Radiographic Resolution Research Articles

Rothia mucilaginosa Pneumonia in an Immunocompromised Patient

Abstract Rothia mucilaginosa is a gram-positive coccus recognized as an opportunistic pathogen capable of causing pneumonia in immunocompromised patients (Antimicrob Agents Chemother. 1995;39:268–270). The organism is often resistant to fluoroquinolones and trimethoprim/sulfamethoxazole, agents routinely used as anti-infective prophylaxis in immunocompromised individuals (Inf Dis Clin Pract. 2020;28:361–365; Infect Dis Now. 2021;51:228–235). Plasma next-generation sequencing (NGS) is increasing in clinical use to aid in diagnosis of infections in immunocompromised patients (Infect Dis (Lond). 2015;47:125–1299). A patient with advanced multiple myeloma was admitted with pneumonia. Plasma NGS initially suggested R. mucilaginosa, which was confirmed by cultures of bronchoalveolar lavage (BAL) fluid. Treatment with eravacycline led to clinical and radiographic resolution of pneumonia.

Safety of Postembolization Antithrombotic Therapy After Middle Meningeal Artery Embolization.

Middle meningeal artery embolization (MMAE) for the management of chronic subdural hematoma (cSDH) has been suggested as a preferred treatment in patients where reinitiating antithrombotic (AT) therapy is necessary. In this study, we evaluate whether reinitiating AT therapy before cSDH resolution after MMAE affects radiographic and clinical resolution. This is a retrospective study of patients who underwent MMAE at our institution between 2018 and 2024. Clinical and radiographic findings were analyzed with standard statistical approaches. Kaplan-Meier curves for nonresolution compared AT and no-AT groups and compared AT resumption before and after 30 days after surgery. In 111 MMAE procedures, the median age was 73 years, 27.9% were female, and 80.6% were White. The median follow-up was 5.1 months. Forty-six patients (41.4%) demonstrated complete resolution of their cSDH. Eleven patients (9.9%) had reoperation after MMAE. The median cSDH depth was 14.0 mm, and the median midline shift was 3.0 mm. Thirty-two patients (28.8%) resumed AT before resolution. The median time to resumption was 35.5 days. Patients in the AT group were less likely to have radiographic resolution (21.9% vs 49.4%, odds ratios = 0.2872, 95% CI = 0.1113-0.7404, P = .0103) but comparable rates of reoperation and residual symptomatic presentations. Resumption of AT therapy before or after 30 days from surgery had no effects on outcome measures on univariate analysis. Major outcomes were similar between patients receiving antiplatelet-only or anticoagulant-only medications. Reinitiating AT therapy before cSDH resolution was associated with decreased rates of resolution, but comparable rates of reoperation and residual symptoms. Our results support the cautious reinitiation of AT therapy in patients requiring it after MMAE.

Clinical course and radiographic resolution of pneumonia in dogs treated with a shorter versus longer course of antimicrobials: a randomized, double-masked, placebo-controlled study.

To describe clinical and radiographic outcomes in dogs with uncomplicated pneumonia receiving a shorter (2-week) versus longer (4-week) duration of antimicrobial therapy. 30 client-owned dogs with radiographic evidence of pneumonia. Dogs were randomly assigned to either a 2-week course of antimicrobials followed by a 2-week course of placebo medication (2-week group) or a 4-week course of antimicrobials (4-week group). All study investigators and owners were masked to the treatment group. Dogs were reevaluated at 12 ± 2 days and again at 28 ± 2 days for a physical examination and thoracic radiography. Standard documentation at visits included owner-reported clinical signs, nurse-acquired history, the clinician's physical examination, the number of affected lung lobe segments, and the global radiographic severity scores assigned. Outcomes investigated included the persistence of clinical and radiographic signs of pneumonia. 28 dogs (93.3%) experienced complete resolution of clinical signs by the first visit, and no dogs in either group experienced relapse of clinical signs during the study period. Eighteen of 30 dogs (60%) and 25 of 30 dogs (83%) experienced complete resolution of radiographic lesions at the first and second study visits, respectively. The remaining 5 dogs (17%) had either stable (4 dogs) or continued (1 dog) improvement in radiographic lesions. Resolution of clinical and radiographic signs followed similar courses in dogs with uncomplicated pneumonia receiving a 2-week course of antimicrobials compared to a 4-week course. Clinical signs may be more useful for guiding discontinuation of antimicrobial therapy for pneumonia than radiographic signs.

