Computed tomography findings, temporal course, and clinical relevance of subpleural pulmonary interstitial emphysema in patients with pneumomediastinum.

BACKGROUND: Subpleural pulmonary interstitial emphysema is defined as the air in the subpleural portion of the lung, and the clinical relevance is not well understood. PURPOSE: to evaluate the frequency, temporal course, risk factors, and clinical significance of subpleural pulmonary interstitial emphysema (PIE) in patients with pneumomediastinum resulting from ruptured alveoli and other causes. MATERIAL AND METHODS: This was a retrospective study of 130 patients with pneumomediastinum on CT between January 2009 and December 2019 at 2 hospitals. Patients were divided into 3 groups as follows: spontaneous pneumomediastinum (n = 101), pneumomediastinum due to blunt trauma (n = 16), and pneumomediastinum due to another known cause (n = 13). The frequencies of radiographic features (subpleural PIE, peribronchovascular PIE, pneumothorax, pulmonary fibrosis, and emphysematous changes) between the 3 groups were compared by the χ2 or Kruskal-Wallis test. Odds ratios were calculated to evaluate candidate risk factors for subpleural and peribronchovascular PIE. RESULTS: Subpleural PIE was observed in 0%, 15.8%, and 31.3% of patients with pneumomediastinum due to another cause, spontaneous mediastinum, and blunt trauma, respectively. In most patients, subpleural PIE resolved spontaneously (85.7% within 8 days). Two patients with pulmonary fibrosis showed recurrent subpleural PIE on follow-up. Young age showed increased risk for subpleural PIE (odds ratio [OR] 0.9, 95% confidence interval [CI] 0-0.99). CONCLUSION: Subpleural PIE was only detected in patients with pneumomediastinum due to ruptured alveoli and resolved spontaneously and rapidly. Subpleural PIE may be one route the air from ruptured alveoli to the mediastinum.

Spontaneous pneumomediastinum and Macklin effect: Overview and appearance on computed tomography.

Spontaneous pneumomediastinum (SPM) is described as free air or gas located within the mediastinum that is not associated with any noticeable cause such as chest trauma. SPM has been associated with many conditions and triggers, including bronchial asthma, diabetic ketoacidosis, forceful straining during exercise, inhalation of drugs, as well as other activities associated with the Valsalva maneuver. The Macklin effect appears on thoracic computed tomography (CT) as linear collections of air contiguous to the bronchovascular sheaths. With the recent availability of multidetector-row CT, the Macklin effect has been seen in the clinical setting more frequently than expected. The aim of this review article is to describe the CT imaging spectrum of the Macklin effect in patients with SPM, focusing on the common appearance of the Macklin effect, pneumorrhachis, and persistent SPM with pneumatocele.

CT scans of the chest in carriers of human T-cell lymphotropic virus type 1: presence of interstitial pneumonia.

RATIONALE AND OBJECTIVES: To evaluate pulmonary findings on computed tomography (CT) scans in carriers of human T-lymphotropic virus type 1 (HTLV-1). MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board at each institution, and informed consent was waived. Patients who were diagnosed with adult T-cell lymphoma/leukemia or collagen vascular disease were excluded from the study. Chest CT of 106 HTLV-1 carriers (54 females and 52 males; age range 44-94 years) were initially evaluated by two chest radiologists. Assessed CT findings included centrilobular nodules, thickening of bronchovascular bundles, ground-glass opacity, bronchiectasis, interlobular septal thickening, consolidation, honeycombing, crazy-paving appearance, enlarged lymph nodes, pleural effusion, and pericardial effusion. Three chest radiologists secondarily evaluated the CT scans with the abnormal findings to judge the presence of interstitial pneumonia patterns or a bronchiolitis/bronchitis pattern. RESULTS: Abnormal CT findings were found in 65 (61.3%) patients, including ground-glass opacity (n = 33), bronchiectasis (n = 28), centrilobular nodules (n = 25), and interlobular septal thickening (n = 19). Honeycombing (n = 5) and crazy-paving appearance (n = 3) were also observed. Based on the CT findings, 10 subjects were diagnosed with interstitial pneumonia (usual interstitial pneumonia pattern, n = 3; nonspecific interstitial pneumonia pattern, n = 5; organizing pneumonia pattern, n = 2; respectively). Twenty subjects were diagnosed with the bronchitis/bronchiolitis pattern. CONCLUSION: Although the bronchiolitis/bronchitis pattern is predominant on chest CT in HTLV-1 carriers, the HTLV-1 infection is associated with various interstitial pneumonias.

Percutaneous ipsilateral portal vein embolization using a modified four-lumen balloon catheter with fibrin glue: initial clinical experience.

PURPOSE: The purpose of the present study was to show the feasibility and safety of ipsilateral portal vein embolization (PVE) using an improved four-lumen balloon catheter with fibrin glue. MATERIALS AND METHODS: To improve the ipsilateral PVE with fibrin glue, we modified a commercially available four-lumen balloon catheter to create a catheter comprising one lumen with a catheter tip for a guidewire, one lumen for an occlusion balloon, and two lumens, each with a side-hole just proximal to the balloon. Eight patients had hepatobiliary disease (three with bile duct carcinoma, two with gallbladder carcinoma, one with hepatocellular carcinoma, one with Caroli disease, and one with metastatic carcinoma). RESULTS: All embolization procedures were technically successful. After embolization, the volume of the future remnant liver increased a mean of 131%. There was no inadvertent embolization of portal vein branches and no major procedure-related complications. CONCLUSION: Our method is potentially easier and safer than the traditional ipsilateral method with fibrin glue using a three-lumen balloon catheter because the fourth lumen makes possible the use of a guidewire to access the targeted portal vein and measurement of any portal vein pressure elevation following PVE via the fourth lumen.