Follow-up Chest CT Research Articles

Thermal Ablation of Pulmonary Nodules by Electromagnetic Navigation Bronchoscopy Combined With Real-Time CT-Based 3D Fusion Navigation:Report of One Case.

A nodule in the right middle lobe of the lung was treated by a combination of cone-beam CT,three-dimensional registration for fusion imaging,and electromagnetic navigation bronchoscopy-guided thermal ablation.The procedure lasted for 90 min,with no significant bleeding observed under the bronchoscope.The total radiation dose during the operation was 384 mGy.The patient recovered well postoperatively,with only a small amount of blood in the sputum and no pneumothorax or other complications.A follow-up chest CT on the first day post operation showed that the ablation area completely covered the lesion,and the patient was discharged successfully.

Acute Q fever pneumonia diagnosed by metagenomic next-generation sequencing.

Q fever, a zoonotic disease caused byCoxiella burnetii(C. burnetii), presents diagnostic challenges due to its clinical and radiological nonspecificity, which often mimics community-acquired pneumonia, coupled with the limitations of traditional diagnostic methods. Metagenomic next-generation sequencing (mNGS) has become an indispensable tool in clinical diagnostics for its high-throughput pathogen identification capabilities. Herein, we detail a case of acute Q fever pneumonia diagnosed with mNGS. The patient exhibited symptoms of fever, cough, expectoration, and diarrhea for three days, with the pathogen undetected in initial laboratory assessments. Bronchoscopy and bronchoalveolar lavage (BAL) were conducted, leading to the identification of C. burnetii in the lavage fluid via mNGS. Consequently, the patient was promptly initiated on a treatment regimen of 100 mg doxycycline, administered orally every 12 hours. Post-treatment, the patient's temperature normalized, and a full recovery was observed. The follow-up chest CT scan revealed complete resolution of the right lower lobe consolidation. The clinical presentation of Q fever pneumonia lacks specificity, making diagnosis based solely on symptoms and imaging challenging. mNGS offers a superior alternative for identifying elusive or rarely cultured pathogens.

Tocilizumab in the treatment of hyperferritinemic syndrome and capillary leak syndrome secondary to rheumatoid arthritis: Case report and literature review.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease, which is mainly characterized by joint swelling, pressure pain and joint destruction. Some patients may suffer from a variety of serious complications, which require prompt diagnosis and treatment. Otherwise, the patient condition may deteriorate rapidly, leading to premature death. We reported a case of RA combined with hyperferritinemic syndrome and capillary leak syndrome (CLS) that was successfully treated with tocilizumab (TCZ), with the aim of improving diagnostic ideas for clinicians and consequently improving the diagnosis and treatment of the hyperferritinemic syndrome and CLS. A 55-year-old female patient was admitted to the Department of Infectious Diseases of our hospital due to "recurrent fever for more than 1 month and aggravation for 3 days." The patient was diagnosed with fever of unknown origin (lung infection?) and received anti-infective therapy with large encirclement of anti-bacterial, antifungal and empirical anti-tuberculosis successively during hospitalization in the Department of Infectious Diseases. Yet her condition continues to progress. The patient was eventually diagnosed with RA combined with hyperferritinemic syndrome and CLS. Then she received glucocorticoids (GC) (160 mg qd) combined with intravenous immunoglobulin (IVIG, 20 g/d, for 3 days). We considered that the patient also had an overwhelming proinflammatory cytokine storm, so she received a strong anti-inflammatory treatment with TCZ (400 mg qm). The patient symptoms and follow-up chest CT showed significant improvement following treatment. TCZ has good efficacy in the treatment of RA combined with hyperferritinemic syndrome and CLS and is expected to be a promising treatment.

Association of Acute Respiratory Disease Events with Quantitative Interstitial Abnormality Progression at CT in Individuals with a History of Smoking.

