Fasano L, Zompatori M, Monetti N, Battista G, Pacilli A M, Scioscio V D i, Sciascia N
Istituto di Fisiopatologia Respiratoria, Policlinico S. Orsola-Malpighi, Bologna.
Radiol Med. 1999 Oct;98(4):268-74.
Three different grades of idiopathic pulmonary fibrosis can be identified by HRCT pattern. Patients with predominant ground-glass opacity (grade I) usually improve after treatment and may have a better prognosis. The subjects with a predominant reticular pattern and honeycombing (grade III) have irreversible fibrosis and usually do not improve after immunosuppressive therapy. Nevertheless, these patients may worsen even in the absence of HRCT features of the so-called alveolitis. We investigated the predictive role of some noninvasive imaging methods (HRCT with visual score of disease extent; Gallium scintigraphy; DTPA scintigraphy) in patients with idiopathic fibrosis and a prevalent macroscopic fibrosis at HRCT study.
Fourteen former smokers with grade III idiopathic fibrosis were examined. None of the patients had been treated. They were all submitted to HRCT, lung function studies, Gallium and DTPA scintigraphy, both at presentation (T0) and follow-up sessions (T1: mean one year post-diagnosis). The HRCT extent of disease was evaluated by means of the visual score as the fraction of the total lung volume. The patients were divided into two groups, using a cut-off value of 50%. All the patients underwent a Gallium scintiscan (using a fixation index of 160 as cut-off) and a ventilatory scintigraphy with DTPA-aerosol, with radionuclide clearance assessment. The lung function tests considered were vital capacity (VC), arterial blood oxygen partial pressure (PaO2) and the diffusing lung capacity for carbon monoxide (DLCO).
After one year of follow-up, the HRCT extent score increased (from 46.6% to 50%) and lung function worsened (VC from 66.8% to 63.4% of predicted; DLCO from 37.6% to 27.1%; PaO2 from 77 to 71 mmHg). The patients presenting with HRCT extension score > 50% had a worse lung function at T0 and showed a significant deterioration of PaO2 and HRCT at T1. On the other hand, VC and DLCO significantly worsened in the subjects with HRCT score < 50% at presentation. The patients with a Gallium fixation index > 160 significantly deteriorated in HRCT score, VC and DLCO. Those with Gallium index < 160 had major worsening only for diffusing lung capacity for carbon monoxide. Thirteen of 14 patients had an abnormal value of DTPA clearance at presentation. No variation was observed at T1.
The majority of patients with idiopathic fibrosis are grade III at presentation. They can further deteriorate both in HRCT extent of disease and lung function impairment. After one year of follow-up HRCT extent score increased in 64% of the patients, with a mean increase of 5%. HRCT worsening was more apparent in the patients with a HRCT score > 50% at presentation. In the remaining patients, the worsening of lung function tests was more apparent than the anatomoradiological changes. DTPA clearance had no predictive value in this series. Gallium scintigraphy was a useful prognostic index. The patients with Gallium fixation index > 160 had better lung function and lower HRCT extent score at T0 but significantly deteriorated at T1. A positive Gallium scan at presentation could be considered a useful index of persisting active "alveolitis" in patients with grade III disease, not visible at HRCT study, due to overwhelming fibrosis. These patients, who were untreated, exhibit quicker radiological and functional worsening.
通过高分辨率计算机断层扫描（HRCT）模式可识别出三种不同等级的特发性肺纤维化。以磨玻璃影为主（I级）的患者通常在治疗后病情改善，预后可能较好。以网状影和蜂窝状改变为主（III级）的患者存在不可逆性纤维化，免疫抑制治疗后通常无改善。然而，即使没有所谓肺泡炎的HRCT特征，这些患者的病情仍可能恶化。我们研究了一些非侵入性成像方法（具有疾病范围视觉评分的HRCT、镓闪烁扫描、二乙三胺五醋酸（DTPA）闪烁扫描）对特发性肺纤维化且HRCT检查显示存在明显宏观纤维化患者的预测作用。
对14名III级特发性纤维化的既往吸烟者进行检查。所有患者均未接受过治疗。在初诊时（T0）及随访期（T1：诊断后平均1年），所有患者均接受HRCT、肺功能检查、镓和DTPA闪烁扫描。通过视觉评分评估HRCT疾病范围，以其占全肺体积的比例表示。以50%为界值将患者分为两组。所有患者均接受镓闪烁扫描（以160的固定指数为界值）及DTPA气雾剂通气闪烁扫描，并评估放射性核素清除情况。所考虑的肺功能检查指标包括肺活量（VC）、动脉血氧分压（PaO2）和一氧化碳弥散量（DLCO）。
随访1年后，HRCT疾病范围评分增加（从46.6%增至50%），肺功能恶化（VC从预测值的66.8%降至63.4%；DLCO从37.6%降至27.1%；PaO2从77 mmHg降至71 mmHg）。初诊时HRCT扩展评分>50%的患者在T0时肺功能较差，且在T1时PaO2和HRCT显著恶化。另一方面，初诊时HRCT评分<50%的患者VC和DLCO显著恶化。镓固定指数>160的患者HRCT评分、VC和DLCO显著恶化。镓指数<160的患者仅一氧化碳弥散量有较大恶化。14名患者中有13名在初诊时DTPA清除值异常。T1时未观察到变化。
大多数特发性纤维化患者初诊时为III级。他们在HRCT疾病范围和肺功能损害方面可能进一步恶化。随访1年后，64%的患者HRCT疾病范围评分增加，平均增加5%。初诊时HRCT评分>50%的患者HRCT恶化更明显。在其余患者中，肺功能检查的恶化比解剖放射学改变更明显。在本系列研究中，DTPA清除无预测价值。镓闪烁扫描是一个有用的预后指标。镓固定指数>160的患者在T0时肺功能较好，HRCT疾病范围评分较低，但在T1时显著恶化。初诊时镓扫描阳性可被视为III级疾病患者存在持续活动性“肺泡炎”的有用指标，由于广泛纤维化，在HRCT检查中不可见。这些未接受治疗的患者放射学和功能恶化更快。
