Imaging Spectrum of Invasive Fungal and Fungal-like Infections

A Single-center Experience of Coccidioides Meningitis in Immunocompetent Patients: Case Series and Literature Review

Recently, the California Department of Public Health issued an advisory related to the substantial rise in Coccidioidomycosis in California, which has been attributed in part to climate change and rapid housing development. Most cases are self-limiting, but some may spread to the meninges, resulting in coccidioidal meningitis (CM). Many providers mistakenly presume that CM is limited to patients who are immunocompromised. In this case series and literature review, we present 12 cases of CM in immunocompetent individuals seen at a single tertiary academic center between 1 January 2019 and 31 December 2023. All 12 cases developed complications, with 10 requiring ventriculoperitoneal shunting, 6 having spinal cord involvement (5 with cervical spine involvement), 4 having strokes, and 3 dying from complications related to CM. It is important to recognize CM as it may be life-threatening if not promptly diagnosed.

Investigating the antifungal potential of genetically modified hybrid chitinase enzymes derived from Bacillus subtilis and Serratia marcescens

Chitinases are glycosyl hydrolase enzymes that break down chitin, an integral component of fungal cell walls. Bacteria such as Bacillus subtilis and Serratia marcescens produce chitinases with antifungal properties. In this study, we aimed to generate hybrid chitinase enzymes with enhanced antifungal activity by combining functional domains from native chitinases produced by B. subtilis and S. marcescens. Chitinase genes were cloned from both bacteria and fused together using overlap extension PCR. The hybrid constructs were expressed in E. coli and the recombinant enzymes purified. Gel electrophoresis and computational analysis confirmed the molecular weights and isoelectric points of the hybrid chitinases were intermediate between the parental enzymes. Antifungal assays demonstrated that the hybrid chitinases inhibited growth of the fungus Fusarium oxysporum significantly more than the native enzymes and also showed fungicidal activity against Candida albicans, Alternaria solani, and Rhizoctonia solani. The results indicate that hybrid bacterial chitinases are a promising approach to engineer novel antifungal proteins. This study provides insight into structure-function relationships of chitinases and strategies for generating biotherapeutics with enhanced bioactive properties. These hybrid chitinases result in a more potent and versatile antifungal agent.

Fungal Intracranial Infections (Central Nervous System-Invasive Fungal Disease) in Patients With Haematological Disorders-A Single-Centre Retrospective Study

BACKGROUND

Invasive fungal disease (IFD) is a sinister complication encountered in patients with haematological disorders. When occurring in the central nervous system (CNS), IFDs can have catastrophic outcomes.

OBJECTIVES

To study the clinical presentation, predisposing etiological factors, and prognosis of a CNS-IFD in a patient with a haematological disorder.

PATIENTS AND METHODS

This is a retrospective study focusing on the clinical profile, diagnosis, treatment strategy and outcomes of 43 patients with an underlying haematological disorder, who were diagnosed with CNS-IFD between 2018 and 2022.

RESULTS

Of the 43 patients, 18 were chemotherapy recipients, while 23 were stem cell transplant (SCT) recipients and 2 presented with CNS-IFD at diagnosis. AML/MDS (37.2%) and ALL (18.6%) were the predominant underlying diagnoses. A sudden deterioration in sensorium (53.5%) was the earliest clinical sign, while T2 hyperintensities (26.8%), vascular involvement (26.8%) and ring-enhancing lesions (16.3%) were the commonest radiological findings, with all patients exhibiting diffusion restriction in diffusion-weighted images. Microbiological evidence of infection was obtained in all patients; however, culture positivity was established in only 25 patients. Rhizopus spp (23.2%) and Aspergillus spp (20.9%) were implicated in most cases. Overall survival of the cohort was 27.9% at a median follow-up of 6 months. In patients who succumbed, the median time to death was 4 days (0-46).

CONCLUSION

CNS-IFD is associated with very poor survival in patients undergoing chemotherapy or an SCT, urging the need for prompt diagnosis and initiation of suitable antifungal therapy.

Imaging of lower extremity infections: predisposing conditions, atypical infections, mimics, and differentiating features

Imaging evaluation for lower extremity infections can be complicated, especially in the setting of underlying conditions and with atypical infections. Predisposing conditions are discussed, including diabetes mellitus, peripheral arterial disease, neuropathic arthropathy, and intravenous drug abuse, as well as differentiating features of infectious versus non-infectious disease. Atypical infections such as viral, mycobacterial, fungal, and parasitic infections and their imaging features are also reviewed. Potential mimics of lower extremity infection including chronic nonbacterial osteomyelitis, foreign body granuloma, gout, inflammatory arthropathies, lymphedema, and Morel-Lavallée lesions, and their differentiating features are also explored.

Fungal Musculoskeletal Infections: Comprehensive Approach to Proper Diagnosis

Fungal musculoskeletal infections often have subacute or indolent manifestations, making it difficult to distinguish them from other diseases and infections, given that they are relatively uncommon. Fungal infections occur by hematogenous spread, direct inoculation, or contiguous extension and may be related to different risk factors, including immunosuppression and occupational activity. The infection can manifest in isolation in the musculoskeletal system or as part of a systemic process. The fungi may be endemic to certain regions or may be found throughout the world, and this can help to narrow the diagnosis of the etiologic agent. Infections such as candidiasis, cryptococcosis, aspergillosis, and mucormycosis are often related to immunosuppression. On the other hand, histoplasmosis, paracoccidioidomycosis, coccidioidomycosis, and blastomycosis can occur in healthy patients in geographic areas where these infections are endemic. Furthermore, infections can be classified on the basis of the site of infection in the body. Some subcutaneous infections that can have osteoarticular involvement include mycetoma, sporotrichosis, and phaeohyphomycosis. Different fungi affect specific bones and joints with greater prevalence. Imaging has a critical role in the evaluation of these diseases. Imaging findings include nonspecific features such as osteomyelitis and arthritis, with bone destruction, osseous erosion, mixed lytic and sclerotic lesions, and joint space narrowing. Multifocal osteomyelitis and chronic arthritis with joint effusion and synovial thickening may also occur. Although imaging findings are often nonspecific, some fungal infections may show findings that aid in narrowing the differential diagnosis, especially when they are associated with the patient's clinical condition and history, the site of osteoarticular involvement, and the geographic location. ©RSNA, 2024.

