Intra-Cranial Arterial Calcifications in Hemodialysis Patients.

Background and objectives: Vascular calcification is an integral part of atherosclerosis and has been reported to be an independent risk factor for cardiovascular diSsease. Intra Cranial Arterial Calcifications (ICAC) in maintenance hemodialysis (MHD) is highly prevalent. Materials and Methods: The aim of this retrospective study was to assess the predictors and outcomes of ICAC in MHD patients compared to a control group without kidney disease. A blinded neuroradiologist graded ICAC in brain imaging (computerized tomography) of MHD patients. Age- and sex-matched patients with normal kidney function served as the control group. Results: A total of 280 patients were included in the cohort; 140 of them were MHD patients with a mean ICAC score of 2.3 ± 0.2 versus a mean ICAC score of 1.4 ± 0.2 in the control group (p < 0.01). More than 90% of hemodialysis patients in our study had some degree of ICAC. Lower albumin and higher phosphorus and CRP levels were associated with increased ICACs. The multivariate analysis model for predictors of 1-year mortality demonstrated an increased odds ratio for mortality as the ICAC score increased. Conclusions: ICAC is very prevalent among MHD patients and results not simply from passive deposition of calcium and phosphate but rather from complex and active processes involving inflammation and structural changes in blood vessels. ICAC independently predicted all-cause mortality and may help with risk stratification of this high-risk population.

Intracranial and heart valve calcifications in hemodialysis patients-Interrelationship and clinical impact.

INTRODUCTION: Arterial calcification is an integral component of active atherosclerosis and is an independent risk factor for cardiovascular disease. Atherosclerosis is a systemic, life-threating disease that may occur at different sites and in various clinical presentations. Intracranial and valvular calcifications are common among dialysis patients and have been associated with poor cardiovascular outcomes. The aim of this study was to assess the clinical impact of valvular and intracranial arterial calcifications on mortality among chronic hemodialysis patients. METHODS: A blinded neuroradiologist graded intracranial calcifications (ICC) of all hemodialysis patients who underwent brain computerized tomography (CT) from 2015 to 2017 in our institution. Valvular calcifications were assessed by echocardiography. Only hemodialysis patients with available echocardiography and brain CT were included. FINDINGS: This study included 119 patients (mean age 70.6 ± 12.6 years, 57.1% men, and mean dialysis vintage 25.8 ± 42.6 months). Among the cohort, 19 (16%) had no cardiac or brain calcifications and 65 (54.6%) had both valvular and intracranial calcifications. Considering the patients with no calcification as the reference group yielded adjusted odds ratios for all-cause mortality of 3.68 (95%CI 1.55-8.75) among patients with any brain calcifications, p = 0.002. While valvular calcifications alone did not increase the 1-year mortality rate, ICC was the most important predictor of all-cause 1-year mortality in the study cohort. DISCUSSION: We found an independent association between ICC and the risk of death among hemodialysis patients. Assessing ICC may contribute to the risk stratification of hemodialysis patients. These calcifications are no less important than valvular calcifications.

Diastolic blood pressure is associated with brain atrophy in hemodialysis patients: A single center case-control study.

Brain atrophy (BA) is often found in neuroimaging of hemodialysis patients, representing parenchymal cerebral damage. Likely contributing factors to BA are age, chronic hypertension, diabetes mellitus and other cardiovascular risk factors of atherosclerosis that are also common among hemodialysis patients. BA may also occur due to focal ischemia and hypoperfusion during hemodialysis. However, data on optimal blood pressure (BP) in these patients are limited. The goal of this study was to determine whether the prevalence and severity of BA would be higher among hemodialysis patients with lower BP. A blinded neuroradiologist graded BA of all hemodialysis patients who underwent brain non-contrast computerized tomography (CT) from 2015 to 2017 in our institution. Age- and sex-matched patients with normal kidney function who underwent brain CT during the same period and technique served as the control group. A total of 280 patients were included in this retrospective study, with average BP of 140/70 mmHg among hemodialysis patients and 142/75 mmHg in the control group. BA was more common in dialysis patients and its severity increased with age and traditional cardiovascular risk factors. We observed a significant negative correlation between diastolic BP (DBP) at dialysis initiation and BA. Average DBP decreased with increasing severity of BA. These findings were observed in both hemodialysis and non-CKD patients. BA was associated with lower DBP, which may induce cerebral hypoperfusion and ischemia. This finding should discourage over-treatment of hypertension among hemodialysis patients.

