Organic changes in the central nervous system in children on chronic inhaled corticosteroid therapy.

Treatment of asthma, the most common chronic respiratory disease in children, includes long-term inhaled corticosteroids (ICS). The purpose of this study was to analyze the impact of chronic inhaled steroids in children with asthma on changes in the central nervous system (CNS). Eleven children (8-17 years) on at least 4 years inhaled corticosteroid therapy were assessed with magnetic resonance imaging (MRI). All participants underwent a pediatric and neurological examination and spirometry. MRI data were obtained using a 1.5 T scanner with parallel imaging capability. Structural images consisted of axial T1, T2 using turbo spin echo, FLAIR and DWI sequences using typical parameters. Images were assessed in three planes (axial, coronal, and sagittal). Pediatric and neurological examination were normal in all children. In six, the MRI studies revealed small subcortical hyperintense foci. Three had more than five lesions, all of which were smaller than 3 mm. Features of mild supratentorial cortical atrophy were apparent in four. The cerebellum was unremarkable in all children imaged. In conclusion, patients receiving chronic inhaled corticosteroids had small subcortical hyperintense foci and features of mild supratentorial cortical atrophy. These findings suggest that ICS exposure may be associated with the development of organic changes in CNS. Further studies are needed to detail the extent of brain ICS-induced changes in children on chronic inhalative corticosteroid therapy as well as delayed impact of these changes on psychomotor functioning in adulthood.

Computed tomographic angiography criteria in the diagnosis of brain death-comparison of sensitivity and interobserver reliability of different evaluation scales.

INTRODUCTION: The standardized diagnostic criteria for computed tomographic angiography (CTA) in diagnosis of brain death (BD) are not yet established. The aim of the study was to compare the sensitivity and interobserver agreement of the three previously used scales of CTA for the diagnosis of BD. METHODS: Eighty-two clinically brain-dead patients underwent CTA with a delay of 40 s after contrast injection. Catheter angiography was used as the reference standard. CTA results were assessed by two radiologists, and the diagnosis of BD was established according to 10-, 7-, and 4-point scales. RESULTS: Catheter angiography confirmed the diagnosis of BD in all cases. Opacification of certain cerebral vessels as indicator of BD was highly sensitive: cortical segments of the middle cerebral artery (96.3 %), the internal cerebral vein (98.8 %), and the great cerebral vein (98.8 %). Other vessels were less sensitive: the pericallosal artery (74.4 %), cortical segments of the posterior cerebral artery (79.3 %), and the basilar artery (82.9 %). The sensitivities of the 10-, 7-, and 4-point scales were 67.1, 74.4, and 96.3 %, respectively (p<0.001). Percentage interobserver agreement in diagnosis of BD reached 93 % for the 10-point scale, 89 % for the 7-point scale, and 95 % for the 4-point scale (p=0.37). CONCLUSIONS: In the application of CTA to the diagnosis of BD, reducing the assessment of vascular opacification scale from a 10- to a 4-point scale significantly increases the sensitivity and maintains high interobserver reliability.

Dynamic evaluation of stasis filling phenomenon with computed tomography in diagnosis of brain death.