Predominantly multiple focal non-cystic renal lesions: an imaging approach

Multiple non-cystic renal lesions are occasionally discovered during imaging for various reasons and poses a diagnostic challenge to the practicing radiologist. These lesions may appear as a primary or dominant imaging finding or may be an additional abnormality in the setting of multiorgan involvement. Awareness of the imaging appearance of the various entities presenting as renal lesions integrated with associated extrarenal imaging findings along with clinical information is crucial for a proper diagnostic approach and patient work-up. This review summarizes the most relevant causes of infectious, inflammatory, vascular, and neoplastic disorders presenting as predominantly multiple focal non-cystic lesions.

Pneumocystis jirovecii Pneumonia in a Liver Transplant Recipient With an Adverse Reaction to Trimethoprim/Sulfamethoxazole Treated With a Sulfonamide Desensitization Protocol: Case Report

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic fungal infection that, in immunocompromised patients, can progress to respiratory failure and death. Since trimethoprim/sulfamethoxazole (TMP/SMX) chemoprophylaxis has become a standard management, the prognosis has improved. However, there are patients with a history of TMP/SMX intolerance who cannot receive chemoprophylaxis.

BACKGROUND

We report on a 53-year-old male liver recipient treated with a standard triple immunosuppressive regimen in whom TMP/SMX was waived because of a history of allergy manifested as a generalized rash with edema more than 30 years ago. At transplantation, the immunologic risk was assessed as low, and liver graft function was normal. In the third month after engraftment, he developed dyspnea at rest required constant passive oxygen therapy. Ceftriaxone, azithromycin, and clindamycin were implemented. Mycophenolate acid was stopped, and tacrolimus was reduced. High-resolution computed tomography revealed interstitial pneumonia. Pneumocystis jirovecii pneumoniae was diagnosed from bronchoalveolar lavage. Instead of TMP/SMX, pentamidine and caspofungin were also used for PJP, with no improvement. After 3 weeks, the patient deteriorated. Because of his life-threatening condition, TMP/SMX was introduced in the sulfonamide desensitization protocol, including hydrocortisone and clemastinum. Within 4 days, the patient stabilized with no signs of TMP/SMX intolerance. Pneumonia subsided within a month, and TMP/SMX was prescribed lifelong.

CONCLUSIONS

Prophylaxis for PJP with TMP/SMX still remains an important issue in transplant recipients. Adverse reaction to TMP/SMX in the past is not always a contraindication to reintroducing prophylaxis. The decision of prophylaxis avoidance should be analyzed carefully; in uncertain cases, a sulfonamide desensitization protocol should be considered.

Clinical and Radiological Features of Pneumocystis jirovecii Pneumonia in Children: A Case Series

BACKGROUND

Pneumocytis jirovecii pneumonia (PJP) has high mortality rates in immunocompromised children, even though routine prophylaxis has decreased in incidence. The aim of this case series is to present the radiological and clinical pathway of PJP in a pediatric population.

DESCRIPTION OF CASES

All PJP cases in non-HIV/AIDS patients diagnosed at Istituto Giannina Gaslini Pediatric Hospital in Genoa (Italy) from January 2012 until October 2022 were retrospectively evaluated. Nine cases were identified (median age: 8.3 years), and of these, 6/9 underwent prophylaxis with trimethoprim/sulfamethoxazole (TMP/SMX; five once-a-week schedules and one three times-a-week schedule), while 3/9 did not receive this. PJP was diagnosed by real-time PCR for P. jirovecii-DNA in respiratory specimens in 7/9 cases and two consecutive positive detections of β-d-glucan (BDG) in the serum in 2/9 cases. Most patients (6/8) had a CT scan with features suggestive of PJP, while one patient did not undergo a scan. All patients were treated with TMP/SMX after a median time from symptoms onset of 3 days. In 7/9 cases, empirical TMP/SMX treatment was initiated after clinical suspicion and radiological evidence and later confirmed by microbiological data. Clinical improvement with the resolution of respiratory failure and 30-day survival included 100% of the study population.

DISCUSSION

Due to the difficulty in obtaining biopsy specimens, PJP diagnosis is usually considered probable in most cases. Moreover, the severity of the clinical presentation often leads physicians to start TMP/SMX treatment empirically. BDG proved to be a useful tool for diagnosis, and CT showed good accuracy in identifying typical patterns. In our center, single-day/week prophylaxis was ineffective in high-risk patients; the three-day/week schedule would, therefore, seem preferable and, in any case, should be started promptly in all patients who have an indication of pneumonia.

Tumefactive Nonneoplastic Proliferative Pseudotumors of the Kidneys and Urinary Tract: CT and MRI Findings with Histopathologic Correlation

A diverse spectrum of pathologically distinct, nonneoplastic, proliferative conditions of the kidneys and urinary tract demonstrate a expansile growth pattern similar to that of neoplasms. The renal pseudotumors include myriad causes of infections as well as rare noninfectious causes such as sarcoidosis, amyloidosis, and immunoglobulin G4-related disease (IgG4-RD). Rare entities such as cystitis cystica, endometriosis, nephrogenic adenoma, and pseudosarcomatous myofibroblastic proliferation and distinct types of prostatitis comprise tumefactive nontumorous disorders that affect specific segments of the urinary tract. The pseudotumors of the kidneys and urinary tract demonstrate characteristic histopathologic and epidemiologic features, as well as protean clinical manifestations, natural history, and imaging findings. Many patients present with genitourinary tract-specific symptoms or systemic disease. Some cases may be incidentally discovered at imaging. Some entities such as perinephric myxoid pseudotumors, IgG4-RD, fibroepithelial polyp, and nephrogenic adenoma display specific anatomic localization and disease distribution. Imaging features of multisystem disorders such as tuberculosis, sarcoidosis, and IgG4-RD provide supportive evidence that may allow precise diagnosis. Fungal pyelonephritis, xanthogranulomatous pyelonephritis, IgG4-RD, actinomycosis, and endometriosis show markedly low signal intensity on T2-weighted MR images. Although some pseudotumors exhibit characteristic imaging findings that permit correct diagnosis, laboratory correlation and histopathologic confirmation are required for definitive characterization in most cases. A high index of suspicion is a prerequisite for diagnosis. Accurate diagnosis is critical for instituting optimal management while preventing use of inappropriate therapies or interventions. Surveillance CT and MRI are frequently used for monitoring the response of pseudotumors to therapy. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Multiparametric imaging in the evaluation of intracerebral abscesses

Cerebral abscesses are uncommon space occupying lesions; they are associated with high morbidity and mortality, though are potentially treatable. Patients often present with non-specific symptoms and may have few clinical signs. Routine clinical imaging may not give a definite diagnosis, as the findings can be indistinguishable from those of other intracranial mass lesions. We review the role of advanced MR techniques to characterise brain abscesses and discuss the role of imaging in monitoring their response to the treatment.

