The growing role of telemedicine - possibilities and regulations concerning teleradiology in Poland.

In recent years, imaging studies have become increasingly used at various stages in the management of patients with various conditions and disorders. This process results in a necessity to provide an increasing number of exams, which involves a growing role of radiologists in assessing and reporting those exams. The article discusses tele-radiology as a method that can improve access to radiology services, presenting its potential benefits, as well as the risks involved. It analyses access to radiology healthcare services in Poland in the context of the international and Polish legal provisions concerning the right to healthcare. While funding for imaging studies for patients is widely available and imaging equipment in Poland is improving despite some shortages, the main barrier is identified in the number of specialists capable of assessing the exams. Teleradiology can alleviate this shortage, so the article presents legal provisions and international good practice guidelines in this area, focusing on documents issued by the European Society of Radiology, the American College of Radiology, and the British Royal College of Radiologists. The guidelines concerning such aspects as patients' rights, teleradiologists' qualifications, communication and reporting, responsibility, and technical requirements may help make teleradiology a safe and valuable component of the healthcare system in Poland.

Metastatic pulmonary calcification as a rare complication of end-stage renal disease with coexistence of pulmonary metastases from renal cell carcinoma: case report and literature review.

PURPOSE: We present a case of metastatic pulmonary calcification (MCP) in an asymptomatic patient with chronic kidney disease after renal transplantation and nephrectomy due to renal cancer. Chest computed tomography (CT) revealed bilateral, diffuse, centrilobular ground-glass opacities and heterogeneous, high-density areas distributed throughout the lungs, predominantly in the upper and middle lobes. Unusually, in our patient the metastatic calcification coexisted with pulmonary metastases from renal cell carcinoma associated with end-stage renal disease. To our knowledge, such coexistence has not been previously described. CASE REPORT: CT, particularly high-resolution chest computed tomography (HRCT), plays an important role in detection and follow-up of MPC findings, which include ground-glass opacities and partially calcified nodules or consolidations, predominantly in the upper lung zones. Correct diagnosis is important because misdiagnosis may lead to improper or unnecessary treatment and/or procedures. CONCLUSIONS: MPC is a rare condition that results from calcium deposition in the normal pulmonary parenchyma. MPC commonly occurs in patients with end-stage chronic kidney disease due to abnormalities in calcium and phosphate metabolism. It is worth pointing out that despite the fact that the condition is called metastatic, it is a relatively benign lung disease with a generally good long-term prognosis.

Usefulness of conventional and low-dose hydro-CT in the diagnosis of gastric tumors in comparison to endoscopy.

PURPOSE: The aim of this retrospective study was to evaluate the usefulness of hydro-CT in the diagnosis of gastric tumors in comparison to endoscopy. MATERIAL AND METHODS: The study involved 40 patients with a diagnosis of gastric tumor established by histopathology who underwent endoscopy and conventional or low-dose hydro-CT. Hydro-CT images were retrospectively analyzed based on the consensus of two radiologists who were blinded to the endoscopy findings. The diagnostic accuracy of hydro-CT and endoscopy for the diagnosis of gastric tumors was evaluated using the results of the histopathological examination as the reference standard. RESULTS: Histopathology confirmed the presence of gastric cancer in 28 patients (70%), while gastrointestinal stromal tumors (GISTs) were recognized in the remaining 12 cases (30%). Correct diagnoses of the type of gastric tumor in hydro-CT were obtained in 37 patients (92.5%). This was not significantly different from the 85% accuracy of endoscopy. Further analysis showed that the correctness of GIST diagnosis in endoscopy and hydro-CT also did not differ significantly (91.7% and 100% respectively). The percentage of correctly diagnosed malignant lesions in hydro-CT was lower than for GISTs at 89.29%, while in endoscopy it was insignificantly lower (82.14%). The diagnostic accuracy of conventional and low-dose hydro-CT in the diagnosis of gastric tumors (95% and 90% respectively) was not significantly different. CONCLUSIONS: Conventional and low-dose hydro-CT may be a valuable non-invasive diagnostic method in the diagnosis of gastric tumors for patients who have contraindications to endoscopy or who are unable to undergo gastric biopsy.

Diagnostic Imaging and Clinical Features of Intracranial Hypotension - Review of Literature.