The Combined Prognostic Significance of Alkaline Phosphatase and Intracranial Arterial Calcifications in Hemodialysis Patients.

INTRODUCTION: The prevalence of intracranial arterial calcification (ICAC) in maintenance hemodialysis (MHD) patients is about 90%, and its severity is correlated with age, hemodialysis vintage, and mineral bone disease. Elevated concentrations of calcium and phosphorus are not sufficient for medial calcification because of inhibition by pyrophosphate. Alkaline phosphatase (ALP) promotes calcification by hydrolyzing extracellular pyrophosphate. Epigenetic mechanisms involving ALP inhibition by apabetalone were investigated as a potential target for preventing vascular calcifications (VCs). This study assessed the combined impact of VCs and elevated serum ALP on mortality among chronic HD patients. METHODS: VCs represented by ICAC were measured simultaneously with mineral bone disease parameters including serum ALP of MHD patients who underwent noncontrast brain computed tomography from 2015 to 2018 in our institution. RESULTS: This retrospective study included 150 MHD patients (mean age 71.3 ± 12.1 years, 60.1% male). Of the total cohort, 12 (7.8%) had no brain calcifications and 69 (45.1%) had multiple intracranial calcifications. Considering the patients with normal ALP and no calcification as the reference group yielded adjusted odds ratios for all-cause mortality of 4.6 (95% CI: 1.7-12.7) among patients with brain calcifications and normal ALP (p = 0.003) and odds ratios for all-cause mortality of 6.1 (95% CI: 2.1-17.7) among patients with brain calcifications and elevated ALP (p= 0.001). CONCLUSION: We found an independent association between ICAC and the risk of death among MHD patients. The combined effect of ICAC and elevated ALP was associated with a higher odds ratio for all-cause mortality in MHD patients and may contribute to the risk stratification of these patients.

Detection of Intraorbital Foreign Bodies Using Magnetic Resonance Imaging and Computed Tomography.

PURPOSE: We analyze the detectability of intraorbital foreign bodies (OrbFBs) of various types and sizes using computed tomography (CT) and magnetic resonance imaging using a three-Tesla machine (MRI 3 T). METHODS: An ex vivo model of sheep eyes with preserved extraocular muscles and orbital fat tissue placed in the orbital cavity of the human skull was created for this study. Foreign bodies made of four different materials - plastic, bottle glass, stone and wood - each in three different sizes (large, intermediate and small) were inserted into the soft tissue of the orbit in the extraocular space. Each orbit was scanned by CT and MRI. Images were analyzed by a senior radiologist and underwent masked review by three oculoplastic surgeons. RESULTS: Analysis of MRI and CT scans identified distinguishing characteristics for each of the four materials. This information was further integrated into a clinical algorithm. CT allowed easier identification of most of the embedded materials compared to MRI. Smaller OrbFB size was associated with lower detectability. Review of CT yielded 94.4% agreement between oculoplastic specialists in detecting OrbFbs using CT scans and allowed detection of most OrbFBs. In contrast, the overall agreement with MRI was lower: 66.7% with T1 MPRAGE, 50% with T1TSE, 88.9% with T2 TSE and 72.2% with T2 TSE FS. Plastic was the most difficult material to detect in all size categories. CONCLUSIONS: CT offers a clear advantage over MRI for detecting and localizing nonmetallic OrbFBs of all sizes, except for plastic. Plastic OrbFBs can be detected with CT depending on size but are more visible in MRI scans.

Does Ostmann's fat pad size correlate with development of chronic otitis media in children?

