Thin-section CT in patients with severe acute respiratory syndrome following hospital discharge: preliminary experience

PURPOSE: To report the initial experience regarding thin-section computed tomographic (CT) findings in patients with severe acute respiratory syndrome (SARS) who improved clinically after treatment. MATERIALS AND METHODS: Twenty-four patients (10 men, 14 women; mean age, 39 years; age range, 23-70 years) with confirmed SARS underwent follow-up thin-section CT of the thorax. The scans were obtained on average 36.5 days after hospital admission and were analyzed for parenchymal abnormality (ground-glass opacification, consolidation, or interstitial thickening) and evidence of fibrosis (parenchymal band, traction bronchiectasis, irregular interfaces). Patients were assigned to group 1 (with CT evidence of fibrosis) and group 2 (without CT evidence of fibrosis) for analysis. Patient demographics, length of hospital stay, rate of intensive care unit admission, peak lactate dehydrogenase level, pulsed intravenous methylprednisolone therapy, and peak opacification on chest radiographs were compared between the two groups. RESULTS: Parenchymal abnormality was found in 96% (23 of 24) of patients and ranged from residual ground-glass opacification and interstitial thickening in group 2 (nine of 24, 38%) to fibrosis in group 1 (15 of 24, 62%). Patients in group 1 were older (mean age, 45 vs 30.3 years), had a higher rate of intensive care unit admission (27% [four of 15] vs 11% [one of nine]), more requirement for pulsed intravenous methylprednisolone (87%, [13 of 15] vs 67% [six of nine]), higher peak lactate dehydrogenase level (438.9 vs 355.6 U/L), and higher peak opacification on chest radiographs (estimated area, 14% vs 11%) than patients in group 2. CONCLUSION: Pulmonary fibrosis may develop early in patients with SARS who have been discharged after treatment. Patients who are older and have more severe disease during treatment are more likely to develop thin-section CT findings of fibrosis.     

Pulmonary sequelae in convalescent patients after severe acute respiratory syndrome: evaluation with thin-section CT

PURPOSE: To prospectively evaluate lung parenchyma on paired inspiration-expiration thin-section computed tomographic (CT) scans in patients recovering from severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: After the institutional review board approved the study and written consent was obtained from patients, 40 patients (25 female, 15 male; mean age, 42.8 years +/- 12.3 [standard deviation]) underwent thin-section CT at 51.8 days +/- 20.2 after onset of SARS symptoms. Twenty of the 40 patients underwent follow-up thin-section CT at 140.7 days +/- 26.7 after symptom onset. Lung findings were scored according to extent and then grouped in three categories (ground-glass opacity, interstitial opacity, and air trapping) for analysis. Mean CT scores for each finding in the various patient subgroups were compared by using the Mann-Whitney test. Clinical parameters and scores were evaluated for correlation by using Spearman rank correlation analysis. Mean scores for each finding were compared between the two serial examinations by using the Wilcoxon matched-pairs signed rank test. RESULTS: Air trapping, ground-glass opacity, and reticulation were found in 37 (92%), 36 (90%), and 28 (70%) of 40 patients, respectively, at initial thin-section CT examination and in 16 (80%), 14 (70%), and 10 (50%) of 20 patients, respectively, at follow-up examination. Scans from patients with adult respiratory distress syndrome (ARDS) had a significantly higher score for ground-glass opacity than did those from patients without ARDS (P = .009). A comparison of scores for the serial thin-section CT examinations indicated a significant reduction in the extent of ground-glass opacity (P < .001) and interstitial opacity (P < .001) but not in that of air trapping (P = .38) at follow-up examination. At initial thin-section CT, scores for ground-glass opacity, interstitial opacity, and air trapping correlated with age; those for ground-glass opacity and air trapping, with peak C-reactive protein level. At the second examination, scores for ground-glass opacity and interstitial opacity correlated with peak lactate dehydrogenase level; that for air trapping, with age and peak C-reactive protein level. CONCLUSION: Thin-section CT scores correlated with clinical and laboratory parameters in patients after SARS. Although ground-glass opacity and interstitial opacity resolve over time, air trapping persists.     