INTRODUCTION: Stasis filling, defined as delayed, weak, and persistent opacification of proximal segments of the cerebral arteries, is frequently found in brain dead patients. This phenomenon causes a major problem in the development of reliable computed tomographic angiography (CTA) protocol in the diagnosis of brain death (BD). The aim of our study was to characterize stasis filling in the diagnosis of BD. To achieve this, we performed a dynamic evaluation of contrast enhancement of the cerebral and extracranial arteries in patients with BD and controls. METHODS: Study population included 30 BD patients, who showed stasis filling in computed tomographic perfusion (CTP) series. Thirty patients, after clipping of an intracranial aneurysm, constituted the control group. The study protocol consisted of CTA, CTP, and angiography. Time-density curves (TDCs) of cerebral and extracranial arteries were generated using 40-s series of CTP. RESULTS: Cerebral TDCs in BD patients represented flat curves in contrast to TDCs in controls, which formed steep and narrow Gaussian curves. We found longer time to peak enhancement in BD patients than in controls (32 vs. 21 s; p < 0.0001). In BD patients, peak enhancement in the cerebral arteries occurred with a median delay of 14.5 s to peak in extracranial arteries, while no delay was noted in controls (p < 0.0001). Cerebral arteries in BD patients showed lower peak enhancement than controls (34.5 vs. 81.5 HU; p < 0.0001). In all BD patients, CTP revealed zero values of cerebral blood flow and volume. Angiography showed stasis filling in 14 (46.7 %) and non-filling in 16 (53.3 %) cases. CONCLUSION: A confrontation of stasis filling with CTP results showed that stasis filling is not consistent with preserved cerebral perfusion, thus does not preclude diagnosis of BD.

Proton magnetic resonance spectroscopy study of brain metabolite changes after antipsychotic treatment.

INTRODUCTION: Proton magnetic resonance spectroscopy (¹H MRS) enables the observation of brain function in vivo. The aim of our study was to evaluate the effects of antipsychotic medication on metabolite levels in the brain of schizophrenic patients based on a ¹H MRS examination. METHODS: We examined 42 patients previously diagnosed with chronic schizophrenia twice: firstly, after the neuroleptic wash-out (baseline) and secondly, under stable medication (follow-up, after treatment). The study had a naturalistic design and several different neuroleptic medications were used during the treatment phase. The clinical evaluation, MRI and MRS procedures were performed. The group of 26 healthy controls were also examined to compare MRS results. RESULTS: We found a significantly lower NAA/Cr (N-acetylaspartate/creatine) ratio in the frontal lobe and thalamus in patients (after the wash-out) as compared to controls. After treatment a significant decrease of the Glx/Cr ratio in the temporal lobe and a trend for an increase of the NAA/Cr ratio in the thalamus were observed. CONCLUSION: Our results confirm that antipsychotic medication modifies brain metabolism measured by means of ¹H MRS. The pattern of the changes suggests a neuroprotective action of antipsychotic medication in schizophrenia.

Efficacy of radionuclide treatment DOTATATE Y-90 in patients with progressive metastatic gastroenteropancreatic neuroendocrine carcinomas (GEP-NETs): a phase II study.

BACKGROUND: To evaluate the clinical and radiological effectiveness of [DOTA(0), D-Phe(1), Tyr(3)]-octreotate (DOTATATE) Y-90 in patients with extensive progressive gastroenteropancreatic neuroendocrine carcinomas (GEP-NETs). MATERIALS AND METHODS: Sixty patients with histologically proven GEP-NETs were treated with DOTATATE Y-90. Clinical responses were assessed 6 weeks after completing therapy and then after each of the 3- to 6-month intervals. The radiological response was classified according to RECIST criteria. RESULTS: At 6 months after final treatment, radiological partial response (PR; at least a 30% decrease in the sum of the longest diameter of target lesions) was observed in 13 patients (23%), and the remaining patients had stable disease (SD; less than 30% decrease in the sum of the longest diameter of target lesions or less than 20% increase in the sum of the longest diameter of target lesions) (77%). Clinical PR at 6 months was in 43 patients (72%), nine patients had SD and progressive disease (PD) was noted in eight patients. Median progression-free survival (PFS) was 17 months, while the median overall survival (OS) was 22 months. In eight patients with early PD, the PFS was 4.5 and OS 9.5 months, while in those with SD or PR, PFS and OS were 19.5 and 23.5 months, respectively. After 12 months of follow-up, five patients had World Health Organization (WHO) grade 2 or 3 renal toxicity. Haematological toxicity (WHO grade 3 and 4) was noted during therapy in 10% of patients and persisted in 5%. CONCLUSIONS: DOTATATE Y-90 therapy is effective and relatively safe in patients with GEP-NET. Standard doses of DOTATATE Y-90 result in a relatively low risk of myelotoxicity. However, due to ongoing risk of renal toxicity, careful monitoring of the kidney is recommended.

