Diffusion-weighted MRI of kidneys in healthy volunteers and living kidney donors

AIM

To establish the normal apparent diffusion coefficient (ADC) values in healthy kidneys, comparing them with the literature, and assessing the correlation between ADC values, creatinine blood level, and glomerular filtration rate (GFR).

MATERIALS AND METHODS

Twenty-four healthy volunteers and 26 living kidney donors were examined on a 1.5 T magnetic resonance imaging (MRI) unit. Two diffusion-weighted imaging (DWI) sequences were included in the study protocol (protocol 1 with 16 b-values, protocol 2 with 10 b-values) before the examination blood and urine samples were collected. The GFR was calculated using Cockcroft & Gault and MDRD (Modification of Diet In Renal Disease) formulas and the ADC values were measured separately for the cortex and medulla of each kidney by two independent observers. All statistical analyses were performed using the STATISTICA (version 10.0) software package. Data were analysed using an unpaired t-test; p < 0.05 indicated a statistically significant difference.

RESULTS

The average ADC value for protocol 1 for the cortex was 2.26 × 10(-3) mm(2)/s, for the medulla 2.21 × 10(-3) mm(2)/s. In protocol 2, the respective values were 2.13 × 10(-3) mm(2)/s and 2.06 × 10(-3) mm(2)/s. Neither statistically significant interobserver differences nor correlation between ADC values, GFR, and creatinine serum level were observed.

CONCLUSION

The reference ADC values were established. The measurements show high interobserver consistency. The differences in ADC values reported in the literature suggest dependence on the equipment and methodology and point to the necessity of obtaining ADC norms for each MRI unit.

Identification of ionic liquid breakdown products in an advanced oxidation system

Commonly used alkylimidazolium ionic liquids are poorly to negligibly biodegradable, and some are toxic, with the potential to poison typical biological test systems. Therefore, when ionic liquids are present in technological wastewaters they could break through classical wastewater treatment systems into natural waters and become potentially persistent pollutants. A recent study investigating different advanced oxidation processes found that the H(2)O(2)/UV system degraded dissolved imidazolium ionic liquids with the greatest efficiency. In the present study, high performance liquid chromatography was coupled with electrospray mass spectrometry to separate, analyse and identify degradation products following the treatment of ionic liquid solutions with H(2)O(2) in the presence of UV irradiation. It was found that hydroxylation in short-chain entities occurred mainly within the ring moiety, whereas in the case of longer alkylated cations, oxidation of the alkyl chain yielded several products. The potential transformation products were identified structurally by MS/MS analysis and are discussed in the light of their putative toxicity and biodegradability.

Assessing toxicity and biodegradation of novel, environmentally benign ionic liquids (1-alkoxymethyl-3-hydroxypyridinium chloride, saccharinate and acesulfamates) on cellular and molecular level

Ionic liquids are widely studied as alternative solvents in organic synthesis and catalysis, in electrochemistry and the separation sciences; with their many applications they will soon be produced on an industrial scale. Available toxicological data of ionic liquids have already suggested initial guidelines for the conscious design of safer chemicals. In this study a new group of such redesigned ionic liquids-1-alkoxymethyl-3-hydroxypyridinium cations+acesulphamate, saccharinate and chloride anions-was assayed with respect to their inhibitory activity towards acetylcholinesterase and their cellular toxicity towards the IPC-81 rat promyelocytic leukaemia cell line: the acute biological activity of these compounds is very low. Effective concentrations lie in the millimole range, which is well above possible intracellular concentrations. Only the compounds with the longest alkoxymethyl chain inhibit the enzyme at effective concentrations that are one order of magnitude smaller. No significant differences are observed when the anion compartment in the enzymatic assay is varied. However, the cytotoxicity data show EC(50) for acesulphamates and saccharinates to be higher than the values for the chloride analogues. Also, a slight alkoxymethyl chain length effect on the overall cytotoxicity is discernible. The biodegradability of the 1-alkoxymethyl-3-hydroxypyridinium salts varies from 21% to 72% and depends on the type of anion the cation is linked with. It improves with lengthening alkyl chain, but only in the range from 4 to 11 carbon atoms.