OBJECTIVE: To compare Ostmann's fat pad (OFP) size between healthy ears and ears with chronic otitis media with cholesteatoma (COMwC) in children, to assess its role in the disease. METHODS: MRI scans of 29 children with unilateral COMwC with conductive hearing loss were used to measure OFP, represented by the maximal diameter of the high intensity area medial to the tensor veli palatini muscle (TVP): M1. A reference diameter was defined from the medial border of OFP reaching the medial border of the medial pterygoid muscle: M2. Values of M1, M2 and the ratio of M1:M2 were compared between the healthy and pathological ear in each patient. RESULTS: No difference in OFP size was observed between healthy (H) ears (mean M1H:M2H ratio 0.72 ± 2.28) compared to ears with COMwC pathology (P) (mean M1P:M2P ratio .68 ± 1.57; P = .943) in children, suggesting that OFP size abnormalities do not have a role in pediatric COMwC. CONCLUSION: OFP size was not correlated to the development of unilateral COMwC in children.

Safety of 3 Tesla Magnetic Resonance Imaging on iStent Implants: An Ex-Vivo Study.

PRCIS: Our study shows that iStent implant does not cause significant image artifacts, heating, or displacement during magnetic resonance imaging (MRI) scan. This device can be safely used in patients undergoing MRI scans using 3 Tesla (3T) machines. PURPOSE: The iStent is a medical grade titanium implant commonly implanted in the anterior chamber angle of glaucomatous eyes in order to reduce intraocular pressure and medication burden. As many people now have these devices implanted in their eyes, the issue of their compatibility with MRI in terms of safety and interference with interpretation of these studies commonly arises. The purpose of this study is to evaluate the safety of 3T MRI scans in eyes that have undergone iStent implantation and to assess the interference of the implant to the scan interpretation. MATERIALS AND METHODS: An ex vivo model of sheep eye with an iStent and proximately placed heat detector probe was used to study changes in the temperature during MRI 3T scan. The study included 2 fresh eyes with preserved extraocular muscles and orbital fat tissue placed in the orbital cavity of a human skull. Each eye with orbital content was scanned with a 3T MRI machine. RESULTS: No displacement of the implant was observed during MRI scanning. The heat detector showed mild temperature elevation during the first minutes of the scan from 14.6 to 16.5°C. The iStent was best visualized in T2 turbo spin echo sequences and showed no significant artifacts. CONCLUSION: iStent implants did not move during the MRI scan, showed minimal interaction with the magnetic field in terms of heating and image distortion. These interactions were not strong enough to present a substantial risk to patients with this implant undergoing an MRI scan.

Ostmann's Fat Pad-Does it Really Matter?

OBJECTIVE: To compare the size of Ostmann's fat pad (OFP) between healthy ears and ears with chronic otitis media with cholestatoma (COMwC) using magnetic resonance imaging (MRI). METHODS: Twenty-six patients with unilateral COMwC underwent mastoidectomy. Pre-operative MRI records were reviewed retrospectively. The healthy ears served as the control group. OFP is represented by the maximum diameter of the high intensity area medial to the tensor veli palatini muscle (TVP); M1. A reference diameter was defined from the medial border of OFP reaching the medial border of the medial pterygoid muscle; M2. Values of M1, M2 and the ratio of M1:M2 was compared between the healthy and pathological ear in each patient. RESULTS: All 26 patients (16 females,10 males) had unilateral cholestatoma. Mean age was 37.6 years (range 19-83). In the healthy (H) ears group, mean M1H was 2.04 ± 0.53 mm, mean M2H was 9.57 ± 2.57 mm.In the pathological (P) ears group; mean M1P was 2.03 ± 0.55 mm, mean M2P was 9.86 ± 2.37 mm. A comparison of M1 and M2 values between the healthy and pathological ear groups was not statistically significant (P = .853 and P = .509, respectively).Mean M1H:M2H ratio in the healthy ears group was 0.22 ± 0.05, mean M1P:M2P ratio in the pathological ear group was 0.21 ± 0.06. A comparison between these ratios found no significant statistical correlation (P = .607). CONCLUSION: The size of Ostmann's fat pad does not affect the development of chronic otitis media with cholestatoma in adults.