High-resolution CT findings in patients with severe acute respiratory syndrome: a pattern-based approach

OBJECTIVE: We retrospectively reviewed high-resolution CT (HRCT) examinations of the lungs performed in 27 confirmed cases of severe acute respiratory syndrome (SARS). The HRCT findings at different phases of the illness were analyzed. CONCLUSION: A defined pattern of HRCT findings is observed in different phases of SARS, which is characterized by focal ground-glass and crazy paving patterns in a scattered distribution at presentation, followed by development of interstitial thickening, consolidation, pleural reaction, and scarring. Spontaneous pneumomediastinum is a distinct complication during the course of the illness.     

严重急性呼吸综合征患者肺内残留病变CT表现的随访观察

目的 探讨严重急件呼吸综合征（SARS）患者临床治疗后，CT复查肺内残留病变的动态变化情况。方法 对124例治疗后的SARS患者进行CT复查随访，失访13例，资料完整111例，对平均病程第3、6、12及18个月行螺旋CT检杏的结果进行对比分析，总结其影像动态变化的特征。结果 病程18个月内，相继有70例（占63．1％）患者肺内CT表现恢复止常。6、12、18个月时CT主要征象：（1）磨玻璃样病变残留率分别为33．3％（37／111）、24．3％（27／111）、20．7％（23／111）。（2）小叶间隔或小叶内间质增厚残留率分别为37．8％（42／111）、28．8％（32／111）、25．2％（28／111）。以上2种主要病变在随访期内的总体变化经对比分析X^2检验，差异有统计学意义（P〈0．01）。（3）胸膜下弧线影15例，随访期内病变有不同程度的吸收，但无一例病变消失。（4）不规则纤维条索影18个月时残留率17．1％（19／111）。少见征象：（1）实变病灶1例，病程第12个月完全吸收。（2）空洞病灶2例，1例于病程第12个月基本吸收，1例随访期内末完全吸收。（3）牵拉性支气管扩张1例，随访期内无明显变化。（4）小结节灶3例，1例病程第12个月基本吸收，2例无明显变化。结论 病程第18个月SARS患者肺内磨玻璃样病变残留率为20．7％。17．1％的患者残留局限性肺间质纤维化改变。对肺内残留磨玻璃样病变的患者继续定期随访间隔6～12个月为宜，其他患者可以延长随访间隔时间至12个月以上。     

严重急性呼吸综合征的影像学表现

目的 :分析严重急性呼吸综合征 (SARS)的X线及CT表现。方法 :回顾性分析 110例SARS患者的影像学表现。所有病例均有较完整的胸片资料 ,其中 5例同时进行了CT检查。结果 :SARS的影像学表现形式多样 ,主要表现为肺实质渗出性病变和肺间质渗出性病变两大类型。根据病变早期表现及进展情况 ,将其分为 5型 :①单纯局限型 3 4例 ,早期为肺内单一局限病灶 ,其后病变扩大或无明显增大 ;②局限 广泛型 2 0例 ,早期为肺内单一局限病灶迅速发展为病灶广泛分布 ;③多发型 2 8例 :早期即见肺内多发片状和 /或结节状病灶 ;④间质 实质型 2 2例 :早期为肺部间质性渗出 ,其后出现肺实质渗出性病变 ;⑤单纯间质型 6例 ,主要表现为肺间质渗出性病变。结论 :X线检查是发现SARS的最基本的影像学检查方法 ,CT能更好地显示病变。在SARS的诊治过程中 ,了解该病的影像学分型和分期有助于判断病情 ,指导治疗 ,估计预后。     

Prognostic significance of the radiographic pattern of disease in patients with severe acute respiratory syndrome

