Magnetic Resonance Imaging in Coronavirus Disease - 2019 Associated Rhino-Orbital-Cerebral Mucormycosis (CA-ROCM) - Imaging Analysis of 50 Consecutive Patients

Imaging Features of Invasive Fungal Rhinosinusitis: A Systematic Review

Fungal rhinosinusitis (FRS) includes non-invasive and invasive subtypes with the latter having significant morbidity and mortality. This systematic review aims to identify the imaging features most correlated with invasive fungal rhinosinusitis (IFRS) and present a checklist of these features to aid diagnosis. PubMed, Embase, CENTRAL, and Science Direct were searched from inception to May 2023, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Primary research articles published in English describing the imaging features of IFRS were included. The systematic review was conducted in accordance with the PRISMA guidelines. Forty-eight articles were identified for inclusion. Six studies examined radiological features in acute invasive fungal rhinosinusitis (AIFRS), and 9 studies of chronic invasive fungal rhinosinusitis (CIFRS). A majority of studies did not specify whether IFRS cases were acute or chronic. On CT, bony erosion and mucosal thickening were the most common features. Other features include nasal soft tissue thickening, nasal cavity opacification, opacification of the affected sinus, and perisinus soft tissue infiltration. Extra-sinus extension was commonly observed on MRI, most often invading intraorbitally and intracranially. Other sites of extra-sinus extension included the cavernous sinus, pterygopalatine fossa, infratemporal fossa, masticator space, and facial soft tissue. IFRS is a condition with potential for high morbidity and mortality. Several radiological features are highly suggestive of IFRS. Early identification of high-risk radiological features using a checklist may aid prompt diagnosis and early treatment. Future research investigating the radiological differentiation between IFRS and other significant pathology including bacterial orbital cellulitis would be beneficial.

Severe mold fungal infections in critically ill patients with COVID-19

The SARS-CoV-2 pandemic put an unprecedented strain on modern societies and healthcare systems. A significantly higher incidence of invasive fungal co-infections was noted compared with the pre-COVID-19 era, adding new diagnostic and therapeutic challenges in the critical care setting. In the current narrative review, we focus on invasive mold infections caused by Aspergillus and Mucor species in critically ill COVID-19 patients. We discuss up-to-date information on the incidence, pathogenesis, diagnosis and treatment of these mold-COVID-19 co-infections, as well as recommendations on preventive and prophylactic interventions. Traditional risk factors were often not recognized in COVID-19-associated aspergillosis and mucormycosis, highlighting the role of other determinant risk factors. The associated patient outcomes were worse compared with COVID-19 patients without mold co-infection.

A Retrospective Study of Imaging of Invasive Rhino-Orbital-Cerebral Mucormycosis in the COVID-19 Pandemic in a Tertiary Care Center

Aim The study aims to analyze the imaging findings of invasive rhino-orbital-cerebral mucormycosis (ROCM) in patients who had COVID-19. Materials and methods This retrospective descriptive study was done on confirmed (culture and histopathology) patients who had a COVID-19 infection. The data was collected from the record section from May 2021 to June 2021. Imaging data were analyzed, and findings were tabulated according to statistical methods. Results Radiological evaluation, including CT and MRI, was done in 48 cases. The ethmoid sinus was the most common sinus involved in 60.41% of cases, followed by the maxillary sinus (52.09%). Unilateral pansinusitis was observed in 21 cases (43.75%). Among periantral extensions, retroantral fat involvement was the most common finding, seen in 24 cases (50%). Lamina papyracea and the walls of the maxillary sinus were involved in eight cases (16.67%). A total of 38 cases (79.17%) exhibited involvement of the extraconal compartment, while 32 cases (66.67%) showed involvement of the intraconal compartment. In intracranial involvement, infarct was noted in 13 cases (27%), and cavernous sinus involvement in nine cases (18.75%). Conclusions ROCM is a life-threatening fungal infection in immunocompromised patients, especially diabetics. Imaging of ROCM plays a pivotal role in early diagnosis, the extent of disease, surgical planning, prognosis, and the response to treatment. Radiologists must know the imaging features and patterns of extension of ROCM.

