[Round atelectasis]

Rounded atelectasis of the lung

Rounded atelectasis of the lung (RA) is a lesion well described in the medical literature, yet often very difficult to diagnose. In recent years, the widespread use of high-resolution imaging modalities employed in the struggle against cancer, coinciding with the peak of the asbestos epidemic, have boosted the detection frequency of RA. However, its differential diagnosis still poses a challenge to the pulmonary specialist and the radiologist, as little is known about its pathogenesis. Furthermore, the multifactorial etiology of RA and its occasional coexistence with lung cancer make the task of confidently ruling out malignancy sometimes daunting. This article attempts to provide an update on RA's etiology, radiological evaluation, clinical management, and prognosis based on recent advances in broadly available diagnostic modalities and minimally invasive interventional procedures. An exemplary case of post-tuberculous RA is illustrated, as RA often presents as an unusual finding of a fairly common disease.

Dynamic magnetic resonance imaging of solitary pulmonary nodules: utility of kinetic patterns in differential diagnosis

OBJECTIVE

The aim of this study was to evaluate the clinical feasibility of dynamic magnetic resonance (MR) imaging with a 3-dimensional (3D) gradient recalled echo (GRE) volumetric interpolated breath-hold examination (VIBE) sequence to differentiate between benign and malignant solitary pulmonary nodules (SPNs).

METHODS

Dynamic 3D GRE VIBE was performed in 45 patients with SPNs. For each lesion, the morphologic parameters, including the edge configuration, presence of peripheral enhancement (PE), and an internal signal on T2-weighted images, and the kinetic enhancement parameters were evaluated.

RESULTS

All 29 of the malignant SPNs had internal enhancement, whereas 13 (81%) of the benign SPNs did not exhibit internal enhancement. A washout pattern was only observed in the malignant SPNs. The presence of PE was found in 56% of the benign SPNs and in 50% of the malignant SPNs. The lesion size was significantly different between malignant SPNs with PE and those without PE (P <0.01). The positive predictive value for malignancy was 91% (29 of 32 malignant SPNs). The negative predictive value was 100% (13 of 13 benign SPNs).

CONCLUSIONS

A combination of morphologic criteria and kinetic information is useful for differentiating between benign and malignant SPNs. In particular, internal enhancement with PE and positive visual washout is thought be a useful tool.

[Lung rounded atelectasis. A benign lesion due to asbestos]

BACKGROUND AND OBJECTIVE

Rounded atelectasis (RA) is an unusual form of pulmonary lesion often confounded with pulmonary neoplasia. We studied the main diagnostic and evolutive characteristics of a series of patients diagnosed with RA.

PATIENTS AND METHOD

Twenty patients diagnosed of RA in a tertiary hospital in Catalonia were included in the study. The diagnostic criterion of RA was strictly based on thoracic CT. Clinical data and pulmonary function tests were also evaluated. Four teen patients underwent a long term follow-up.

RESULTS

Asbestos was the cause of RA in 13 cases (65%); 7 had previously had homolateral pleural effusion; 5 pulmonary tuberculosis and in 1 case RA appeared at the lung biopsy site. The most frequent localization was inferior lobes and left side (70%). Eighteen patients had a ventilatory disorder: 10 restrictive, 6 mixed and 2 obstructive. In no case, RA evolved to malignancy.

CONCLUSIONS

RA is a benign lesion mainly due to asbestos showing well-defined morphological characteristics.