Secondary organizing pneumonia associated with protracted COVID: A case series.

OBJECTIVES: Immunocompromised B-cell-depleted patients are at risk of developing protracted COVID-19, a clinical syndrome characterized by prolonged viral shedding and respiratory symptoms that can lead to hypoxemic pneumonia. Our aim is to describe this unusual condition and its treatment. PATIENTS AND METHODS: This monocentric retrospective study reports six cases of severe organizing pneumonia that developed during the clinical course of protracted COVID-19. RESULTS: All patients developed organizing pneumonia (OP) in the setting of protracted COVID. Clinical improvement was obtained after several treatment lines including specific antiviral agents and occurred simultaneously with control of the viral load. CONCLUSION: As it was the most frequent presentation of protracted COVID-19 in our survey, we believe that this specific form of organizing pneumonia warrants increased awareness. Furthermore, specific antiviral therapy seems to control this condition.

Preliminary experience of CT imaging of the ischaemic brain penumbra through spectral processing of multiphasic CTA datasets.

To assess ischaemic penumbra through the post-processing of the spectral multiphasic CT Angiography (mCTA) data in acute ischaemic stroke (AIS) patients. Thirty one consecutive patients strongly suspected of severe Middle Cerebral Artery AIS presenting less than 6 h after onset of symptoms or with unknown time of onset of symptoms underwent a standardized CT protocol in spectral mode including Non Contrast CT, mCTA, and Perfusion CT (CTP) on a dual-layer MDCT system. Areas disclosing delayed enhancement on iodine density (ID) maps were highlighted by subtraction of the serial mCTA datasets. Two neuroradiologists independently rated the correspondence between delayed enhancing areas at mCTA and the penumbral/infarcted areas delineated by two validated CTP applications using a 5-levels scoring scale. Interobserver agreement between observers was evaluated by kappa statistics. Dose delivery was recorded for each acquisition. Averaged correspondence score between penumbra delineation using subtracted mCTA-derived ID maps and CTP ones was 2.76 for one application and 2.9 for the other with best interobserver agreement kappa value at 0.59. All 6 stroke mimics out of the 31 patients' cohort were correctly identified. Average dose delivery was 7.55 mSv for the whole procedure of which CTP accounted for 39.7%. Post-processing of spectral mCTA data could allow clinically relevant assessment of the presence or absence of ischaemic penumbra in AIS-suspected patients if results of this proof-of-concept study should be confirmed in larger patients'series.

Fungal pneumonia in kidney transplant recipients.

Fungal pneumonia is a dreaded complication encountered after kidney transplantation, complicated by increased mortality and often associated with graft failure. Diagnosis can be challenging because the clinical presentation is non-specific and diagnostic tools have limited sensitivity and specificity in kidney transplant recipients and must be interpreted in the context of the clinical setting. Management is difficult due to the increased risk of dissemination and severity, multiple comorbidities, drug interactions and reduced immunosuppression which should be applied as an important adjunct to therapy. This review will focus on the main causes of fungal pneumonia in kidney transplant recipients including Pneumocystis, Aspergillus, Cryptococcus, mucormycetes and Histoplasma. Epidemiology, clinical presentation, laboratory and radiographic features, specific characteristics will be discussed with an update on diagnostic procedures and treatment.

Benefit of dual-layer spectral CT in emergency imaging of different organ systems.

Computed tomography (CT) has been the first choice of imaging technique in the emergency department and has a crucial role in many acute conditions. Since its implementation, spectral CT has gained widespread application with the potential to improve diagnostic performance and impact patient care. In spectral CT, images are acquired at two different energy levels allowing this technique to differentiate tissues by exploiting their energy-dependent attenuation properties. Dual-layer spectral CT provides additional information with its material decomposition applications that include virtual non-contrast imaging, iodine density, and effective atomic number (Zeff) maps along with virtual monoenergetic images without the need for preselection of a protocol. This review aims to demonstrate its added value in the emergency department in different organ systems enabling better evaluation of inflammatory and ischaemic conditions, assessment of organ perfusion, tissue/lesion characterisation and mass detection, iodine quantification, and the use of lower volumes of contrast medium. With improved diagnostic performance, spectral CT could also aid in rapid decision-making to determine the treatment method in many acute conditions without increased radiation dose to the patient.