OBJECTIVE: This study was performed to evaluate the prognostic significance of the radiographic pattern of disease in probable cases of severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: A retrospective review of 439 radiographs was performed for 51 patients with a final diagnosis of probable SARS. Forty-nine patients were followed up for a mean interval of 23 days (range, 2-63 days). RESULTS: Abnormal findings on a chest radiograph were noted at presentation in 80.4% (41/51) of patients. Four radiographic patterns were seen: normal (group 1) in 19.6% (10/51), focal opacity (group 2) in 39.2% (20/51), multifocal opacities (group 3) in 27.5% (14/51), and diffuse air-space opacification (group 4) in 13.7% (7/51). Radiographic progression of disease occurred in 38.8% (19/49) of the patients in groups 1-4. There were no deaths in groups 1 and 2. In group 3, one (7.7%) of the 13 patients died. Five (71.4%) of the seven patients in group 4 died. Overall, 12.2% (6/49) of the patients died, all of whom had diffuse air-space opacification on the last chest radiograph. In these patients, medical comorbidity was present in 66.7% (4/6), and the exposure history was known in 83.3% (5/6). Death occurred at a mean interval of 18.2 days (range, 9-36 days) from the initial exposure. CONCLUSION: Patients presenting with normal findings or focal air-space opacity on chest radiographs had a good clinical outcome. Patients with multifocal opacities that progressed to diffuse air-space opacification and patients presenting with diffuse air-space opacification had a high fatality rate, but patients in this group were also older and more likely to have comorbid conditions. Patients with SARS present with recognizable patterns of disease that have prognostic significance.     

SARS的CT表现及动态变化

目的 探讨严重急性呼吸综合征的CT表现及动态变化。方法 对60例严重急性呼吸综合征患者进行X线胸片(已有另文报道)和高分辨率CT(HRCT）的动态观察。患者在入院时及入院后连续进行CT观察检查，间隔4～6d。结果 发病初期进行影像检查者25例，CT表现为小片状影像者22例，占88.0％(22／25)；其中类圆形磨玻璃样影20例，占80．0％(20／25)。其余35例在进行影像检查时已发病3d，病变已经有所进展。3d后患者肺部均出现多发大片状影像，其中呈单一磨玻璃样影者10例，占16.7％(10／60)；磨玻璃样影合并实变影者4：5例，占75．0％(45／60)；主要呈肺实变影者5例，占8.3％(5／60)。入院10～14d内病变明显进展者50例，占83.3％(50／60)；病变范围减少者10例，占16．7％(10／60)；合并肺间质增生者4例，占6．7％。结论 HRCT可清楚反映SARS病变的密度、形态和范围，以及显示肺间质增生改变。因而，HRCT可以用于早期诊断和了解病变的动态变化。     

Late-stage adult respiratory distress syndrome caused by severe acute respiratory syndrome: abnormal findings at thin-section CT

PURPOSE: To evaluate thin-section computed tomographic (CT) abnormalities in patients in the intensive care unit during the late stage of adult respiratory distress syndrome (ARDS) caused by severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: Eight patients in the late stage of ARDS (ie, more than 2 weeks after onset) were imaged with thin-section CT. Images were evaluated for ground-glass opacification, consolidation, interstitial thickening, evidence of fibrosis, and any other abnormalities. Patient records were reviewed, and relevant respiratory and ventilatory parameters, total steroid dose, and outcome were recorded. RESULTS: All patients received high-dose pulse methylprednisolone (minimum, 2.5 g total), and all patients who received ventilation received low-pressure, low-volume ventilation. Five patients received prolonged mechanical ventilation (for more than 14 days), one received ventilation for 72 hours, and two patients did not receive ventilation. Three patients died, four were discharged from the hospital, and one continued to require ventilation. Ground-glass opacification and interstitial thickening were present at CT in all eight patients. Consolidation was present in six patients. Three patients had evidence of fibrosis. Patients who received long-term ventilation, those who received short-term ventilation, and those who did not receive ventilation had similar pulmonary changes at CT. Pulmonary cysts, most of which were small (<1 cm), were present in five patients. Cysts were present in one patient who received only short-term low-pressure and low-volume ventilation and in one patient who received no mechanical ventilation. CONCLUSION: The CT features of late-stage ARDS caused by SARS are similar to those seen in late-stage ARDS of other causes, with no apparent differences between patients who do and patients who do not receive prolonged mechanical ventilation. The presence of cysts in one patient who received short-term and one patient who received no mechanical ventilation suggests that severe SARS-induced ARDS may independently result in cyst formation.     

