香港发生严重非典型肺炎的个案所呈现的放射学征状

　香港中文大学放射诊断学系及器官成像学系对威尔斯亲王医院病者的X光平片及计算机扫描影像经过分析后（约二千二百张X光平片及一百四十个计算机扫描个案），初步归纳出以下的放射学征状，可有助大家在面对这病症时，能及早诊断并作出治疗。

IMAGING FINDINGS IN SARS

Radiographs:

In the early stage of the disease, a peripheral / pleural-based opacity may be the only abnormality. This may range from ground-glass to consolidation in appearance. A particular area to review is the paraspinal region behind the heart. In our experience, this is frequently where lung lesions are detected on HRCT in suspected SARS patients with normal radiographs.

In the more advanced cases, there is widespread opacification which may be ground-glass or consolidative affecting large areas. This tends to affect the lower zones first and is not uncommonly bilateral. Calcification, cavitation, pleuraleffusion or lymphadenopathy are not features of this disease.

HRCT:

Solitary or multiple patchy area(s) of

　　1、Ground-glass opacification with or without thickening of the intra-lobular interstitium or interlobular interstitium.
　　2、Consolidation
　　3、A combination of 1 & 2

These tend to occupy a sub-pleural position rather than axial. Again, calcification, cavitation, pleural effusion or lymphadenopathy are not features of this disease

CXR WITH CORRESPONDING HRC

Patient Three		Patient Four
24 year old symptomatic female. Frontal view shows vague paraspinal opacity in the left lower zone		29 year old symptomatic female with normal radiographic appearance
Click		Click
here		here
to view corresponding HRCT		to view corresponding HRCT
Patient One
27 year old symptomatic female with subtle left lower zone opacity
Click
here
to view corresponding HRCT

PROGRESS CXR

Case 1: A 31-year-old health-care worker presented with 2-day history of fever, chills and myalgia.

Figure 1 - CXR at the time of diagnosis showed ill-defined air space opacification in right lower zone		Figure 2 - CXR after 3 days showed partial resoulation of consolidatve changes in right lower zone. There is a new finding of ill-defined air space opacification in left lower zone		Figure 3 - CXR after another 4 days showed progressive resolution of the changes in both lower zones

Case 2: A 34-year-old presented with 3-day history of fever, chills and malaise.

Figure 1 - CXR (7 days after admission) showed ill-defined air space opacification in periphery of right lower zone		Figure 2 - CXR (2 days later) showed progression of air space opacification in right lower zone and a new finding of similar changes in left mid and lower zones after initial treatment		Figure 3 - CXR (after another 4 days) showed marked resolution of the consolidative changes in both lungs after treatment

NEW! Case 3: A 34-year-old health care worker presented with fever, chills and myalgia for 2 days.

Figure 1 - CXR showed ill-defined air-space opacity in periphery of left upper and mid zones		Figure 2 - CXR (after 5 days) showed progressive air-space opacities in both lungs		Figure 3 - CXR (after another 7 days) showed resolution of radiographic changes after successful treatmen

IMAGES FROM OTHER CENTERS

Boca Raton, Florida, USA

Courtesy of Dr. Michael E. Katz M D

52-year-old symptomatic female from Virginia
15 MARCH 2003 (On presentation to A&E)		19 MARCH 2003		20 MARCH 2003

Changi General Hospital, Singapore

Courtesy of Dr Augustine Tee

24-year-old Philipino nursing aid from nursing home with one week history of fever, dry cough and myalgia.
Day 1 - CXR showed subtle left lower zone airspace infiltrates.		Day 5 - CXR showed left lower zone consolidation became more obvious.		Day 7 - Patient became hypoxic & required subsequent intubation. CXR showed bilateral widespread airspace infiltrates.