Magnetic resonance imaging in COVID-19-associated acute invasive fungal rhinosinusitis - Diagnosis and beyond

Objectives

The aim of the study was to evaluate the magnetic resonance imaging (MRI) features of acute invasive fungal rhinosinusitis (AIFRS) at presentation and on follow-up imaging when patients receive treatment with systemic antifungal therapy and surgical debridement.

Material and Methods

This is a retrospective analysis of imaging data from a cohort of patients diagnosed with AIFRS during the second wave of COVID-19 in single tertiary referral hospital in South India between March 2021 and May 2021 (n = 68). Final diagnosis was made using a composite reference standard which included a combination of MRI findings, clinical presentation, nasal endoscopy and intraoperative findings, and laboratory proof of invasive fungal infection. Analysis included 62 patients with "Definite AIFRS" findings on MRI and another six patients with "Possible AIFRS" findings on MRI and laboratory proof of invasive fungal infection. Follow-up imaging was available in 41 patients.

Results

The most frequent MRI finding was T2 hypointensity in the sinonasal mucosa (94%) followed by mucosal necrosis/loss of contrast-enhancement (92.6%). Extrasinosal inflammation with or without necrosis in the pre-antral fat, retroantral fat, pterygopalatine fossa, and masticator space was seen in 91.1% of the cases. Extrasinosal spread was identified on MRI even when the computed tomography (CT) showed intact bone with normal extrasinosal density. Orbital involvement (72%) was in the form of contiguous spread from either the ethmoid or maxillary sinuses; the most frequent presentation being orbital cellulitis and necrosis, with some cases showing extension to the orbital apex (41%) and inflammation of the optic nerve (32%). A total of 22 patients showed involvement of the cavernous sinuses out of which 10 had sinus thrombosis and five patients had cavernous internal carotid artery involvement. Intracranial extension was seen both in the form of contiguous spread to the pachymeninges over the frontal and temporal lobes (25%) and intra-axial involvement in the form of cerebritis, abscesses, and infarcts (8.8%). Areas of blooming on SWI were noted within the areas of cerebritis and infarcts. Perineural spread of inflammation was seen along the mandibular nerves across foramen ovale in five patients and from the cisternal segment of trigeminal nerve to the root exit zone in pons in three patients. During follow-up, patients with disease progression showed involvement of the bones of skull base, osteomyelitis of the palate, alveolar process of maxilla, and zygoma. Persistent hyperenhancement in the post-operative bed after surgical debridement and resection was noted even in patients with stable disease.

Conclusion

Contrast-enhanced MRI must be performed in all patients with suspected AIFRS as non-contrast MRI fails to demonstrate tissue necrosis and CT fails to demonstrate extrasinosal disease across intact bony walls. Orbital apex, pterygopalatine fossa, and the cavernous sinuses form important pathways for disease spread to the skull base and intracranial compartment. While cerebritis, intracranial abscesses, and infarcts can be seen early in the disease due to the angioinvasive nature, perineural spread and skull base infiltration are seen 3-4 weeks after disease onset. Exaggerated soft-tissue enhancement in the post-operative bed after debridement can be a normal finding and must not be interpreted as disease progression.

Therapeutic plasma-exchange improves short-term, but not long-term, outcomes in patients with acute-on-chronic liver failure: A propensity score-matched analysis

BACKGROUND

Acute-on-chronic liver failure (ACLF) is associated with a high short-term mortality rate in the absence of liver transplantation. The role of therapeutic plasma exchange (TPE) in improving the outcomes of ACLF and acute decompensation (AD) is unclear. In this retrospective analysis, we aimed to determine the impact of TPE on mortality in patients with ACLF.

METHODS

ACLF patients receiving TPE with standard medical treatment (SMT) were propensity score matched (PSM) with those receiving SMT alone (1:1) for sex, grades of ACLF, CLIF C ACLF scores, and the presence of hepatic encephalopathy. The primary outcomes assessed were mortality at 30 and 90 days. Survival analysis was performed using Kaplan Meier survival curves.

RESULTS

A total of 1151 patients (ACLF n = 864 [75%], AD [without organ failure] n = 287 [25%]) were included. Of the patients with ACLF (n = 864), grade 1, 2, and 3 ACLF was present in 167 (19.3%), 325 (37.6%), and 372 (43.0%) patients, respectively. Thirty-nine patients received TPE and SMT, and 1112 patients received only SMT. On PSM analysis, there were 38 patients in each group (SMT plus TPE vs SMT alone). In the matched cohort, the 30-days mortality was lower in the TPE arm compared to SMT (21% vs 50%, P = .008), however, the 90-day mortality was not significantly different between the two groups (36.8% vs 52.6%, P = .166); HR, 0.82 (0.44-1.52), P = .549.

CONCLUSION

TPE improves short-term survival in patients with ACLF, but has no significant impact on long-term outcomes. Randomized control trials are needed to obtain a robust conclusion in this regard.

Endemic mycoses in children in North America: a review of radiologic findings

Clinically significant endemic mycoses (fungal infections) in the United States (U.S.) include Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides immitis/posadasii. While the majority of infections go clinically unnoticed, symptomatic disease can occur in immunocompromised or hospitalized patients, and occasionally in immune-competent individuals. Clinical manifestations vary widely and their diagnosis may require fungal culture, making the rapid diagnosis a challenge. Imaging can be helpful in making a clinical diagnosis prior to laboratory confirmation, as well as assist in characterizing disease extent and severity. In this review, we discuss the three major endemic fungal infections that occur in the U.S., including mycology, epidemiology, clinical presentations, and typical imaging features with an emphasis on the pediatric population.

Schematic approach to the diagnosis of multifocal lung opacities in the emergency department

Radiologists in the emergency department must be prepared to deal with any type of disease in any organ at any time. Many entities involving the chest can result in patients' presenting at the emergency department. This chapter deals with entities that manifest with multifocal lung opacities and that can be mistaken for pneumonia. To facilitate their identification, this chapter approaches these entities by considering their most characteristic distribution on chest X-rays, the main diagnostic modality used for thoracic problems in the emergency department. Our schematic approach includes the key findings in patients' personal histories, clinical examination, laboratory tests, and imaging studies that can be available during the initial workup.