Providing optimal radiology service in the severe acute respiratory syndrome outbreak: use of mobile CT

OBJECTIVE: Severe acute respiratory syndrome (SARS) is a serious atypical pneumonia caused by a novel pathogen. We describe our experience using a mobile CT scanner in an improvised isolation ward with life-support systems, portable lead shielding, and strict barrier nursing. This scanner was used exclusively for patients with SARS and patients with other illnesses who were also thought to have SARS. This arrangement freed the other CT scanners in the main department for non-SARS patients. In 5 weeks, 90 studies were performed; no cases of cross infection of health care workers were reported. CONCLUSION: Mobile CT may be used to provide dedicated radiology services to seriously ill patients requiring strict isolation during an infectious disease outbreak.     

Thin-section CT findings of patients with acute Streptococcus pneumoniae pneumonia with and without concurrent infection

Objectives

The aim of this study was to compare the pulmonary thin-section CT findings of patients with acute Streptococcus pneumoniae pneumonia with and without concurrent infection.

Methods

The study group comprised 86 patients with acute S. pneumoniae pneumonia, 36 patients with S. pneumoniae pneumonia combined with Haemophilus influenzae infection, 26 patients with S. pneumoniae pneumonia combined with Pseudomonas aeruginosa infection and 22 patients with S. pneumoniae pneumonia combined with methicillin-susceptible Staphylococcus aureus (MSSA) infection. We compared the thin-section CT findings among the groups.

Results

Centrilobular nodules and bronchial wall thickening were significantly more frequent in patients with pneumonia caused by concurrent infection (H. influenzae: p<0.001 and p<0.001, P. aeruginosa: p<0.001 and p<0.001, MSSA: p<0.001 and p<0.001, respectively) than in those infected with S. pneumoniae alone. Cavity and bilateral pleural effusions were significantly more frequent in cases of S. pneumoniae pneumonia with concurrent P. aeruginosa infection than in cases of S. pneumoniae pneumonia alone (p<0.001 and p<0.001, respectively) or with concurrent H. influenzae (p<0.05 and p<0.001, respectively) or MSSA infection (p<0.05 and p<0.05, respectively).

Conclusions

When a patient with S. pneumoniae pneumonia has centrilobular nodules, bronchial wall thickening, cavity or bilateral pleural effusions on CT images, concurrent infection should be considered.Streptococcus pneumoniae has long been recognised as the most common cause of community-acquired pneumonia (CAP) and is responsible for the increasing frequency of nosocomial pneumonia [1-3]. The mortality associated with pneumonia is linked to inadequate initial antibiotic therapy; therefore, early detection of S. pneumoniae pneumonia is important for reducing morbidity and mortality.A rapid immunochromatographic membrane test was developed for the detection of S. pneumoniae antigens in urine samples [4]. It is a useful technique for the rapid diagnosis of pneumococcal pneumonia; however, the urinary antigens cannot be detected a few days after S. pneumoniae infection, and this test is unable to detect concurrent pathogen infections.Most cases of CAP are probably caused by a single pathogen, but dual or multiple infections have been increasingly reported in the literature [5-8]. There is growing concern for the concurrent presence of a second pathogen in a significant proportion of cases of CAP previously thought to be monomicrobial [5,7-10]. De Roux et al [8] reported that in 82 patients with mixed CAP, S. pneumoniae was the most prevalent microorganism (n=44), that the most frequent combination of organisms was S. pneumoniae with Haemophilus influenzae (n=17) and that patients with mixed pyogenic pneumonia more frequently developed shock than patients with single pyogenic pneumonia.The classic chest radiographic appearances of pneumococcal pneumonia have been described as sublobar, lobar or multilobar opacities, often homogeneous with an air bronchogram [11-13]. As for CT findings, a few studies have been reported in patients with S. pneumoniae pneumonia; Miyashita et al [14] reported CT findings in 68 patients with S. pneumoniae pneumonia who were not infected with any other microorganisms.However, to the best of our knowledge, no studies have been published that compare CT findings in patients with S. pneumoniae pneumonia alone with those displaying concurrent pneumonia caused by S. pneumoniae and another pathogen. The present study therefore compared the pulmonary thin-section CT findings of patients with acute S. pneumoniae pneumonia alone with those of patients with concurrent S. pneumoniae pneumonia.     