Intracranial hypotension (IH) is an uncommon, benign, and usually self-limiting condition caused by low cerebrospinal fluid (CSF) pressure, usually due to CSF leakage. The dominant clinical finding is an orthostatic headache. Other common clinical features include fever, nausea, vomiting, and tinnitus. Magnetic resonance imaging (MRI) plays an important role in the diagnosis and follow-up of patients with IH. Specific MRI findings include intracranial pachymeningeal enhancement, sagging of the brain, pituitary enlargement, and subdural fluid collections. Intracranial hypotension can mimic other conditions such as aseptic meningitis or pituitary adenomas. Differential diagnosis is important, because misdiagnosis may lead to unnecessary procedures and prolonged morbidity.

Novel COL4A1 mutation in an infant with severe dysmorphic syndrome with schizencephaly, periventricular calcifications, and cataract resembling congenital infection.

BACKGROUND: A clinical case is described of growth retardation, severe developmental delay, facial dysmorphic features with microcephaly, as well as congenital cataract, schizencephaly, periventricular calcifications, and epilepsy. METHODS: TORCH infection was suspected, but all tests for toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus were negative for the child and her mother; however, an increased level of antibodies against parvovirus B19 was detected in the proband. RESULTS: Chromosomal analysis and array-CGH showed no aberration. Target capture sequencing for COL4A1 and COL4A2 revealed a de novo COL4A1 mutation (c.2123G>T [p.Gly708Val]). The mutation occurred at a highly conserved Gly residue in the Gly-X-Y repeat of the collagen triple helical domain, suggesting that these mutations may alter the collagen IV α1α1α2 heterotrimers. The mutation was predicted to be damaging. CONCLUSION: We suggest that COL4A1 testing should be considered in patients with schizencephaly as well as with phenotype suggesting TORCH infection without any proven etiological factors.

Head CT: Image quality improvement of posterior fossa and radiation dose reduction with ASiR - comparative studies of CT head examinations.

OBJECTIVES: To evaluate head CT protocol developed to improve visibility of the brainstem and cerebellum, lower bone-related artefacts in the posterior fossa and maintain patient radioprotection. METHODS: A paired comparison of head CT performed without Adaptive Statistical Iterative Reconstruction (ASiR) and a clinically indicated follow-up with 40 % ASiR was acquired in one group of 55 patients. Patients were scanned in the axial mode with different scanner settings for the brain and the posterior fossa. Objective image quality analysis was performed with signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality analysis was based on brain structure visibility and evaluation of the artefacts. RESULTS: We achieved 19 % reduction of total DLP and significantly better image quality of posterior fossa structures. SNR for white and grey matter in the cerebellum were 34 % to 36 % higher, respectively, CNR was improved by 142 % and subjective analyses were better for images with ASiR. CONCLUSIONS: When imaging parameters are set independently for the brain and the posterior fossa imaging, ASiR has a great potential to improve CT performance: image quality of the brainstem and cerebellum is improved, and radiation dose for the brain as well as total radiation dose are reduced. KEY POINTS: •With ASiR it is possible to lower radiation dose or improve image quality •Sequentional imaging allows setting scan parameters for brain and posterior-fossa independently •We improved visibility of brainstem structures and decreased radiation dose •Total radiation dose (DLP) was decreased by 19.

Evaluation of the Degradation of the Selected Projectile, Commissural and Association White Matter Tracts Within Normal Appearing White Matter in Patients with Multiple Sclerosis Using Diffusion Tensor MR Imaging - a Preliminary Study.

BACKROUND: The aim of the study was to assess the impairment of the selected white matter tracts within normal appearing white matter (NAWM) in multiple sclerosis (MS) patients using diffusion tensor imaging (DTI). MATERIAL/METHODS: Thirty-six patients (mean age 33.4 yrs) with clinically definite, relapsing-remitting MS and mild disability (EDSS - Expanded Disability Status Scale 1-3.5) and 16 control subjects (mean age 34.4 yrs) were enrolled in the study. DTI examinations were performed on a 1.5T MR scanner. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained with a small ROI method in several white matter tracts within NAWM including: the middle cerebellar peduncles (MCP), the inferior longitudinal fasciculi (ILF), inferior frontooccipital fasciculi (IFOF), genu (GCC) and splenium of the corpus callosum (SCC), posterior limbs of the internal capsules (PLIC), superior longitudinal fasciculi (SLF) and posterior cingula (CG). There were no demyelinative lesions within the ROIs in any of the patients. RESULTS: A significant decrease in FA was found in MS patients in both the ILFs and IFOFs (p<0.001) and in the left MCP and right SLF (p<0.05), compared to the normal subjects. There were no significant differences in FA values in the remaining evaluated ROIs, between MS patients and the control group. A significant increase in ADC (p<0.05) was found only in the right PLIC and the right SLF in MS subjects, compared to the control group. CONCLUSIONS: The FA values could be a noninvasive neuroimaging biomarker for assessing the microstructural changes within NAWM tracts in MS patients.

