Accuracy of chest high-resolution computed tomography in diagnosing diffuse cystic lung diseases

Abstract

Accuracy of chest high-resolution computed tomography in diagnosing diffuse cystic lung diseasesTo the Editor:The diffuse cystic lung diseases (DCLDs) are a group of pathophysiologically heterogeneous processes characterised by the presence of multiple, thin-walled, air-filled spaces within the pulmonary parenchyma [1]. The differential diagnosis of DCLDs includes lymphangioleiomyomatosis (LAM), follicular bronchiolitis (FB), lymphocytic interstitial pneumonia (LIP), Birt-Hogg-Dubé syndrome (BHD), pulmonary Langerhans cell histiocytosis (PLCH), amyloidosis, light chain deposition disease, cystic metastases, infectious entities such as Pneumocystis, and other aetiologies [2]. Bronchiectasis and bullous changes seen in chronic obstructive pulmonary disease can also produce high-resolution computed tomography (HRCT) patterns that mimic the DCLDs.The utility of HRCT in the diagnosis of LAM and differentiation from other DCLDs is not completely defined. According to the European Respiratory Society (ERS) guidelines, characteristic HRCT features along with a compatible clinical history are sufficient to confidently diagnose LAM, without the need for a tissue biopsy [3]. However, previously reported accuracy rates for diagnosing LAM based on HRCT findings may not be sufficient in an era when interventions with substantial risks are becoming available. Two prior studies have reported accuracy rates of 72-84% in diagnosing LAM based on imaging characteristics alone [4,5]. The aim of our study was to determine the diagnostic accuracy of HRCT evaluation by radiologists and pulmonologists, at various levels of expertise, in patients with DCLDs presenting to referral centres.We retrospectively obtained HRCTs from 89 patients referred to LAM Foundation Clinics at the University of Cincinnati (Cincinnati, OH, USA), Mayo Clinic Rochester ( Rochester, MN, USA) and National Kinki-Chou Hospital (Osaka, Japan) for further evaluation of DCLDs. All scans were non-contrast HRCTs and only thin section (1-3 mm) images were employed in the analysis. Patient 1196 identifiers were removed and the digital image files and a DICOM viewer (Santesoft, Athens, Greece), with full scrolling and magnification capabilities, were distributed to all reviewers. When necessary, abdominal cuts of the HRCT were removed to ensure that pathognomonic abdominal features, such as the presence of angiomyolipomas, would not influence the interpretation. The scans were analysed by three expert thoracic radiologists, and 12 pulmonary physicians with varying levels of expertise, subclassified as DCLD expert pulmonologists (n=5), general pulmonologists (n=4) and pulmonary fellows (n=3).Observers were asked to record the most likely diagnosis and degree of confidence (confident or not confident). Observers were blind to all clinical or pathological data. Images used for analysis were exclusively derived from patients with definite diagnoses established by biopsy, genetic testing or professional society guidelines. The results were used to calculate sensitivity and sp...

Pulmonary manifestations in tuberous sclerosis complex

“…Characteristic LAM cysts on HRCT are thin-walled, round, uniform, and are present bilaterally in a diffuse distribution (Figure 1) (N. Gupta, Meraj, et al, 2015; Johnson et al, 2010).…”

Spontaneous pneumothorax in diffuse cystic lung diseases

“…HRCT in LAM reveals the presence of multiple, bilateral, uniform, thin-walled cysts devoid of septations or internal structures, present in a diffuse distribution with normal-appearing intervening lung parenchyma (Figure 1) (8). The diagnosis of LAM can be made in a non-invasive manner if one of the following is present in addition to characteristic HRCT features: 1) presence of TSC, 2) angiomyolipomas, or lymphangioleiomyomas on abdominal imaging, 3) chylous effusions, or 4) elevated serum vascular endothelial growth factor-D, greater than 800pg/ml (9, 10).…”

Chest Computed Tomographic Image Screening for Cystic Lung Diseases in Patients with Spontaneous Pneumothorax Is Cost Effective

“…radiologists can accurately diagnose LAM in 72-91% of cases on the basis of HRCT features alone (9,20,21).…”

“…An expert radiologist can accurately diagnose PLCH, LAM, and BHD in 74, 91, and 93% of cases, respectively, on the basis of HRCT analysis alone (9). Routine CT chest imaging is not currently recommended in patients presenting with a primary spontaneous pneumothorax, however (4).…”