High-resolution CT findings of severe acute respiratory syndrome at presentation and after admission

OBJECTIVE: The aim of this study was to assess the high-resolution CT (HRCT) findings at presentation and after hospital admission in patients with severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: We reviewed the HRCT findings at presentation (n = 12) and after hospital admission (n = 25) of 29 patients with SARS and compared the HRCT findings with the radiographic findings. HRCT scans were obtained using 1-mm (n = 28) or 2-mm (n = 1) collimation. The radiographs and HRCT scans were reviewed independently by two observers who reached a decision by consensus. RESULTS: All patients had abnormal findings on HRCT at presentation. Eight of these 12 patients had normal findings on radiographs. The predominant HRCT findings at presentation consisted of unilateral (n = 6) or bilateral (n = 2) ground-glass opacities or focal unilateral (n = 2) or bilateral (n = 2) areas of consolidation. All patients showed progression of disease on follow-up. The predominant HRCT findings on follow-up CT scans consisted of unilateral (n = 2) or bilateral ground-glass opacities (n = 13), unilateral (n = 2) or bilateral consolidation (n = 5), or a mixed bilateral pattern of ground-glass attenuation, consolidation, and reticulation (n = 3). Reticulation with associated architectural distortion and mild traction bronchiectasis was present in eight patients. CONCLUSION: HRCT can show parenchymal abnormalities in patients with SARS who have normal findings on radiographs at presentation. Follow-up CT scans obtained in hospitalized patients show findings consistent with fibrosis in a small percentage of patients.     

重症急性胰腺炎合并急性呼吸窘迫综合征36例临床分析

目的:探讨急性重症胰腺炎并发ARDS综合治疗效果及其意义。方法:对2000-10~2006-10我院收治的重症胰腺炎合并ARDS 36例患者的临床资料进行回顾性分析。结果:I组给予常规治疗基础上行人工呼吸机辅助通气,死亡8例,死亡率47.06%(8/17)。Ⅱ组在常规治疗基础上,尽快应用呼吸机纠正缺氧,强调"最佳"呼气末正压(PEEP),低平台压,适当潮气量,所谓"保护性肺通气"。在Ⅱ组中我们对胆总管下端有梗阻征象的病人(10例)行ERCP及EST术;治愈14例,死亡5例,死亡率26.32%(5/19)。结论:对重症急性胰腺炎合并ARDS综合治疗技术的应用,提高了急性重症胰腺炎并发ARDS的抢救成功率。     

严重急性呼吸综合征糖皮质激素治疗后膝关节骨坏死的MRI评价

目的分析严重急性呼吸综合征（SARS）糖皮质激素治疗后膝关节骨缺血性坏死的发生和MRI特点。方法4所医院感染SARS并经糖皮质激素治疗的医护人员共18例，均行双侧膝关节和双髋关节MR检查，确定骨坏死发生与否、病变特点及其与糖皮质激素用量的关系。结果18例中，11例出现膝关节骨坏死，3例合并双侧髋关节股骨头坏死。7例为双侧膝关节骨坏死，4例为单侧。膝关节骨坏死病灶共计38个，34个位于股骨内、外侧髁以及相邻的股骨干，4个位于胫骨内或外侧髁。膝关节骨坏死的大、中病灶多为不规则形，周边呈细带状低信号，其中4个在T2WI上可见“双边征”；坏死灶内T1WI多为等或稍低信号，T2WI多为高、等或混杂信号。小病灶在T1WI上为低信号，T2WI上多为低或高信号。髋关节股骨头坏死灶位于其中上部、软骨下，呈类椭圆形异常信号，病灶内T1WI为等信号，TW2I为高或混杂信号；周边有不规则低信号带，其中1例双侧病灶T2WI上可见“双边征”。结论该组SARS病例糖皮质激素治疗后骨缺血性坏死以膝关节为多，对这类病人应注意早期行膝关节MR检查。膝关节坏死以股骨内、外侧髁和相邻的股骨干最多见，胫骨内外、侧髁亦可发生。骨缺血性坏死的发生及严重程度与静脉糖皮质激素用量有关。     