A New Proposed Combined CT and MRI Staging System for Covid-19-Associated Rhino-Orbito-Cerebral Fungal Infection: A Multi-center Study with Pathological Correlation

RATIONALE AND OBJECTIVES

To propose a combined computed tomography (CT) and magnetic resonance imaging (MRI) based classification system in the management of COVID-19-associated rhino-orbito-cerebral (C-ROC) fungal infection and to assess the reliability of such proposed staging system.

MATERIALS AND METHODS

This was a multi-center prospective study conducted on 122 adults with previously confirmed COVID-19 infection. CT and contrast-enhanced MRI (CE-MRI) were performed for all patients. Three radiologists (with experience of 8, 10, and 14 years) independently assessed all images. Then, each patient was assigned a radiological stage based on the five stages of the proposed system according to the radiological extent of the fungal infection. The intra-class correlation coefficient (ICC) test assessed the inter-rater agreement. Based on the pathological evaluation of post-operative specimens, a diagnosis of fungal infection was documented.

RESULTS

The most prevalent severity stage among all raters was stage IV in 29.5-31.1% patients. The overall inter-rater agreement of the proposed staging system was excellent (ICC 0.971, 95% CI;0.960-0.979). Moreover, the most common detected pathogen was Mucormycosis (n = 87, 71.3%). Furthermore, there was a statistically significant association between the patients' outcome and the severity stage (P value 0.001) and there was no statistically significant association between ethmoid and sphenoid sinus affection and cranial extension (P value 0.081).

CONCLUSION

Our proposed combined CT and MRI severity staging system has a high inter-rater agreement. Moreover, it can aid in the early detection of the C-ROC fungal infection, improve preoperative planning, and subsequently improve the patient's outcome.

Topographical Distribution of Neuroanatomical Abnormalities Following COVID-19 Invasion : A Systematic Literature Review

PURPOSE

This systematic review is aimed at synthesising the literature base to date on the frequency and topographical distribution of neuroanatomical changes seen on imaging following COVID-19 invasion with a focus on both the acute and chronic phases of the disease.

METHODS

In this study, 8 databases were systematically searched to identify relevant articles published from December 2019 to March 2022 and supplemented with a manual reference search. Data were extracted from the included studies and narrative synthesis was employed to integrate the findings.

RESULTS

A total of 110 studies met the inclusion criteria and comprised 119,307 participants (including 31,073 acute and 143 long COVID-19 patients manifesting neurological alterations) and controls. Considerable variability in both the localisation and nature of neuroanatomical abnormalities are noted along the continuum with a wide range of neuropathologies relating to the cerebrovascular/neurovascular system, (sub)cortical structures (including deep grey and white matter structures), brainstem, and predominant regional and/or global alterations in the cerebellum with varying degrees of spinal involvement.

CONCLUSION

Structural regional alterations on neuroimaging are frequently demonstrated in both the acute and chronic phases of SARS-CoV‑2 infection, particularly prevalent across subcortical, prefrontal/frontal and cortico-limbic brain areas as well as the cerebrovascular/neurovascular system. These findings contribute to our understanding of the acute and chronic effects of the virus on the nervous system and has the potential to provide information on acute and long-term treatment and neurorehabilitation decisions.

Predicting intracranial involvement: Unveiling perineural spread in COVID-19-associated mucormycosis, a novel phenomenon

This study aimed to investigate the risk factors associated with intracranial involvement in COVID-19-associated mucormycosis (CAM) and to develop a nomogram model for predicting the risk of intracranial involvement, with a specific focus on perineural spread. An ambispective analysis was conducted on 275 CAM patients who received comprehensive treatment. Univariable and multivariable logistic regression analyses were performed to identify independent risk factors, and a nomogram was created based on the results of the multivariable analysis. The performance of the nomogram was evaluated using a receiver operating characteristic (ROC) curve, and the discriminatory capacity was assessed using the area under the curve (AUC). The model's calibration was assessed through a calibration curve and the Hosmer Lemeshow test. In the results, the multivariable logistic regression analysis revealed that age (OR: 1.23, 95% CI 1.06-3.79), HbA1c (OR: 7.168, 95% CI 1.724-25.788), perineural spread (OR: 6.3, 95% CI 1.281-19.874), and the disease stage were independent risk factors for intracranial involvement in CAM. The developed nomogram demonstrated good discriminative capacity with an AUC of 0.821 (95% CI 0.713-0.909) as indicated by the ROC curve. The calibration curve showed that the nomogram was well-calibrated, and the Hosmer Lemeshow test yielded a P-value of 0.992, indicating a good fit for the model. In conclusion, this study found that CAM particularly exhibits perineural spread, which is a predictive factor for intracranial involvement. A nomogram model incorporating age, HbA1c, disease stage, and perineural spread was successfully developed for predicting intracranial involvement in CAM patients in both in-patient and out-patient settings.