Improving diagnostic value of CT examinations in hyperacute ischemic stroke.

This paper presents a computer assisted support of ischemic stroke diagnosis based on nonenhanced CT examinations acquired in the hyperacute phase of stroke. Computational analysis, recognition, and image understanding methods were used for extraction of the subtlest signs of hypodensity in diagnostically important areas. Starting from perception improvement, suggestive and coarse image data visualization was designed as a complement of the standard diagnosis procedure based on CT scan soft-copy review. The proposed method includes an evidence-based description of ischemic conditions and changes, de-skulling and segmenting of unusual areas, the analysis of hypodensity signs across scales and subbands with noise reduction, and hypodensity extraction. Following visualization, forms of empowered hypodensity symptoms localize suggested ischemic areas in source brain image space. Increased visibility of cerebral ischemia for difficult-to-diagnose cases was experimentally noticed and improved diagnostic value of CT was concluded.

Normal 3T MR Anatomy of the Prostate Gland and Surrounding Structures.

Development on new fast MRI scanners resulted in rising number of prostate examinations. High-spatial resolution of MRI examinations performed on 3T scanners allows recognition of very fine anatomical structures previously not demarcated on performed scans. We present current status of MR imaging in the context of recognition of most important anatomical structures.

Computed Tomography Perfusion is a Useful Adjunct to Computed Tomography Angiography in the Diagnosis of Brain Death.

BACKGROUND: In the diagnosis of brain death (BD), computed tomography angiography (CTA) results in some cases show intracranial filling, leading to diagnostic confusion. Because cerebral circulatory arrest commences at the capillary level, we hypothesized that computed tomography perfusion (CTP) would be a more sensitive approach than CTA; therefore, the aim of the study was to compare the sensitivities of CTP and CTA in the diagnosis of BD. MATERIAL AND METHODS: Whole brain CTP was performed in patients in the intensive care unit diagnosed with BD and CTA was derived from CTP datasets. Cerebral blood flow (CBF) and volume (CBV) were calculated in all brain regions. The CTP findings were interpreted as being consistent with a diagnosis of BD (positive) when CBF and CBV in all regions of interest (ROIs) were below 10 ml/100 g/min and 1.0 ml/100 g, respectively. The CTA findings were interpreted using a 4-point grading system. RESULTS: A total of 50 patients were included in the study. The CTP results revealed CBF from 0.00 to 9.98 ml/100 g/min (mean, 1.98 ± 1.68 ml/100 g/min) and CBV from 0.00 to 0.99 ml/100 g (mean, 0.14 ± 0.12 ml/100 g) and were thus interpreted as positive in all 50 patients. In contrast, the CTA results suggested 7 negative cases, providing a sensitivity of 86%. The difference between the CTP and CTA sensitivity results for the diagnosis of BD was statistically significant (p = 0.006). CONCLUSION: Whole brain CTP may potentially be a feasible and highly sensitive test for diagnosing BD: therefore, performing CTP in combination with CTA in cases when CTA results are negative for BD could increase the sensitivity of CTA.

Shear-wave elastography in the diagnosis of ulnar tunnel syndrome.