Virtual unenhanced phase with spectral dual-energy CT: Is it an alternative to conventional true unenhanced phase for abdominal tissues?

PURPOSE: To compare attenuation measurements and image quality of virtual unenhanced phase (VUP) images with those of conventional true unenhanced phase (TUP) images on spectral dual energy computed tomography (DECT) with dual layer detector on abdominal tissues and to assess potential reduction in radiation dose. MATERIAL AND METHOD: A total of 295 patients (185 men, 110 women; mean age 61±17.6 [SD] years [range: 17-95 years]) who had undergone abdominal or thoraco-abdominal CT with pre- and post-contrast imaging (portal phase) with spectral DECT with dual layer detector were retrospectively analyzed. VUP images based on portal-venous phase DECT acquisition were generated. Regions of interest were defined in abdominal tissues (liver, spleen, kidney, muscle and fat) by two independent readers. Inter-technique agreement (VUP images vs. TUP images) on attenuation measurements was assessed. Signal-to noise ratio (SNR) and image quality of TUP and VUP images were compared. The radiation dose delivered to patients was compared with the radiation dose of protocols without TUP images. RESULTS: A total of 9880 ROIs were drawn in the abdominal tissues. The difference in mean attenuation values between TUP and VUP images was less than 15 HU in 98.3% and less than 10 HU in 92.3% of all measurements. VUP images overestimated attenuation in fat comparatively to TUP images. Image quality was evaluated as good or excellent in 77% (37/48) of TUP images and 54% (26/48) of VUP images. Using VUP images instead of TUP images could decrease the radiation dose by 32%. CONCLUSION: VUP images demonstrate good agreement with TUP images in different abdominals tissues and can be obtained with similar image quality as TUP. VUP images appear as an alternative to TUP images, resulting in reduction of radiation dose delivered to the patient.

Bacterial pneumonia in kidney transplant recipients.

Bacterial pathogens are the most frequent cause of pneumonia after transplantation. Early after transplantation, recipients are at higher risk for nosocomial infections. The most commonly encountered pathogens during this period are gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa …), but gram-positive coccus such as Staphylococcus aureus or Streptococcus pneumoniae and anaerobic bacteria can also be found. Empirical antibiotic therapy should be guided by previous colonisation of the recipient and bacterial resistance pattern in the hospital. Six months after transplantation, pneumonias are mostly due to community-acquired bacteria (S. pneumonia, H. influenza, Mycoplasma, Chlamydia and others). Opportunistic pathogens take advantage of the state of immunosuppression which is usually highest from one to six months after transplantation. During this period, but also occurring many years later in the setting of a chronically depressed immune system, bacterial pathogens with low intrinsic virulence can cause pneumonia. The diagnosis of pneumonia caused by opportunistic pathogens can be challenging. The delay in diagnosis preventing the early instauration of adequate treatment in kidney transplant recipients with a depressed immune system, frequently coupled with co-morbid conditions and a state of frailty, will affect prognosis and outcome, increasing morbidity and mortality. This review will focus on the most common opportunistic bacterial pathogens causing pneumonia in kidney transplant recipients: Legionella, Nocardia, Mycobacterium tuberculosis/nontuberculous, and Rhodococcus. Recognition of their specificities in the setting of immunosuppression will allow early diagnosis, crucial for initiation of effective therapy and successful outcome. Interactions with immunosuppressive therapy should be considered as well as reducing immunosuppression if necessary.

Evaluation of lung tumor response to therapy: Current and emerging techniques.

Lung tumor response to therapy may be evaluated in most instances by morphological criteria such as RECIST 1.1 on computed tomography (CT) or magnetic resonance imaging (MRI). However, those criteria are limited because they are based on tumoral dimensional changes and do not take into account other morphologic criteria such as density evaluation, functional or metabolic changes that may occur following conventional or targeted chemotherapy. New techniques such as dual-energy CT, PET-CT, MRI including diffusion-weighted MRI has to be considered into the new technical armamentarium for tumor response evaluation. Integration of all informations provided by the different imaging modalities has to be integrated and represents probably the future goal of tumor response evaluation. The aim of the present paper is to review the current and emerging imaging criteria used to evaluate the response of therapy in the field of lung cancer.

Iatrogenic cardiac perforation due to pacing lead displacement: Imaging findings.