Background Acute respiratory disease (ARD) events are often thought to be airway-disease related, but some may be related to quantitative interstitial abnormalities (QIAs), which are subtle parenchymal abnormalities on CT scans associated with morbidity and mortality in individuals with a smoking history. Purpose To determine whether QIA progression at CT is associated with ARD and severe ARD events in individuals with a history of smoking. Materials and Methods This secondary analysis of a prospective study included individuals with a 10 pack-years or greater smoking history recruited from multiple centers between November 2007 and July 2017. QIA progression was assessed between baseline (visit 1) and 5-year follow-up (visit 2) chest CT scans. Episodes of ARD were defined as increased cough or dyspnea lasting 48 hours and requiring antibiotics or corticosteroids, whereas severe ARD episodes were those requiring an emergency room visit or hospitalization. Episodes were recorded via questionnaires completed every 3 to 6 months. Multivariable logistic regression and zero-inflated negative binomial regression models adjusted for comorbidities (eg, emphysema, small airway disease) were used to assess the association between QIA progression and episodes between visits 1 and 2 (intercurrent) and after visit 2 (subsequent). Results A total of 3972 participants (mean age at baseline, 60.7 years ± 8.6 [SD]; 2120 [53.4%] women) were included. Annual percentage QIA progression was associated with increased odds of one or more intercurrent (odds ratio [OR] = 1.29 [95% CI: 1.06, 1.56]; P = .01) and subsequent (OR = 1.26 [95% CI: 1.05, 1.52]; P = .02) severe ARD events. Participants in the highest quartile of QIA progression (≥1.2%) had more frequent intercurrent ARD (incidence rate ratio [IRR] = 1.46 [95% CI: 1.14, 1.86]; P = .003) and severe ARD (IRR = 1.79 [95% CI: 1.18, 2.73]; P = .006) events than those in the lowest quartile (≤-1.7%). Conclusion QIA progression was independently associated with higher odds of severe ARD events during and after radiographic progression, with higher frequency of intercurrent severe events in those with faster progression. Clinical trial registration no. NCT00608764 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Little in this issue.

Pulmonary Involvement during Varicella in a Patient with Sickle Cell Disease: Diagnosis and Treatment

Introduction: Pulmonary involvement during chickenpox is one of the most serious complications. However, it can be difficult to distinguish between varicella pneumonia, bacterial superinfection and an acute chest syndrome. We report a case of varicella complicated by pneumonia in a young adult with sickle cell disease.
 Observation: It was a 24-year-old woman with sickle cell disease. Examination on admission revealed generalized skin lesions of varying ages, associated with scratching lesions. On day 3 of hospitalization, she presented an acute respiratory distress associated with fever (40°C). Thoracic CT angiography revealed diffuse pulmonary nodules and micronodules in both lung fields. Blood culture isolated Staphylococcus spp. The patient was put on oxygen therapy combined with antiviral treatment and antibiotic therapy. The course was marked by symptoms regression, with disappearance of respiratory distress on day 2 and apyrexia on day 3 of treatment. The follow-up chest CT scan carried out at month 4, came back normal.
 Conclusion: Although pneumonia is one of the most common complications of varicella, it can be difficult to diagnose in patients with sickle cell disease, considering the frequency of pulmonary involvement of various etiologies

Assessment of Treatment Response in Patients With Severe Asthma Using Visual and Quantitative Analysis of Chest CT.

To evaluate the role of visual and quantitative chest CT parameters in assessing treatment response in patients with severe asthma. Korean participants enrolled in a prospective multicenter study, named the Precision Medicine Intervention in Severe Asthma study, from May 2020 to August 2021, underwent baseline and follow-up chest CT scans (inspiration/expiration) 10-12 months apart, before and after biologic treatment. Two radiologists scored bronchiectasis severity and mucus plugging extent. Quantitative parameters were obtained from each CT scan as follows: normal lung area (normal), air trapping without emphysema (AT without emph), air trapping with emphysema (AT with emph), and airway (total branch count, Pi10). Clinical parameters, including pulmonary function tests (forced expiratory volume in 1 s [FEV1] and FEV1/forced vital capacity [FVC]), sputum and blood eosinophil count, were assessed at initial and follow-up stages. Changes in CT parameters were correlated with changes in clinical parameters using Pearson or Spearman correlation. Thirty-four participants (female:male, 20:14; median age, 50.5 years) diagnosed with severe asthma from three centers were included. Changes in the bronchiectasis and mucus plugging extent scores were negatively correlated with changes in FEV1 and FEV1/FVC (ρ = from -0.544 to -0.368, all P < 0.05). Changes in quantitative CT parameters were correlated with changes in FEV1 (normal, r = 0.373 [P = 0.030], AT without emph, r = -0.351 [P = 0.042]), FEV1/FVC (normal, r = 0.390 [P = 0.022], AT without emph, r = -0.370 [P = 0.031]). Changes in total branch count were positively correlated with changes in FEV1 (r = 0.349 [P = 0.043]). There was no correlation between changes in Pi10 and the clinical parameters (P > 0.05). Visual and quantitative CT parameters of normal, AT without emph, and total branch count may be effective for evaluating treatment response in patients with severe asthma.

