Morphological and Functional Neuroradiology of Brain Metastases.

Neuroimaging plays a key role in the diagnosis and differentiation of brain metastases (BM) in patients with known or unknown malignancies. Computed tomography and magnetic resonance imaging are the key imaging modalities used in the detection of BM. Advanced imaging techniques including proton magnetic resonance spectroscopy, magnetic resonance perfusion, diffusion weighted imaging, and diffusion tensor imaging may aid in arriving at the correct diagnosis, in particular cases, such as newly diagnosed solitary enhancing brain lesions in patients without known malignancy. Imaging is also performed to predict and/or assess the efficacy of treatment, and to differentiate residual or recurrent tumors from therapy-related complications. Furthermore, the recent advent of artificial intelligence is opening up a vast scenario for the analysis of quantitative information deriving from neuroimaging. In this image-rich review, we provide an up-to-date overview on the application of imaging in patients with BM. We describe typical and atypical imaging findings of parenchymal and extra-axial BM on Computed tomography, magnetic resonance imaging, and positron emission tomography, focusing on the role of advanced imaging techniques, that can serve as problem-solving tools in the management of patients with BM.

Diagnostic neuroradiology of intracranial meningiomas presenting with hemorrhagic onset: a double center 14-year experience.

PURPOSE: This study aims to increase awareness of the hemorrhagic presentation of intracranial meningiomas in the emergency department and present clues for neuroradiological diagnosis, which is crucial for pertinent management. We described the prevalence of hemorrhage in a large population of meningioma patients, with emphasis on clinical presentation, computed tomography (CT), magnetic resonance (MR), and digital subtraction angiography (DSA) findings. METHODS: This retrospective analysis has been performed at two reference institutions between January 2002 and December 2015, and includes 1304 patients with histologically proven newly diagnosed intracranial meningioma. Clinical features and neuroradiological findings of intracranial meningiomas presenting with hemorrhage have been reviewed. RESULTS: Twenty-four patients (1.8%, 16 females, 8 males, age range: 29-88 years) were found to have spontaneous hemorrhagic onset of the newly diagnosed meningioma. A sudden onset occurred in 23/24 patients. Sixteen patients showed isolated intralesional hemorrhage, four had subdural hematomas, and the remaining four presented combined intralesional and subarachnoid (n = 2) or intraventricular (n = 2) hemorrhages. In 13 patients, CT showed both the hemorrhage and the meningioma. In the other 11 patients, diagnosis was achieved by emergency or early surgery (n = 5), MRI (n = 5), and DSA (n = 1). CONCLUSIONS: The presence of an underlying meningioma has to be considered in the differential diagnosis of spontaneous intracranial hemorrhage, although this is a rare event. CT, MRI, and occasionally DSA were useful to obtain the diagnosis; however, in up to a fifth of patients, this was achieved at surgery.

Imaging of metabolic and overload disorders in tissues and organs.

Metabolic and overload disorders are a heterogeneous group of relatively uncommon but important diseases. While imaging plays a key role in the early detection and accurate diagnosis in specific organs with a pivotal role in several metabolic pathways, most of these diseases affect different tissues as part of a systemic syndromes. Moreover, since the symptoms are often vague and phenotypes similar, imaging alterations can present as incidental findings, which must be recognized and interpreted in the light of further biochemical and histological investigations. Among imaging modalities, MRI allows, thanks to its multiparametric properties, to obtain numerous information on tissue composition, but many metabolic and accumulation alterations require a multimodal evaluation, possibly using advanced imaging techniques and sequences, not only for the detection but also for accurate characterization and quantification. The purpose of this review is to describe the different alterations resulting from metabolic and overload pathologies in organs and tissues throughout the body, with particular reference to imaging findings.

Dynamic contrast-enhanced (DCE) imaging: state of the art and applications in whole-body imaging.

