endoscopic evaluation of swallowing, and transnasal esophagoscopy) and fluoroscopic swallow studies were the investigations most often utilized. These techniques can be used to arrive at a diagnosis in 80% of cases.

背景与目标：