IMAGE GALLERY

CHEST RADIOGRAPHS

Fig 1: (day 3 after onset of symptoms) Ill-defined air-space opacification in right lower zone		Fig 2: (day 4 after onset of symptoms) Confluent air-space opacification in left lower zone		Fig 3: (day 5 after onset of symptoms) Air-space opacification in the periphery of middle lobe abutting the superior aspect of the horizontal fissure
Fig 4: (day 3 after onset of symptoms) Ill-defined opacity in left lower zone		Fig 5: (day 4 after onset of symptoms) Bilateral lower zones air-space opacities in para-cardiac areas		Fig 6: (day 2 after onset of symptoms) Middle lobe air-space opacity obscuring part of right heart border
Fig 7: (day 4 after onset of symptoms) Peripheral segmental air-space opacification in right upper lobe		Fig 8: (day 5 after onset of symptoms) Patchy peripheral opacities involving both lower lobes		Fig 9: (day 6 after onset of symptoms) Multi-focal ill-defined air-space opacities in both lower and right upper zones
Fig 10: (day 5 after onset of symptoms) Patchy air-space opacification in both mid and lower zones		Fig 11: (day 4 after onset of symptoms) Peripheral patchy opacification in right upper and left lower zones		Fig 12: (day 7 after onset of symptoms) Multi-focal diffuse air-space opacities in both lungs
				Note: ARDS (Adult Respiratory Distress Syndrome) may be a feature in severe disease
Fig 13: (day 5 after onset of symptoms) Multi-focal confluent areas of air-space opacities in both lungs		Fig 14: (day 6 after onset of symptoms) Diffuse and widespread consolidative changes in both lungs (patient is intubated)

PAEDIATRICS

2-year-old boy presented with febrile convulsion and cough. CXR on admission showed air-space opacities in left mid and lower zones.		6-year-old girl presented with fever, running nose and cough. CXR on admission showed focal air-space consolidation in left upper zone.		5-year-old girl presented with fever for 4 days. CXR showed air-space opacity in left lower zone.

CT

Fig 1: (day 3 after onset of symptoms) Peripheral ill-defined consolidation in the lateral basal segment of left lower lobe		Fig 2: (day 2 after onset of symptoms) Peripheral ground-glass opacification in middle lobe		Fig 3: (day 3 after onset of symptoms) Ground-glass opacification in perihilar region of right upper lobe
Fig 4: (day 3 after onset of symptoms) Ill-defined consolidation with air-bronchogram in apical segment of right lower lobe		Fig 5: (day 5 after onset of symptoms) Multi-focal peripheral consolidation in posterior basal segments of both lower lobes and an area of ground-glass opacification in left lingular segment		Fig 6: (day 5 after onset of symptoms) Patchy, multi-focal, ground-glass opacification and consolidation in both upper lobes
Fig 7: (day 4 after onset of symptoms) Multiple confluent areas of consolidation in the middle lower and both lower lobes

成像常规指引

目前我们的成像常规指引是：

　　1、临床上怀疑SARS个案，应进行胸部X光平片检查。
　　2、如胸部平片异常，则无须作进一步检查(跟进病况除外)。
　　3、如胸部平片正常，则应进行高解像计算机扫描(HRCT)，因HRCT可比胸部X光平片早一至两天显示异常变化
　　4、现时所有住院的SARS病人都有异常的胸部成像影像。
　　5、由于此病的传染性高，当值人员必须严格执行防疫措施，并彻底清洁有关仪器。

注意：初时，我们为病者进行常规和高解像的胸部计算机扫描，以比较两者成效，当累积一定经验后，因发现病者皆无肺积水或淋巴结节病变情况，故现选择只进行HRCT，以减低病者接受的幅射剂量。

严格防疫措施

　详情请参阅「感染控制措施」。

　　1、检查后，清洁X光及CT的检查床架，以及检查室的地板。
　　2、检查后，更换床单。
　　3、所有当值人员须配戴口罩、手套及保护衣。

所有放射部门人员必须清楚并严格遵行防疫措施守则。

对SARS的成像检查建议流程：

*为要提防HRCT过于敏感，应用时过份诊断，以假作真，故请只在下列情况下方可应用。

　　1、有接触SARS病者的病历
　　2、有清楚的临床征状，包括连续发热发烧，低白血球数量等
　　3、初步胸部X光平片正常
故此我们必须为成像检查订出清楚的临床指引。

病者出院时的成像方针

　　由于这是SARS的首次爆发。我们没法从医学文献取得前人经验可作参考，以订立在病者出院时的成像检查方针。经结合其它在处理SARS个案之医疗中心同仁的意见，我们初步提出以下的成像指引。这个指引因经验所限，或许尚有改善的空间。我们订立过程中有考虑过资源调配，病者数量，幅射剂量，个别成像检查的敏感度，以及指引的可行性等因素。因应临床需要，病者出院时的成像检查指引如下：

　　对于病者在进院时，胸部X光平片有明确异常，并在治疗时其X光征状有分解减退情，我们初步定为这类病者在出院及覆诊时进行胸部X光平片，以监察其康复进展。

　　对于病者在进院时，胸部X光平片无异常，而只从其HRCT发现肺部有肺炎病变，我们初步定为这类病者在出院及覆诊时进行HRCT，以监察其康复进展。

　　我们医疗界同仁务须同舟共济，协力同心对抗SARS，在此我们极欢迎各位对本页的资科作出响应和建议。