Imaging of Invasive Fungal Infections- The Role of PET/CT

Over the last decades, the population at risk for invasive fungal disease (IFD) has increased because of medical therapy advances and diseases compromising patients' immune systems. The high morbidity and mortality associated with invasive fungal disease in the immunocompromised present the challenge of early diagnosis of the IFD and the need to closely monitor the infection during treatment. The definitive diagnosis of invasive fungal disease based on culture or histopathological methods often has reduced diagnostic accuracy in the immunocompromised and may be very invasive. Less invasive and indirect evidence of the fungal infection by serology and imaging has been used for the early diagnosis of fungal infection before definitive results are available or when the definitive methods of diagnosis are suboptimal. Imaging in invasive fungal disease is a non-invasive biomarker that helps in the early diagnosis of invasive fungal disease but helps follow-up the infection during treatment. Different imaging modalities are used in the workup to evaluate fungal disease. The different imaging modalities have advantages and disadvantages at different sites in the body and may complement each other in the management of IFD. Positron emission tomography integrated with computed tomography with [18F]Fluorodeoxyglucose (FDG PET/CT) has helped manage IFD. The combined functional data from PET and anatomical data from the CT from almost the whole body allows noninvasive evaluation of IFD and provides a semiquantitative means of assessing therapy. FDG PET/CT adds value to anatomic-based only imaging modalities. The nonspecificity of FDG uptake has led to the evaluation of other tracers in the assessment of IFD. However, these are mainly still at the preclinical level and are yet to be translated to humans. FDG PET/CT remains the most widely evaluated radionuclide-based imaging modality in IFD management. The limitations of FDG PET/CT must be well understood, and more extensive prospective studies in uniform populations are needed to validate its role in the management of IFD that can be international guidelines.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

The rising burden of invasive fungal infections in COVID-19, can structured CT thorax change the game

Background

The occurrence of invasive fungal infections in COVID-19 patients is on surge in countries like India. Several reports related to rhino-nasal-sinus mucormycosis in COVID patients have been published in recent times; however, very less has been reported about invasive pulmonary fungal infections caused mainly by mucor, aspergillus or invasive candida species. We aimed to present 6 sputum culture proved cases of invasive pulmonary fungal infection (four mucormycosis and two invasive candidiasis) in COVID patients, the clues for the diagnosis of fungal invasion as well as difficulties in diagnosing it due to superimposed COVID imaging features.

Case presentation

The HRCT imaging features of the all 6 patients showed signs of fungal invasion in the form of cavities formation in the pre-existing reverse halo lesions or development of new irregular margined soft tissue attenuating growth within the pre-existing or in newly formed cavities. Five out of six patients were diabetics. Cavities in cases 1, 2, 3 and 4 of mucormycosis were aggressive and relatively larger and showed relatively faster progression into cavities in comparison with cases 5 and 6 of invasive candidiasis.

Conclusion

In poorly managed diabetics or with other immunosuppressed conditions, invasive fungal infection (mucormycosis, invasive aspergillosis and invasive candidiasis) should be considered in the differential diagnosis of cavitary lung lesions.

Fungal colonization and infections in patients with COVID-19 in intensive care units: A real-life experience at a tertiary-care hospital

PURPOSE

To evaluate the management of patients with COVID-19 in the intensive care units (ICUs) with fungal infection/colonization and to highlight diagnostic problems in these patients.

METHODS

We included all patients with a COVID-19 diagnosis who were aged ≥18 years and followed in the ICU for the first 8 months. Patient data were obtained from medical records. We compared the risk factors, laboratory data, and outcomes of patients with fungal infection/colonization.

RESULTS

A total of 118 patients (81 men and 37 women) were included. The mean age was 70.3 ± 14.8 (35-94) years. Of the patients, 79 (66.9%) patients were ≥65 years old. Fungal infection/colonization was detected in 39 (33.1%) patients. Fungi were isolated from 34 (28.8%) patients. Ten fungal species were isolated from 51 samples (the most common being Candida albicans). Three patients (2.5%) had proven candidemia. We observed two (1.7%) possible cases of COVID-19-associated pulmonary aspergillosis (CAPA). Eighteen patients (15.3%) underwent antifungal therapy. The risk of fungal infection/colonization increased as the duration of invasive mechanical ventilation increased. The fatality rate was 61.9% and increased with age and the use of mechanical ventilation. The fatality rate was 4.2-times-higher and the use of mechanical ventilation was 35.9-times-higher in the patients aged ≥65 years than in the patients aged <65 years. No relationship was found between fungal colonization/infection, antifungal treatment, and the fatality rate.

CONCLUSION

During the pandemic, approximately one-third of the patients in ICUs exhibited fungal infection/colonization. Candida albicans was the most common species of fungal infection as in the pre-pandemic area. Because of the cross-contamination risk, we performed diagnostic bronchoscopy and control thorax computed tomography during the ICU stay, and our patients mainly received empirical antifungal therapy.

Tubo-ovarian mass with raised CA-125 in a 21-year-old female

Introduction

Peritonitis associated with fungal species Curvularia lunata seldom occurs with only five cases reported in the literature, all in middle-age patients with comorbidities undergoing dialysis.

Case report

A 21-year-old female who was referred to surgical oncology OPD with a diagnosis of ovarian malignancy, based on raised cancer antigen 125 (CA 125) and suspected tubo-ovarian mass (TOM) on magnetic resonance imaging (MRI). A review of the MRI showed a pelvic collection with TOM, suggestive of infective pathology. Fungal culture and mass spectroscopy of the cystic collection identified the presence of Curvularia lunata. She was treated with oral itraconazole which showed symptomatic improvement and radiological response. In the follow-up period, the patient developed chest wall swelling, aspiration and geneXpert® revealed multidrug-resistant (MDR) tuberculosis, and treatment was started.

Conclusions

Unusual causes of TOM and raised CA 125 should be kept in mind when dealing with young patients, as the possibility of epithelial ovarian cancer in this age is very low.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02651-w.

Imaging Approach to Pulmonary Infections in the Immunocompromised Patient

Pulmonary infections are the major cause of morbidity and mortality in immunocompromised patients and almost one-third of intensive care unit patients with pulmonary infections belong to the immunocompromised category. Multiple organisms may simultaneously infect an immunocompromised patient and the overwhelming burden of mixed infections further predisposes critically ill patients to acute hypoxemic respiratory failure. Notwithstanding that lung ultrasound is coming into vogue, the primary imaging investigation is a chest radiograph, followed by thoracic CT scan. This review based on our experience at tertiary care teaching hospitals provides insights into the spectrum of imaging features of various pulmonary infections occurring in immunocompromised patients. This review is unique as, firstly, the imaging spectrum described by us is categorized on basis of the etiological infective agent, comprehensively and emphatically correlated with the clinical setting of the patient. Secondly, a characteristic imaging pattern is emphasized in the clinical setting-imaging-pattern conglomerate, to highlight the most likely diagnosis possible in such a combination. Thirdly, the simulating conditions for a relevant differential diagnosis are discussed in each section. Fourthly, not only are the specific diagnostic and tissue sampling techniques for confirmation of the suspected etiological agent described, but the recommended pharmaco-therapeutic agents are also enumerated, so as to provide a more robust insight to the radiologist. Last but not the least, we summarize and conclude with a diagnostic algorithm, derived by us from the characteristic illustrative cases. The proposed algorithm, illustrated as a flowchart, emphasizes a diagnostic imaging approach comprising: correlation of the imaging pattern with clinical setting and with associated abnormalities in the thorax and in other organs/systems, which is comprehensively analyzed in arriving at the most likely diagnosis. Since a rapid evaluation and emergent management of such patients is of pressing concern not only to the radiologist, but also for the general physicians, pulmonologists, critical care specialists, oncologists and transplant surgery teams, we believe our review is very informative to a wide spectrum reader audience.

