Radiologic Manifestations of Mycobacterium chimaera Infection After Open Heart Surgery.

PURPOSE: The objective of this study is to identify and detail the radiologic manifestations of surgical site and disseminated Mycobacterium chimaera (MC) infection. The aim is to facilitate early identification and diagnosis of MC, considering its indolent nature and the challenges involved in clinically and pathologically establishing the diagnosis. PATIENTS AND METHODS: This was a retrospective cohort study reviewing computed tomography (CT), positron emission tomography (PET)/CT, and magnetic resonance imaging examinations in patients over the age of 18 years with a history of open heart surgery and a clinical or pathologic diagnosis of MC. Two radiology residents, a fellowship-trained nuclear medicine radiologist, and a fellowship-trained cardiothoracic radiologist performed consensus reads to determine the imaging findings seen in MC infection. RESULTS: Twenty-five patients were included. Localized, surgical site infection was more common than disseminated disease. Typical CT findings included peristernal soft tissue thickening, sinus tracts often extending to the cutaneous surface, slowly enlarging fluid collections, and sternal osteolysis. PET/CT findings demonstrated hypermetabolic activity in nearly all patients localized to sites of infection. Imaging findings for disseminated infection included hepatosplenomegaly, lymphadenopathy, involvement of the central nervous system, discitis/osteomyelitis, and distant abscesses. CONCLUSIONS: Imaging plays a vital role in suggesting possible surgical sites and disseminated MC infection acquired from open heart surgery. Radiologists must keep a high index of suspicion given the indolent nature and subtle imaging change over time. PET/CT is most useful in diagnosis and helps in differentiating between a sterile postoperative fluid collection or scarring and active MC infection and helps provide a target for debridement.

Relapsed Breast Implant-Associated Anaplastic Large-Cell Lymphoma Presenting as Refractory Fluid Collections With Low Uptake on FDG PET/CT Scan.

ABSTRACT: Breast implant-associated anaplastic large-cell lymphoma is a rare type of non-Hodgkin lymphoma that occurs years after placement of textured surface breast implants. Patients typically present after the development of pain, a palpable mass, or swelling. We present a case of a 45-year-old woman with recurrent breast implant-associated anaplastic large-cell lymphoma presenting as refractory fluid collections, and the unusual finding of low uptake on FDG PET/CT scan despite being confirmed by cytology.

Rationale and methods to characterize the acute exercise response in aging and Alzheimer's Disease: the AEROBIC pilot study.

There is evidence that exercise benefits the brain, but the mechanisms for this benefit are unclear. The chronic benefits of exercise are likely a product of discreet, acute responses in exercise-related blood biomarkers and brain metabolism. This acute exercise response has not been compared in aging and Alzheimer's Disease (AD). It is known that acute exercise elicits a powerful peripheral response in young individuals, and exercise-related biomarkers such as glucose and lactate readily penetrate the brain. How this changes with aging and neurodegenerative disease is less clear. It is critical to characterize and understand the acute effects of exercise, including different exercise intensities, in terms of the peripheral metabolic response and relationship with brain metabolism. This will help determine potential mechanisms for brain benefits of exercise and better inform the design of future clinical trials. The primary goal of the AEROBIC study is to characterize the acute exercise response of brain glucose metabolism and exercise-related blood biomarkers. We will measure how cerebral metabolism is affected by an acute bout of moderate and higher intensity exercise and characterize the extent to which this differs between cognitively healthy older adults and individuals with AD. Related to this primary goal, we will quantify the peripheral biomarker response to moderate and higher intensity exercise and how this relates to brain metabolic change in both groups.

Evaluating cross contamination on a shared ventilator.