[Interaction evaluation between APOE epsilon 4 alleles and hippocampal atrophy. Preliminary communication]

In CT images the atrophy of medial parts of temporal lobes was evaluated in 60 patients with Alzheimer-type dementia. In the genotype of 30 patients at least one APOE epsilon 4 allele was identified, the other 30 patients served as the control group. The results of in vivo measurements of temporal lobe atrophy in the examined patients did not show statistically significant relations with APOE genotype which was probably due to entirely different nature and application of both tests.

[Morphologic and functional assessment of renal artery stenosis: use of combined MR angiography and MR renography--preliminary report]

PURPOSE

To assess the possibility of use of multiphase magnetic resonance angiography for simultaneous acquiring of angiographic images and curves of contrast enhancement of renal cortex, medulla and pyelocalyceal system and evaluation of quality of obtained images.

MATERIAL AND METHODS

Twenty-four patients suspected of having renal artery stenosis underwent power-injection of 30 ml of Gd-DTPA (3 ml/sec). From 10 to 360 seconds after the beginning of the injection, 3D MRA sequence was performed multiple times. Acquisition time of single phase of MR examination was 7.5-8 sec (TR = 5 ms, TE = 1:6 ms, single 7 cm thick slab with 35 partitions, 164 x 512 matrix). First three phases were used to obtain angiographic images. All phases were used to obtain curves of renal cortical, medullary and pyelocaliceal enhancement. Two readers evaluated quality of MRA images, as well as, quality of enhancement curves.

RESULTS

21 of 24 MRA examinations were of good, 2 of fair and none of poor quality. Quality of enhancement curves was good in 22 cases. It was suboptimal in 2 cases because of irregular breath-holding. Maximum number of acquisitions per minute was 4-5. Eight accessory, 2 obstructed and 9 stenosed renal arteries were visualized. Renographic curves were abnormal in 8 patients.

CONCLUSIONS

MRA sequence with short acquisition time enables simultaneous acquisition of angiographic images and renographic curves of good quality. With further reduction in acquisition time it may be possible to obtain more points on MR renographic curves.

[Vascular risk factors in demented elderly: analysis of Alzheimer Clinic materials]

In recent years evidence is increasing that vascular disease is associated with cognitive impairment and dementia. Moreover, presence of cerebrovascular disease may intensify the clinical symptoms of Alzheimer's disease (AD). The aim of the study was to determine the prevalence of vascular risk factors in age and sex matched patients with dementia. We studied 109 patients with AD and 37 patients vascular dementia (VD). DSM-III-R test for dementia, NINCDS-ADRDA guidelines for AD and NINDS-ARIEN for VD were applied.

RESULTS

Mean age of dementia onset in AD and VD was 65.8 SD 7.8 and 67.4 SD 7.0 years (p > 0.05), the duration of dementia, MMS and GDS for patients with AD and VD was not significantly different. Arterial hypertension was associated in 51.3% VD and 30.3% AD (p < 0.05), hypotension in 11.1 and 23.6% respectively (p > 0.05), atrial fibrillation was similar in AD and VD, coronary artery disease was presents 64.8% AD and 46.8 VD (p > 0.05) and type 2 diabetes in 21.6% and 10.1% (p > 0.05) respectively. No significant differences in serum lipid profile were found in both groups, except two times higher incidence of normal HDL-cholesterol concentration in AD compare to VD. The relation between alcohol consumption, cigarette smoking and head trauma was similar in both types of dementia.

CONCLUSION

Vascular disease and AD have to some extent a shared aetiology, and risk factors that they have in common increase the risk of both disorders independently and vascular disease is perhaps involved in the aetiology of AD.