Six-minute walk test among silicosis patients: Its correlation with abnormal radiographic findings on chest radiograph and high resolution computed tomography scan

Six-minute walk test among silicosis patients: Its correlation with abnormal radiographic findings on chest radiograph and high resolution computed tomography scan

Intra‐arterial Selective Bevacizumab Administration in the Middle Meningeal Artery for Chronic Subdural Hematoma: An Early Experience in 12 Hemispheres

Background Chronic subdural hematoma (cSDH) has a rising incidence associated with an increasing burden of disability and mortality worldwide. Vascular endothelial growth factor plays an integral role in the inflammation and formation of subdural membranes responsible for the origin and propagation of cSDH. We report an early experience of intra‐arterial bevacizumab, a vascular endothelial growth factor receptor antagonist, to the middle meningeal artery of 12 hemispheres in 8 patients with cSDH. Methods Eight patients with either unilateral or bilateral cSDH received intra‐arterial infusion of 2 mg/kg bevacizumab into the middle meningeal artery of each treated hemisphere. The primary outcome was hematoma recurrence or reaccumulation requiring surgical drainage or middle meningeal artery embolization within 3 months posttreatment. Results Of 12 hemispheres treated, no treatment‐related complications were reported. Median duration of follow‐up was 5 months (interquartile range 3–7.5). By 3 months posttreatment, no patients experienced hematoma recurrence or reaccumulation. One patient required concurrent evacuation at the time of bevacizumab administration. There were no major strokes or mortality within 3 months. Four hemispheres (33.3%) demonstrated complete radiographic hematoma resolution by 3 months. All hemispheres achieved 50% reduction in hematoma size by 3 months. Conclusion For all hemispheres treated, there was no hematoma recurrence or progression requiring surgical drainage or middle meningeal artery embolization within 3 months except 1 who required concurrent evacuation 24 hours after treatment. Our initial experience supports bevacizumab as a novel, potentially viable agent for cSDH treatment in select patients. Future studies in larger cohorts are necessary to confirm efficacy and safety and appropriate dosing.

Longitudinal analysis of the lung proteome reveals persistent repair months after mild to moderate COVID-19

In order to assess homeostatic mechanisms in the lung after COVID-19, changes in the protein signature of bronchoalveolar lavage from 45 patients with mild to moderate disease at three phases (acute, recovery, and convalescent) are evaluated over a year. During the acute phase, inflamed and uninflamed phenotypes are characterized by the expression of tissue repair and host defense response molecules. With recovery, inflammatory and fibrogenic mediators decline and clinical symptoms abate. However, at 9months, quantified radiographic abnormalities resolve in the majority of patients, and yet compared to healthy persons, all showed ongoing activation of cellular repair processes and depression of the renin-kallikrein-kinin, coagulation, and complement systems. This dissociation of prolonged reparative processes from symptom and radiographic resolution suggests that occult ongoing disruption of the lung proteome is underrecognized and may be relevant to recovery from other serious viral pneumonias.

Imaging Review of Different Subchondral Insufficiency Fractures.

Subchondral fractures are a common cause of joint pain that may ultimately lead to articular collapse and the need for arthroplasty. This type of fracture has been reported at multiple joints throughout the body. While clinical and radiographic resolution can be achieved, progressive bone collapse can occur and lead to a variety of complications. Understanding the pertinent imaging findings can aid in the early evaluation of subchondral fractures and in the prevention of their associated complications.

