COVID-19 pneumonia: Perfusion abnormalities shown on subtraction CT angiography in apparently well-ventilated lungs. A prospective cohort study.

Purpose: To evaluate whether a subtraction CT angiography (sCTA) perfusion score may have prognostic value in patients with COVID-19 pneumonia. Method: This prospective cohort study included adult patients with RT-PCR-confirmed SARS-CoV-2 infection admitted to the ED and a sCTA performed within 24 h of admission between June and September 2020. Perfusion abnormalities (PA) in areas of apparently spared lung parenchyma on conventional CT images were assessed with sCTA perfusion score. Airspace disease extension was assessed with CT severity scores, which were then correlated with clinical outcomes (admission to ICU, requirement of IMV, and death). Inter-rater reliability (IRR) was assessed using Cohen's Kappa. Independent predictors of adverse outcomes were evaluated by multivariable logistic regression analyses using the Hosmer and Lemeshow's test. Results: 191 patients were included: 112 males (58%), median age of 60.8 years (SD ± 16.0). The IRR was very high (median Kappa statistic: 0.95). No association was found between perfusion CT scores and D-dimer levels (Kendall's Tau-B coefficient = 0.08, p = 0.16) or between PaO2/FiO2 ratios and D-dimer levels (Kendall's Tau-B coefficient = -0.10, p = 0.07). Multivariate analyses adjusting for parenchymal disease extension, vascular beaded appearance, pulmonary embolism, sex, and age showed that severe PA remained a significant predictor for ICU admission (AOR: 6.25, 95% CI 2.10-18.7, p = 0.001). The overall diagnostic capacity of this model was adequate (ROC AUC: 0.83; 95% CI 0.77-0.89). Conclusions: The assessment of pulmonary perfusion abnormalities in areas of apparently spared lung parenchyma on conventional CT images via sCTA perfusion scoring has prognostic value in COVID-19 pneumonia.

Role of CT in Two-Stage Liver Surgery.

Complete resection is the only potentially curative treatment for primary or metastatic liver tumors. Improvements in surgical techniques such as conventional two-stage hepatectomy (TSH) with portal vein embolization and ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) promote hypertrophy of the future liver remnant (FLR), expanding resection criteria to include patients with widespread hepatic disease who were formerly not considered candidates for resection. Radiologists are essential in the multidisciplinary approach required for TSH. In particular, multidetector CT has a critical role throughout the various stages of this surgical process. The aims of CT before the first stage of TSH are to define the feasibility of surgery, assess the number and location of liver tumors in relation to relevant anatomy, and provide a detailed anatomic evaluation, including vascular and biliary variants. Volume calculation with CT is also essential to determine if the FLR is sufficient to avoid posthepatectomy liver failure. The objectives of CT between the first and second stages of TSH are to recalculate liver volumes (ie, assess FLR hypertrophy) and depict expected liver changes and complications that could modify the surgical plan or preclude the second stage of definitive resection. In this review, the importance of CT throughout different stages of TSH is discussed and key observations that contribute to surgical planning are highlighted. In addition, the advantages and limitations of MRI for detection of liver metastases and assessment of complications are briefly described. ©RSNA, 2022.

Sildenafil for treating patients with COVID-19 and perfusion mismatch: a pilot randomized trial.

BACKGROUND: SARS-CoV-2 seems to affect the regulation of pulmonary perfusion. Hypoperfusion in areas of well-aerated lung parenchyma results in a ventilation-perfusion mismatch that can be characterized using subtraction computed tomography angiography (sCTA). This study aims to evaluate the efficacy of oral sildenafil in treating COVID-19 inpatients showing perfusion abnormalities in sCTA. METHODS: Triple-blinded, randomized, placebo-controlled trial was conducted in Chile in a tertiary-care hospital able to provide on-site sCTA scans and ventilatory support when needed between August 2020 and March 2021. In total, 82 eligible adults were admitted to the ED with RT-PCR-confirmed or highly probable SARS-COV-2 infection and sCTA performed within 24 h of admission showing perfusion abnormalities in areas of well-aerated lung parenchyma; 42 were excluded and 40 participants were enrolled and randomized (1:1 ratio) once hospitalized. The active intervention group received sildenafil (25 mg orally three times a day for seven days), and the control group received identical placebo capsules in the same way. Primary outcomes were differences in oxygenation parameters measured daily during follow-up (PaO2/FiO2 ratio and A-a gradient). Secondary outcomes included admission to the ICU, requirement of non-invasive ventilation, invasive mechanical ventilation (IMV), and mortality rates. Analysis was performed on an intention-to-treat basis. RESULTS: Totally, 40 participants were enrolled (20 in the placebo group and 20 in the sildenafil group); 33 [82.5%] were male; and median age was 57 [IQR 41-68] years. No significant differences in mean PaO2/FiO2 ratios and A-a gradients were found between groups (repeated-measures ANOVA p = 0.67 and p = 0.69). IMV was required in 4 patients who received placebo and none in the sildenafil arm (logrank p = 0.04). Patients in the sildenafil arm showed a significantly shorter median length of hospital stay than the placebo group (9 IQR 7-12 days vs. 12 IQR 9-21 days, p = 0.04). CONCLUSIONS: No statistically significant differences were found in the oxygenation parameters. Sildenafil treatment could have a potential therapeutic role regarding the need for IMV in COVID-19 patients with specific perfusion patterns in sCTA. A large-scale study is needed to confirm these results. TRIAL REGISTRATION: Sildenafil for treating patients with COVID-19 and perfusion mismatch: a pilot randomized trial, NCT04489446, Registered 28 July 2020, https://clinicaltrials.gov/ct2/show/NCT04489446 .