CURVULARIA PULMONARY FUNGAL INFECTION ASSOCIATED WITH IMMUNOCOMPROMISED PATIENT: HOW CT SCAN COULD HELP IN MAKING DIAGNOSIS

Pulmonary fungal infections can be found in immunocompetent and immunocompromised patients. The Curvularia species of fungi are rarely seen in humans. These fungi can be clinically significant and cause a range of disease processes, particularly in immunocompromised patients. We present a 24-year-old male patient diagnosed with SLE 5 years ago, complaining of fever five days before hospital administration concerning pneumonia. A CT scan revealed consolidation and multiple lung nodules compatible with a fungal pulmonary infection. The result of the sputum culture indicated Curvularia. A chest radiograph showed infiltrates with consolidation in the middle-lower lobes of both lungs. Early and second CT-scan findings revealed ground-glass opacity surrounding multiple irregular nodules (halo signs), cavitary nodules, and reverse halo signs. Afterward, the result of the patient’s sputum culture demonstrated fungal growth of the Curvularia species. The patient then underwent fungal treatment with fluconazole and voriconazole. The patient showed improvements, and a follow-up chest CT scan revealed the resolution of the lesion after fungal treatment. CT-scan examination, clinical condition, and microbiology culture can help diagnose Curvularia pulmonary fungal infection in immunocompromised patients. Keyword: Phaeohyphomycosis; Curvularia; Halo sign; Reverse halo sign

Abstract 12877: Giant Pericardial Cyst Causing Syncope

A 30 year old male presented with episodes of near syncope with dizziness, palpitations, chest tightness, and left arm paresthesias. Upon presentation, his vitals were normal. Initial imaging of a chest radiograph showed an enlarged cardiac silhouette and a follow-up chest CT demonstrated a 10 cm cystic mass in the anterior mediastinum concerning for a giant pericardial cyst. Echocardiogram was performed which showed a normal ejection fraction, no valvular abnormalities, and a trivial pericardial effusion. A CT-guided drainage was performed with 440mL of fluid removed and shrinkage of the cyst to 27x63mm. The aspirate was loaded with leukocytes without organisms identified. The following day, the cyst recollected to 85x69mm. Repeat CT-guided drainage was attempted however was unsuccessful due to right pneumothorax. After resolution of the pneumothorax, he was asymptomatic prompting discharge with close outpatient follow-up. Outpatient imaging demonstrated increased size of the pericardial cyst to 11 cm in diameter. A third drainage via CT-guidance was attempted however only minimal fluid was able to be drained. As the patient remained asymptomatic, it was recommended the patient have repeat imaging in 6 months and monitor for symptoms. Pericardial cysts are relatively rare and comprise 7% of mediastinal masses. They originate from failed fusion of the mesenchymal lacunae that form the pericardial coelom. Pericardial cysts typically range from 1 to 5 cm in diameter, with those over 10cm being termed 'giant pericardial cysts'. Most cysts are asymptomatic, although if symptoms do occur they are generally in response to mass effect and compression of local structures, such as shortness of breath and chest discomfort. If a patient remains asymptomatic, conservative management with serial imaging is recommended. However, if a patient becomes symptomatic or develops complications, surgical management via a pericardectomy or percutaneous aspiration is recommended.

