Lesson by SARS-CoV-2 disease (COVID-19): whole-body CT angiography detection of "relevant" and "other/incidental" systemic vascular findings.

OBJECTIVES: Increasing evidence suggests that SARS-CoV-2 infection may lead to severe and multi-site vascular involvement. Our study aimed at assessing the frequency of vascular and extravascular events' distribution in a retrospective cohort of 42 COVID-19 patients. METHODS: Patients were evaluated by whole-body CT angiography between March 16 and April 30, 2020. Twenty-three out of the 42 patients evaluated were admitted to the intensive care unit (ICU). Vascular and extravascular findings were categorized into "relevant" or "other/incidental," first referring to the need for immediate patient care and management. Student T-test, Mann-Whitney U test, or Fisher exact test was used to compare study groups, where appropriate. RESULTS: Relevant vascular events were recorded in 71.4% of cases (n = 30). Pulmonary embolism was the most frequent in both ICU and non-ICU cases (56.5% vs. 10.5%, p = 0.002). Ischemic infarctions at several sites such as the gut, spleen, liver, brain, and kidney were detected (n = 20), with multi-site involvement in some cases. Systemic venous thrombosis occurred in 30.9% of cases compared to 7.1% of systemic arterial events, the first being significantly higher in ICU patients (p = 0.002). Among incidental findings, small-sized splanchnic arterial aneurysms were reported in 21.4% of the study population, with no significant differences in ICU and non-ICU patients. CONCLUSIONS: Vascular involvement is not negligible in COVID-19 and should be carefully investigated as it may significantly affect disease behavior and prognosis. KEY POINTS: • Relevant vascular events were recorded in 71.4% of the study population, with pulmonary embolism being the most frequent event in ICU and non-ICU cases. • Apart from the lung, other organs such as the gut, spleen, liver, brain, and kidneys were involved with episodes of ischemic infarction. Systemic venous and arterial thrombosis occurred in 30.9% and 7.1% of cases, respectively, with venous events being significantly higher in ICU patients (p = 0.002). • Among incidental findings, small-sized splanchnic arterial aneurysms were reported in 21.4% of the whole population.

Looking for Lepidic Component inside Invasive Adenocarcinomas Appearing as CT Solid Solitary Pulmonary Nodules (SPNs): CT Morpho-Densitometric Features and 18-FDG PET Findings.

OBJECTIVE: To investigate CT morphologic and densitometric features and 18-FDG PET findings of surgically excised lung adenocarcinomas "mixed subtype" with predominant lepidic component, appearing as solid solitary pulmonary nodules (SPNs) on CT scan. MATERIALS AND METHODS: Approval for this study was given from each local institutional review board according to its retrospective nature. Nodules pathologically classified as lung adenocarcinoma mixed subtype with bronchioloalveolar otherwise lepidic predominant component, in three different Italian institutions (Napoli; Varese; Parma), were retrospectively selected. RESULTS: 22 patients were identified. The number of SPNs with smooth margins was significantly lower with respect to the number of SPNs with spiculated margins (p: 0.033), radiating spiculations (p: 0.019), and notch sign (p: 0.011). Mean contrast enhancement (CE) was 53.34 HU (min 5.5 HU, max 112 HU); considering 15 HU as cut-off value, CE was positive in 20/22 cases. No significant correlation was found between size and CE. Mean SUVmax was 2.21, ranging from 0.2 up to 7.5 units; considering 2.5 units as cut-off, SUVmax was positive in 7/22 cases. The number of SPNs with positive CE was significantly higher than the number of SPNs with positive SUVmax (p: 0.0005). CONCLUSION: CT generally helps in identifying solid SPN suspicious for malignancy but 18-FDG PET may result in false-negative evaluation; when 18-FDG PET findings of a solid SPN are negative even though CT morphology and CE suggest malignancy, radiologist should consider that lepidic component may be present inside the invasive tumor, despite the absence of ground glass.

MDCT and US of intrathoracic extrapleural space soft tissue-containing lesions: US extrapleural fat sign and MDCT fat ghost ribs sign.

PURPOSE: The purpose of this study was to review the normal anatomy of the extrapleural space, its soft tissue-containing lesions, and to illustrate the extrapleural fat sign with Multidetector Computed Tomography (MDCT) and Ultrasound (US), which was never described so far. MATERIALS AND METHODS: The study includes 28 patients. 24 with histologically or surgically proven extrapleural soft tissue-containing lesions and 4 pleural lesions. Six patients underwent unenhanced MDCT of the chest, while 22 patients had a contrast-enhanced chest MDCT. Furthermore, 9/28 patients underwent Thoracic Ultrasound after MDCT. The lesions included 12 extrapleural hematomas (8 post-traumatic and 4 from other causes), 3 extrapleural lesions from pleural infection extension, 9 extrapleural lesions from metastases. MDCT multiplanar Minimum Intensity Projection (MinIP) reconstructions were always obtained; T-US and MDCT findings were correlated. RESULTS: Among 9 patients who underwent T-US 4/9 showed the "UltraSonography fat extrapleural sign". Among 24 patients who underwent chest MDCT all show the well-known computed tomography (CT) extrapleural fat sign and new auxiliary (MDCT) findings that serve to "strengthen" the diagnosis of correct intrathoracic extrapleural space attribution of lesion. CONCLUSIONS: MDCT with its multiplanar capabilities and post-processing MinIP reconstructions and Thoracic US play a prominent role in the identification and characterization of abnormalities of the frequently overlooked extrapleural space. In conjunction with main CT thoracic findings they provides relevant information in the diagnostic process and correct management.