Presentaciones infrecuentes y atípicas del carcinoma hepatocelular en tomografía computarizada y resonancia magnética / Rare and atypical presentations of hepatocellular carcinoma on CT and MRI

Resumen La apariencia en imágenes típicas del carcinoma hepatocelular (HCC) es ampliamente reconocida y consiste en hiperrealce en fase arterial con lavado en las fases venosa portal y tardía, tanto en tomografía computada como en resonancia magnética. Este patrón se observa en el 60% de los casos y se ha incorporado en las directrices diagnósticas de las diferentes organizaciones que participan en el estudio de las enfermedades hepáticas y su presencia evita la necesidad de una biopsia. Además, son signos auxiliares útiles en el diagnóstico del HCC la hiperintensidad en secuencias ponderadas en T2, la presencia de grasa, la trombosis tumoral venosa y el crecimiento entre intervalos en los estudios de seguimiento. Sin embargo, no todos los pacientes con HCC presentan estas características y en el 40% de los casos las presentaciones atípicas plantean un reto diagnóstico y de manejo de los pacientes.

Abstract The typical imaging appearance of hepatocellular carcinoma (HCC) is widely recognized and consists in hyper enhancement in the arterial phase with lavage in the portal and late venous phases, as on computed tomography (CT) as on magnetic resonance imaging (MRI). This pattern is observed in 60% of cases and has been incorporated into the diagnostics directives of the different organizations which participates in the hepatic diseases studies and its presence avoid the necessity of a biopsy. Besides, are auxiliar signs useful on the HCC diagnostic, T2 hyperintensity, presence of grease, venous tumor thrombosis and the growth between intervals in follow up studies. However, not all HCC patients harbor these characteristics and in 40% of cases the atypical introduction proposes a diagnostic and handling challenge of patients.

COVID-19: What Iodine Maps From Perfusion CT can reveal-A Prospective Cohort Study.

BACKGROUND: Subtraction CT angiography (sCTA) is a technique used to evaluate pulmonary perfusion based on iodine distribution maps. The aim of this study is to assess lung perfusion changes with sCTA seen in patients with COVID-19 pneumonia and correlate them with clinical outcomes. MATERIAL AND METHODS: A prospective cohort study was carried out with 45 RT-PCR-confirmed COVID-19 patients that required hospitalization at three different hospitals, between April and May 2020. In all cases, a basic clinical and demographic profile was obtained. Lung perfusion was assessed using sCTA. Evaluated imaging features included: Pattern predominance of injured lung parenchyma in both lungs (ground-glass opacities, consolidation and mixed pattern) and anatomical extension; predominant type of perfusion abnormality (increased perfusion or hypoperfusion), perfusion abnormality distribution (focal or diffuse), extension of perfusion abnormalities (mild, moderate and severe involvement); presence of vascular dilatation and vascular tortuosity. All participants were followed-up until hospital discharge searching for the development of any of the study endpoints. These endpoints included intensive-care unit (ICU) admission, initiation of invasive mechanical ventilation (IMV) and death. RESULTS: Forty-one patients (55.2 ± 16.5 years, 22 men) with RT-PCR-confirmed SARS-CoV-2 infection and an interpretable iodine map were included. Patients with perfusion anomalies on sCTA in morphologically normal lung parenchyma showed lower Pa/Fi values (294 ± 111.3 vs. 397 ± 37.7, p = 0.035), and higher D-dimer levels (1156 ± 1018 vs. 378 ± 60.2, p < 0.01). The main common patterns seen in lung CT scans were ground-glass opacities, mixed pattern with predominant ground-glass opacities and mixed pattern with predominant consolidation in 56.1%, 24.4% and 19.5% respectively. Perfusion abnormalities were common (36 patients, 87.8%), mainly hypoperfusion in areas of apparently healthy lung. Patients with severe hypoperfusion in areas of apparently healthy lung parenchyma had an increased probability of being admitted to ICU and to initiate IMV (HR of 11.9 (95% CI 1.55-91.9) and HR 7.8 (95% CI 1.05-61.1), respectively). CONCLUSION: Perfusion abnormalities evidenced in iodine maps obtained by sCTA are associated with increased admission to ICU and initiation of IMV in COVID-19 patients.