Magnetic Resonance Imaging in COVID-19 Associated Rhino-Sinusal Mucormycosis

Rhino-sinusal mucormycosis is an acute invasive fungal infection rarely encountered in the clinical setting, occurring in severe immunosuppressed patients. However, in patients suffering from COVID-19 disease a dramatic increase in the incidence of mucormycosis has been recorded. The aim of the study is to discuss the MRI findings of patients with COVID-19 associated mucormycosis. This is a retrospective review of 10 hospitalized and operated patients in three Otolaryngologic Departments between the 1st of February 2021 and the 30th of October 2021. All patients presented nasal mucormycosis, histologically verified along with documented SARS-CoV-2 positive RT-PCR test. The sinus involvement, extra sinus spread and peri-sinus invasion were documented in all patients. The correlation between MRI and intra-operative findings was also assessed. The black turbinate sign and peri-antral soft tissue infiltration are early MRI signs characteristic of mucormycosis. Moreoever, MRI has a significantly high positive predictive value for intra-operative findings in COVID-19 associated mucormycosis.

Radiological features of COVID-19-associated mucormycosis: A report of 36 cases along with a literature review

The pandemic of COVID-19 along with high use of corticosteroids resulted in the emergence of invasive fungal infection. Here, we reported the radiologic feature of mucormycosis in COVID-19-infected cases and reviewed with available literature.

Imaging Spectrum of Coronavirus Disease- 2019 Associated Rhino-Orbital-Cerebral Mucormycosis; From Sinonasal Inflammation to Intracranial Involvement

RATIONALE AND OBJECTIVES

Rhino‑Orbital‑Cerebral Mucormycosis (ROCM) is a life-threatening opportunistic fungal infection, which mostly affects immunocompromised patients. There has been a notable rise in the incidence of ROCM during the COVID-19 outbreak. In this study we described imaging characteristics of ROCM in detail, from early sinonasal inflammation to late intracranial involvement.

MATERIALS AND METHODS

In this retrospective study, Computed Tomography (CT) scan and Magnetic Resonance Imaging (MRI) of 48 patients with proven ROCM in biopsy or culture were evaluated. All the patients had a history of COVID-19 infection within the previous three months. The imaging findings were described and the frequency of different parameters was reported.

RESULTS

Paranasal inflammation was detected in all the patients on imaging. The most common involved paranasal sinuses were ethmoid sinuses (97.9%). On diffusionweighted images, restricted diffusion was seen in the paranasal sinuses of 81.1% of the patients. In addition, sinus wall bone involvement was observed in 87.5% of the cases. The most common anatomical sites for extrasinus involvement were the retroantral soft tissue (89.6%) and orbital cavity (87.5%). Dacryocystitis in 50%, optic nerve inflammation in 43.2%, globe involvement in 18.9%, and trigeminal nerve involvement in 16% of the patients were detected. There was extension of inflammation through the cavernous sinuses and alongside the internal carotid arteries in 24% of the patients.

CONCLUSION

Characteristic imaging findings of ROCM not only play a vital role in the early diagnosis of this infection, but they also contribute to the assessment of the extension of inflammation, which is vitally important in surgical planning.