Spot size measurement of a deuterium-tritium dense plasma focus using neutron radiography.

Neutron radiography is a technique uniquely suited to applications in nuclear diagnostics, non-destructive testing, and subcritical experiments. The spatial resolution of neutron radiographs is degraded by optical blur in the imaging system and the neutron source size, where the ideal source is point-like to optimize the point-spread function. A potential neutron source for radiography is the dense plasma focus (DPF), a coaxial Z-pinch that produces thermonuclear and beam-target neutrons. To assess if the source size is suitable for radiography, a neutron imaging system was used to measure the source size of the 4 MA Sodium DPF at the Nevada National Security Site operating with deuterium-tritium gas-fill. The source size was measured using the edge-spread function of tungsten objects, each having a rolled (convex) edge. The spot size was found to be 7-12mm full-width at half-max(FWHM) assuming a Gaussian source, though comparison is presented for Lorentzian and Bennett distributions. The average FWHM was found to be 8.6 ± 1.2mm vertically and 10.8 ± 1.2mm horizontally with respect to the image plane, averaging over varied edges and alignments. The results were sensitive to source alignment and edge metrology, which introduced notable uncertainties. These results are consistent with separate experimental measurements as well as magnetohydrodynamics simulations of this DPF, which suggest that neutron production can originate from pinches ∼5-7mm off-axis. These results suggest that the DPF should be used for radiography at low magnification (M < 1) where spot size does not dominate spatial blur.

Early predictors of delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae in children: a retrospective study in China.

Lobar pneumonia caused by Mycoplasma pneumoniae is a relatively difficult-to-treat pneumonia in children. The time of radiographic resolution after treatment is variable, a long recovery time can result in several negative effects, and it has attracted our attention. Therefore, exploring factors associated with delayed radiographic resolution will help to identify these children at an early stage and prepare for early intervention. The data of 339 children with lobar pneumonia caused by Mycoplasma pneumoniae were collected from the Department of Pediatrics of Fu Yang People's Hospital, China from January 2021 to June 2022. After discharge, the children were regularly followed up in the outpatient department and on the WeChat platform for > 8 weeks. According to whether pulmonary imaging (chest radiography or plain chest computed tomography) returned to normal within 8 weeks, the children were divided into the delayed recovery group (DRG) (n = 69) and the normal recovery group (NRG) (n = 270). The children's general information, laboratory examination findings, bronchoscopy results, and imaging findings were retrospectively analyzed. Single-factor analysis was performed to identify the risk factors for delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae, and the factors with statistically significant differences underwent multiple-factor logistic regression analysis. Receiver operating characteristic (ROC) analysis was then performed to calculate the cutoff value of early predictive indicators of delayed radiographic resolution. Single-factor analysis showed that the following were significantly greater in the DRG than NRG: total fever duration, the hospitalization time, C-reactive protein (CRP) level, lactate dehydrogenase (LDH) level, D-dimer level, pulmonary lesions involving two or more lobes, a large amount of pleural effusion, the time to interventional bronchoscopy, and mucus plugs formation. Multivariate logistic regression analysis showed that the hospitalization time, CRP level, LDH level, pulmonary lesions involving two or more lobes, and a large amount of pleural effusion were independent risk factors for delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae. The cutoff values on the receiver operating characteristic curve were a hospitalization time of ≥ 10.5 days, CRP level of ≥ 25.92mg/L, and LDH level of ≥ 378 U/L. If patients with lobar pneumonia caused by Mycoplasma pneumoniae have a hospitalization time of ≥ 10.5 days, CRP level of ≥ 25.92mg/L, and LDH level ≥ 378 U/L, the time of radiographic resolution is highly likely to exceed 8 weeks. Pediatricians must maintain a high level of vigilance for these factors, control the infection as early as possible, strengthen airway management, and follow up closely to avoid complications and sequelae of Mycoplasma pneumoniae pneumonia.

Radiographic Outcomes in Pediatric Bronchiectasis and Factors Associated with Reversibility.