Gastrointestinal Manifestations of Immunodeficiency: Imaging Spectrum

There is a wide spectrum of hereditary and acquired immunodeficiency disorders that are characterized by specific abnormalities involving a plethora of humoral, cellular, and phagocytic immunologic pathways. These include distinctive primary immunodeficiency syndromes due to characteristic genetic defects and secondary immunodeficiency syndromes, such as AIDS from HIV infection and therapy-related immunosuppression in patients with cancers or a solid organ or stem cell transplant. The gut mucosa and gut-associated lymphoid tissue (the largest lymphoid organ in the body), along with diverse commensal microbiota, play complex and critical roles in development and modulation of the immune system. Thus, myriad gastrointestinal (GI) symptoms are common in immunocompromised patients and may be due to inflammatory conditions (graft versus host disease, neutropenic enterocolitis, or HIV-related proctocolitis), opportunistic infections (viral, bacterial, fungal, or protozoal), or malignancies (Kaposi sarcoma, lymphoma, posttransplant lymphoproliferative disorder, or anal cancer). GI tract involvement in immunodeficient patients contributes to significant morbidity and mortality. Along with endoscopy and histopathologic evaluation, imaging plays an integral role in detection, localization, characterization, and distinction of GI tract manifestations of various immunodeficiency syndromes and their complications. Select disorders demonstrate characteristic findings at fluoroscopy, CT, US, and MRI that permit timely and accurate diagnosis. While neutropenic enterocolitis affects the terminal ileum and right colon and occurs in patients receiving chemotherapy for hematologic malignancies, Kaposi sarcoma commonly manifests as bull's-eye lesions in the stomach and duodenum. Imaging is invaluable in treatment follow-up and long-term surveillance as well. Online supplemental material is available for this article. ^©RSNA, 2022.

Radiological spectrum of invasive mucormycosis in COVID-19

Mucormycosis, commonly known as the “black fungus” is recently emerging as a deadly complication in COVID patients in the Indian subcontinent. A growing number of cases are being reported from all over the country, with a majority of the patients either undergoing treatment or having recovered from COVID.

Here, we report three cases of multisystem mucormycosis in COVID positive patients showing, rhino-orbital, cerebral, pulmonary, and genitourinary involvement. The first is a case of a 41-year-old male patient who during his treatment developed left periorbital swelling with ecchymosis and headache. CT and CE-MRI of the paranasal sinuses and brain revealed features of pan fungal sinusitis and subsequent invasion into the left orbit. The second case is of a 52-year-old male patient who after complaining of a severe left-sided hemicranial headache was diagnosed with cavernous sinus thrombosis. The third is of a 57-year-old male patient who presented with left flank pain and dysuria. HRCT (High-resolution CT) chest revealed a thick-walled cavitary lesion, and NCCT KUB (Non-contrast CT of Kidneys, ureters, and bladder) revealed left-sided pyelonephritis. A cystoscopic and microbiological evaluation revealed fungal growth.

In all three patients, a biopsy from the involved area revealed broad aseptate filamentous fungal hyphae suggestive of mucormycosis, which was confirmed on culture.

These are all unusual cases and physicians should be aware of the possibility of secondary invasive fungal infections in patients with COVID-19 infection.

Post-Covid Renal Mucormycosis: A Case Report

The Pandora's box has been opened in the twenty-first century unleashing “the Coronavirus.” There has been an increase in the incidence of mucormycosis during this coronavirus disease 2019 (COVID-19) pandemic with many case reports of rhino-orbito-cerebral and pulmonary mucormycosis. Diabetes mellitus, COVID, and Mucor fungus together are a dangerous trio associated with high mortality. We report a rare case of renal mucormycosis following COVID pneumonia in a 64-year-old patient with uncontrolled diabetes; with the imaging findings of left emphysematous pyelonephritis and cystitis, nonfunctioning left kidney, and left main renal artery and vein thrombosis. This is the first such case reported to our knowledge. A high degree of clinical suspicion with prompt recognition of imaging findings is essential to improve the chances of survival in such patients.

Imaging Primer on Chimeric Antigen Receptor T-Cell Therapy for Radiologists

Chimeric antigen receptor (CAR) T-cell therapy is a recently approved breakthrough treatment that has become a new paradigm in treatment of recurrent or refractory B-cell lymphomas and pediatric or adult acute lymphoid leukemia. CAR T cells are a type of cellular immunotherapy that artificially enhances T cells to boost eradication of malignancy through activation of the native immune system. The CAR construct is a synthetically created functional cell receptor grafted onto previously harvested patient T cells, which bind to preselected tumor-associated antigens and thereby activate host immune signaling cascades to attack tumor cells. Advantages include a single treatment episode of 2-3 weeks and durable disease elimination, with remission rates of over 80%. Responses to therapy are more rapid than with conventional chemotherapy or immunotherapy, with intervening short-interval edema. CAR T-cell administration is associated with therapy-related toxic effects in a large percentage of patients, notably cytokine release syndrome, immune effect cell-associated neurotoxicity syndrome, and infections related to immunosuppression. Knowledge of the expected evolution of therapy response and potential adverse events in CAR T-cell therapy and correlation with the timeline of treatment are important to optimize patient care. Some toxic effects are radiologically evident, and familiarity with their imaging spectrum is key to avoiding misinterpretation. Other clinical toxic effects may be occult at imaging and are diagnosed on the basis of clinical assessment. Future directions for CAR T-cell therapy include new indications and expanded tumor targets, along with novel ways to capture T-cell activation with imaging. An invited commentary by Ramaiya and Smith is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Clinical Profile, Risk Factors, and Therapeutic Outcome of Cavitating Fungal Pneumonia Coinfection in COVID-19 Patients: A Retrospective Analysis

BACKGROUND

An end to the novel coronavirus disease 2019 (COVID-19) pandemic appears to be a distant dream. To make matters worse, there has been an alarming upsurge in the incidence of cavitating invasive fungal pneumonia associated with COVID-19, reported from various parts of the world including India. Therefore, it remains important to identify the clinical profile, risk factors, and outcome of this group of patients.