THU018 Remarkable Response Of ACTH-secreting Pituitary Carcinoma To Immune Checkpoint Inhibitors: A Case Report

Abstract Disclosure: J. Park: None. W. Choi: None. A. Hong: None. J. Yoon: None. H. Kim: None. H. Kang: None. Background: ACTH-secreting pituitary carcinoma transformed from Cushing’s disease is very rare and has aggressive characteristics with limited treatment options. We report a case of ACTH-secreting pituitary carcinoma patient who showed a excellent response to immune checkpoint inhibitors (ICIs). Clinical Case: A 70-year-old female presented with a rapidly growing pituitary carcinoma transformed from Cushing’s disease after bilateral adrenalectomy. Her tumor initially responded to 6 cycles of temozolomide and 7 cycles of temozolomide plus capecitabine. However, multiple brain and pulmonary metastases were newly seen on following imaging studies and the patient had worsening generalized pigmentation on her whole body with newly developed headache, diplopia, and ptosis of the left eye. After introduction of three cycles of ipilimumab plus nivolumab therapy, her plasma ACTH level decreased dramatically from 58,000 pg/ml to 198 pg/ml with improving skin pigmentation and headache episodes. We maintained nivolumab and observed that the plasma ACTH level be normalized to 44 pg/ml (normal range: 6 – 60 pg/ml). Her follow-up brain MRI and chest CT scan also showed marked response, some of the chest lesions even showed nearly complete response (figure 1). On the last follow-up visit, we confirmed that she was in good general condition and tolerable to nivolumab maintenance therapy with glucocorticoid replacement. Conclusion: Immune checkpoint inhibitors (ICIs) may be effective therapeutic options in aggressive pituitary carcinoma and can be considered in temozolomide resistant cases. Moreover, because of the excessively high cost, we emphasize the necessity of clinical trials of ICIs for rare diseases like pituitary carcinomas to expand insurance coverage and reduce the unmet needs of medical care.

RECIST 1.1 Target Lesion Categorical Response in Metastatic Renal Cell Carcinoma: A Comparison of Conventional versus Volumetric Assessment.

Purpose To investigate Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) approximations of target lesion tumor burden by comparing categorical treatment response according to conventional RECIST versus actual tumor volume measurements of RECIST target lesions. Materials and Methods This is a retrospective cohort study of individuals with metastatic renal cell carcinoma enrolled in a clinical trial (from 2003 to 2017) and includes individuals who underwent baseline and at least one follow-up chest, abdominal, and pelvic CT study and with at least one target lesion. Target lesion volume was assessed by (a) Vmodel, a spherical model of conventional RECIST 1.1, which was extrapolated from RECIST diameter, and (b) Vactual, manually contoured volume. Volumetric responses were determined by the sum of target lesion volumes (Vmodel-sum TL and Vactual-sum TL, respectively). Categorical volumetric thresholds were extrapolated from RECIST. McNemar tests were used to compare categorical volume responses. Results Target lesions were assessed at baseline (638 participants), week 9 (593 participants), and week 17 (508 participants). Vmodel-sum TL classified more participants as having progressive disease (PD), compared with Vactual-sum TL at week 9 (52 vs 31 participants) and week 17 (57 vs 39 participants), with significant overall response discordance (P < .001). At week 9, 25 (48%) of 52 participants labeled with PD by Vmodel-sum TL were classified as having stable disease by Vactual-sum TL. Conclusion A model of RECIST 1.1 based on a single diameter measurement more frequently classified PD compared with response assessment by actual measured tumor volume. Keywords: Urinary, Kidney, Metastases, Oncology, Tumor Response, Volume Analysis, Outcomes Analysis ClinicalTrials.gov registration no. NCT01865747 © RSNA, 2023 Supplemental material is available for this article.