Dynamic contrast-enhanced (DCE) imaging is a non-invasive technique used for the evaluation of tissue vascularity features through imaging series acquisition after contrast medium administration. Over the years, the study technique and protocols have evolved, seeing a growing application of this method across different imaging modalities for the study of almost all body districts. The main and most consolidated current applications concern MRI imaging for the study of tumors, but an increasing number of studies are evaluating the use of this technique also for inflammatory pathologies and functional studies. Furthermore, the recent advent of artificial intelligence techniques is opening up a vast scenario for the analysis of quantitative information deriving from DCE. The purpose of this article is to provide a comprehensive update on the techniques, protocols, and clinical applications - both established and emerging - of DCE in whole-body imaging.

Imaging side effects and complications of chemotherapy and radiation therapy: a pictorial review from head to toe.

Newer biologic drugs and immunomodulatory agents, as well as more tolerated and effective radiation therapy schemes, have reduced treatment toxicity in oncology patients. However, although imaging assessment of tumor response is adapting to atypical responses like tumor flare, expected changes and complications of chemo/radiotherapy are still routinely encountered in post-treatment imaging examinations. Radiologists must be aware of old and newer therapeutic options and related side effects or complications to avoid a misinterpretation of imaging findings. Further, advancements in oncology research have increased life expectancy of patients as well as the frequency of long-term therapy-related side effects that once could not be observed. This pictorial will help radiologists tasked to detect therapy-related complications and to differentiate expected changes of normal tissues from tumor relapse.

The role of diffusion tensor imaging in idiopathic normal pressure hydrocephalus: A literature review.

Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome that comprises a triad of gait disturbance, dementia and urinary incontinence, associated with ventriculomegaly in the absence of elevated intraventricular cerebrospinal fluid (CSF) pressure. It is important to identify patients with iNPH because some of its clinical features may be reversed by the insertion of a CSF shunt. The diagnosis is based on clinical history, physical examination and brain imaging, especially magnetic resonance imaging (MRI). Recently, some papers have investigated the role of diffusion tensor imaging (DTI) in evaluating white matter alterations in patients with iNPH. DTI analysis in specific anatomical regions seems to be a promising MR biomarker of iNPH and could also be used in the differential diagnosis from other dementias. However, there is a substantial lack of structured reviews on this topic. Thus, we performed a literature search and analyzed the most recent and pivotal articles that investigated the role of DTI in iNPH in order to provide an up-to-date overview of the application of DTI in this setting. We reviewed studies published between January 2000 and June 2020. Thirty-eight studies and four reviews were included. Despite heterogeneity in analysis approaches, the majority of studies reported significant correlations between DTI and clinical symptoms in iNPH patients, as well as different DTI patterns in patients with iNPH compared to those with Alzheimer or Parkinson diseases. It remains to be determined whether DTI could predict the success after CSF shunting.

Developmental venous anomalies in patients with multiple sclerosis: is that a coincidence or an ancillary finding?

PURPOSE: Developmental venous anomalies (DVAs) have been found to be more prevalent in patients with multiple sclerosis (MS). The aim of the study was to compare the prevalence of DVAs in a large population of patients with MS compared with controls and to investigate the correlation of 3D Fluid Attenuated Inversion Recovery (FLAIR) hyperintense signal abnormalities adjacent to DVAs between MS patients and controls having DVAs, as well as DVA potential role in differential diagnosis. METHODS: Between January 2001 and December 2019, 349 patients who met the McDonald criteria for MS diagnosis (249 females, 100 males, age range 18-70 years) were retrospectively included in the study. All patients and 340 age-matched healthy controls had brain MRIs performed on a 1.5 Tesla MR system. Two radiologists reviewed all images to identify DVAs; their presence was compared between the MS and control groups. Among the subjects having DVAs, age, gender, adjacent FLAIR anomalies, and DVA location were compared between the two groups. RESULTS: Fifty (14.3%) out 349 patients presented 51 DVAs (35 supratentorial and 16 infratentorial), in comparison to 21/340 (6.2%) controls (P = 0.0005). One patient showed 2 simultaneous DVAs, while 3 patients had coexisting pontine capillary telangiectasias. FLAIR white matter changes adjacent to DVAs were found in 46.2% of patients and in 28.1% of controls (P = 0.0001). CONCLUSIONS: DVAs demonstrated a higher prevalence in the MS group in comparison to controls. We confirmed the association between DVAs and FLAIR anomalies in MS patients. However, currently there are no evidences that the presence of DVAs may be used in MS differential diagnosis.