Part 1: Mucormycosis: Prevalence, Risk Factors, Clinical Features and Diagnosis

INTRODUCTION

Mucormycosis (MCR) is caused by filamentous molds within the Class Zygomycetes and Order Mucorales. Infections can result from inhalation of spores into the nares, oropharynx or lungs, ingestion of contaminated food or water, or inoculation into disrupted skin or wounds. In developed countries, MCR occurs primarily in severely immunocompromised hosts. In contrast, in developing/low income countries, most cases of MCR occur in persons with poorly controlled diabetes mellitus and some cases in immunocompetent subjects following trauma. Mucormycosis exhibits a propensity to invade blood vessels, leading to thrombosis and infarction of tissue. Mortality rates associated with invasive MCR are high and can exceed 90% with disseminated disease. Mucormycosis can be classified as one of six forms: (1) rhino-orbital-cerebral mucormycosis (ROCM); (2) pulmonary; (3) cutaneous; (4) gastrointestinal or renal (5); disseminated; (6) uncommon (focal) sites.

AREAS COVERED

The authors discuss the prevalence, risk factors and clinical features of mucormycosis.A literature search of mucormycosis was performed via PubMed (up to November 2022), using the key words: invasive fungal infections; mold; mucormycosis; Mucorales; Zyzomyces; Zygomycosis; Rhizopus, diagnosis.

EXPERT OPINION

Mucormycosis occurs primarily in severely immunocompromised hosts. Mucormycosis can progress rapidly, and delay in initiating treatment by even a few days worsens outcomes.

COVID-19 associated mold infections: Review of COVID-19 associated pulmonary aspergillosis and mucormycosis

COVID-19-associated mold infection (CAMI) is defined as development of mold infections in COVID-19 patients. Co-pathogenesis of viral and fungal infections include the disruption of tissue barrier following SARS CoV-2 infection with the damage in the alveolar space, respiratory epithelium and endothelium injury and overwhelming inflammation and immune dysregulation during severe COVID-19. Other predisposing risk factors permissive to fungal infections during COVID-19 include the administration of immune modulators such as corticosteroids and IL-6 antagonist. COVID-19-associated pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) is increasingly reported during the COVID-19 pandemic. CAPA usually developed within the first month of COVID infection, and CAM frequently arose 10-15 days post diagnosis of COVID-19. Diagnosis is challenging and often indistinguishable during the cytokine storm in COVID-19, and several diagnostic criteria have been proposed. Development of CAPA and CAM is associated with a high mortality despiteappropriate anti-mold therapy. Both isavuconazole and amphotericin B can be used for treatment of CAPA and CAM; voriconazole is the primary agent for CAPA and posaconazole is an alternative for CAM. Aggressive surgery is recommended for CAM to improve patient survival. A high index of suspicion and timely and appropriate treatment is crucial to improve patient outcome.

Clinical Phenotypes of COVID-19 Associated Mucormycosis (CAM): A Comprehensive Review

A mucormycosis surge was reported during the COVID-19 pandemic in India. A literature search until 14 July 2022, with the aim of updating COVID-19-associated mucormycosis (CAM), identified 663 studies and 88 met inclusion criteria (8727 patients). India reported 8388 patients, Egypt 208 and Europe 40. Rhino-orbito-cerebral mucormycosis (ROCM) was identified among 8082 (98.3%) patients, followed by 98 (1.2%) with pulmonary. In India, 82.6% of patients had diabetes mellitus, with 82% receiving corticosteroids. In Europe, 75% presented pulmonary CAM, 32.5% had diabetes and 40% were immunocompromised. CAM was identified at a median of 17.4 days (IQR 7.5 days) post COVID-19 diagnosis, and PCR was performed in five studies. Rhino-orbital invasion is clinically obvious, while cerebral involvement presents with cavernous sinus thrombosis, meningitis and cerebrovascular disease. Symptoms of pulmonary CAM usually overlap with severe COVID-19 pneumonia. High-dose liposomal Amphotericin B (and early surgical debridement in ROCM) are the mainstay of therapy. The median mortality rate was estimated to be 21.4% (IQR 31.9%), increased by the presence of pulmonary (80% (IQR 50%) or cerebral involvement (50% (IQR 63.9%). In summary, different CAM clinical phenotypes need to be distinguished, influenced by geographical presentation. Opportunities exist for diagnosis and therapy optimization, based on earlier high-dose antifungal therapy, early source control, strict glycemic control and restriction of steroids to COVID-19 patients with oxygen requirements.