BACKGROUND: Disasters have the potential to cause critical shortages of life-saving equipment. It has been postulated that during patient surge, multiple individuals could be maintained on a single ventilator. This was supported by a previous trial that showed one ventilator could support four sheep. The goal of our study is to investigate if cross contamination of pathological agents occurs between individuals on a shared ventilator with strategically placed antimicrobial filters. METHODS: A multipatient ventilator circuit was assembled using four sterile, parallel standard tubing circuits attached to four 2 L anaesthesia bags, each representing a simulated patient. Each 'patient' was attached to a Heat and Moisture Exchange filter. An additional bacterial/viral filter was attached to each expiratory limb. 'Patient-Lung' number 1 was inoculated with an isolate of Serratia marcescens, and the circuit was run for 24 hours. Each 'lung' and three points in the expiratory limb tubing were washed with broth and cultured. All cultures were incubated for 48 hours with subcultures performed at 24 hours. RESULTS: Washed cultures of patient 2, 3 and 4 failed to demonstrate growth of S. marcescens. Cultures of the distal expiratory tubing, expiratory limb connector and expiratory limb prefilter tubing yielded no growth of S. marcescens at 24 or 48 hours. CONCLUSION: Based on this circuit configuration, it is plausible to maintain four individuals on a single ventilator for 24 hours without fear of cross contamination.

Incidental dedifferentiated mediastinal liposarcoma on F-18-fluciclovine PET/CT.

Fat-containing mediastinal masses, particularly mediastinal liposarcomas, are rare neoplasms that can grow to large sizes before becoming symptomatic and may be incidentally found on radiology examinations. In this case report, a 67-year-old male with a history of prostate cancer status post prostatectomy presented for an F-18-fluciclovine PET/CT for a rising, clinically detectable PSA and indeterminate pelvic lymph nodes seen on multiparametric MRI of the prostate. No local tumor recurrence or metastatic disease from prostate cancer was identified, but the PET/CT demonstrated a mixed soft tissue and fat density prevascular (anterior) mediastinal mass with low-level radiotracer uptake. Following surgical consultation and resection, the final pathology revealed a dedifferentiated mediastinal liposarcoma. The case presented describes the appearance of an uncommon fat-containing mediastinal mass and describes several other fat-containing mediastinal masses that are important for radiologists to recognize in order to formulate accurate differential diagnoses and ensure appropriate further management for patients. Additionally, this case demonstrates that the radiotracer F-18-fluciclovine is not specific for prostate cancer, and its uptake can be seen with other entities such as in this case of sarcomatous malignancy.

Adrenal Histoplasmosis.

An 89-year-old woman presented with seizure and hyponatremia. CT and MRI demonstrated mass-like enlargement of the adrenal glands and multiple pulmonary nodules. PET/CT performed to evaluate for metastatic disease demonstrated intense F-FDG uptake within enlarged adrenal glands. Given mild uptake in the pulmonary nodules, the differential diagnosis for the adrenal uptake included lymphoma, granulomatous infection, and less likely, metastatic lung cancer.

Rare Variant of Intravascular Large B-Cell Lymphoma With Hemophagocytic Syndrome.

Intravascular lymphoma (IVL) is a rare subtype of diffuse large B-cell lymphoma characterized by a clonal proliferation of lymphocytes restricted to the intravascular space. We present the case of a 60-year-old man with hemophagocytic syndrome secondary to IVL. F-FDG PET/CT demonstrated hepatosplenomegaly with marked diffuse hepatic, splenic, and bone marrow hypermetabolism. The case report illustrates the imaging findings of this uncommon variant of IVL.

False-Positive Heat-Damaged RBC Scan for Splenosis: Case of Retroperitoneal Extramedullary Hematopoiesis.

Extramedullary hematopoiesis (EMH) is a well-known compensatory response to severe anemia, most commonly due to a chronic hemolytic anemia such as thalassemia or sickle cell disease. We present a case of a 72-year-old man with autoimmune hemolytic anemia refractory to steroids and splenectomy. An incidental retroperitoneal mass on CT was suggestive of ectopic splenic tissue. However, an alternative diagnosis of EMH was considered, given an atypical appearance on heat-damaged Tc-RBC scan, and was confirmed with biopsy. The case report illustrates the imaging characteristics of EMH, widely known to have increased activity on Tc-sulfur colloid scans.