Impact of coronavirus disease 2019 (COVID-19) emergency on Italian radiologists: a national survey.

OBJECTIVES: To perform an online survey aimed at evaluating the impact of COVID-19 on Italian radiology departments. METHODS: We launched a survey composed of 25 questions about how COVID-19 has changed the safety and organization of daily activity in Italian radiology units. RESULTS: A total of 2136/10,564 (20.2%) radiologists of the Italian Society of Medical and Interventional Radiology participated. Two-thirds performed at least one diagnostic/interventional procedure on COVID-19 patients. The 88.1% reported a reduction in the elective imaging volumes, with US, mammography, and MRI having shown the greater decrease (41.1%, 23.9%, and 21.1%, respectively). In 69.6% of cases, institutions had trouble getting personal protective equipment (PPE), especially public hospitals and southern institutions. Less than 30% of participants were subjected to RT-PCR swab test, although 81.5% believed that it should be done on all health workers and 70% suggested it as the most important measure to improve safety at work. Slightly more than half of participants declared to work safely and felt to be adequately protected by their institutions. Up to 20% of northern participants were redeployed to clinical services. The first imaging examination performed by admitted COVID-19 patients was chest radiography in 76.3% of cases. Almost half of participants reported that less than 30% of health workers were infected in their radiology department, with higher rates in northern regions and public institutions. CONCLUSIONS: This snapshot of the current situation in Italian radiology departments could be used to harmonize the organization of working activity in order to safely and effectively face this pandemic. KEY POINTS: • More than two-thirds of institutions had trouble getting PPE for health workers, with public hospitals and southern institutions that presented more procurement problems • A substantial drop of imaging volumes was observed in the vast majority of Italian radiology departments, mostly due to the decrease of ultrasound, mammography, and MRI, especially in private practice were working activity was stopped in 13.3% of institutions • RT-PCR swab to health workers was reported as the most suggested measure by Italian radiologists to improve safety at work, as more than 80% of them believed that it should be performed to all health workers, although less than 30% were subjected to this test.

Diffusion-Weighted Imaging in Oncology: An Update.

To date, diffusion weighted imaging (DWI) is included in routine magnetic resonance imaging (MRI) protocols for several cancers. The real additive role of DWI lies in the "functional" information obtained by probing the free diffusivity of water molecules into intra and inter-cellular spaces that in tumors mainly depend on cellularity. Although DWI has not gained much space in some oncologic scenarios, this non-invasive tool is routinely used in clinical practice and still remains a hot research topic: it has been tested in almost all cancers to differentiate malignant from benign lesions, to distinguish different malignant histotypes or tumor grades, to predict and/or assess treatment responses, and to identify residual or recurrent tumors in follow-up examinations. In this review, we provide an up-to-date overview on the application of DWI in oncology.

Diffusion tensor imaging in idiopathic normal pressure hydrocephalus: clinical and CSF flowmetry correlations.

PURPOSE: Diffusion tensor imaging is a magnetic resonance technique that provides information about the orientation and anisotropy of the white matter tracts. The aim of this study was to analyse diffusion tensor imaging quantitative parameters in idiopathic normal pressure hydrocephalus patients, in order to determine whether this method could correlate to clinical scores and cerebrospinal fluid flowmetry data. METHODS AND MATERIALS: Fifteen consecutive patients with idiopathic normal pressure hydrocephalus and 15 age-matched controls underwent cerebrospinal fluid flowmetry and diffusion tensor imaging using a 1.5 Tesla system. Fractional anisotropy, mean diffusivity, axial diffusivity and radial diffusivity values were calculated using region of interest atlas-based tract-mapping in nine cerebral areas and compared among the two groups. In addition, for idiopathic normal pressure hydrocephalus patients, diffusion tensor imaging parameters were correlated to clinical scores (mini mental state examination and frontal assessment battery) and cerebrospinal fluid flowmetry data. RESULTS: Mean fractional anisotropy was significantly lower for the idiopathic normal pressure hydrocephalus group than for the control group in the forceps minor and motor cortex; the idiopathic normal pressure hydrocephalus group had significantly higher mean axial diffusivity for the genu of the corpus callosum and forceps minor. We did not find significant correlation between diffusion tensor imaging parameters and cerebrospinal fluid flowmetry and mini mental state examination, while we observed a correlation between forceps minor fractional anisotropy and frontal assessment battery; no correlation between flowmetry and clinical scores was found. CONCLUSION: Our findings suggest that diffusion tensor imaging provides a non-invasive biomarker of white matter changes in idiopathic normal pressure hydrocephalus patients. Forceps minor is the best site to analyse. As diffusion tensor imaging offers a better correlation to clinical status than cerebrospinal fluid flowmetry, it should be included in the routine idiopathic normal pressure hydrocephalus protocol.