An interesting alternative to traditional diagnostic techniques of the upper extremity nerve entrapments might be an ultrasound elastography that has started to gain attention in recent research. The aim of this preliminary study was to verify whether a quantitative analysis of the ulnar nerve stiffness by shear-wave elastography can be used to diagnose ulnar tunnel syndrome (UTS), an ulnar nerve neuropathy at Guyon's canal. The study included 46 patients (39 women) and 39 healthy controls (34 women). All diagnoses in patients and controls were confirmed with nerve conduction studies. Measurements of nerve stiffness were taken at three levels: Guyon's canal (G), distal forearm (DF), and mid forearm (MF). Additionally, the ulnar nerve cross-sectional area at the canal's level was determined by ultrasonography. Patients with UTS presented with significantly greater nerve stiffness than the controls (mean, 99.41 kPa vs. 49.08 kPa, P < 0.001). No significant intergroup differences were found in the nerve elasticity at DF and MF levels (P < 0.836 and P < 0.881, respectively). An ulnar nerve stiffness value of 80 kPa and G:DF and G:MF ratios equal to 1.5 provided 100% sensitivity, specificity, and positive and negative predictive values in the detection of the syndrome. The mean nerve cross-sectional area in the Guyon's canal was significantly greater in patients than in the controls (4.63 mm2, range, 2-7 mm2 vs. 3.23 mm2, range, 2-5 mm2, P < 0.001). In conclusion, we believe that shear-wave elastography has the potential to become a useful adjunct diagnostic test for UTS.

Prefrontal N-acetylaspartate and poststroke recovery: a longitudinal proton spectroscopy study.

BACKGROUND AND PURPOSE: Functional imaging studies suggest that poststroke recovery is related to the reorganization in both contralesional and ipsilesional prefrontal cortex. Little is known, however, about how longitudinal metabolic changes in prefrontal regions relate to the improvement after stroke. We sought to determine whether poststroke recovery is associated with changes in N-acetylaspartate/creatine (NAA/Cr) ratio within contralesional prefrontal regions. MATERIALS AND METHODS: Twenty-seven patients with a first ischemic stroke located outside the frontal lobes were included. Proton MR spectroscopy ((1)H-MRS) was performed on a 1.5T scanner. Point-resolved spectroscopy sequence (PRESS) was used. NAA/Cr was measured both in ipsilesional and contralesional prefrontal regions in early (14 +/- 6 days after stroke) and chronic phases of the disease (110 +/- 30 days after). Patients' neurologic status was assessed using Scandinavian Stroke Scale (SSS) at discharge from the stroke unit and during second (1)H-MRS examination. RESULTS: Subjects showing increased contralesional NAA/Cr from first to follow-up examination improved significantly more on the SSS than patients not showing this increase. Analysis was performed while correcting for change in NAA/Cr levels in the ipsilesional hemisphere. For the whole group, the change in contralesional NAA/Cr was significantly correlated to the change in SSS scores (r = 0.40, P = .03). Change in the ipsilesional NAA/Cr measures did not correlate with the change in SSS scores. CONCLUSION: Poststroke recovery was related to the increase in contralesional prefrontal NAA/Cr. This association may reflect recovery mechanisms involving the nonaffected hemisphere. Further assessment of these regions may provide information about mechanisms contributing to neurologic improvement.

The predictive value of arterial renal blood flow parameters in renal graft survival.

BACKGROUND: Renal allograft survival depends on a number of factors, however, no reliable simple parameter has been shown to predict long-term outcome after transplantation. Ultrasound is recognized and relatively inexpensive, providing information about renal location, contour, and size. Doppler ultrasonography shows kidney morphology and hemodynamics. The aim of this study was the evaluation of whether Doppler ultrasound of renal arteries performed in the early stage after transplantation was a valuable predictor for long-term-outcomes. MATERIAL AND METHODS: The study included 17 female and 24 male patients, aged 17-69 years with stable graft function. The Doppler ultrasound of renal flow was done on the 1st and 3rd day after transplantaion, and estimated glomerular filtration rate (eGFR) on the 20th day. The measured indices were as follows: maximum blood flow velocity (V(max)), minimum blood flow velocity (V(min)), resistive index (RI), and pulsatile index (PI). The creatinine concentration was evaluated, and eGFR calculated. RESULTS: Mean renal and intrarenal artery RI increased to day 3 after transplantation, and then reduced. The mean renal and intrarenal V(max) at day 3 correlated positively with eGFR (r = 0.38; P = .015); (r = 0.45; P = .003, respectively). Mean renal and intrarenal V(min) correlated positively with eGFR (r = 0.50; P = .001; r = 0.41; P = .008, respectively). The mean renal and intrarenal V(max) and V(min) on day 1 did not correlate with eGFR. CONCLUSIONS: Early Doppler Ultrasonography of renal graft hemodynamics may be a valuable predictor of graft survival and long-term outcomes. Blood flow velocity within renal arteries seemed to be an important factor.