Comparison of MRI Findings in Diabetic and Nondiabetic Patients with Rhino-Orbito-Cerebral Mucormycosis

Objective Rhino-orbito-cerebral mucormycosis (ROCM) has emerged as a key concern during the period of coronavirus disease 2019 (COVID-19) pandemic. Diabetes mellitus is a known risk factor for invasive fungal infection. The aim of this article was to study and compare the radiological features of COVID-19-associated ROCM between diabetic and nondiabetic patients using magnetic resonance imaging.

Materials and Methods A retrospective observational study comprising 78 diabetics and 40 nondiabetics who developed ROCM after COVID-19 was conducted. The imaging data of both groups were analyzed, findings tabulated and compared using statistical methods.

Results Maxillary and ethmoid sinuses were commonly involved in both groups. Periantral fat and orbits were the most common sites of disease extension. The spread of infection to periantral soft tissue was significantly higher in diabetics (p = 0.049). Diabetics were more likely to have bone, orbit, and brain involvement than nondiabetics, although the difference was not statistically significant. Diabetic patients were the only ones to experience complications such as fungal abscess and cavernous sinus and internal carotid artery involvement. However, a considerable number of nondiabetic patients (22.5%) also had an intracranial extension of disease.

Conclusion The radiological appearances and common sites of invasion in ROCM are similar in diabetic and nondiabetic patients. The extensive spread of infection to extra-sinus regions can occur in nondiabetic patients with COVID-19 but is less frequent compared with diabetics.

Imaging of COVID-19-associated rhino-orbital-cerebral mucormycosis: imaging analysis of 120 patients

Background

With the ongoing pandemic of COVID-19, there has been a rapid upsurge in cases of rhino-orbital-cerebral mucormycosis (ROCM). It is an opportunistic fungal infection associated with high morbidity and mortality. Rapid and appropriate application of clinical and radiological methods is crucial for early diagnosis, to limit the associated morbidity and improve post-treatment outcomes. In our study, we analyzed imaging features, common sites, and the extent of infection in patients suffering from ROCM.

Results

The majority of the patients were either diabetics or developed uncontrolled blood glucose levels during COVID-19 infection. 79.17% of patients had a history of treatment with steroid therapy. Headache and facial pain were the most common clinical features seen in 76.67% and 60% of patients, respectively. Maxillary and ethmoid sinuses were commonly involved. The most common extra-sinus site of involvement was periantral fat and orbit, seen in 91 (75.83%) and 84 (70%) patients, respectively. Bone erosion or marrow edema was seen in 72 (60%) patients. Intracranial extension in the form of meningitis, cavernous sinus thrombophlebitis/thrombosis, and brain abscess were seen in 20%, 10%, and 3.3% of patients, respectively. MRI-based staging showed that 24.7% of patients had stage I, 5.83% had stage II, 50% had stage III, and 20% had stage IV disease.

Conclusion

The spread of COVID-19-associated rhinomucormycosis to extra-sinus sites is common, which can be detected adequately on MRI. The radiological signs of invasion and devitalization of tissues are crucial for the early diagnosis of ROCM.

Intracranial manifestations of rhinocerebral mucormycosis: a pictorial essay

Rhinocerebral mucormycosis has emerged as a common coinfection in coronavirus disease 2019 (COVID-19) patients during the convalescence period. Frequent spread of disease from sinonasal mucosa to bone, neck spaces, orbit, and brain occurs along the perivascular/perineural routes or through direct invasion. Brain involvement represents severe manifestation and is often associated with poor functional outcomes and high mortality rates. Magnetic resonance imaging (MRI) is the modality of choice for the intracranial assessment of disease severity in mucormycosis. Early and accurate identification of intracranial extension is imperative to improve survival rates. With this pictorial essay, we aim to familiarize the readers with the cross-sectional imaging features of intracranial complications of mucormycosis. The radiological details in this essay should serve as a broad checklist for radiologists and clinicians while dealing with this fulminant infection.