Neuroimaging of Takayasu Arteritis in a Patient with Ulcerative Rectocolitis.

BACKGROUND: Takayasu arteritis (TA), also known as aortoarteritis and pulseless disease, is an autoimmune, idiopathic, large-vessel vasculitis that primarily affects the aorta and its major branches, the coronary arteries, and the pulmonary arteries. METHODS: This is a peculiar clinical and radiological pattern of TA in a young female Caucasian. Her medical history included diagnosis of ulcerative rectocolitis at the age of 14. Because of the occurrence of anemia and exacerbation of rectocolitis, she had started infliximab associated with low doses of cortisone and mesalazine. Three months before admission, therapy with infliximab was discontinued because of the onset of fever, sore throat, and the increase in the neck pain. Imaging is crucial to achieve a proper diagnosis and the main differential diagnosis of this setting is arterial dissection. Magnetic resonance angiography (MRA) and color Doppler sonography (CDS) have been able to demonstrate rare but possible arteriovenous fistula in TA patients. This is the first report on arteriovenous fistula of cervical venous plexus in TA patients. CONCLUSION: (1) TA has to be suspected in young woman with neck pain, even without neurological symptoms. (2) Magnetic resonance imaging and CDS can depict wall thickening and abnormal caliber in the involved vessels. (3) MRA and CDS are able to demonstrate rare but possible arteriovenous fistula in TA patients. (4) Rectocolitis therapy could be a trigger factor of wall vessel involvement.

The spectrum of magnetic resonance findings in cerebrotendinous xanthomatosis: redefinition and evidence of new markers of disease progression.

Cerebrotendinous xanthomatosis (CTX) is a metabolic disease characterized by systemic signs and neurological impairment, which can be prevented if chenodeoxycholic acid (CDCA) treatment is started early. Despite brain MRI represents an essential diagnostic tool, the spectrum of findings is worth to be reappraised, and follow-up data are needed. We performed clinical evaluation and brain MRI in 38 CTX patients. Sixteen of them who were untreated at baseline examination underwent clinical and MRI follow-up after long-term treatment with CDCA. Brain MRI abnormalities included cortical and cerebellar atrophy, and T2W/FLAIR hyperintensity involving subcortical, periventricular, and cerebellar white matter, the brainstem and the dentate nuclei. Regarding the dentate nuclei, we also observed T1W/FLAIR hypointensity consistent with cerebellar vacuolation and T1W/FLAIR/SW hypointense alterations compatibly with calcification in a subgroup of patients. Long-term follow-up showed that clinical and neuroradiological stability or progression were almost invariably associated. In patients with cerebellar vacuolation at baseline, a worsening over time was observed, while subjects lacking vacuoles were clinically and neuroradiologically stable at follow-up. The brains of CTX patients very often show both supratentorial and infratentorial abnormalities at MRI, the latter being related to clinical disability and including a wide spectrum of dentate nuclei alterations. The presence of cerebellar vacuolation may be regarded as a useful biomarker of disease progression and unsatisfactory response to therapy. On the other hand, the absence of dentate nuclei signal alteration should be considered an indicator of better prognosis.