Improved early stroke detection: wavelet-based perception enhancement of computerized tomography exams.

Nonenhanced computerized tomography (CT) exams were used to detect acute stroke by notification of hypodense area. Infarction perception improvement by data denoising and local contrast enhancement in multi-scale domain was proposed. The wavelet-based image processing method enhanced the subtlest signs of hypodensity, which were often invisible in standard CT scan review. Thus improved detection efficiency of perceptual ischemic changes was investigated. Data processing became more effective by initial segmentation of brain tissue and extraction of regions susceptible to tissue density changes. The new method was experimentally verified. Sensitivity of stroke diagnosis increased to 56.3% in comparison to 12.5% of standard CT scan preview.

Renal artery resistance index, thyroid hormones, and thyroid volume in the early kidney transplants recipients.

BACKGROUND: Thyroid hormones could affect renal function, and, on the other hand, renal dysfunction may affect thyroid function. Disturbances of concentrations of thyroid hormones are often associated with thyroid gland enlargement. The aim of the study was to assess the function and morphology of the thyroid (volume and hormones concentration) and kidney function after transplantation (creatinine concentration and resistance index [RI] of transplant artery). MATERIAL AND METHODS: The group included 13 females, 19 males; aged 19-69 years, mean 44.75 +/- 14.8 years after transplantation with stable graft function. Thyroid volume, renal artery RI, creatinine concentration, and concentrations of T3, rT3, FT3, FT4, and TSH were estimated the day before surgery, and at 1, 3, 6, and 10 days after transplantation. RESULTS: The statistical analysis revealed a negative correlation between delta RI (difference between RI at 3 and 6 days after transplantation) and serum creatinine concentration, 10 days after transplantation (r = -0.63; P < 0.01). We also observed a negative correlation between creatinine serum concentration at 10 days after transplantation and delta thyroid volume (Delta Vol; r = - 0.48; p < .05), a positive correlation between delta FT4 (Delta FT4) serum concentration, and delta creatinine (Delta Crea; r = 0.73; P < .001). CONCLUSIONS: The dynamics of RI changes in the transplant kidney artery between 3 and 6 days after transplantation may predict graft function. Together with improved kidney function at 10 days after transplantation, we observed a regression of goiter.

Early diagnosis of Nelson's syndrome.

Nelson's syndrome is a specific form of Cushing's disease treated by bilateral adrenalectomy, presenting with a deep hyperpigmentation caused by a pituitary adenoma (corticotropinoma). These ACTH-secreting tumors are frequently aggressive, so early diagnosis is of prime importance. We have studied 33 patients with Nelson's syndrome, 28 women and 5 men, aged 14-56 yr at the time of adrenalectomy and 16-58 yr at the time of Nelson's syndrome diagnosis (observed for 5-32 yr). Methods of examination included simultaneous adrenocorticotropic hormone (ACTH) and cortisol measurements during routine hydrocortisone replacement therapy, computed tomography (CT), pituitary magnetic resonance imaging (MRI), and visual field examination. The results obtained in a group of six patients diagnosed in the last 3 yr were compared with those obtained in a group of 27 patients examined before 1992. High plasma ACTH levels accompanied by normal serum cortisol concentration were characteristic for a late stage of the disease. Absolute temporal scotomas were an early finding. MRI, especially with the gadolinium enhancement, was superior to CT in demonstrating pituitary microadenomas in Nelson's syndrome. Thus, MRI diagnosis allowed for an early neurosurgical treatment of the patients with Nelson's tumors.