Three to Six-Months Follow-Up Chest CT Findings after COVID-19 Pneumonitis, Incidence of Complications and Correlation to Different Risk Factors

Background Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2, has become a global pandemic. As of November 19, 2020, World Health Organization stated that this disease has been found in more than 200 countries. Pathology studies have shown that COVID-19 causes injuries in multiple organs and tissues, with extensive pulmonary involvement similar to that found in other coronavirus infections (ie, severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus infection). Aim of the Work to evaluate pulmonary changes on 3-6 months follow-up chest CT scans and to explore the risk factors for fibrotic-like changes in the lung in patients who recovered from COVID-19 pneumonia. Patients and Methods This was a retrospective and prospective study that included 50 patients who had Symptoms of variable degree of fever, cough, and dyspnea with RT-PCR confirmed COVID- 19 infection at Ain Shams University Hospitals referred to the Radiodiagnosis Department for HRCT chest examination. All patients were evaluated for: (I): Incidence of complications (residual fibrotic like changes in their follow up CT chest scans). (Il): Correlation to different risk factors such as (smoking, diabetes mellitus, hypertension, pre-existing pulmonary disease, pre-existing renal disease and steroid therapy). Results 56% of cases showed residual fibrotic like changes in their follow up chest CT scans while 44% of cases showed total resolution of the disease process. Smoking and old age were significant risk factors while steroid therapy decreased risk of fibrotic like change. Conclusion Twenty eight cases (56%) showed residual fibrotic like changes in their 3-6 months follow-up chest CT scan (CO-RADS III to V). Patients with older age and smokers have higher incidence of residual fibrotic like changes in their follow up chest CT scans, while patients on steroid therapy have less liability to develop fibrotic changes.

Quantitative Computed Tomography Analysis of the Longitudinal Change Between Centrilobular and Paraseptal Emphysema Subtypes: A Retrospective Study.

This study aimed to investigate the difference between the extent of centrilobular emphysema (CLE) and paraseptal emphysema (PSE) on follow-up chest CT scans and their relationship to the cross-sectional area (CSA) of small pulmonary vessels. Sixty-two patients (36 CLE and 26 PSE) who underwent 2 chest CT scans were enrolled in this study. The percentage of low attenuation volume (%LAV) and total CSA of the small pulmonary vessels <5 mm2 (%CSA < 5) were measured at the 2 time points. Analysis of the initial %CSA < 5 and the change in the %LAV and %CSA < 5 on follow-up imaging was performed. The initial %CSA < 5 was not significantly different between the CLE and the PSE groups (CLE, 0.66 vs. PSE, 0.71; P = 0.78). There was no significant difference in the longitudinal change in the %LAV between the 2 groups (CLE, -0.048% vs. PSE, 0.005%; P = 0.26). The longitudinal change in the %CSA < 5 in patients with PSE significantly decreased compared with those with CLE (CLE, 0.025% vs. PSE, -0.018%; P = 0.02). The longitudinal change in the %CSA < 5 was significantly different for patients with CLE and PSE, demonstrating an important pathophysiological difference between the subtypes.

Immediate and Follow-up Imaging Findings after Cone-Beam CT–guided Transbronchial Lung Cryobiopsy

To evaluate findings after transbronchial lung cryobiopsy (TBLC) using intraprocedural cone-beam CT (CBCT) and follow-up chest CT examinations. A single-center, prospective cohort study was performed with 14 participants (mean age, 65 years ± 13 [SD]; eight male participants) undergoing CBCT-guided TBLC between August 2020 and February 2021 who underwent follow-up chest CT imaging. Intraprocedural CBCT and follow-up chest CT images were interpreted for changes compared with baseline CT images. Statistical analyses were performed using independent samples t test and analysis of variance. A total of 62 biopsies were performed, with 48 in the field of view of CBCT immediately after biopsy. All 48 biopsy sites had evidence of postprocedural hemorrhage, and 17 (35%) had pneumatoceles at the biopsy site. Follow-up CT images showed resolution of these findings. Solid nodules developed at 18 of the 62 (29%) biopsy sites. Postbiopsy hemorrhage and pneumatoceles on intraprocedural CBCT images (which were clinically occult and resolved spontaneously) and new solid nodules on follow-up chest CT images were commonly observed after TBLC. These findings may help alleviate unnecessary follow-up imaging and tissue sampling.Keywords: Biopsy/Needle Aspiration, CT, Lungs, Lung Biopsy, Interventional Bronchoscopy© RSNA, 2023.