Size-Specific Dose Estimates for Evaluation of Individual Patient Dose in CT Protocol for Renal Colic.

OBJECTIVE: The purpose of this study is to retrospectively evaluate size-specific dose estimates of a renal-colic CT protocol and to assess the quality and diagnostic value of obtained images. MATERIALS AND METHODS: The study population included 82 consecutive adult patients with acute renal colic undergoing CT with a reduced radiation dose (noise index, 59.1). The control group included 82 consecutive patients who underwent clinically indicated CT examination of the abdomen and pelvis with a routine-dose CT protocol (noise index, 22.0). The size-specific dose estimate was calculated with volume CT dose index and patient effective diameter. Subjective image quality analysis was based on visibility of the ureter. Ureters were tracked from the renal pelvis to the vesicoureteral junction. Objective image quality was based on the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR). RESULTS: The size-specific dose estimates in the renal-colic group were 2.7 times lower than those in the control group. A linear relationship between patient size and size-specific dose estimate was noted. In the smallest patient, the conversion factor for the size-specific dose estimate calculation was 1.65. Overall image quality was better for the control patients, but there was no statistically significant difference in ureter visibility. The SNR was higher for the control group, whereas no difference in CNR was found. CONCLUSION: Small patients need the biggest correction for body size and require special attention in radiation dose estimation. We suggest the modification of scanning parameters on the basis of size-specific dose estimate to decrease patient dose in large patients.

The Role of MR Imaging in the Assessment of Clinical Outcomes in Children with X-Linked Adrenoleukodystrophy after Allogeneic Haematopoietic Stem Cell Transplantation.

BACKGROUND: The aim of the study was to analyse MR images of the brain, including advanced MR techniques, such as single voxel spectroscopy (MRS) and diffusion tensor imaging (DTI), in children with X-linked adrenoleukodystrophy (X-ALD) before and after haematopoietic stem cell transplantation (HSCT) and to establish the imaging criteria which may be helpful in the assessment of disease staging, qualification to HSCT and follow-up. MATERIAL/METHODS: Seven boys, aged 5-10 years, (mean 8.14 years) with biochemically proved X-ALD, underwent plain MR imaging with a 1.5 T unit before and after HSCT. Structural images were analyzed using an MRI severity scale (Loes scale). In one patient the follow-up examinations included MRS with the assessment of metabolite ratios (NAA/Cr, Cho/Cr, mI/Cr), as well as DTI with evaluation of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in several white matter tracts. RESULTS: Two boys had an MRI severity score before HSCT equal to <8 points, and after HSCT they showed no clinical or radiological progression. In 5 patients with a higher severity score (from 8 to 16 points, mean 10.9) before HSCT, clinical and radiological progression was observed (MRI severity score from 17 to 25 points, mean 20.9). Follow-up advanced MRI techniques in one boy showed metabolic alterations, as well as decreased FA and ADC values in all evaluated areas. CONCLUSIONS: Children at an early stage of X-ALD (below 8 points in MRI severity scale) are more likely to benefit from HSCT. DTI and MRS seem to be more useful imaging methods to assess the progression of X-ALD.

Central nervous system lymphoma in a 3-year-old male suffering from a severe juvenile xanthogranuloma - the usefulness of perfusion weighted imaging and diffusion weighted imaging in the diagnostics of pediatric brain tumors.

