Three-dimensional constructive interference in steady state (3D CISS) is a steady-state gradient-echo sequence in magnetic resonance imaging (MRI) that has been used in an increasing number of applications in the study of brain disease in recent years. Owing to the very high spatial resolution, the strong hyperintensity of the cerebrospinal fluid signal and the high contrast-to-noise ratio, 3D CISS can be employed in a wide range of scenarios, ranging from the traditional study of cranial nerves, the ventricular system, the subarachnoid cisterns and related pathology to more recently discussed applications, such as the fundamental role it can assume in the setting of acute ischemic stroke, vascular malformations, infections and several brain tumors. In this review, after briefly summarizing its fundamental physical principles, we examine in detail the various applications of 3D CISS in brain imaging, providing numerous representative cases, so as to help radiologists improve its use in imaging protocols in daily clinical practice.

Objectives: To compare dual-energy CT (DECT) and MRI for assessing presence and extent of traumatic bone marrow edema (BME) and fracture line depiction in acute vertebral fractures. Methods: Eighty-eight consecutive patients who underwent dual-source DECT and 3-T MRI of the spine were retrospectively analyzed. Five radiologists assessed all vertebrae for presence and extent of BME and for identification of acute fracture lines on MRI and, after 12 weeks, on DECT series. Additionally, image quality, image noise, and diagnostic confidence for overall diagnosis of acute vertebral fracture were assessed. Quantitative analysis of CT numbers was performed by a sixth radiologist. Two radiologists analyzed MRI and grayscale DECT series to define the reference standard. Results: For assessing BME presence and extent, DECT showed high sensitivity (89% and 84%, respectively) and specificity (98% in both), and similarly high diagnostic confidence compared to MRI (2.30 vs. 2.32; range 0–3) for the detection of BME (p = .72). For evaluating acute fracture lines, MRI achieved high specificity (95%), moderate sensitivity (76%), and a significantly lower diagnostic confidence compared to DECT (2.42 vs. 2.62, range 0–3) (p < .001). A cutoff value of − 0.43 HU provided a sensitivity of 89% and a specificity of 90% for diagnosing BME, with an overall AUC of 0.96. Conclusions: DECT and MRI provide high diagnostic confidence and image quality for assessing acute vertebral fractures. While DECT achieved high overall diagnostic accuracy in the analysis of BME presence and extent, MRI provided moderate sensitivity and lower confidence for evaluating fracture lines. Key Points: • In the setting of spinal trauma, dual-energy CT (DECT) is highly accurate in the evaluation of acute vertebral fractures and bone marrow edema presence and extent. • MRI provides moderate sensitivity and lower diagnostic confidence for the depiction of acute fracture lines, when compared to DECT, which might result in potentially inaccurate and underestimated severity assessment of injuries in certain cases when no fracture lines are visible on MRI. • DECT may represent a valid imaging alternative to MRI in specific settings of acute spinal trauma and in follow-up examinations, especially in elderly or unstable patients and in cases of subtle or complex orientated fracture lines.

Objective: Rare co-existance of disease or pathology Background: Superior mesenteric artery syndrome is caused by vascular compression of the third portion of the duodenum between the aorta and the superior mesenteric artery. It may occur with acute or chronic symptomatology, such as vomiting or postprandial abdominal pain, and it is usually caused by a lack of mesenteric fat pad under conditions of severe weight loss. Crohn's disease can be one of them. Case Reports: We report 2 cases of Crohn's disease patients with clinical suspicion of jejunal stricture who underwent MR-enterography with a novel approach. In fact, the examinations were performed including prone position of the patients inside the scanner, drinking of contrast medium during the examination, and prompt acquisition of fluoroscopic sequences. Both the exams showed an abrupt termination of the duodenum on its third portion and a decreased aortomesenteric distance, allowing the diagnosis of superior mesenteric artery syndrome. Conclusions: A correlation between Crohn's disease and superior mesenteric artery syndrome has never before been reported in the literature. The present study provides some practical steps that may be useful in order to improve MRE standard protocol in recognizing this condition while evaluating Crohn's disease bowel lesions.

Background: Rhinocerebral mucormycosis (ROCM) is an opportunistic fungal infection originating from the paranasal sinuses with extension to the brain. A delayed diagnosis can rapidly result in a poor prognosis. ROCM commonly affects patients with diabetes or immunocompromised states with a variable progression. Case Description: We report the case of a 59-year old patient with an untreated diabetes who developed a ROCM with rapidly progressive neurological symptoms. From the onset of sinus pain, nasal congestion, he rapidly developed facial swelling and masticatory dysfunction. The patient underwent sinus surgery which allowed Rhizopus oryzae to be isolated. Accordingly, a systemic therapy by intensive intravenous amphotericin B was started. Nevertheless, the infection rapidly resulted in bilateral cavernous sinuses thrombosis and occlusion of the left internal carotid artery providing the subsequent patient death. Conclusion: Mucormycosis is a life-threatening fungal infection in diabetic and/or immunosuppressed patients. Our case demonstrates the three main mechanisms for infection spreading that are direct, perineural, and perivascular diffusion. Clear identification of the main risk factors, proper assessment of clinical features, and radiological findings may improve the chance for an early diagnosis and patient survival.

Purpose: The aim of this observational study was to highlight high resolution CT scan characteristics of COVID-19-associated pulmonary aspergillosis (CAPA) with a focus on the detection of de-novo appeared or evolved bronchiectasis. Methods: From March 2020 to May 2021, we enrolled 350 consecutive mechanically ventilated ICU patients with COVID-19. Patients with CAPA and at least one chest CT scan performed within 15 days from the diagnosis were included. Two radiologists were asked to identify typical and atypical signs of COVID-19 pneumonia. Bronchiectasis locations were described and a modified Reiff score was calculated, as severity score. A total of 19 CAPA patients (median age 71.0, Interquartile range (IQR) 62.5–75.0; male 16, 84.2%) were included. Results: According to the 2020 ECMM/ISHAM criteria, 18 patients had probable CAPA and one had proven CAPA. The median time between hospital admission and CT scan was 21 days (IQR 14.5–25.0). The incidence of bronchiectasis in the study population was 57.9% (n = 11). Tubular bronchiectasis was detected in 10 patients and were scored as follows: three patients had a score of 1, three patients had a score of score 2, one patient had a score of 5 and four patients had a score of 6. Eight patients had a previous CT scan (performed at hospital admission), among them: 5 patients developed de-novo bronchiectasis, while 2 patients demonstrated a volumetric increase of bronchiectasis. At the 6-months follow-up, the mortality rate for patients with CAPA was >60%. Conclusion: the radiologic detection of de-novo appearance or volumetric increase of bronchiectasis in COVID-19 should lead clinicians to search for fungal superinfections.