Carolina A. Souza

The radiological spectrum of pulmonary lymphoproliferative disease

Pulmonary lymphoproliferative disorders (LPD) are characterised by abnormal proliferation of indigenous cell lines or infiltration of lung parenchyma by lymphoid cells. They encompass a wide spectrum of focal or diffuse abnormalities, which may be classified as reactive or neoplastic on the basis of cellular morphology and clonality. The spectrum of reactive disorders results primarily from antigenic stimulation of bronchial mucosa-associated lymphoid tissue (MALT) and comprises three main entities: follicular bronchiolitis, lymphoid interstitial pneumonia and (more rarely) nodular lymphoid hyperplasia. Primary parenchymal neoplasms are most commonly extranodal marginal zone lymphomas of MALT origin (MALT lymphomas), followed by diffuse large B-cell lymphomas (DLBCLs) and lymphomatoid granulomatosis (LYG). Secondary lymphomatous parenchymal neoplasms (both Hodgkin and non-Hodgkin lymphomas) are far more prevalent than primary neoplasms. Acquired immune deficiency syndrome (AIDS)-related lymphoma (ARL) and post-transplantation lymphoproliferative disorder (PTLD) may also primarily affect the lung parenchyma. Modern advances in treatments for AIDS and transplant medicine are associated with an increase in the incidence of LPD and have heightened the need to understand the range of imaging appearance of these diseases. The multidetector CT (MDCT) findings of LPD are heterogeneous, thereby reflecting the wide spectrum of clinical manifestations of these entities. Understanding the spectrum of LPD and the various imaging manifestations is crucial because the radiologist is often the first one to suggest the diagnosis and has a pivotal role in differentiating these diseases. The current concepts of LPD are discussed together with a demonstration of the breadth of MDCT patterns within this disease spectrum.

Reversed Halo Sign: High-Resolution CT Scan Findings in 79 Patients

BACKGROUND The purpose of this study was to evaluate the high-resolution CT (HRCT) scan findings of patients with the reversed halo sign (RHS) and to identify distinguishing features among the various causes. METHODS Two chest radiologists reviewed the HRCT scans of 79 patients with RHS and determined the CT scan findings by consensus. We studied the morphologic characteristics, number of lesions, and presence of features associated with RHS. RESULTS Forty-one patients presented with infectious diseases (paracoccidioidomycosis, TB, zygomycosis, invasive pulmonary aspergillosis, Pneumocystis jiroveci pneumonia, histoplasmosis, cryptococcosis), and 38 presented with noninfectious diseases (cryptogenic organizing pneumonia, pulmonary embolism, sarcoidosis, edema, lepidic predominant adenocarcinoma [formerly bronchiolo-alveolar carcinoma], granulomatosis with polyangiitis [Wegener]). The RHS walls were smooth in 58 patients (73.4%) and nodular in 21 patients (26.6%). Lesions were multiple in 40 patients (50.6%) and single in 39 patients (49.4%). CONCLUSION The presence of nodular walls or nodules inside the halo of the RHS is highly suggestive of granulomatous diseases.

Conventional High-Resolution CT Versus Helical High-Resolution MDCT in the Detection of Bronchiectasis

OBJECTIVE The purpose of this study was to compare conventional high-resolution CT (HRCT) with helical 16-MDCT in the detection of bronchiectasis. MATERIALS AND METHODS We retrospectively evaluated 80 patients including 61 with bronchiectasis (mean age, 64 years; range, 22-87 years) and a control group of 19 patients with normal MDCT of the chest. Two sets of images were blindly, randomly analyzed by two observers: contiguous 1-mm slices (MDCT set) and 1-mm slices every 10 mm (HRCT set) derived from the MDCT set. Images were scored independently for presence, extent, and severity of bronchiectasis, followed by a consensus interpretation. Kappa analysis assessed inter- and intraobserver agreement. MDCT was the radiologic gold standard. RESULTS Of the 61 patients with bronchiectasis diagnosed with MDCT, 56 (92%) were positive for bronchiectasis on conventional HRCT. Seven patients had positive MDCT scans only, and two patients had positive HRCT scans only. Of 479 lobes, 59 were positive for bronchiectasis on MDCT and negative on HRCT, and 19 lobes were positive for bronchiectasis on HRCT and negative on MDCT (p < 0.0001). MDCT showed 25 more lobes with cylindric, 11 more lobes with varicose, and four more lobes with cystic bronchiectasis than did HRCT. Sensitivity, specificity, and positive and negative predictive values of HRCT in detecting bronchiectasis were 71%, 93%, 88%, and 81%, respectively. Interobserver agreement for presence, extent, and severity of bronchiectasis ranged from moderate to good for MDCT (kappa values, 0.64, 0.5, and 0.48, respectively) and poor to good for HRCT (kappa values, 0.65, 0.46, and 0.25, respectively). CONCLUSION Contiguous helical 16-MDCT with 1-mm collimation is superior to HRCT at 10-mm intervals in showing the presence and extent of bronchiectasis.