Rationale: Conventionally considered irreversible, bronchiectasis has been demonstrated to be reversible in children in small studies. However, the factors associated with radiographic reversibility of bronchiectasis have yet to be defined. Objectives: In a large cohort of children with bronchiectasis, we aimed to determine: 1) if and to what extent bronchiectasis is reversible and 2) factors associated with radiographic chest high-resolution computed tomography (cHRCT) resolution. Methods: We identified children with bronchiectasis who had a repeat multidetector cHRCT scan between 2010 and 2021. We excluded those with cystic fibrosis, surgical pulmonary resection, traction bronchiectasis only, or lobar opacification. Measurements and Main Results: cHRCT scans were scored using the modified Reiff score (MRS) with a pediatric correction. Resolution was defined as an absence of abnormal bronchoarterial ratio (>0.8) on the second cHRCT scan. We included 142 children (median age, 5 years; IQR, 2.6-7.4). Inter- and intrarater agreement in MRSs was excellent (weighted κ = 0.83-0.86 and 0.95, respectively). There was radiographic resolution in 57 of 142 patients (40.1%), improvement in 56 of 142 (39.4%), and no change or worsening in 29 of 142 (20.4%). Pseudomonas aeruginosa (PsA) was absolutely associated with a lack of resolution. On multivariable regression, in those without PsA cultured, younger age at the time of diagnosis (risk ratio [RR], 0.94; 95% confidence interval [CI], 0.88-0.99), lower MRS (RR, 0.89; 95% CI, 0.82-0.97), and lower annual rate of exacerbations requiring intravenous antibiotic therapy (RR, 0.60; 95% CI, 0.37-0.98) increased the likelihood of radiographic resolution. Conclusions: This first large cohort confirms that bronchiectasis in children is often reversible with appropriate management. Younger children and those with lesser radiographic severity at diagnosis were most likely to exhibit radiographic reversibility, whereas those with PsA infection were least likely.

Improving Resolution of Panoramic Radiographs: Super Resolution Concept.

Improving Resolution of Panoramic Radiographs: Super Resolution Concept.

A denoising method based on deep learning for proton radiograph using energy resolved dose function

Objective. Proton radiograph has been broadly applied in proton radiotherapy which is affected by scattered protons which result in the lower spatial resolution of proton radiographs than that of x-ray images. Traditional image denoising method may lead to the change of water equivalent path length (WEPL) resulting in the lower WEPL measurement accuracy. In this study, we proposed a new denoising method of proton radiographs based on energy resolved dose function curves. Approach. Firstly, the corresponding relationship between the distortion of WEPL characteristic curve, and energy and proportion of scattered protons was established. Then, to improve the accuracy of proton radiographs, deep learning technique was used to remove scattered protons and correct deviated WEPL values. Experiments on a calibration phantom to prove the effectiveness and feasibility of this method were performed. In addition, an anthropomorphic head phantom was selected to demonstrate the clinical relevance of this technology and the denoising effect was analyzed. Main results. The curves of WEPL profiles of proton radiographs became smoother and deviated WEPL values were corrected. For the calibration phantom proton radiograph, the average absolute error of WEPL values decreased from 2.23 to 1.72, the mean percentage difference of all materials of relative stopping power decreased from 1.24 to 0.39, and the average relative WEPL corrected due to the denoising process was 1.06%. In addition, WEPL values correcting were also observed on the proton radiograph for anthropomorphic head phantom due to this denoising process. Significance. The experiments showed that this new method was effective for proton radiograph denoising and had greater advantages than end-to-end image denoising methods, laying the foundation for the implementation of precise proton radiotherapy.