Fitz-Hugh-Curtis Syndrome Caused by Gonococcal Infection in a Patient with Systemic Lupus Erythematous: A Case Report and Literature Review.

BACKGROUND Fitz-Hugh-Curtis (FHC) syndrome is a perihepatitis linked to inflammatory pelvic disease. It can be caused by Neisseria gonorrhoeae or Chlamydia trachomatis infections. FHC syndrome usually presents with pain in the right hypochondrium and fever, associated with symptoms and signs of pelvic infection in women. CASE REPORT We present the case of a 22-year-old woman with systemic lupus erythematous (SLE) who presented with polyarthritis, cutaneous lesions, and abdominal pain. The diagnosis of FHC syndrome was based on the findings of abdominal computerized tomography (CT) and the isolation of Neisseria gonorrhoeae (NG) in blood cultures. The association of arthritis and cutaneous lesions was diagnosed as a syndrome of arthritis-dermatitis, also caused by systemic NG infection. The patient had a favorable outcome with antibiotic treatment. CONCLUSIONS FHC syndrome should be considered in sexually active young patients, mainly women, with pelvic infection and perihepatitis. It may be caused by disseminated gonococcal infection. An important risk factor is the serum complement deficit, which may predispose to severe forms. Low serum complement level is a frequent manifestation of active SLE. CT images showing the typical findings of perihepatitis allow making the correct diagnosis.

Multidetector CT for Evaluation of the Extrapleural Space.

The extrapleural space (EPS) is an anatomic space at the periphery of the chest that can be involved in a number of disease processes. This space lies between the inner surface of the ribs and the parietal pleura and contains adipose tissue, loose connective tissue, lymph nodes, vessels, endothoracic fascia, and the innermost intercostal muscle. It is often overlooked on cross-sectional imaging studies and almost invariably overlooked on conventional radiographic studies. At conventional radiography, the EPS occasionally can be seen when there is extrapleural fat proliferation, which might be confused with pleural thickening or pleural effusion. Knowledge of the normal anatomy of the EPS depicted at computed tomography (CT) and of the relationship of the EPS with parenchymal, pleural, and chest wall processes is key to the detection of extrapleural abnormalities. Disease entities that most commonly affect the EPS include chronic inflammatory disorders, infection, trauma, and neoplasms. Chronic inflammatory conditions and infectious processes of the lungs and pleurae induce adipocyte proliferation adjacent to the inflamed tissue, resulting in increased extrapleural fat. Chest wall trauma with extrapleural hematoma formation causes characteristic CT findings that enable differentiation of the extrapleural hematoma from hemothorax and warrant a different treatment approach. Extrapleural air is commonly seen in patients with pneumomediastinum and should be distinguished from pneumothorax because it requires a different treatment approach. Intrathoracic neoplasms can cause an increase in the attenuation of normal extrapleural fat owing to pleural inflammation, lymphatic obstruction, lymphangitic spread, or direct invasion by tumor. The normal and pathologic appearances of the EPS, as depicted at thoracic CT, and the differential diagnosis of findings in the EPS are reviewed. ©RSNA, 2017.

Eculizumab in paroxysmal nocturnal hemoglobinuria with Budd-Chiari syndrome progressing despite anticoagulation.

Paroxysmal nocturnal hemoglobinuria (PNH) is a progressive, life-threatening disorder characterized by chronic intravascular hemolysis caused by uncontrolled complement activation. Hepatic vein thrombosis (Budd-Chiari syndrome) is common in PNH patients. This case report describes the response to eculizumab (a humanized monoclonal antibody that inhibits terminal complement activation) in a 25-year-old male with progressive liver function deterioration despite standard anticoagulation therapy and transjugular intrahepatic porto-systemic shunt. The patient presented with anemia, severe thrombocytopenia, headache, abdominal pain, and distention. He was diagnosed with PNH, cerebral vein thrombosis, and Budd-Chiari syndrome. Despite adequate anticoagulation, diuretic administration, and placement of a transjugular shunt, additional thrombotic events and progressive liver damage were observed. Eculizumab therapy was initiated, resulting in rapid blockade of intravascular hemolysis, increased platelet counts, ascites resolution, and liver function recovery, all of which are presently sustained. Since starting eculizumab the patient has had no further thrombotic events and his quality of life has dramatically improved. This is the first report to confirm the role of complement-mediated injury in the progression of Budd-Chiari syndrome in a patient with PNH. This case shows that terminal complement blockade with eculizumab can reverse progressive thromboses and hepatic failure that is unresponsive to anticoagulation therapy and suggests that early initiation of eculizumab should be included in the therapeutic regimen of patients with PNH-related Budd-Chiari syndrome.