Pseudolesions Impersonating Osseous Tumor Involvement on Both Contrast Enhanced CT and FDG PET/CT.

A 27-year-old man with stage IV-B Hodgkin's lymphoma status post autologous peripheral stem cell transplant in 2015 with complete response, presented in 2017 with increasing back pain. Restaging contrast enhanced CT demonstrated left brachiocephalic vein occlusion with peripheral nodular high density areas within C7-T2 vertebral bodies with corresponding radiotracer uptake on same day PET/CT. No matching lesion was seen on noncontrast CT. Findings were consistent with pooling of contrast and radiotracer within vertebral venous plexus collaterals at the cervicothoracic junction secondary to brachiocephalic vein occlusion. Repeat PET/CT with contralateral injection of radiotracer and MRI confirmed absence of osseous lymphomatous involvement.

Lhermitte-Duclos Disease in association with Cowden Syndrome.

Cowden syndrome (CS) is a rare genetic disorder with autosomal dominant inheritance, linked to germline mutations in the PTEN tumor suppressor gene on chromosome 10. Cowden syndrome often co-exists with Lhermitte-Duclos disease (LDD), with LDD included as a major criterion in CD diagnosis. This case involves a woman presenting with many of the classic diagnostic criterions and associations of CD, as well as with several comorbidities and unique objective findings.

Implementation of a novel real-time platelet inventory management system at a multi-site transfusion service.

BACKGROUND: Blood platelets (PLTs) are a valuable commodity. Management of their inventory has implications both for patient care and for the cost of health care delivery. There are a variety of different methods of managing PLT inventory currently in practice and multiple theoretical models aimed at improving PLT inventory metrics. In this study we evaluate the ability of a novel electronic dashboard system that monitors and displays both PLT inventory and patient data to improve transfusion metrics at a quaternary health care center. STUDY DESIGN AND METHODS: The Capital District Health Authority is a quaternary health care center that transfuses approximately 2500 PLT units annually. To improve PLT discard rates a novel, low-overhead system that interfaces with the laboratory information system and displays real-time data between transfusion sites on PLT inventory and orders was implemented in November 2011. This study examines the transfusion quality metrics data from the 24 months before and after implementation. RESULTS: A significant reduction in mean monthly PLT outdate rate was observed after the implementation of the PLT dashboard suite from 24.5% (n = 24, SD ± 6.4%) to 15.1% (n = 24, SD ± 6.4%; p < 0.001). PLT age at time of transfusion was also reduced from 3.60 days (n = 4796, SD ± 0.97 days) to 3.46 days (n = 4881, SD ± 1.00 days; p < 0.001). CONCLUSIONS: This study describes the implementation of a novel PLT dashboard suite. This suite significantly reduced PLT outdate rates at our institution over the 48-month study period.

Mandatory physical exercise for the prevention of mental illness in medical students.

Medical students experience higher rates of mental illness than the general population. With competition rising for success in medical school, and residency, increasing incidence of distress are leading this population to experience higher rates of thoughts of dropping out of school, and even suicide. Since many stigmas deter medical students from receiving mental health counseling, such as the perceived inability to handle the stresses of medical school, and the potential lack of competitiveness for residencies if reported, prevention of mental illness may be a better course to take in reducing prevalence in this population. Regular exercise has demonstrated a positive effect on not only promoting physical health, but also mental health. Exercise encourages a healthy mood, positive self esteem, and better cognition, while decreasing the chances of depression, anxiety, and burnout. Implementing exercise time into medical school curriculums, just like the basic sciences, albeit for less time in the day, could provide a feasible way to ensure that all students are taking time to partake in this important activity for their well being. Though medical schools are rigid with attempts to make changes in their curriculum, thirty minutes a day, three to five times a week of exercise of the students' choice not only is more cost effective than counseling, but it also reduces the chances that they will experience burnout, which if left untreated could transcend into a compromised training experience.