Recurrent Infective Endocarditis of the Mitral Valve after Orthotopic Heart Transplantation.

Introduction: Orthotopic heart transplantation is the gold standard for the treatment of advanced heart failure in the absence of contraindications. Infective endocarditis is a rare complication in patients after heart transplantation. The treatment of endocarditis after heart transplantation is challenging since there is a need for ongoing immunosuppression. Case description: We present the case of a 51-year-old orthotopic heart transplant recipient enrolled in a chronic dialysis program, in whom we diagnosed and successfully treated recurrent infective endocarditis of the mitral valve caused by Enterococcus and Enterobacter species. Despite the complicated course of the disease, the treatment was successful. Conclusions: Recurrent infective endocarditis after heart transplantation can be treated successfully with a multidisciplinary approach and robust antimicrobial therapy. LEARNING POINTS: There is a high risk of bacteraemia and subsequent endocarditis in patients with recurrent catheter-related sepsis.The spectrum of bacteria causing endocarditis in patients after heart transplantation differs from that in the general population.Scrupulous targeted antibiotic treatment is warranted for the treatment of immunosuppressed patients with endocarditis.

Photon-counting CT using multi-material decomposition algorithm enables fat quantification in the presence of iron deposits.

PURPOSE: A new generation of CT detectors were recently developed with the ability to measure individual photon's energy and thus provide spectral information. The aim of this work was to assess the performance of simultaneous fat and iron quantification using a clinical photon-counting CT (PCCT) and its comparison to dual-energy CT (DECT), MRS and MRI at 3 T. METHODS: Two 3D printed cylindrical phantoms with 32 samples (n = 12 fat fractions between 0 % and 100 %, n = 20 with mixtures of fat and iron) were scanned with PCCT and DECT scanners for comparison. A three-material decomposition approach was used to estimate the volume fractions of fat (FF), iron and soft tissue. The same phantoms were examined by MRI (6-echo DIXON, a.k.a. Q-DIXON) and MRS (multi-echo STEAM, a.k.a. HISTO) at 3 T for comparison. RESULTS: PCCT, DECT, MRI and MRS computed FFs showed correlation with reference fat fraction values in samples with no iron (r > 0.98). PCCT decomposition showed slightly weaker correlation with FFref in samples with added iron (r = 0.586) compared to MRI (r = 0.673) and MRS (r = 0.716) methods. On the other hand, it showed no systematic over- or underestimation. Surprisingly, DECT decomposition-derived FF showed strongest correlation (r = 0.758) in these samples, however systematic overestimation was observed. FF values computed by three-material PCCT decomposition, DECT decomposition, MRI and MRS were unaffected by iron concentration. CONCLUSIONS: This in-vitro study shows for the first time that photon-counting computed tomography may be used for quantification of fat content in the presence of iron deposits.

Cognitive changes associated with cerebral emboli during coronary intervention.

OBJECTIVE: To investigate factors influencing the frequency and type of microembolic signals (MES) detected using transcranial Doppler (TCD) in patients undergoing elective coronary intervention, and to correlate MES with silent stroke detected using magnetic resonance imaging (MRI) and cognitive dysfunction. METHODS: The subset study of a randomized clinical trial was conducted on 70 patients (58 males; mean age 59.9 ± 8.4 years) who underwent bilateral TCD monitoring of middle cerebral arteries (MCAs) during elective coronary interventions. Neurologic examination and brain MRI were performed prior to, and 24 h post­intervention. Cognitive function tests were performed prior to, and on day 30 post­intervention. RESULTS: The incidence of detected MES was 94.3 %. Eighteen (25.7 %) patients had new clinically asymptomatic ischemic lesions on MRI. The number of solid MES negatively correlated with changes in revised Addenbrooke's Cognitive Examination test (ACE-R) and, the number of solid MES and combinations of solid and gaseous MES negatively correlated with changes in Mini Mental­State Examination (MMSE) conducted on day 30 after the intervention (p < 0.05 in all cases). CONCLUSION: Cardiac catheterization was associated with a high risk of cerebral embolism in our patients. A higher number of solid MES and combinations of solid and gaseous MES was associated with the deterioration in cognitive tests (Tab. 5, Fig. 3, Ref. 30).

Diagnostic performance of edited 2HG MR spectroscopy of central glioma in the clinical environment.

OBJECTIVE: Oncometabolite D-2-hydroxyglutarate (2HG) is pooled in isocitrate dehydrogenase (IDH)-mutant glioma cells. Detecting 2HG by MR spectroscopy (MRS) has been proven viable in the last decade but has not entirely found its way into the clinical routine. This study aimed to explore the adoption of 2HG MRS while acknowledging factors that influence its performance in the clinical environment. METHODS: Thirty-nine MR spectra were acquired and reported prospectively in patients with suspected glioma using a 3 T system with Mescher-Garwood point-resolved spectroscopy (MEGA-PRESS) sequence utilizing averaged free induction decay (FID) signals. Postprocessing and evaluation of spectra were performed with jMRUI and LCModel. 2HG concentration estimates, 2HG/Cr ratio, together with quality measures, including Cramér-Rao lower bounds (CRLBs), full-width at half-maximum (FWHM) values, and signal-to-noise ratio (SNR) were calculated using LCModel. Immunohistochemistry and genomic analysis results used as a ground truth were available for 15 patients. RESULTS: The threshold for test positivity was set according to the ROC curve at 1 mM. Calculated sensitivity was 57.14% (95% CI 0.20-0.88), specificity 87.5% (95% CI 0.46-0.99), positive predictive value 80%, and negative predictive value 70%. Overall diagnostic accuracy was 73.33% (95% CI 0.45-0.92). The 2HG/Cr ratio with the cutoff value 0.085 significantly improved sensitivity and overall diagnostic accuracy [85.71%, 95% CI 0.42-1.00 and 86.67%, (95% CI 0.60-0.98), respectively]. CONCLUSION: Multiple factors compromising spectral quality in the clinical adoption of edited 2HG MRS resulted in diminished sensitivity but clinically acceptable specificity. Furthermore, the 2HG/Cr ratio performs better than the sole 2HG concentration estimate in the pre-operative setting.

Imaging of juvenile spondyloarthritis. Part II: Ultrasonography and magnetic resonance imaging.

Juvenile spondyloarthropathies are mainly manifested by symptoms of peripheral arthritis and enthesitis. Early involvement of sacroiliac joints and spine is exceptionally rare in children; this usually happens in adulthood. Conventional radiographs visualize late inflammatory lesions. Early diagnosis is possible with the use of ultrasonography and magnetic resonance imaging. The first part of the article presented classifications and radiographic presentation of juvenile spondyloarthropathies. This part discusses changes seen on ultrasonography and magnetic resonance imaging. In patients with juvenile spondyloarthropathies, these examinations are conducted to diagnose inflammatory lesions in peripheral joints, tendon sheaths, tendons and bursae. Moreover, magnetic resonance also shows subchondral bone marrow edema, which is considered an early sign of inflammation. Ultrasonography and magnetic resonance imaging do not show specific lesions for any rheumatic disease. Nevertheless, they are conducted for early diagnosis, treatment monitoring and identifying complications. This article presents a spectrum of inflammatory changes and discusses the diagnostic value of ultrasonography and magnetic resonance imaging.