Platelet-rich Plasma Injection for the Treatment of Partial Achilles Tendon Rupture: A Case Report

Introduction: Achilles tendon rupture is one of the most common adult tendon injuries and continues to increase in incidence. This case report outlines a comprehensive approach for stand-alone leukocyte-poor platelet-rich plasma treatment of a partial subacute Achilles tendon rupture in a professional athlete who had received prior autologous conditioned serum injections with an interleukin-1 receptor antagonist. Patient History: A 32-year-old male professional ice hockey player presented with persistent left ankle pain approximately seven months after suffering a partial acute Achilles tendon tear. Imaging confirmed a subacute partial Achilles tendon rupture. Injection: Following local anesthesia, a 25-gauge 1.5-inch needle was advanced to the target structure under ultrasound guidance and 3 mL of autologous platelet-rich plasma was divided amongst several areas of the patient's Achilles tendon, while simultaneously tenotomizing the tendon. No complications were observed. Imaging: Follow-up magnetic resonance imaging approximately 9 months after platelet-rich plasma injection revealed complete resolution of the Achilles tendon rupture. Conclusion: Ultrasound-guided leukocyte-poor platelet-rich plasma injection could be considered an effective treatment option for acute Achilles tendon rupture during the subacute stages of tendon healing, leading to complete radiographic resolution of the tear and enabling a return to high-level athletics.

Successful Crizotinib-targeted Therapy of Pediatric Unresectable ERC1::ALK Fusion Sarcoma.

Anaplastic lymphoma kinase ( ALK )-fusion sarcomas are rare part of the emerging theoretically targetable tyrosine kinase RAS::MAPK pathway fusion myopericytic-ovoid sarcomas. We report our clinicopathologic and treatment experience with an ALK fusion sarcoma. A novel ELKS/RAB6-interacting/CAST family member 1 - unaligned ALK fusion infiltrative nonmetastatic low-grade sarcoma of the right hand of a 15-month-old male was treated with crizotinib, an ALK tyrosine kinase inhibitor as oral monotherapy, inducing complete radiographic and clinical resolution by 10 months and sustained response now over 12 months after elective discontinuation. Crizotinib can successfully be used to treat unresectable novel ALK fusion sarcomas.

ARIA‐E, ARIA‐H, and CAA‐related inflammation: time of reconsiderations?

AbstractBackgroundEvidence from published clinical trials suggests that high‐dose of monoclonal antibodies (mAbs) are needed to significantly remove parenchymal‐deposited Aβ plaques. However, high‐dosing mAbs resulted in a 25‐35% increased risk of amyloid‐related imaging abnormalities‐edema (ARIA‐E) and ARIA‐hemorrhage (ARIA‐H) side events. Although most ARIA‐E are incidentally recognized as clinically silent during pre‐planned safety monitoring MRI scans and suggested to be managed by dose reduction or suspension, it is noticeable that half of ARIA‐E progressed to symptomatic at continued dosing and to associate with late occurrence of ARIA‐H. Of particular importance, a few of them aggravated to potentially severe brain injury or death due to fatal CAA‐related events. Increased evidence from natural history studies suggests that ARIA‐E is the iatrogenic manifestation of cerebral amyloid angiopathy‐related inflammation (CAA‐ri), a rare autoimmune encephalopathy due to raised anti‐Aß autoAbs levels in the cerebrospinal fluid (CSF).MethodNatural history study of CAA‐ri demonstrated that immunotherapy‐related ARIA‐E share several commonalities with the spontaneous occurrence of autoAbs‐related ARIA‐E, including fluid, MRI, and PET biomarker changes and the potential response to treatment outcomes.ResultThe prospective longitudinal monitoring of patients with CAA‐ri provide evidence for a regional and temporal association of ARIA‐E on MRI with focal peaks of neuroinflammation on microglial‐PET imaging. This association was strong in patients with positive CSF markers of AD (ATN positive) and comorbid CAA pathology on MRI, while it was negligible in patients with CAA disease w/o AD (ATN negative). Raised CSF concentrations of anti‐Aß autoAbs were found in all patients at (sub)acute presentation, and reduced within 5 months from the ARIA‐E index event, in parallel with evidence of radiographic resolution of ARIA‐E. At follow‐up MRI scan, the occurrence of new hemorrhagic markers (aka ARIA‐H in trials) were found only in patients with coexisting CAA and AD comorbid pathology. The MRI scales for ARIA commonly used in clinical trials only partially paralleled the clinical, biological, and MRI findings.ConclusionThis suggests that to mitigate and monitor the risk of ARIA, more sensitive, specific, cost‐effective and easy to interpret diagnostic tools and biomarkers than MRI alone will be needed for precision drug‐dose tailoring.