MDCT evaluation of acute aortic syndrome (AAS).

Non-traumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy and management. There is a common pathway for the various manifestations of AAS that eventually leads to a breakdown of the aortic intima and media. Improvements in biology and health policy and diffusion of technology into the community resulted in an associated decrease in mortality and morbidity related to aortic therapeutic interventions. Hybrid procedures, branched and fenestrated endografts, and percutaneous aortic valves have emerged as potent and viable alternatives to traditional surgeries. In this context, current state-of-the art multidetector CT (MDCT) is actually the gold standard in the emergency setting because of its intrinsic diagnostic value. Management of acute aortic disease has changed with the increasing realization that endovascular therapies may offer distinct advantages in these situations. This article provides a summary of AAS, focusing especially on the MDCT technique, typical and atypical findings and common pitfalls of AAS, as well as recent concepts regarding the subtypes of AAS, consisting of aortic dissection, intramural haematoma, penetrating atherosclerotic ulcer and unstable aortic aneurysm or contained aortic rupture. MDCT findings will be related to pathophysiology, timing and management options to achieve a definite and timely diagnostic and therapeutic definition. In the present article, we review the aetiology, pathophysiology, clinical presentation, outcomes and therapeutic approaches to acute aortic syndromes.

MDCT distinguishing features of focal aortic projections (FAP) in acute clinical settings.

Focal aortic projections (FAP) are protrusion images of the contrast medium (focal contour irregularity, breaks in the intimal contour, outward lumen bulging or localized blood-filled outpouching) projecting beyond the aortic lumen in the aortic wall and are commonly seen on multidetector computed tomography (MDCT) scans of the chest and abdomen. FAP include several common and uncommon etiologies, which can be demonstrated both in the native aorta, mainly in acute aortic syndromes, and in the post-surgical aorta or after endovascular therapy. They are also found in some types of post-traumatic injuries and in impending rupture of the aneurysms. The expanding, routine use of millimetric or submillimetric collimation of current state-of-the-art MDCT scanners (16 rows and higher) all the time allows the identification and characterization of these small ulcer-like lesions or irregularities in the entire aorta, as either an incidental or expected finding, and provides detailed three-dimensional pictures of these pathologic findings. In this pictorial review, we illustrate the possible significance of FAP and the discriminating MDCT features that help to distinguish among different types of aortic protrusions and their possible evolution. Awareness of some related and distinctive radiologic features in FAP may improve our understanding of aortic diseases, provide further insight into the pathophysiology and natural history, and guide the appropriate management of these lesions.

Multi-detector computed tomography in the evaluation of variants and anomalies of aortic arch and its branching pattern.

OBJECTIVE: Evaluate the prevalence of aortic arch anatomy and branching pattern variants and anomalies in 1359 patients by Multi-Detector Computed Tomography Angiography. METHODS: Retrospective multi-centric study including exams performed for various clinical issues with the same acquisition and injection protocols on 64-slices scanners. Multi-Planar reformations and Volume Rendering Images were available in all cases. RESULTS: A total of 965 patients (71%) had normal aortic arch anatomy and branching pattern. Anatomical variations and anomalies were present in the remaining 394 patients (29%). The most common variation was the common origin of the brachiocephalic and the left common carotid arteries (302/1359 cases, about 22%). The most common anomaly were aberrant right subclavian artery (4/1359, about 0.5%) and right aortic arch (4/1359 cases, about 0.5%). CONCLUSIONS: Our multicentric series is, as far as we know, the largest reported to date for the definition of the prevalence of variation and anomalies of aortic arch anatomy and branching pattern. Knowledge of such findings may avoid both in the immediate and in the long term an injury to the patient, decreasing the rate of complications during surgery and interventional radiology procedures in the head and neck district.

Asymptomatic isolated partial hiatal herniation of the pancreas: MDCT evaluation and anatomical explanation: case report and review of literature.

Isolated herniation of the pancreas through a gastroesophageal hiatus is an extremely rare condition, and only one case has been reported in the world literature. We describe a MDCT diagnosis of isolated partial hiatal hernia containing the body of a normal pancreas in an asymptomatic patient, give an anatomical explanation and review the corresponding literature.