High-resolution MDCT of pulmonary septic embolism: evaluation of the feeding vessel sign.

OBJECTIVE The objective of this study was to use high-resolution MDCT to assess the relation of the pulmonary vasculature to septic emboli with particular attention to the feeding vessel sign. MATERIALS AND METHODS The MDCT scans of nine patients with septic emboli were retrospectively, blindly evaluated by two observers. A control group of 10 patients with documented pulmonary metastasis and pathologically proven carcinoma also were included. Transverse images, multiplanar reconstructions, and maximum intensity projections were used to analyze nodules and the pulmonary vasculature. The CT scans were obtained with 1- to 1.25-mm collimation on a 4-, 8-, or 16-MDCT scanner. The feeding vessel sign was defined as a vessel coursing directly into a nodule. RESULTS The patients with septic embolism had a total of 141 nodules and 52 wedge-shaped opacities. Transverse images showed that 52 (37%) of the nodules and 11 (22%) of the wedge-shaped opacities had a vessel that appeared to enter the nodule, but multiplanar reconstructions (without IV contrast enhancement) and maximum intensity projections (with IV contrast enhancement) showed the vessels passed around the nodules. Twenty-one (15%) of the spherical nodules and seven (13%) of the wedge-shaped opacities exhibited a central vessel entering the lesion in all imaging planes. All of these vessels were traced to the left atrium on transverse images, a finding consistent with pulmonary vein branches. Similar findings were seen in pulmonary metastatic lesions. CONCLUSION Although pulmonary septic emboli often appear to have a feeding vessel on conventional cross-sectional images, multiplanar reconstructions show that most of these vessels course around the nodule and that the others are pulmonary veins.

Systemic arterial air embolism after percutaneous lung biopsy.

Systemic arterial air embolism is a rarely encountered but much feared complication of percutaneous lung biopsy. We present a comprehensive review of iatrogenic air embolism post-lung biopsy, a complication that is often suboptimally managed. This review was inspired by our own institutional experience and we use this to demonstrate that excellent outcomes from this complication can be seen with prompt treatment using hyperbaric oxygen chamber therapy, after initial patient stabilization has been achieved. Pathophysiology, clinical features, and risk factors are reviewed and misconceptions regards venous versus arterial air embolism are examined. An algorithm is provided for radiologists to ensure suspected patients are appropriately managed with more favourable outcomes.

Silicoproteinosis: High-Resolution CT Findings in 13 Patients

OBJECTIVE The purpose of this study was to evaluate the high-resolution CT findings of silicoproteinosis. CONCLUSION Silicoproteinosis usually manifests as bilateral consolidation in the posterior portions of the lungs and as numerous centrilobular nodules. Calcification within areas of consolidation is a common finding.

Birt-Hogg-Dubé syndrome: a rare cause of pulmonary cysts.

2Department of Surgery, Vancouver General Hospital and University of British Columbia, Vancouver, BC, V5Z 1M9 Canada. irt-Hogg-Dube syndrome is a rare autosomal-dominant inherited disorder characterized by the presence of firm facial papules that on biopsy are shown to represent fibrofolliculomas [1–3]. Patients with Birt-HoggDube syndrome have a high predisposition to malignant renal tumors, which are often bilateral and multifocal [2–4]. Several studies have shown that the prevalence of bullous emphysema, thin-walled cysts, and spontaneous pneumothorax is increased in these patients [2, 3, 5]. The description of the pulmonary complications has been limited to radiographs and published in the dermatologic literature [2, 3, 5]. We report the radiographic and high-resolution CT findings in a 54-year-old woman with Birt-Hogg-Dube syndrome and history of renal cell carcinoma. The pulmonary abnormalities consisted of multiple thin-walled cysts measuring 1–5.5 cm in diameter and involving mainly the lower lobes.