Efficacy of Direct Oral Anticoagulants Vs Warfarin Vs Low Molecular Weight Heparin in the Treatment of Acute Splanchnic Vein Thrombosis in Patients with Underlying Myeloproliferative Disorder

Introduction: Myeloproliferative neoplasms (MPNs) are hematopoietic stem cell disorders characterized by clonal proliferation of myeloid-lineage cells. Venous thrombosis poses a significant morbidity risk for MPN patients. The current recommended treatments for acute splanchnic vein thrombosis (SVT) are warfarin and low molecular weight heparin (LMWH). Direct oral anticoagulants (DOACs) are potential alternatives due to their predictable dose response and oral administration, but limited data exists for their use in acute SVTs. This retrospective study aims to assess the efficacy and outcomes of DOACs, LMWH, and warfarin in treating acute SVTs in patients with underlying MPN. Methods: We included patients of all ages with underlying myeloproliferative neoplasms and splanchnic vein thrombosis, with no underlying liver diseases, from Henry Ford Hospital Clinics in metropolitan Detroit, Michigan between 2013 and 2023. Patient data, which included age, gender, race, and BMI were recorded. The primary outcome was complete radiographic resolution (CRR) of the SVT, and secondary outcomes included recanalization, thrombosis progression, recurrent thrombosis, major bleeding, thrombocytopenia, and skin necrosis. The outcomes were compared between the three anticoagulant groups and patients using aspirin. Results: Among the 34 MPN patients with SVT, warfarin was prescribed most frequently (n=19), followed by enoxaparin (n=5) and DOACs (n=5). Although no significant differences were observed, warfarin showed the highest CRR rates (41.2%), while enoxaparin and DOACs had equal CRR rates (25%). DOACs showed recanalization rates similar to warfarin and higher than enoxaparin (44.4% and 47.1% vs. 20.0%, respectively). LMWH was associated with increased recurrent thrombosis rates (50.0%), while DOACs had a higher risk of major bleeding. All three anticoagulants had similar effects on thrombocytopenia and SVT progression. Aspirin use was linked to a higher risk of major bleeding (42.9%), but not using aspirin correlated with complete SVT resolution (30.8%), SVT progression (20.8%), recurrent thrombosis (29.2%), and thrombocytopenia (28.6%). Conclusions: Although limited by a small sample size, our study found no significant differences among the three anticoagulant groups. This contributes to establishing the role of DOACs in treating SVTs in patients with underlying MPN. Further studies with larger sample sizes are needed to explore the efficacy of DOACs compared to warfarin. Additionally, investigating the potential benefits of early thrombolysis in conjunction with anticoagulation for SVT patients with underlying MPN should be pursued, as the rates of complete resolution in these patients were low.

Granulocyte Transfusion Therapy as a Bridge to Hematopoietic Stem Cell Transplant in a Child with Aplastic Anemia and Refractory Perirectal Abscess

Granulocyte Transfusion Therapy as a Bridge to Hematopoietic Stem Cell Transplant in a Child with Aplastic Anemia and Refractory Perirectal Abscess

Abstract 031: Onyx versus nBCA in MMA Embolization for cSDH: A Single Center Experience of 234 hemispheres