[Frequency and intensity of behavioral and psychological symptoms in the course of Alzheimer's disease]

The aim of the study was: 1) to estimate the occurrence and intensity of some psychopathological symptoms in the course of Alzheimer's disease, and 2) to examine whether the occurrence of behavioral and psychological symptoms increases with the deepening of dementia process among persons with Alzheimer's disease living in their homes with outpatient treatment. The study was conducted among 94 persons (38 men and 56 women ageing from 52 to 86 years (x = 72.4 +/- 6.9), with education: from 2 to 17 years (x = 11.2 +/- 3.7). Three subgroups were selected for study with regard to the intensity of dementia process, estimated according to Clinical Dementia Rating (CDR): very mild (n = 16, x = 71.4 +/- 6.7), mild (n = 43, x = 72.6 +/- 7.9), moderate (n = 35, x = 72.5 +/- 6.9). Subjects in group II and III fulfill diagnostic criteria of dementia according to ICD-10, DSM IV and criteria of probable AD according to NINCDS-ADRDA. In the estimation of occurrence of behavioral and psychological disturbances: Alzheimer's Disease Assessment Scale--non-cognitive behavior (ADAS-non-cog) and subscale "Change in Personality, Interests, Drive" of Blessed Dementia Scale were used. The results have shown that with the progress of dementia process, the occurrence of the following psychopathological symptoms such as: hallucinations, intensive motor activity, purposeless hyperactivity, pacing, rigidity increases and there is a relinquishment of hobbies. In addition, regardless of the stage of dementia, such behaviors as: apathy, depression, tearfullness, impaired emotional control and disturbances of appetite were observed relatively frequently.

Frontotemporal dementia: An attempt at clinical characteristics

The clinical recognition of frontotemporal dementia (FTD) depends on its differentiation from Alzheimer's disease (AD). From 212 patients primarily diagnosed as probable AD, 24 cases with mild dementia, absence of disturbances the presence of which would have prevented a full neuropsychological assessment, and brain CT with detailed visualization of hippocampus atrophy were chosen. On the basis of neuropsychological examination the patients were divided into two groups: 11 cases with predominant deficit in frontal system tasks (FTD group) and 13 cases with changes in cognitive functions typical of AD (AD group). Age at onset, duration, behavioral changes, psychotic symptoms, depression, speech disorders, neurologic deficit and hippocampal atrophy were analyzed in both groups. Statistically significant differences for behavioral disturbances and hippocampal atrophy were found. Early behavioral changes and lack of early hippocampal atrophy on CT may be useful features for differentiating between FTD and AD, especially when SPECT is not available.

[The use of iodinated contrast agents in neuroradiology]

The authors describe iodinated contrast materials, which are commonly used in neuroradiological applications. The adverse reactions after their, administration are discussed. The indications for safer, non-ionic contrast media are presented. The protocol of prophylactic treatment of high risk patients is also formulated. We present the contrast material protocol used at our institution for neuroradiology.

[The significance of cerebral white matter changes in CT images in Alzheimer's disease]

White matter changes in Alzheimer's disease patients were the subject of the study. One hundred and seventeen cases clinically diagnosed according to NINCDS-ADRDA criteria as probable Alzheimer's disease were assessed. In computer tomography two types of pathological changes were observed; the so called leucoaraiosis and the perivascular focal alterations. Leucoaraiosis appeared in 20% of cases and focal changes were visible only in 4 cases A significant correlation was found between the presence of leucoaraiosis and the age and the presence of coronary disease. Hypertension, diabetes and brain atrophy did not seem to influence the occurrence of white matter alterations of either type.

[Evolution of the growth of multiple intracranial tumors in a case of type 2 neurofibromatosis]

A sporadic case of neurofibromatosis type 2 in a 23-year old woman is described with clinical and neuroimaging (CT or MRI) 4 years follow-up. Together with bilateral acoustic tumours multiple intracranial tumours and solitary orbital meningioma were present, the latter being confirmed surgically and histopathologically. Ocular findings of congenital cataract but lack of other external stigmata of neurofibromatosis completed the clinical picture of the disease. Diagnostic criteria of NF2, difficulties in establishing the optimal management options are described and the importance of evaluating of family members is underlined. Neuroimaging pictures showed tumour expansion over 4 years leading to severe disability with total blindness, deafness, paresis and cerebellar syndrome.