Ultrathin Fine-Needle Aspiration Biopsy of the Lung with Transfissural Approach: Does It Increase the Risk of Pneumothorax?

OBJECTIVE Transthoracic fine-needle aspiration is an accurate and safe method for diagnosis of pulmonary lesions, and pneumothorax is the most frequent complication of the procedure. Crossing a lung fissure during biopsy has been thought to increase the risk of pneumothorax, and the need to cross a fissure is considered a relative contraindication. The purpose of this study was to assess the incidence and clinical significance of pneumothorax during needle aspiration biopsy performed with a transfissural approach in comparison with biopsies in which a fissure was not crossed. MATERIALS AND METHODS Retrospective review of the medical records of patients who underwent fluoroscopically guided transthoracic biopsy of pulmonary nodules with a 25-gauge needle yielded the cases of 107 consecutively registered patients (59 men, 48 women; mean age, 62 years). In 43 of the biopsies, the major fissure was crossed, and in 64 biopsies, the control procedures, the fissure was avoided. CT scans were assessed for lesion size and location, biopsy approach, length of needle path, number of needle punctures, and presence of emphysema. RESULTS Pneumothorax occurred in 11 patients (25%) in the transfissural biopsy group and in 19 patients (30%) in the group in which the fissure was avoided (p = 0.64). Pneumothorax necessitated chest tube placement in two patients (5%) in the transfissural biopsy group and seven patients (11%) in the control group (p = 0.25). In both groups, emphysema in the needle path was associated with increased risk of pneumothorax (p < 0.01). CONCLUSION Transthoracic needle biopsy with an ultrathin needle that crosses a lung fissure can be safely performed without increasing the rate of pneumothorax or the need for chest tube insertion.

Comparative study of clinical, pathological and HRCT findings of primary alveolar proteinosis and silicoproteinosis

OBJECTIVE To compare the clinical, high-resolution computed tomography (HRCT) and pathological findings of primary alveolar proteinosis (PAP) and silicoproteinosis. MATERIAL AND METHODS The study included 15 patients with PAP (6 women, 9 men, mean age 31 years) and 13 with silicoproteinosis (13 men, mean age 29.5 years). PAP was diagnosed by lung biopsy in 13 and bronchoalveolar lavage in two patients and silicoproteinosis by bronchoalveolar lavage in 10 and autopsy in three cases. HRCT images were reviewed by two chest radiologists with consensus for the presence, extent and distribution of ground-glass opacities, septal thickening, consolidation and nodules. Radiological-pathological correlation was performed by one radiologist and one chest pathologist. RESULTS Seven (46%) patients with PAP were asymptomatic; the remainder presented slowly progressive dyspnea and dry cough. All silicoproteinosis patients had dry cough and rapidly progressive dyspnea. The most common HRCT finding on PAP was the crazy-paving pattern (93%). All cases had areas of geographic sparing in the affected lung. The most common finding in silicoproteinosis (92%) was dependent consolidation with calcification in 83%. Centrilobular nodules were common (85%). On pathology, both diseases demonstrated intra-alveolar accumulation of PAS material, thickening of interlobular septae and alveolar walls and no evidence of fibrosis. A few silica particles were seen in silicoproteinosis. CONCLUSION Despite the pathological similarities, PAP and silicoproteinosis have distinct clinical and imaging features and prognosis. Bilateral crazy-paving pattern with areas of geographic sparing is characteristic for PAP. Silicoproteinosis presents with bilateral dependent consolidation often with areas of calcification. The crazy-paving pattern is not seen in silicoproteinosis.

Pulmonary Complications of Illicit Drug Use Differential Diagnosis Based on CT Findings

Objective The aim of this manuscript is to summarize an approach to the differential diagnosis of the pulmonary complications of illicit drug use based on the computed tomography findings. Conclusions The various pulmonary complications of illicit drug use result in 5 main patterns of parenchymal abnormality: nodules, ground-glass opacities, consolidation, air trapping, and emphysema. Other thoracic manifestations of illicit drug use include pulmonary arterial hypertension, pneumomediastinum, bacterial endocarditis, discitis, and septic arthritis.