Application of dynamic computed tomography scan and computed tomography densitometry in the evaluation of brain volume enlargement.

Cats with brain cold injury and epidural balloon compression with sudden decompression were used as models of vasogenic or ischemic edema and vasoparalysis of the brain vessels. Dynamic CT scan and CT densitometric studies were performed to diagnose and differentiate between brain edema and vasoparalytic changes. The CT methods were found to be useful in CBF and edema zone estimation. The correlation of CT scan and CT densitometry enabled us to evaluate the degree of autoregulation disorders and can be also applied in clinical investigations.

Assessment of fetal distress based on magnetic resonance examinations: preliminary report.

RATIONALE AND OBJECTIVES: Hypoxia is the main cause of injuries and intrauterine death of the fetus. Therefore, the main aim of monitoring and assessment of the fetus should be diagnosis of fetal distress before irreversible changes occur. Besides the fetal condition assessment methods used so far, in recent years in obstetrics new non-invasive imaging methods were introduced such as magnetic resonance (MR). This method enables morphologic evaluation of brain and brain tissue metabolism using magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: Twenty pregnant women with pregnancy-induced hypertension (11 cases, including 3 with coexisting diabetes mellitus and 2 with intrauterine growth retardation), chronic hypertension (2 cases), gestational diabetes mellitus (6 cases), and suspected intrauterine fetal growth retardation (IUGR) participated in the study. Cardiotocography (CTG) and Doppler ultrasound examination of the blood flow in the umbilical artery and in the middle cerebral artery were performed. RESULTS: In case of abnormal CTG and Doppler study records that indicated fetal hypoxia, MR studies showed the existence of ischemic focus in 5 patients and abnormal spectral images in 6 patients. CONCLUSION: The results of the preliminary study suggests that the use of MR in prenatal diagnosis may revolutionize the early detection of fetal injury in fetal distress. It is a valuable component of the diagnostic process, supplementing other examinations. The use of MR to assess fetal condition gives additional information and helps to make decisions about therapeutic actions.

Role of short TE 1H-MR spectroscopy in monitoring of post-operation irradiated patients.

Post-surgical radiation therapy is a routine procedure in the treatment of primary malignant brain tumors. Along with modest therapeutic effects conventional fractionated radiotherapy, in spite of any modifications, produces damage to non-malignant brain tissues lying within the treatment volume, the extent of which depends on radiation dose. Serial 1H-MRS allows non-invasive investigation of tissue metabolic profiles. In the present study the ratios of resonance signals assigned to the major 1H-MRS-visible metabolites (N-acetylaspartate, choline, creatine, inositol, lactate and lipid methylene group) were evaluated before, during and after post-surgical fractionated radiotherapy in brain regions close to and more distant from the tumor bed, receiving different radiation exposures (60 and < 40 Gy, respectively). The study group consisted of ten patients (aged 28-51). A MRI/MRS system (Elscint 2T Prestige) operating at the field strength of 2 T and the proton resonance frequency of 81.3 MHz has been used and the 1H-MR spectra were acquired using single voxel double-spin-echo PRESS sequence with a short TE. The spectra were post-processed with automatic fitting in the frequency domain. It was found that although the metabolite profiles depend on the dose obtained, but other stress factors (like surgery) seem to contribute to the overall picture of the metabolic status of the brain as well. In studies of early irradiation injuries, an increase of choline related ratios may serve rather as cell proliferation indictors than as cell injury ones, whereas the mI/Cr ratio appears as one of the first indicators of local irradiation injury. In order to establish the prognostic marker for early radiation damage, however, it seems necessary to analyze all visible metabolites as well. None of the metabolites separately may serve as such an indicator due to the complexity of tissue metabolism. Interestingly, MRI reveals no changes during the therapy process, whereas the metabolite ratios are being affected in the course of time, thus supporting the presumption that the 1H-MRS is a valuable method of radiation therapy monitoring.