METHODS

Out of 50 moderate to severe COVID-19 inpatients with thoracic computed tomographic (CT) evidence of lung cavitation, we retrospectively collected demographic and clinical data of those diagnosed with fungal pneumonia for further investigation. We determined the association between risk factors related to 30-day and 60-day mortality.

RESULTS

Of the 50 COVID-19 patients with cavitating lung lesions, 22 (44 %) were identified to have fungal pneumonia. Most of these patients (n = 16, 72.7 %) were male, with a median (range) age of 56 (38-64) years. On chest CT imaging, the most frequent findings were multiple cavities (n = 13, 59.1 %) and consolidation (n = 14, 63.6 %). Mucormycosis (n = 10, 45.5 %) followed by Aspergillus fumigatus (n = 9, 40.9 %) were the common fungi identified. 30-day and 60-day mortalities were seen in 12 (54.5 %) and 16 (72.7 %) patients, respectively. On subgroup analysis, high cumulative prednisolone dose was an independent risk factor associated with 30-day mortality (p = 0.024).

CONCLUSION

High cumulative prednisolone dose, baseline neutropenia, hypoalbuminemia, multiple cavities on CT chest, leukopenia, lymphopenia and raised inflammatory markers were associated with poor prognosis in severe COVID-19 patients with cavitating fungal pneumonia.

Fungal infections diagnosis - Past, present and future

Despite the scientific advances observed in the recent decades and the emergence of new methodologies, the diagnosis of systemic fungal infections persists as a problematic issue. Fungal cultivation, the standard method that allows a proven diagnosis, has numerous disadvantages, as low sensitivity (only 50% of the patients present positive fungal cultures), and long growth time. These are factors that delay the patient's treatment and, consequently, lead to higher hospital costs. To improve the accuracy and quickness of fungal infections diagnosis, several new methodologies attempt to be implemented in clinical microbiology laboratories. Most of these innovative methods are independent of pathogen isolation, which means that the diagnosis goes from being considered proven to probable. In spite of the advantage of being culture-independent, the majority of the methods lack standardization. PCR-based methods are becoming more and more commonly used, which has earned them an important place in hospital laboratories. This can be perceived now, as PCR-based methodologies have proved to be an essential tool fighting against the COVID-19 pandemic. This review aims to go through the main steps of the diagnosis for systemic fungal infection, from diagnostic classifications, through methodologies considered as "gold standard", to the molecular methods currently used, and finally mentioning some of the more futuristic approaches.

Pediatric Lower Respiratory Tract Infections: Imaging Guidelines and Recommendations

Lower respiratory tract infection (LRTI) remains a major cause of morbidity and mortality in children. Various organisms cause LRTI, including viruses, bacteria, fungi, and parasites, among others. Infections caused by 2 or more organisms also occur, sometimes enhancing the severity of the infection. Medical imaging helps confirm a diagnosis but also plays a role in the evaluation of acute and chronic sequelae. Medical imaging tests help evaluate underlying pathology in pediatric patients with recurrent or long-standing symptoms as well as the immunocompromised.

Is the combination of bilateral pulmonary nodules and mosaic attenuation on chest CT specific for DIPNECH?

Background

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is characterized by multifocal proliferation of pulmonary neuroendocrine cells. On chest CT, DIPNECH exhibits bilateral pulmonary nodules and mosaic attenuation in most patients. We sought to: (1) assess the specificity of this pattern (i.e., bilateral pulmonary nodules together with mosaic attenuation) for DIPNECH; (2) describe its differential diagnosis; and (3) identify the clinico-radiologic features that may help prioritize DIPNECH over other diagnostic considerations.

Methods

We searched the Mayo Clinic records from 2015 to 2019 for patients with bilateral pulmonary nodules and mosaic attenuation on CT who had a diagnostic lung biopsy. A thoracic radiologist reviewed all CT scans. Chi-square test was used for categorical variables, and odds ratios were utilized to measure the association between certain variables and DIPNECH.

Results

Fifty-one patients met our inclusion criteria; 40 (78%) were females and 34 (67%) were never-smokers. Median age was 65 (interquartile range 55–73) years. Lung biopsy was surgical in 21 patients (41%), transbronchial in 17 (33%), and transthoracic in 12 (24%); explanted lungs were examined in 1 (2%). Metastatic/multifocal cancer was the most common diagnosis, and was found in 17 (33%) cases. Bronchiolitis was diagnosed in 12 patients (24%), interstitial lung disease in 10 (20%), and DIPNECH in 5 (10%). Previous diagnosis of an obstructive lung disease (odds ratio 15.8; P = 0.002), and peribronchial nodular distribution on CT (odds ratio 14.4; P = 0.006) were significantly correlated with DIPNECH. Although statistical significance was not reached, DIPNECH nodules were more likely to display solid attenuations (80% vs. 67%, P = 0.45), and were more numerous; > 10 nodules were seen in 80% of DIPNECH cases vs. 52% in others (P = 0.23). Because DIPNECH primarily affects women, we analyzed the women-only cohort and found similar results.

Conclusions

Various disorders can manifest the CT pattern of bilateral pulmonary nodules together with mosaic attenuation, and this combination is nonspecific for DIPNECH, which was found in only 10% of our cohort. Previous diagnosis of an obstructive lung disease, and peribronchial distribution of the nodules on CT increased the likelihood of DIPNECH vs. other diagnoses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02103-w.

Side Effects of Oncologic Treatment in the Chest: Manifestations at FDG PET/CT

Fluorodeoxyglucose (FDG) PET/CT is a vital imaging technique used for staging, assessing treatment response, and restaging following completion of therapy in patients who are undergoing or have completed oncologic treatment. A variety of adverse effects from chemotherapy, targeted therapy, immunotherapy, and radiation therapy are commonly encountered in oncologic patients. It is important to be aware of the manifestations of these adverse effects seen on FDG PET/CT images to avoid misinterpreting these findings as disease progression. Furthermore, early identification of these complications is important, as it may significantly affect patient management and even lead to a change in treatment strategy. The authors focus on the FDG PET/CT manifestations of a broad spectrum of oncologic therapy-related adverse effects in the thorax, as well as some treatment-related changes that may potentially mimic malignancy. Online supplemental material is available for this article. ^©RSNA, 2021.

