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.
Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disorder with high prevalence among middle-aged women. Collagen-induced arthritis (CIA) is the most widely used animal model of RA, however, sex differences and long-term effects of CIA in mice are poorly described in the literature. Aim: Therefore, the present study aimed to analyze the long-term effects of CIA on the joints of middle-aged mice of both sexes and to describe potential sex differences. Materials and methods: CIA was induced in middle-aged DBA/1J mice by immunization with bovine type II collagen and complete Freund's adjuvant. Saline was administered to control mice. Arthritis score assessment, plethysmometry, and thermal imaging of the joints were performed weekly for 15 weeks. Locomotor activity, micro-computed tomography, joint histology and biochemical analyses were performed at the end of the experiment. Results: Our results indicate a similar prevalence of arthritis in both sexes of mice-67% (8/12) of females and 89% (8/9) males with an earlier onset in males (day 14 vs. day 35). After the arthritis scores peaked on day 56 for males and day 63 for females, they steadily declined until the end of the experiment on day 105. A similar dynamics was observed in paw volume and temperature analyzing different aspects of joint inflammation. Long-term consequences including higher proteinuria (by 116%), loss of bone density (by 33.5%) and joint damage in terms of synovial hyperplasia as well as bone and cartilage erosions were more severe in CIA males compared to CIA females. There were no significant differences in locomotor activity between CIA mice and CTRL mice of any sex. Conclusion: This is the first study to describe the long-term effects of the CIA model in terms of sex differences in DBA/1J mice. Our results indicate sex differences in the dynamics, but not in the extent of arthritis. An earlier onset of arthritis and more severe consequences on joints, bones and kidneys were found in males. The underlying immune pathomechanisms responsible for the limited duration of the arthritis symptoms and the opposite sex difference in comparison to RA patients require further investigation.
- Publikační typ
- časopisecké články MeSH
Symptomatické neurologické komplikácie sa vyskytujú u 15-30 % pacientov s infekčnou endokarditídou. Zároveň sa u 35-60 % pacientov vyskytujú klinicky nemé mozgové embólie. Staphylococcus aureus je patogén, ktorý najčastejšie spôsobuje postihnutie nervového systému. Uvádzame prípad 67-ročného muža s infekčnou endokarditídou po stomatologickom výkone, ktorý sa prejavil ako spondylodiscitída a mnohopočetná embolizácia do mozgu, vrátane mozgového abscesu, ktorý si vyžiadal neurochirurgickú drenáž. Po 6 týždňoch liečby širokospektrálnymi antibiotikami a komplexnej podpornej terapii sme pacienta prepustili v uspokojivom somatickom a psychickom stave. Pokračuje príprava pacienta na kardiochirurgický výkon.
Symptomatic neurological complications occur in 15-30% of patients with infective endocarditis. At the same time, other clinically silent cerebral embolisms occur in 35-60% of patients. Staphylococcus aureus is the pathogen that causes nervous system involvement most frequently. We report a case of a 67-year-old man with infective endocarditis following a dental procedure that manifested as spondylodiscitis and multiple brain embolization, including a brain abscess that required drainage. After six weeks of treatment with broad-spectrum antibiotics and complex supportive therapy, we discharged the patient in a satisfactory mental and somatic condition. The preparation of the patient for cardiac surgery is ongoing.
- MeSH
- absces mozku diagnostické zobrazování etiologie patologie terapie MeSH
- discitida diagnostické zobrazování komplikace patologie MeSH
- echokardiografie transezofageální MeSH
- endokarditida * diagnostické zobrazování farmakoterapie komplikace patologie terapie MeSH
- extrakce zubů škodlivé účinky MeSH
- intrakraniální embolie * diagnostické zobrazování komplikace patologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mitrální insuficience diagnostické zobrazování etiologie farmakoterapie MeSH
- senioři MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