Rhino-orbital mucormycosis

PURPOSE OF REVIEW

The current article will update and review the clinical and radiological manifestations and management of rhino-orbital mucormycosis (ROM).

RECENT FINDINGS

There has been an increase in cases of ROM worldwide, especially in India. Immunosuppression (especially diabetes mellitus) is a known predisposing risk factor for ROM. Delayed diagnosis and treatment of ROM can be vision or life-threatening. This article reviews the clinical and radiologic features, treatment, and prognosis of ROM with special emphasis on new and emerging therapies.

SUMMARY

ROM is an angioinvasive fungal infection that affects the sinuses and orbits and may present to ophthalmologists. Clinicians should have a high index of suspicion for ROM, especially in patients with poorly controlled diabetes mellitus or other immunosuppression. Corticosteroid treatment (including the recent COVID-19 pandemic) may be a predisposing risk factor for ROM.

Deadly Fungi: Invasive Fungal Rhinosinusitis in the Head and Neck

Invasive fungal rhinosinusitis (IFRS) is a serious infection that is associated with high morbidity and mortality rates. The incidence of IFRS has been increasing, mainly because of the increased use of antibiotics and immunosuppressive drugs. Rhino-orbital cerebral mucormycosis has recently reemerged among patients affected by COVID-19 and has become a global concern. The detection of extrasinus involvement in its early stage contributes to improved outcomes; therefore, imaging studies are essential in establishing the degree of involvement and managing the treatment properly, especially in immunocompromised patients. The common sites of extrasinus fungal invasion are the intraorbital, cavernous sinus, and intracranial regions. Fungi spread directly to these regions along the blood vessels or nerves, causing devastating complications such as optic nerve ischemia or compression, optic neuritis or perineuritis, orbital cellulitis, cavernous sinus thrombosis, mycotic aneurysm, vasculitis, internal carotid arterial occlusion, cerebral infarction, cerebritis, and brain abscess. IFRS has a broad imaging spectrum, and familiarity with intra- and extrasinonasal imaging features, such as loss of contrast enhancement of the affected region, which indicates tissue ischemia due to angioinvasion of fungi, and the surrounding anatomy is essential for prompt diagnosis and management. The authors summarize the epidemiology, etiology, risk factors, and complications of IFRS and review the anatomy and key diagnostic imaging features of IFRS beyond the sinonasal regions. ^©RSNA, 2022.

Clinical Features and Mortality of COVID-19-Associated Mucormycosis: A Systematic Review and Meta-Analysis

The recent increase of COVID-19-associated mucormycosis (CAM) has been commanding global attention. However, basic epidemiologic characteristics have not firmly been established. In this systematic review and meta-analysis, we sought to determine the clinical manifestations, potential risk factors, and outcomes of CAM. Observational studies reporting CAM were searched with PubMed and EMBASE databases in January 2022. We collected data on comorbidities and treatment for COVID-19, and performed a one-group meta-analysis on the frequency of orbital exenteration procedure and mortality of CAM using a random-effect model. Fifty-one observational studies, including a total of 2,312 patients with proven CAM, were identified. Among the 51 studies, 37 were conducted in India, 8 in Egypt, and 6 in other countries. The most common comorbidity was diabetes mellitus (82%). While 57% required oxygenation, 77% received systemic corticosteroids. Among CAM, 97% were rhino-orbital-cerebral (ROCM), and 2.7% were pulmonary mucormycosis. Usual presentations were headache (54%), periorbital swelling/pain (53%), facial swelling/pain (43%), ophthalmoplegia (42%), proptosis (41%), and nasal discharge/congestion (36%). Regarding the outcomes, orbital exenteration was performed in 17% (95% CI: 12–21%, I² = 83%) of the COVID-19-associated ROCM patients. The mortality of CAM was 29% (95% CI; 22–36%, I² = 92%). In conclusion, this systematic review and meta-analysis indicated that the most prevalent type of CAM was ROCM, and most CAM patients had diabetes mellitus and received systemic glucocorticoids. Clinicians in the endemic areas should have a high index of suspicion for this invasive fungal complication of COVID-19 when a diabetic patient who received high-dose systemic glucocorticoids developed rhino-orbital symptoms.