On March 11, 2020, the World Health Organization raised the coronavirus disease 2019 (COVID-19) status to a pandemic level. The disease caused a global outbreak with devastating consequences, and a fair percentage of patients who have recovered from it continue experiencing persistent sequelae. Hence, identifying the medium and long-term effects of the COVID-19 disease is crucial for its future management. In particular, cardiac complications, from affected function to myocardial injuries, have been reported in these patients. Considering that cardiovascular magnetic resonance (CMR) imaging is the gold standard in diagnosing myocardial involvement and has more advantages than other medical imaging modalities, assessing the outcomes of patients who recovered from COVID-19 with CMR could prove beneficial. This review compiles common findings in CMR in patients from the general population who recovered from COVID-19. The CMR-based techniques comprised parametric mapping for analyzing myocardial composition, feature tracking for studying regional heart deformation, and late gadolinium enhancement for detecting compromised areas in the cardiac muscle. A total of 19 studies were included. The evidence suggests that it is more likely to find signs of myocardial injury in patients who recovered from COVID-19 than in healthy controls, including changes in T1 and T2 mapping relaxation times, affected strain, or the presence of late gadolinium enhancement (LGE) lesions. However, more than two years after the outbreak, there is still a lack of consensus about how these parameters may indicate cardiac involvement in patients who recovered from the disease, as limited and contradictory data is available.

OBJECTIVE: In radiotherapy (RT) for locally advanced cervical cancer, high soft tissue contrast on magnetic resonance imaging (MRI) can ensure accurate delineation of target volumes (TVs) and optimal dose distribution to the RT target and organs at risk (OAR). MRI-guided adaptive RT (MRIgART) is a novel technology that revises RT plans according to anatomical changes occurring throughout the treatment to improve target coverage and minimise OAR toxicity. This review aims to assess the evidence and gaps of MRI use in RT planning and MRIgART in the treatment of cervical cancer, as well as challenges in its clinical implementation.
METHODS: Ovid Medline and PubMed were searched using keywords for MRI in RT for cervical cancer. After applying the inclusion and exclusion criteria, the initial search was deduced to 32 studies. A total of 37 final studies were reviewed, including eight additional articles from references.
UNASSIGNED: In the primary studies, TVs and organ motion were assessed before, during, and after treatment. MRI was used to investigate dose distribution and therapeutic response to the treatment in association with its outcome. Lastly, rationales for MRIgART were evaluated.
CONCLUSIONS: It was concluded that MRI enables accurate target delineation, assessment of organ motion and interfraction changes, and monitoring of treatment response through dynamic parameters. Enhanced target coverage and reduced OAR irradiation through MRIgART can improve local control and the overall outcome, although its rationales against the logistical challenges need to be evaluated on further research.

We report a patient with whole neuroaxis dissemination of a sporadic supratentorial hemangioblastoma (HB) for more than 15 years. A 68-year-old female patient presented with severe radiating pain in the right leg. Gadolinium-enhanced lumbar spine MRI showed an intradural mass (2.5 cm in diameter) at the L4 level. The patient had been severely disabled for 22 years after a previous intraventricular brain tumor resection. At that time, the diagnosis was angioblastic meningioma, which was thought to be incorrect. At 14 years after the brain surgery, gamma knife radiosurgery was performed three times for newly developed or recurred supratentorial and infratentorial tumors in the cerebrospinal fluid pathway. The patient underwent lumbar spinal surgery, and a gross total removal of the mass was performed, which confirmed the histopathological diagnosis of HB. We reexamined the old histopathological specimen of the intraventricular tumor from 20 years ago and changed the diagnosis from angioblastic meningioma to supratentorial HB. Six months after spinal surgery, the patient underwent a second spinal surgery and brain surgery, and the histopathological diagnosis was HB following both surgeries, which was the same following the first spinal surgery. Here, we report a sporadic supratentorial HB patient who showed cranial and spinal disseminations for more than two decades along with a literature review.

Intraneural lipoma of the ulnar nerve is a rare peripheral nerve tumor in an uncommon location. Although its benign course, it can cause disabling symptoms such as pain, diminished sensation or paraesthesia, tenderness, and occasionally even loss of strength. We present the case of a middle age woman with insidious paresthesias and swelling of the hypothenar eminence of the left hand for over 1 year. A hand and wrist radiograph first confirmed a focal soft tissue mass with fat density and excluded potential bone lesions. Then, an ultrasound was performed that showed a slightly hyperechoic mass with a fibrillated pattern in contiguity with the proximal aspect of the ulnar nerve. The morphological arrangement of this mass, its location along ulnar nerve distribution and the main signal characteristics in magnetic resonance imaging such as hyperintensity in T1- and T2-weighted images and hypointensity in fat saturation sequences inferred an intraneural lipoma. Due to the progressive symptoms, elective resection of the lesion was performed with full recovery of the symptoms.

OBJECTIVE: To explore the clinical manifestations, diagnosis, treatment, and pathogenesis of diabetic striatopathy (DS) to improve the understanding of the disease and avoid misdiagnosis or underdiagnosis.
METHODS: The clinical, laboratory, and imaging data of 6 patients (5 Asian females and 1 Asian male) with diabetic striatum were analyzed retrospectively, and the related literature was reviewed.
RESULTS: All 6 patients showed hyperglycemia, 5 patients presented with involuntary movement of unilateral limbs, and 1 with unilateral limb numbness. Besides, 5 patients (except case 3) underwent MRI examinations that showed hyperintensity in unilateral caudate and lentiform nucleus on T1-weighted images. And all 6 patients who underwent brain CT examinations showed hyperdensity or isodensity in unilateral caudate and lentiform nucleus. None had a family history of similar abnormal movements. After blood glucose control and symptomatic support treatment, the symptoms of all patients improved to various degrees, and reexaminations showed that the lesions gradually disappeared.
CONCLUSIONS: Diabetic striatal disease is a rare complication of diabetes mellitus, the result of a combination of different pathogenesis. It is characterized by hyperglycemia, hemichorea, and contralateral striatal T1WI hyperintensity or CT hyperdensity. Both ketosis and nonketotic hyperglycemic hemichorea have typical imaging manifestations. The prognosis is excellent when this disease is detected early, and the lesions can be gradually absorbed and dissipated with glycemic control.