Metabolite ratios measured with a short echo time 1H-MRS in the frontal lobe of young healthy subjects: an approach to generate reference 1H-MRS data.

Proton magnetic resonance spectroscopy (1H-MRS) performed with a semi-automated Elscint Prestige 2 Tesla tomograph/spectroscope was used to determine the ratios of the most prominent resonances recorded from the 2 x 2 x 2 cm voxels located in the frontal lobe of healthy young males and females. The values of major metabolite ratios (NAA/Cr, Cho/Cr and ml/Cr) were normally distributed and comparable to results reported by other groups using advanced automated equipment. The coefficients of variation were smaller when the composed metabolite ratios (i.e. the ratios of a given resonance signal to the sum of all signals considered) were calculated. The composed metabolite ratios approach may be more sensitive for discrimination between normal and pathologically changed brain.

Is there any relation between thyroid gland function and kidney transplant function?

INTRODUCTION: Patients with chronic renal failure exhibit abnormalities of thyroid function. Reports regarding thyroid function in kidney transplant recipients (TX) are rare, particularly those individuals on long-term immunosuppression. The aim of this study was to investigate correlations between FT3, FT4, TSH concentrations, thyroid volume, and graft function. MATERIAL AND METHODS: The study enrolled 46 kidney allograft recipients (aged 27-67 years,) engrafted between years 1994 and 2000 and clinically stable. The mean time after TX was 45.3 +/- 37.4 months. Transplanted patients received prednisone, cyclosporine, and azathioprine. The control group included 22 patients with normal renal function. In addition to serum creatinine, TSH, FT3, and FT4 concentrations, thyroid examinations were performed with a 7.5-MHz linear probe to calculated the thyroid volume. RESULTS: Thyroid volume in TX patients was 25.3 +/- 13.3 mL. A positive correlation existed between thyroid volume and serum creatinine (P <.05), and a negative one between thyroid volume and TSH (P <.05). No correlation was observed between TSH, FT4, and serum creatinine. The time after TX was negatively related to TSH (P <.05). A negative correlation existed also between FT3 and creatinine in TX patients (P <.05). In the control group the concentrations of TSH and FT3 were within normal ranges. CONCLUSION: The FT3 concentration correlates with function of the renal graft. In TX patients the supplementary thyroid hormone therapy should be considered.

Malignancy of brain tumors evaluated by proton magnetic resonance spectroscopy (1H-MRS) in vitro.

Biopsies of 6 malignant gliomas (grade 3 or 4) and 11 low-grade meningiomas were extracted with perchloric acid or methanol/water, and the fully-relaxed 1H-MRS spectra of the extracts containing water-soluble metabolites and a concentration and chemical shift standard were recorded at 11.4 T. The resonance signals assigned to inositol (Ino), glycerophospho- and phosphocholine (GPC + PC), choline (Cho), creatine and phosphocreatine (Cr + PCr), glutamate (Glu), acetate (Ac), alanine (Ala) and lactate (Lac) were integrated, and analyzed by two methods. First, the concentrations of the aforementioned substances in the bioptates were estimated from their resonance signals in the extracts. Second, these signals were normalized to the Cr + PCr resonance signal. The Mann-Whitney U-test was used to verify statistical significance between the data sets obtained for gliomas and meningiomas. When the first method of analysis was used, the only difference was in the Ala concentration, which in meningiomas was on average 4 times higher than in gliomas (P < 0.01). However, when the second method of analysis was applied, gliomas expressed lower normalized resonance signals of Ala and Glu (P < 0.001, ranges not overlapping), Lac (P < 0.005), as well as Ino and GPC + PC (P < 0.05). In proton MR spectra of brain tumor tissue extracts containing water soluble metabolites, the resonance signals normalized to that of total creatine may provide a very good discrimination between malignant gliomas and low-grade meningiomas.