Introduction There is growing evidence supporting endovascular treatment with middle meningeal artery embolization (MMAE) for the treatment of chronic subdural hematoma (cSDH). We aimed to compare Onyx vs. N‐Butyl cyanoacrylate (n‐BCA) as liquid embolic materials for MMAE. Methods We included all eligible patients undergoing MMAE for cSDH at University of Pittsburgh Medical Center from April 2019 to December 2022. The main outcomes included radiographic resolution of cSDH with at least 50% reduction of hematoma thickness as a surrogate for treatment success in addition to the need for rescue surgical intervention. Additional outcomes including complication rates and hematoma thickness at the last available follow up. Results A total of 195 patients underwent embolization of 234 hemispheres including 39 bilateral procedures and had available data for final analysis (168 (71.8%) in Onyx group vs. 66 (28.2%) in n‐BCA group). There were no significant differences in age, sex, co‐morbidities, prior SDH/evacuation, pre‐operative cSDH thickness, or use of antithrombotic therapy(P&gt;0.05) while concurrent surgical intervention and midline shift showed a statistically significant difference (P&lt;0.05). On last follow‐up imaging, radiographical treatment success defined as ≥ 50% reduction in hematoma thickness was comparable in Onyx and the n‐BCA groups (50.9% vs 54.8%, P=0.6). Similarly, there was no statistically significant difference in the proportion of patients requiring rescue surgery between both groups (4.8% vs. 7.6%, P=0.4). Excluding concurrent surgical intervention patients yielded similar comparable results. Hematoma thickness at late follow‐up was not statistically significant between both group (8.25 (4.8‐12) mm vs 6.9 (3.1‐11) mm, P =0.11). There was no statistically significant difference in procedural complications between both groups (1.2% vs 1.5%, P=0.84). Conclusion Onyx and n‐BCA in MMAE seem to have comparable outcomes when used in the endovascular treatment of cSDH treatment. Further prospective studies with larger sample sizes are needed to confirm these findings.

Liver Abscesses Due to Fusobacterium nucleatum: A Case Series

Abstract Fusobacteriae are anaerobic gram-negative bacilli, classically involved in the development of septic thrombophlebitis of the internal jugular vein in Lemierre syndrome. The goal of this study is to describe the various presentations, treatment course, and outcomes of patients with Fusobacterium liver abscess(es) and review available literature on this topic. We retrospectively reviewed our microbiologic database for positive cultures of Fusobacteriae species in a tertiary care hospital from July 2018 through November 2022 and identified 5 cases of liver abscess that involved Fusobacterium nucleatum species. Patients presented with a syndrome of fever and chills, abdominal pain, and nausea and vomiting. Laboratory investigations revealed leukocytosis and transaminitis, and imaging revealed liver abscess(es). The identification of the F. nucleatum bacteria involved invasive aspiration of the abscess in all but one case, where it was identified on blood cultures. One patient had a florid picture of sepsis and acute respiratory distress syndrome. All patients responded well with intravenous antibiotics and were discharged home to complete a prolonged course until radiographic resolution. In 3 patients, history and imaging were suggestive of possible sources that may have hematogenously spread to the liver, with history of recent appendectomy in 1 patient, possible appendicitis on computed tomography of the abdomen in another patient, and recent dental manipulation in the third patient. In conclusion, Fusobacteriae should be included in the differential diagnosis of liver abscess, especially in the setting of recent appendicitis or dental disease. Effective treatment includes surgical drainage when feasible and prolonged course of antibiotics with goal of radiologic resolution.

Optimisation of a neutron imaging system using the modulation transfer function

The use of the modulation transfer function was explored for the characterisation and optimisation of the optical system used for tomographic imaging on the DINGO instrument at the Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia. Both a Siemens star and a phantom were used to determine the modulation transfer function and the results are compared. This allowed the optimal configuration of the instrument to be determined and the establishment of a relationship between sample dimension, exposure time and radiograph resolution to be developed. For tomographic studies of large samples, best results were achieved with DINGO configured in high-flux mode (L/D = 500), with a 6LiF/ZnS scintillator screen, an Iris 15TM sCMOS detector, a 50 mm lens, and an exposure time between 4 and 8 s.