Acute Pneumothorax

Effect of Contrast Level and Image Format on a Deep Learning Algorithm for the Detection of Pneumothorax with Chest Radiography

Under the black-box nature in the deep learning model, it is uncertain how the change in contrast level and format affects the performance. We aimed to investigate the effect of contrast level and image format on the effectiveness of deep learning for diagnosing pneumothorax on chest radiographs. We collected 3316 images (1016 pneumothorax and 2300 normal images), and all images were set to the standard contrast level (100%) and stored in the Digital Imaging and Communication in Medicine and Joint Photographic Experts Group (JPEG) formats. Data were randomly separated into 80% of training and 20% of test sets, and the contrast of images in the test set was changed to 5 levels (50%, 75%, 100%, 125%, and 150%). We trained the model to detect pneumothorax using ResNet-50 with 100% level images and tested with 5-level images in the two formats. While comparing the overall performance between each contrast level in the two formats, the area under the receiver-operating characteristic curve (AUC) was significantly different (all p < 0.001) except between 125 and 150% in JPEG format (p = 0.382). When comparing the two formats at same contrast levels, AUC was significantly different (all p < 0.001) except 50% and 100% (p = 0.079 and p = 0.082, respectively). The contrast level and format of medical images could influence the performance of the deep learning model. It is required to train with various contrast levels and formats of image, and further image processing for improvement and maintenance of the performance.

Spontaneous Pneumothorax: A Tale of Two Unique Cases

We herein present two cases of spontaneous pneumothorax. The first one is occurring in an elderly female who has an extensive history of smoking and an underlying chronic obstructive lung disease, whereas the second case represents a congenital bleb in a male patient who has no other underlying pulmonary disorder. Both cases presented to our facility with a spontaneous pneumothorax following pulmonary bleb rupture. Both patients underwent thoracoscopic surgery with subsequent partial pleurectomy and pleurodesis.

Neonatal Pneumothorax Outcome in Preterm and Term Newborns

Background and Objectives: Pneumothorax implies the presence of air in the pleural space between the visceral and parietal pleura. The aim of this study was to investigate the incidence, clinical characteristics, risk factors, therapy and perinatal outcome in neonates with pneumothorax in a tertiary care center. Materials and Methods: A retrospective study based on a five-year data sample of neonates with pneumothorax was conducted in a Maternity Hospital with a tertiary NICU from 2015 to 2020. We included all neonates with pneumothorax born in our hospital and compared demographic characteristics, perinatal risk factors, anthropometric parameters, comorbidities, clinical course and method of chest drainage between term (≥37 GW) and preterm (<37 GW) neonates. Results: The study included 74 newborns with pneumothorax, of which 67.6% were male and 32.5% were female. The majority of women (59.5%) had no complications during pregnancy. Delivery was mainly performed via CS (68.9%). Delivery occurred on average in 34.62 ± 4.03 GW. Significantly more (p = 0.001) children with pneumothorax were born prematurely (n = 53; 71.6%) than at term (n = 21; 28.4%). Most of the neonates had to be treated with ATD (63.5%) and nCPAP (39.2%), but less often they were treated with surfactant (40.5%) and corticosteroids (35.1%). O2 therapy lasted an average of 8.89 ± 4.57 days. Significantly more (p = 0.001) neonates with pneumothorax had additional complications, pneumonia, sepsis, convulsions and intraventricular hemorrhage (68.9%). However, most children had a good outcome (83.8%) and were discharged from the clinic. Fatal outcomes occurred in six cases, while another six neonates had to be transferred to referral neonatal centers for further treatment and care. Conclusion: Significantly more children with pneumothorax were born prematurely than at term. With adequate therapy, even premature newborns can successfully recover from pneumothorax.

I cannot picture it in my mind: acquired aphantasia after autologous stem cell transplantation for multiple myeloma

Aphantasia, the loss of mental imagery, is a rare disorder and even more infrequent when acquired. No previous cases have been identified that were caused by transplant-related treatment. We describe a case of acquired aphantasia in a 62-year-old male with refractory IgG kappa multiple myeloma after receiving an autologous stem cell transplant (ASCT) following high-dose melphalan with a complicated hospital admission. The etiology of aphantasia remains unidentified, but we provide viable explanations to include direct effects from ASCT treatment and indirect effects from transplant-related complications.

Blunt trauma related chest wall and pulmonary injuries: An overview

Physical traumas are tragic and multifaceted injuries that suddenly threaten life. Although it is the third most common cause of death in all age groups, one out of four trauma patients die due to thoracic injury or its complications. Blunt injuries constitute the majority of chest trauma. This indicates the importance of chest trauma among all traumas. Blunt chest trauma is usually caused by motor vehicle accident, falling from height, blunt instrument injury and physical assault. As a result of chest trauma, many injuries may occur, such as pulmonary injuries, and these require urgent intervention. Chest wall and pulmonary injuries range from rib fractures to flail chest, pneumothorax to hemothorax and pulmonary contusion to tracheobronchial injuries. Following these injuries, patients may present with a simple dyspnea or even respiratory arrest. For such patient, it is important to understand the treatment logic and to take a multidisciplinary approach to treat the pulmonary and chest wall injuries. This is because only 10% of thoracic trauma patients require surgical operation and the remaining 90% can be treated with simple methods such as appropriate airway, oxygen support, maneuvers, volume support and tube thoracostomy. Adequate pain control in chest trauma is sometimes the most basic and best treatment. With definite diagnosis, the morbidity and mortality can be significantly reduced by simple treatment methods.

The incidence and risk factors of asymptomatic primary spontaneous pneumothorax detected during health check-ups

BACKGROUND

Patients with primary spontaneous pneumothorax (PSP) usually complain of sudden-onset dyspnea and pleuritic chest pain. However, asymptomatic PSP has been incidentally detected on chest X-rays. In this study, we analyzed the incidence, characteristics, risk factors, and prognosis of asymptomatic PSP detected during regular medical check-ups in university students.

METHODS

In this study, 101,709 chest X-rays were performed during medical check-ups for students at the University of Tokyo between April 2011 and March 2016. Among them, 43 cases of asymptomatic PSP (0.042%) were detected. We calculated the lung collapse rate of pneumothorax using Kircher's method. We also analyzed risk factors associated with asymptomatic PSP using characteristics inspected in medical check-ups.

RESULTS

The incidence of asymptomatic PSP was significantly higher in men than in women (0.050% vs 0.018%). Multivariate analysis revealed an association of younger age, greater height, lower body mass index, and greater height growth per year with an increased risk of asymptomatic PSP in male students. Mild lung collapse (<10%) was present in 22 of 43 students with asymptomatic PSP; among these, eight students eventually underwent an invasive therapy.

CONCLUSIONS

The prevalence of asymptomatic PSP among university students was as high as 0.042%. In addition to known risk factors for conventional PSP, greater height growth was a risk factor for asymptomatic PSP. Careful follow-up is very important because a considerable number of patients with mild lung collapse eventually require an invasive medical procedure.