Almonertinib-induced interstitial lung disease in a lung adenocarcinoma patient complicated with interstitial lung abnormality

BackgroundWith the use of targeted drugs in lung cancer patients, targeted drug-induced interstitial lung disease (ILD) has attracted more and more attention. The incidence, time, and severity of different targeted drug-induced ILD vary. Almonertinib/HS-10296 is a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). Post-marketing safety and effectiveness of almonertinib have been confirmed. The reported adverse events of almonertinib were mainly an increase in creatine phosphokinase, aspartate aminotransferase, and alanine aminotransferase, and onset of rash. Almonertinib-induced ILD is rare.Case reportThis paper reported the case of a patient with lung adenocarcinoma complicated with interstitial lung abnormality (ILA). Gene detection showed L858R mutation in exon 21 of the EGFR gene. After operation, almonertinib (110 mg per day) was prescribed. 3 months later, ILD was found by chest CT due to dyspnea.Management and outcomeSubsequently, almonertinib was stopped. With the administration of intravenous glucocorticoid and oxygen inhalation, the patient's dyspnea was significantly regressed and lung lesions regressed on follow-up chest CT done after discharge.DiscussionThis case suggested that we should pay attention to the existence of ILD/ILA before using targeted drugs. The use of targeted drugs should be more strictly controlled and monitored in patients with previous ILA or ILD. This paper also reviewed the relevant literature on the drug characteristics and summarized the risk factors of ILD caused by EGFR-TKI.

Abstract P544: Post-COVID-19: Predictors of Pulmonary Fibrosis

Introduction: From observational studies, it is known that some survivors of COVID-19 pneumonia have developed fibrotic pulmonary remodeling, restrictive lung abnormalities, associated with impaired exercise tolerance and poor quality of life at follow-up. Post-COVID-19 pulmonary fibrosis may be defined as the presence of persistent fibrotic changes identified on follow-up CT scans, such as traction bronchiectasis. It is important to identify the potential risk factors for the occurrence of pulmonary fibrosis in this context, although they have not yet been completely defined. Hypothesis: We hypothesize that lung fibrosis may be also a possible long-term consequence of COVID-19 pneumonia and the risk factors associated with the acute phase that enhance the risk of pulmonary sequelae, such as duration of hospitalization and intensive care stay, of high-flow oxygen support, and need for mechanical ventilation. Methods: We undertook a cohort study of COVID-19 survivors, that required supplemental oxygenation during the acute phase, who had been discharged from hospitals April 2020 to March 2022 in public hospitals of Curitiba/PR (BRAZIL). At 1-month and 6-month follow-up visit, survivors were interviewed with questionnaires symptoms, received a physical examination, sit-to-stand test, laboratory test ant chest CT scan was performed between two visits. The primary outcomes were persistent fibrotic changes, such as traction bronchiectasis, on follow-up chest CT. Multivariable adjusted logistic regression models were used to evaluate the risk factors of CT scan outcomes. Results: We followed 63 COVID-19 survivors with CT scan follow-up. The median age of patients was 52 years (±13.3) and 37 (58.7%) were women. The median CT scan follow-up time was 151 days (38-428). The median hospitalization time during acute phase was 13 (3-48) days. The proportion of patients with persistent dyspnoea, characterized by mMRC score of 1 or more, was 52 (82,5%). The proportion of patients with at least one fibrotic change on CT scan was 35 (55.6%), traction bronchiectasis was identified on 16 (25.4%). Hospitalization time during acute phase was associated with traction bronchiectasis, main persistent fibrotic change on CT scan (OR, 1.19; 95% CI:1.036, 1.207; p=0,004). Conclusion: In a follow-up, the duration of hospitalization COVID-19 acute phase was associated with higher odds of traction bronchiectasis on chest CT follow-up.

Radiological Evolution of Patients with COVID-19 Pneumonia Treated with Low-Dose Radiotherapy