PURPOSE: Cardiac perforations due to pacing and implantable defibrillator lead displacement are rare and their detection may be difficult. The goal of this study was to review the clinical and imaging presentation of cardiac perforation related to pacing lead displacement. PATIENTS AND METHODS: The clinical and imaging files of four patients (two men and two women) who experienced cardiac perforation related to pacing lead displacement were reviewed. The four patients were investigated in our radiology department over a 24-month-period. RESULTS: Two patients had clinical symptoms at the time lead displacement was detected and the other two were free of symptoms. In all patients, lead displacement was visible on imaging examinations in retrospect but was not detected prospectively. CONCLUSION: Radiologists should pay attention to the position of the tips of the leads on chest X-ray and CT, even late after the implantation and in asymptomatic patients.

Sclerostin Serum Levels and Vascular Calcification Progression in Prevalent Renal Transplant Recipients.

CONTEXT: Vascular calcification (VC) is prevalent and progressive in renal transplant recipients (RTRs). Recent cross-sectional data suggest that activated Wnt signaling contributes to VC. OBJECTIVE: The objective was to investigate whether circulating levels of the Wnt antagonist sclerostin associate with progression of VC. DESIGN: This was a post hoc analysis of the longitudinal observational Brussels Renal Transplant Cohort study. SETTING: The setting was a tertiary care academic hospital. PATIENTS: Coronary artery calcification and aorta calcification were measured by multislice spiral computerized tomography in 268 prevalent RTRs (age, 53 ± 13 y; 61% male) at baseline and remeasured in 189 patients after a median follow-up of 4.4 years. Baseline serum sclerostin levels were assessed on stored blood samples. Regression analysis was performed to identify determinants of baseline VC and progression. MAIN OUTCOME MEASURE: The main outcome measure was progression of VC. RESULTS: VC was present in up to 84% of participants at baseline. Almost half of the patients showed progression of VC, according to Hokanson criteria. The cross-sectional analysis at baseline demonstrated a direct association between sclerostin levels and VC score in univariate analysis, which became inverse after adjustment for age, gender and PTH level. Remarkably, a lower sclerostin level was identified as an independent determinant of a higher baseline aorta calcification score in the final regression model. Moreover, baseline sclerostin levels showed an inverse association with VC progression, at least after adjustment for traditional risk factors. CONCLUSIONS: Serum sclerostin levels inversely associated with VC burden and progression in prevalent RTRs after adjustment for traditional risk factors. Our data corroborate previous findings in nontransplanted chronic kidney disease patients and support the notion that sclerostin may be up-regulated in the vascular wall during the VC process as part of a local counterregulatory mechanism directed to suppress VC. Additional clinical and experimental data are required for confirmation.

CT and MRI Aspects of an Abdominal Hemophilic Pseudotumor.

We report the computed tomography (CT) and magnetic resonance imaging (MRI) aspects of a rare case of a patient with a large abdominal hemophilic pseudotumor, a chronic, encapsulated, slowly expanding hematoma occurring in severe hemophilia, without involvement of iliopsoas muscles and iliac bones.

Multiple Splenic Infarctions Complicating Granulomatosis with Polyangiitis.

BACKGROUND: A 57-year-old patient was admitted for high-grade fever, asthenia, sweating, dry cough and diffuse arthro-myalgias. Two years earlier, elevated titers of anticytoplasmic antibodies (ANCA) of anti-proteinase 3 specificity and renal biopsy led to a diagnosis of granulomatosis with polyangiitis (GPA) with lung and renal involvement. GPA was treated by steroids, cyclophosphamide and rituximab with subsequent clinical and biological remission. The current chest CT scan was performed for a lung opacity that eventually was proved to be an organising pneumonia. CT also showed an unsuspected pattern of the spleen that was compared with a previous chest CT.

Spontaneous pneumomediastinum and epidural pneumatosis after oral ecstasy consumption.

A 19-year-old man was admitted with acute dyspnoea. Physical examination revealed subcutaneous emphysema in the cervical and thoracic area. This was further confirmed by the total body computed tomography that also demonstrated mediastinal emphysema. Epidural pneumatosis of the thoracis spine was also evident. There was no history of trauma, but well of a recent oral ecstasy consumption during a techno rave party, associated with intense dancing and jumping. Clinical course was favourable with conservative therapy.