严重急性呼吸综合征无创通气胸部CT影像变化的研究

目的探讨严重急性呼吸综合征（SARS）患者使用无创通气后对胸部CT影像变化的影响及临床意义。方法回顾性分析18例SARS患者使用无创通气前及使用后（4～12d）胸部CT影像变化，并做远期（3～36个月）胸部CT随访。设未使用无创通气SARS患者27例为对照组。结果（1）使用无创通气18例患者中15例出现特殊CT表现：7例肺内实性病灶密度减低呈磨玻璃密度灶；5例肺下叶支气管血管束周围环形肺气肿；8例出现胸膜下肺气肿；2例出现纵隔气肿及气胸。远期随访（36个月）观察，2例患者残留胸膜下弧形线状影但有吸收。（2）对照组27例治疗过程中未出现上述CT表现。结论使用无创通气对SARS患者胸部CT影像表现产生影响，全面认识SARS影像动态变化有利于合理使用无创通气治疗相关性肺炎。     

Musculoskeletal complications of severe acute respiratory syndrome

The severe acute respiratory syndrome (SARS) was a highly infectious pneumonia that emerged in southern China early in 2003. A large number of SARS patients experienced large joint arthralgia, although this was, for the most part, not associated with any abnormality on magnetic resonance imaging. The main musculoskeletal complications of SARS were osteonecrosis and reduced bone mass, and these arose not from the disease per se but as a sequel to treatment of SARS with high-dose steroids. SARS patients were almost universally steroid naive with no other known predisposition to osteonecrosis. Prevalence of osteonecrosis in SARS patients treated with steroids ranged from 5% to 58%. Osteonecrosis most commonly affected the proximal femur and femoral condyles and was most strongly related to cumulative steroid dose and duration of steroid therapy. Osteonecrosis risk was <1% in patients receiving <3 g and 13% in patients receiving >3 g cumulative prednisolone-equivalent dose. Most osteonecrotic lesions tended to improve with a reduction in lesion volume over a follow-up period of 5 years. The relative reduction in osteonecrotic lesion volume was greatest for smaller lesions.     

Osteonecrosis of hip and knee in patients with severe acute respiratory syndrome treated with steroids

PURPOSE: To evaluate whether there is a relationship between steroid treatment and risk for osteonecrosis of the hip and knee in patients with severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: The hospital ethics committee approved the study, and all patients provided written informed consent. A total of 254 patients with confirmed SARS treated with steroids underwent evaluation with magnetic resonance (MR) imaging for osteonecrosis. Clinical profiles, joint symptoms, relevant past medical and drug history, steroid dose, and radiographic and MR imaging evidence of osteonecrosis and other bone abnormalities were evaluated. Mann-Whitney, Kruskal-Wallis, and Pearson exact chi(2) tests were performed, and univariate and multivariate logistic regression analyses were applied. RESULTS: One hundred thirty-four (53%) of 254 patients had recent onset of large joint pain, but 211 (80%) of 264 painful joints were not associated with abnormality on MR images. MR images in 12 (5%) of 254 patients showed evidence of subchondral osteonecrosis in the proximal femur (n = 9), distal femur (n = 2), and proximal and distal femora and proximal tibiae (n = 1). Additional nonspecific subchondral and intramedullary bone marrow abnormalities were present in 77 (30%) of 254 patients. Results of multiple logistic regression analysis confirmed cumulative prednisolone-equivalent dose to be the most important risk factor for osteonecrosis. The risk of osteonecrosis was 0.6% for patients receiving less than 3 g and 13% for patients receiving more than 3 g prednisolone-equivalent dose. No relationship was found between additional nonspecific bone marrow abnormalities and steroid dose. CONCLUSION: An appreciable dose-related risk was found for osteonecrosis in patients receiving steroid therapy for SARS. Additional nonspecific bone marrow abnormalities were frequent. Joint pain was common after SARS infection and was not a useful clinical indicator of osteonecrosis.