Background: The main objective of this work is to describe the findings and radiological evolution on chest CT of 27 patients with COVID-19 pneumonia after being treated with LD-RT in a prospective study. We also evaluated the interobserver agreement in assessing the extent of lung involvement. Patients and Methods: 3 CTs were compared: day of treatment, one week later, and at 4-7 months. In each CT the following radiological findings were evaluated in each lobe: extension score (0: none, 0%; 1: minimal, 1-5%; 2: mild, 5-25%, 3: mild-moderate, 26-50%; 4: moderate, 51-75%; 5: severe, 76-100%), GGO, consolidation, crazy-paving pat-tern, subpleural lines, parenchymal bands, and pulmonary fibrosis. Results: A statistically significant decrease in the number of affected lobes with consolidations and GGO was found between the second and third CT (p=0.023 and p=0.003, respectively) and between the first and third CT (p=0.012 and p=0.006). No significant changes were identified regarding the presence of fibrosis. There was a significant decrease of the extension score when comparing the three studies (1st vs 2nd p=0.029, 2nd vs 3rd p&lt;0.001, and 1st vs 3rd p&lt;0.001). A very good concordance was found in the evaluation of the extension score and the presence of consolidations, there was a moderate agreement when assessing the fibrosis and only a mild agreement on the GGO. Conclusions: Our study suggests that patients with COVID-19 pneumonia treated with LD-RT show radiological improvement of consolidations and GGO on long-term follow-up chest CT, with no significant increase in pulmonary fibrosis identified.

Severe COVID-19 pneumonia leads to post-COVID-19 lung abnormalities on follow-up CT scans

PurposeTo investigate the association of the maximal severity of pneumonia on CT scans obtained within 6-week of diagnosis with the subsequent development of post-COVID-19 lung abnormalities (Co-LA). MethodsCOVID-19 patients diagnosed at our hospital between March 2020 and September 2021 were studied retrospectively. The patients were included if they had (1) at least one chest CT scan available within 6-week of diagnosis; and (2) at least one follow-up chest CT scan available ≥ 6 months after diagnosis, which were evaluated by two independent radiologists. Pneumonia Severity Categories were assigned on CT at diagnosis according to the CT patterns of pneumonia and extent as: 1) no pneumonia (Estimated Extent, 0%); 2) non-extensive pneumonia (GGO and OP, <40%); and 3) extensive pneumonia (extensive OP and DAD, >40%). Co-LA on follow-up CT scans, categorized using a 3-point Co-LA Score (0, No Co-LA; 1, Indeterminate Co-LA; and 2, Co-LA). ResultsOut of 132 patients, 42 patients (32%) developed Co-LA on their follow-up CT scans 6–24 months post diagnosis. The severity of COVID-19 pneumonia was associated with Co-LA: In 47 patients with extensive pneumonia, 33 patients (70%) developed Co-LA, of whom 18 (55%) developed fibrotic Co-LA. In 52 with non-extensive pneumonia, 9 (17%) developed Co-LA: In 33 with no pneumonia, none (0%) developed Co-LA. ConclusionsHigher severity of pneumonia at diagnosis was associated with the increased risk of development of Co-LA after 6–24 months of SARS-CoV-2 infection.

462: PURULENT TEETH AND PURULENT PLEURAL SPACE

Introduction: Empyema is a rare but serious complication of pneumonia. Most common causative organisms include streptococcus species, staphylococcus, and anaerobes. We present a case of empyema secondary to Fusobacterium nucleatum and Porphyromonous gingivalis in a patient with periodontitis. Description: A 70-year-old male with a history of Cerebral Palsy presented with 2 weeks of generalized weakness. He was afebrile, heart rate of 160bpm, respiratory rate of 35/min, Oxygen saturation of 87% on room air, and a BP of 113/76. He was ill-appearing with decreased air entry on the right side of the chest on the exam. His labs showed a WBC of 11.2 k/ul, and high Lactic acid and procalcitonin. CXR showed subtotal opacification of the right hemithorax. CT Scan of the chest showed a large loculated right hydropneumothorax with adjacent atelectasis. Vancomycin, cefepime, and metronidazole were started. A chest tube was inserted for source control with immediate drainage of 120 ml of Purulent turbid fluid. Culture from the pleural fluid grew Fusobacterium nucleatum and Porphyromonous gingivalis. Repeat imaging showed multiple sites of undrained pleural effusion and incomplete expansion of the lung. TPA and DNase were instilled in the pleural cavity every 12 hours over a period of 72 hours to help with drainage and lysis of loculations. Follow-up chest CT showed trapped unexpanded lung with loculations, scarring, and pneumothorax around it. The patient underwent a right thoracotomy with complete visceral and parietal pleural decortication that resulted in the gradual expansion of the lungs and removal of his chest tube. Due to the organisms involved, a panorex xray was done and showed periodontitis. The patient underwent extraction of infected teeth to prevent recurrent empyema. He was discharged on ampicillin/ sulbactam for a total course of four weeks. Discussion: Fusobacterium nucleatum and Porphyromonous gingivalis are gram negative oral anaerobes that frequently cause periodontitis. Aspiration of oral and dental secretions containing these organisms resulted in pneumonia and empyema in our patient. Identifying those organisms allowed us to search and treat for the underlying conditions. Treatment strategies include appropriate antibiotic therapy along with pleural space drainage.