Endobronchial blastomycoses: A rare pathogen in a unique location

A middle-aged woman from Southwest Virginia presented to pulmonary clinic with 4 months of dry cough. Further imaging with Computed Tomography (CT) of the chest showed an infiltrative lung mass. The patient underwent bronchoscopy that showed an endobronchial lesion on right and left main stem bronchi. Endobronchial biopsy of the lesion showed acute and chronic granulomatous inflammation and tissue cultures grew Blastomycoses dermatitides. We hereby present a rare case of endobronchial blastomycoses with pulmonary infiltrates presenting as chronic cough.

Mimics of perineural tumor spread in the head and neck

Perineural spread (PNS) is an important potential complication of head and neck malignancy, as it is associated with decreased survival and a higher risk of local recurrence and metastasis. There are many review articles focused on the imaging findings of PNS. However, a false-positive diagnosis of PNS can be just as harmful to the patient as an overlooked case. In this manuscript, we delineate and classify various imaging mimics of PNS. Mimics can be divided into the following categories: normal variants (including vascular structures and failed fat suppression), infections, inflammatory disease (including granulomatous disease and demyelination), neoplasms, and post-traumatic/surgical changes. Knowledge of potential mimics of PNS will prevent false-positive imaging interpretation, and enable appropriate oncologic management.

Revisiting rhino-orbito-cerebral acute invasive fungal sinusitis in the era of COVID-19: pictorial review

COVID-19 patients have been found to have an increased incidence of superadded fungal infections because of multiple factors such as impaired cell-mediated immunity, immunosuppressive therapy, and coexistent diabetes mellitus. Recently, there has been a significant rise in the COVID-19-associated mucormycosis and aspergillosis cases involving the sinonasal cavity and the lungs. Rhino-orbito-cerebral acute invasive fungal rhinosinusitis (AIFR) is a potentially life-threatening, invasive fungal infection. Early diagnosis followed by prompt medical management and surgical intervention is crucial for patient survival. The role of cross-sectional imaging (CT/MRI) is not only to suggest a diagnosis of invasive fungal sinusitis but also to delineate the complete extent of disease. Mapping the extent of orbital and intracranial disease has prognostic as well as management implications, as involvement of these sites marks a worse prognosis. A stepwise approach to evaluation of imaging of AIFR along with a pictorial depiction of the key imaging findings is presented.

Clinicomycological overview of brain abscess in a tertiary care center: A 38 year retrospection: Fungal brain abscess

INTRODUCTION

Brain abscesses (BA) form approximately 8% of intracranial masses in developing and 1-2% in western countries. Fungal BA (FBA) are aggressive and represent a catastrophic manifestation compared to protozoan and bacterial BA. Diagnosis of FBA is rare and usually done postmortem.

OBJECTIVES

The present retrospective study analyses the clinico-mycological aspects of FBA presented to our neurosurgical services over a period of 38 years, from January 1979 to April 2017.

MATERIALS AND METHODS

Patients diagnosed as definitive cases of FBA were included in the study. Clinico- demographic and microbiological data were collected from medical records. BA pus was examined for fungal etiology using standard microbiological procedures.

RESULTS

During the period of 38 years out of total 2,916 brain abscesses, 29 cases of FBA were diagnosed with an overall incidence rate of 0.99% per year. Cladophialophora bantiana (44%) was the most predominant isolate followed by Aspergillus spp and others. Male preponderance was seen with a male:female ratio of 4.8:1. There was no predilection for any age group. Headache, limb weakness and fever were the most common presentations. Amphotericin B was given in 44.8% of cases. Craniotomy with excision (48.2%) was the predominant surgical management. Outcome was fatal in 62% of the cases.

CONCLUSION

Neurotropic C. bantiana is the predominant isolate causing fungal brain abscess. The incidence and trends of fungi causing brain abscess do not show significant change. Young immunocompetent outdoor working males were predominantly susceptible to fungal infection. Advance in the diagnostic modalities show promising in diagnosis of FBA. High index of suspicion with early diagnosis, prompt antifungal therapy and aggressive surgical management is required as FBA are associated with high mortality rate.

Clinical features in maxillary sinus fungus ball in patients with malignant hematological disease

PURPOSE

Previous studies on fungus balls have primarily focused on immunocompetent patients, and only a few studies have described the clinical characteristics of fungus balls in malignant hematological disease (MHD) patients. Therefore, we compared the clinical features of maxillary sinus fungus ball (MSFB) between immunosuppressive patients with MHD and immunocompetent patients.

METHODS

Twenty patients with MHD and 40 randomly selected immunocompetent patients were enrolled and divided into MHD and non-MHD groups. All patients were diagnosed with MSFB and their clinical features were retrospectively analyzed.

RESULTS

Patients in the MHD group had non-specific clinical symptoms and endoscopic manifestations of MSFB, similar to those in the non-MHD group. On computed tomography (CT), the MHD group showed higher Lund-Mackay scores, lesser single sinus opacifications, more multiple sinus opacifications on the affected side, and more bilateral opacifications compared to the non-MHD group. The MHD group had a lower frequency of central hyper-density and heterogeneous opacifications than the non-MHD group. There were no significant differences between the two groups in terms of the fungal-infected side, lateral sinus wall ratio, sclerosis of the lateral sinus wall, erosion of the inner sinus wall, and nasal septum deviation.

CONCLUSION

The clinical symptoms and endoscopic manifestations of MSFB in patients with MHD were similar to those of immunocompetent patients. However, more atypical signs and wider mucosal inflammation were found on CT scans of MSFB patients with MHD. These results indicate that caution should be executed when excluding the possibility of fungus balls in immunosuppressive patients.

COVID-19 imaging: Diagnostic approaches, challenges, and evolving advances

The role of radiology and the radiologist have evolved throughout the coronavirus disease-2019 (COVID-19) pandemic. Early on, chest computed tomography was used for screening and diagnosis of COVID-19; however, it is now indicated for high-risk patients, those with severe disease, or in areas where polymerase chain reaction testing is sparsely available. Chest radiography is now utilized mainly for monitoring disease progression in hospitalized patients showing signs of worsening clinical status. Additionally, many challenges at the operational level have been overcome within the field of radiology throughout the COVID-19 pandemic. The use of teleradiology and virtual care clinics greatly enhanced our ability to socially distance and both are likely to remain important mediums for diagnostic imaging delivery and patient care. Opportunities to better utilize of imaging for detection of extrapulmonary manifestations and complications of COVID-19 disease will continue to arise as a more detailed understanding of the pathophysiology of the virus continues to be uncovered and identification of predisposing risk factors for complication development continue to be better understood. Furthermore, unidentified advancements in areas such as standardized imaging reporting, point-of-care ultrasound, and artificial intelligence offer exciting discovery pathways that will inevitably lead to improved care for patients with COVID-19.