Cerebral venous thrombosis (CVT) is a rare form of venous thromboembolism. The presentation of symptoms is highly variable in this disease. The findings on MRI vary depending on the age of the thrombus within the vessel. We report a 53-year-old male patient with CVT who presented with a sudden-onset grand mal seizure and limb paralysis. Primary MRI presented long T1 long T2 signals, persistent high signals on DWI and ADC maps in the cortex of right frontal lobe. Contrast-enhanced MR detected a lesion with ring-like enhancement in right frontal lobe. His symptoms were significantly improved with anticoagulant therapy of Warfarin. Our findings represent the description of abnormal MRI contrast enhancing tumor-like masses. CVT should be added to the differential diagnosis of supratentorial ring-enhancing lesions.

Artificial intelligence (AI) for medical imaging is a technology with great potential. An in-depth understanding of the principles and applications of magnetic resonance imaging (MRI), machine learning (ML), and deep learning (DL) is fundamental for developing AI-based algorithms that can meet the requirements of clinical diagnosis and have excellent quality and efficiency. Moreover, a more comprehensive understanding of applications and opportunities would help to implement AI-based methods in an ethical and sustainable manner. This review first summarizes recent research advances in ML and DL techniques for classifying human brain magnetic resonance images. Then, the application of ML and DL methods to six typical neurological and psychiatric diseases is summarized, including Alzheimer\'s disease (AD), Parkinson\'s disease (PD), major depressive disorder (MDD), schizophrenia (SCZ), attention-deficit/hyperactivity disorder (ADHD), and autism spectrum disorder (ASD). Finally, the limitations of the existing research are discussed, and possible future research directions are proposed.

BACKGROUND: Stroke is the second leading cause of death worldwide. There is a real need to develop treatment strategies for reducing neurological deficits in stroke survivors, and stem cell (SC) therapeutics appear to be a promising alternative for stroke therapy that can be used in combination with approved thrombolytic or thrombectomy approaches. However, the efficacy of SC therapy depends on the SC homing ability and engraftment into the injury site over a long period of time. Nonetheless, tracking SCs from their niche to the target tissues is a complex process.
OBJECTIVE: To evaluate SC migration homing, tracking and therapeutic efficacy in the treatment of stroke using nanoparticles.
METHODS: A systematic literature search was performed to identify articles published prior to November 2019 that were indexed in PubMed and Scopus. The following inclusion criteria were used: (1) Studies that used in vivo models of stroke or ischemic brain lesions; (2) Studies of SCs labeled with some type of contrast agent for cell migration detection; and (3) Studies that involved in vivo cellular homing and tracking analysis.
RESULTS: A total of 82 articles were identified by indexing in Scopus and PubMed. After the inclusion criteria were applied, 35 studies were selected, and the articles were assessed for eligibility; ultimately, only 25 studies were included. Most of the selected studies used SCs from human and mouse bone marrow labeled with magnetic nanoparticles alone or combined with fluorophore dyes. These cells were administered in the stroke model (to treat middle cerebral artery occlusion in 74% of studies and for photothrombotic induction in 26% of studies). Fifty-three percent of studies used xenogeneic grafts for cell therapy, and the migration homing and tracking evaluation was performed by magnetic resonance imaging as well as other techniques, such as near-infrared fluorescence imaging (12%) or bioluminescence assays (12%).
CONCLUSIONS: Our systematic review provided an up-to-date evaluation of SC migration homing and the efficacy of cellular therapy for stroke treatment in terms of functional and structural improvements in the late stage.

Herein, we described 2 patients with posterior spinal artery syndrome (PSAS) caused by vertebral artery dissection. The patients complained of sudden neck pain or walking instability. Neurological examination revealed sensory loss, muscle weakness, and sensory ataxia. Angiography showed double lumen sign or intimal flap in the vertebral artery. T2-weighted imaging and diffusion-weighted imaging of MRI showed a hyperintense lesion in the dorsal side of the cervical spinal cord at different times after onset. Both patients had good outcome after antiplatelet therapy and physiotherapy. A review of previously reported PSAS cases was also conducted in order to improve the understanding and awareness of this rare myelopathy.

Posterior reversible encephalopathy syndrome (PRES) is a reversible vasogenic brain edema in patients who present with seizure, headache, visual disturbance, and altered mental status, and a characteristic neuroimaging profile. Although PRES predominantly affects the bilateral parieto-occipital areas, involvement of the frontal and temporal lobes, basal ganglia, brainstem, and cerebellum is not uncommon. Isolated involvement of the brainstem and cerebellum sparing the parieto-occipital lobe is rarely reported. Here, we describe a 47-year-old man with end-stage renal disease on chronic hemodialysis who presented with prominent hypertension and coma after missing three dialysis sessions. On examination, there was paucity of focal neurologic signs. Diagnosis of PRES was based on brain magnetic resonance imaging findings that were consistent with vasogenic edema of the pons and cerebellum without involvement of other areas. With antihypertensive therapy and intense ultrafiltration during hemodialysis, the patient\'s blood pressure and consciousness returned to normal, along with complete resolution of the abnormal imaging findings. This case stresses that noncompliance with dialysis should be considered a risk factor for PRES. This case is considered relative to the available literature on three patients with brainstem variant of PRES.