Mid-term follow-up chest CT findings in recovered COVID-19 patients with residual symptoms.

More than a year has passed since the initial outbreak of SARS-CoV-2, which caused many hospitalizations worldwide due to COVID-19 pneumonia and its complications. However, there is still a lack of information detailing short- and long-term outcomes of previously hospitalized patients. The purpose of this study is to analyze the most frequent lung CT findings in recovered COVID-19 patients at mid-term follow-ups. A total of 407 consecutive COVID-19 patients who were admitted to the Fondazione IRCCS Policlinico San Matteo, Pavia and discharged between February 27, 2020, and June 26, 2020 were recruited into this study. Out of these patients, a subset of 108 patients who presented with residual asthenia and dyspnea at discharge, altered spirometric data, positive lung ultrasound and positive chest X-ray was subsequently selected, and was scheduled to undergo a mid-term chest CT study, which was evaluated for specific lung alterations and morphological patterns. The most frequently observed lung CT alterations, in order of frequency, were ground-glass opacities (81%), linear opacities (74%), bronchiolectases (64.81%), and reticular opacities (63.88%). The most common morphological pattern was the non-specific interstitial pneumonia pattern (63.88%). Features consistent with pulmonary fibrosis were observed in 32 patients (29.62%). Our work showed that recovered COVID-19 patients who were hospitalized and who exhibited residual symptoms after discharge had a slow radiological recovery with persistent residual lung alterations. This slow recovery process should be kept in mind when determining the follow-up phases in order to improve the long-term management of patients affected by COVID-19.

Chest CT in covid-19 pneumonia's follow-up: A 30 patients case series.

Lung abnormalities do not fully resolve in all Covid-19 survivors and may progress to fibrosis. Understanding post-COVID lung changes helps identify patients susceptible of post-COVID-19 sequelae. We analyzed scannographic residual lung abnormalities and the full resolution percentage on intermediate- and long-term follow-up (3 months or more). Data from 30 RT-PCR positive COVID-19 patients undergoing at least one follow-up chest CT at Ibn Sina Hospital, with a minimal time interval of 3 months between the RT-PCR and the CT performance were gathered retrospectively. The following elements were analyzed: (1) lung opacities, (2) distribution, (3) dominant lung opacity, (4) Sub-pleural bands, (5) Interlobular septal thickening, (6) Vascular dilatation, (7) Bronchiectasis, (8) Honey combing, (9) Architectural distortion, (10) mosaic attenuation, and (11) Additional findings: Enlarged lymph nodes, Pleural and Pericardial fluid. To evaluate the degree of lung opacification, a score founded on visual evaluation of the lung involvement's percentage was employed. Patients were then subdivided into two categories: (1) no residual opacities and (2) remaining pulmonary opacities. 30 patients were enrolled. The age ranged between 40 and 87 years. CT was indicated for symptoms or functional impairment. The time range between the positive RT-PCR and Follow-up CT varied between 3 and 12 months. CT severity score ranged between o and 23. Residual lung opacities were present in 24 cases (80%). The dominant lung opacities were Ground glass (46.7%), and linear/curvilinear opacities (23.3%). Signs of fibrosis were present in 9 patients (30%). CT abnormalities following Covid-19 pneumonia's prevalence varies based on the extent of the original lung affection and the time gap since the acute phase. Residual anomalies' effects on respiratory physiology, symptoms, and quality of living are unknown. Maintained monitoring of COVID-19 survivors with clinical examination, iterative pulmonary function tests, and HRCT is advised.