A New Antifungal-Loaded Sol-Gel Can Prevent Candida albicans Prosthetic Joint Infection

Fungal PJI is one of the most feared complications after arthroplasty. Although a rare finding, its high associated morbidity and mortality makes it an important object of study. The most frequent species causing fungal PJI is C. albicans. New technology to treat this type of PJI involves organic-inorganic sol-gels loaded with antifungals, as proposed in this study, in which anidulafungin is associated with organophosphates. This study aimed to evaluate the efficacy of an anidulafungin-loaded organic-inorganic sol-gel in preventing prosthetic joint infection (PJI), caused by Candida albicans using an in vivo murine model that evaluates many different variables. Fifty percent (3/6) of mice in the C. albicans-infected, non-coated, chemical-polished (CP)-implant group had positive culture and 100% of the animals in the C. albicans-infected, anidulafungin-loaded, sol-gel coated (CP + A)-implant group had a negative culture (0/6) (p = 0.023). Taking the microbiology and pathology results into account, 54.5% (6/11) of C. albicans-infected CP-implant mice were diagnosed with a PJI, whilst only 9.1% (1/11) of C. albicans-infected CP + A-implant mice were PJI-positive (p = 0.011). No differences were observed between the bone mineral content and bone mineral density of noninfected CP and noninfected CP + A (p = 0.835, and p = 0.181, respectively). No histological or histochemical differences were found in the tissue area occupied by the implant among CP and CP + A. Only 2 of the 6 behavioural variables evaluated exhibited changes during the study: limping and piloerection. In conclusion, the anidulafungin-loaded sol-gel coating showed an excellent antifungal response in vivo and can prevent PJI due to C. albicans in this experimental model.

Imaging features of fungal pneumonia in haematopoietic stem cell transplant patients

Patients who have received haematopoietic stem cell transplantation (HSCT) have a high rate of pulmonary complications, and in this immunosuppressed population, fungal pneumonia is of great concern. Fungal pneumonia can have a similar appearance to non-infectious pulmonary processes in HSCT patients, and radiologists should be familiar with the subtle features that may help to differentiate these disease entities. The focus of this article is on the diagnosis of fungal pneumonia in HSCT patients with an emphasis on radiologists’ roles in establishing the diagnosis of fungal pneumonia and the guidance of clinical management.

Imaging of abdominal and pelvic infections in the cancer patient

Infections are the most commonly encountered complications in patients with cancer. The classical signs and symptoms of infections are often not present in this patient population, which makes the diagnosis more challenging. Host factors play a major role in the development and prognosis of infections in cancer patients; these can be related to the underlying type of malignancy (solid organ versus hematological), tumor burden, anatomic obstruction, altered integrity of barriers (skin or mucosa), treatment-related factors (from chemotherapy, radiation treatment, surgery, interventional procedures, and/or medical device placement) and the degree of immunosuppression. This article reviews common, as well as less common, imaging manifestations of infections and their potential mimics in the abdomen and pelvis in cancer patients and discusses their differentiating features, with the role of imaging in various organs in the abdomen and pelvis taking into consideration relevant clinical background information and the main risk factors.

Evaluating the efficacy of anti-fungal blue light therapies via analyzing tissue section images

Anti-fungal blue light (ABL) therapies have been studied and applied in treating various diseases caused by fungal infection. The existing work has been mainly devoted to study the effect of various light dosages on the fungal viability and on the induced cytotoxic reactive oxygen species (ROS) in the pathogens. While in vivo experimental studies have also been reported, there is still no work targeted on quantifying the effect of light on prohibiting the pathogens from invading into the deeper sites in the skin of their host. This can be attributed to the lack of methods to analyze the tissue section images, which are the main means of examining infected tissues. This work has been devoted to solve such problems, so as to improve dosimetric analyses of ABL therapies on treating fungal infections. Specifically, the invasion depth of the fungi and their ratios to the tissue in four bins at different depths inside the skin were extracted from the tissue section images. The significance of the treatment with different dosages on inhibiting the fungi was also tested by each of these depth-related metrics. The ABL experiments using 415-nm-wavelength LED light were performed on BALB/c mice, whose skin was infected by Candida albicans (C. albicans). The proposed methods were applied to the tissue sections of the experimental animals. The results clearly verified that the fluence up to 180J/cm² can significantly prohibit the fungal infection into the skin in terms of almost all the newly proposed metrics.

Imaging Spectrum of Granulomatous Diseases of the Abdomen and Pelvis

A granuloma is a compact organization of mature macrophages that forms because of persistent antigenic stimulation. At the microscopic level, granulomas can undergo various morphologic changes, ranging from necrosis to fibrosis, which along with other specialized immune cells define the appearance of the granulomatous process. Accordingly, the imaging features of granulomatous diseases vary and can overlap with those of other diseases, such as malignancy, and lead to surgical excisions and biopsy. However, given the heterogeneity of granulomas as a disease group, it is often hard to make a diagnosis on the basis of the histopathologic features of granulomatous diseases alone owing to overlapping microscopic features. Instead, a multidisciplinary approach is often helpful. Radiologists need to be familiar with the salient clinical manifestations and imaging findings of granulomatous diseases to generate an appropriate differential diagnosis. ^©RSNA, 2021.

Targeted Drug Delivery Using Tuftsin-bearing Liposomes: Implications in the Treatment of Infectious Diseases and Tumors

Tuftsin, a tetrapeptide (Thr-Lys-Pro-Arg), acts as an immunopotentiating molecule with its ability to bind and activate many immune cells, including macrophages or monocytes, neutrophils and dendritic cells. The specific targeting activity of tuftsin has been further increased by its palmitoylation followed by its incorporation into the lipid bilayer of liposomes. Tuftsin-bearing liposomes (Tuft-liposomes) possess several characteristics that enable them to act as a potential drug and vaccine carriers. Tuft-liposomes-loaded anti-microbial drugs have been shown to be highly effective against many infectious diseases, including tuberculosis, leishmaniasis, malaria, candidiasis and cryptococosis. Moreover, Tuft-liposomes also increased the activity of anticancer drug etoposide against fibrosarcoma in mice. Tuft-liposomes showed the immune-potentiating effect and rejuvenated the immune cells in the leukopenic mice. In addition, antigens encapsulated in Tuftsin-bearing liposomes demonstrated greater immunogenicity by increasing the T cell proliferation and antibody secretion. Keeping into consideration their specific targeting and immunopotentiating effects, Tuft-liposomes may potentially be used as promising drug and vaccine delivery systems.