An atypical Bickerstaff's brainstem encephalitis with involvement of spinal cord.

Bickerstaff brainstem encephalitis (BBE) is a rare neurological disease that generally has a good prognosis. We describe an atypical case of a patient with severe BBE; the presentation was uncommon because of the lack of ophthalmoplegia and because of evidence of both peripheral neuropathy and brainstem encephalitis. The article reports clinical and biochemical evaluation and focuses on magnetic resonance imaging (MRI) findings in diagnosis and management of the patient. Notably, we found a previously unreported dramatic spinal cord involvement on MRI. We believe these findings could add to diagnostic tools, and that this case may represent a new variant of BBE with more aggressive behavior.

Neuroimaging of the Postoperative Spine.

Operative treatments of the spine are becoming increasingly more common for the availability of a wide range of surgical and minimally invasive procedures. MR imaging allows for excellent evaluation of both normal and abnormal findings in the postoperative spine. This article provides the basic tools to evaluate complications after different operative procedures and offers an overview on the main topics a radiologist may encounter during his or her professional carrier.

Early relapsing calcified cerebral embolism.

Calcified cerebral emboli are rarely reported, but may be recurrent and devastating. Misdiagnosis at interpretation of initial brain computed tomography (CT) scan may occur in up to 27% of cases. The purpose of this case report was to describe clinical, CT, and CT angiography findings in a 79-year-old woman undergoing early recurrent stroke from calcified cerebral embolism. Neuroradiology should not overlook calcified cerebral embolism, and this confirms the role of CT in the assessment of stroke.

Cerebral circulation time is prolonged and not correlated with EDSS in multiple sclerosis patients: a study using digital subtracted angiography.

Literature has suggested that changes in brain flow circulation occur in patients with multiple sclerosis. In this study, digital subtraction angiography (DSA) was used to measure the absolute CCT value in MS patients and to correlate its value to age at disease onset and duration, and to expand disability status scale (EDSS). DSA assessment was performed on eighty MS patients and on a control group of forty-four age-matched patients. CCT in MS and control groups was calculated by analyzing the angiographic images. Lesion and brain volumes were calculated in a representative group of MS patients. Statistical correlations among CCT and disease duration, age at disease onset, lesion load, brain volumes and EDSS were considered. A significant difference between CCT in MS patients (mean = 4.9s; sd = 1.27 s) and control group (mean = 2.8s; sd = 0.51 s) was demonstrated. No significant statistical correlation was found between CCT and the other parameters in all MS patients. Significantly increased CCT value in MS patients suggests the presence of microvascular dysfunctions, which do not depend on clinical and MRI findings. Hemodynamic changes may not be exclusively the result of a late chronic inflammatory process.

Wake-up (or wake-up for) stroke: a treatable stroke.

A 74-year-old man was admitted to the Emergency Room of our institution with worsening dysarthria, left-side weakness and hypoesthesia (NIHSS score: 5) since his awakening at 7:30 a.m. The evening before, he had gone to sleep at 10:30 p.m. Brain computed tomography (CT) and cervicocranial CT angiography showed low density attenuation of the right caudate nucleus head and lenticular nucleus and sub-total occlusion of ipsilateral middle cerebral artery (MCA) pre-bi/trifurcation M1 segment. Brain CT perfusion showed an ischemic core in the right striatal region, surrounded by a wide region of ischemic penumbra. Although the onset of symptoms, defined as "time last-seen well", was 14 hours before presentation, the following worsening of neurological conditions (NIHSS score: 12) and the evidence of cerebral blood flow / cerebral blood volume mismatch at CT perfusion led us to propose neuroendovascular treatment on the basis of an off-label use. Neuroendovascular treatment by Penumbra system was achieved and the right MCA was only partially recanalized. The patient was discharged with NIHSS score of 12. At six months, modified Rankin scale score was 3. To the best of our knowledge, this is the first Italian case report describing a patient who underwent successful neuroendovascular treatment for a "wake-up stroke" without clinical worsening nor major complications and an acceptable clinical outcome. This was possible thanks to an extension of the therapeutic window guided by CT perfusion.