BACKGROUND: Primary Central Nervous System Lymphomas (PCNSLs) are rare, malignant brain tumors derived from lymphocytes B. Juvenile xanthogranuloma (JXG) is a non-Langerhans histiocytic cell disorder in children which mostly affects the skin. Rare fatalities have been reported in extracutaneous manifestation. Brain magnetic resonance imaging (MRI) is a method of choice in the diagnostics of all neoplastic CNS lesions. Perfusion weighted imaging (PWI) and diffusion weighted imaging (DWI) allow for more detailed analysis of brain tumors including the rate of neoangiogenesis and cellularity. We presented a pediatric patient suffering from JXG with CNS involvement and the role of brain MRI including DWI and PWI in the evaluation of brain focal lesions. CASE REPORT: A 3-year-old male with severe JXG underwent two stem cell transplantations with a development of neurological complications. The patient underwent emergency CT and MRI which revealed a non-specific enhancing focal brain lesion. In DWI it showed restricted diffusion while PWI revealed low values of rCBV and the signal intensity curve returning above the baseline level. Advanced MRI techniques such as DWI and PWI suggested PCNSL. Stereotactic biopsy confirmed PCNSL due to Ebstein-Barr virus reactivation. CONCLUSIONS: The use of advanced MRI sequences is important to differentiate brain lesions in pediatric patients. The use of PWI and DWI facilitated the diagnosis of PCNSL. It is important to remember that PCNSLs show a very typical pattern of changes visualized with MRI such as: usually strong homogenous enhancement, restricted diffusion and low perfusion.

Intracranial Lesions with Low Signal Intensity on T2-weighted MR Images - Review of Pathologies.

In this article we presented intracranial pathological substances and lesions with low signal intensity on T2-weighted images. Eight groups of substances were discussed i.e. 1. Gadolinium-based contrast materials, 2. hemoglobin degradation products 3. melanin, 4. mucous- or protein-containing lesions, 5. highly cellular lesions, 6. lesions containing mineral substances such as: calcium, copper and iron, 7. turbulent and rapid blood or CSF flow 8. air-containing spaces. Appropriate interpretation of signal intensity as well as analysis of lesion location and clinical symptoms enable a correct choice of a further diagnostic algorithm or, in many cases, final diagnosis based exclusively on an MRI examination.

Odontogenic inflammatory processes of head and neck in computed tomography examinations.

BACKGROUND: Infections of odontogenic origin are the most common cause of inflammatory disease of head and neck region. Computed tomography allows for defining localization and extent of inflammatory lesions, visualizes soft tissue involvement, presence of an abscess or an osteolytic lesion around causative tooth. THE AIM OF THIS STUDY WAS TO ASSESS PATHWAYS, BY WHICH ODONTOGENIC INFECTIONS SPREAD INTO RESPECTIVE DEEP HEAD AND NECK STRUCTURES IN COMPUTED TOMOGRAPHY EXAMINATION, TAKING INTO ACCOUNT THE FOLLOWING CRITERIA: frequency of involvement of respective deep cervical spaces, possibility to determine a probable causative tooth and concordance with the results of clinical examination. MATERIAL/METHODS: Thirty-eight patients cervicofacial inflammatory disease had undergone CT examination of head and neck region with a 64-slice CT scanner after intravenous contrast administration. RESULTS: Abscess was reported in 30 (79%) cases, while inflammatory infiltration was diagnosed in remaining 8 (21%) patients. There was full concordance between radiological report and intraoperative report In 33 cases (87%). The most commonly involved cervical space was masticator space - 31 patients (82%), followed by submandibular space - 27 patients (71%). Dental examination was impossible in 29 patient because of trismus. During analysis of CT studies we evaluated maxillary and mandibular alveolar processes for presence of osteolytic bone lesions around causative teeth roots and we found them in 30 cases (79%). In 32 cases (84%) cervicofacial infection were of mandibular odontogenic origin. CONCLUSIONS: In most cases CT study in patients suspected of odontogenic craniofacial infection revealed presence of an abscess, needing urgent surgery. Inflammatory infiltration of dental origin most frequently involves masticator space, followed by submandibular space. In most cases CT scanning allows for identification of causative teeth, especially when trismus makes detailed clinical examination impossible.

Value of perfusion-weighted MR imaging in the assessment of early cerebral alterations in neurologically asymptomatic HIV-1-positive and HCV-positive patients.

BACKGROUND AND PURPOSE: Asymptomatic central nervous system (CNS) involvement occurs in the early stage of the human immunodeficiency virus (HIV) infection. It has been documented that the hepatitis C virus (HCV) can replicate in the CNS. The aim of the study was to evaluate early disturbances in cerebral microcirculation using magnetic resonance (MR) perfusion-weighted imaging (PWI) in asymptomatic HIV-1-positive and HCV-positive patients, as well as to assess the correlation between PWI measurements and the clinical data. MATERIALS AND METHODS: Fifty-six patients: 17 HIV-1-positive non-treated, 18 HIV-1-positive treated with combination antiretroviral therapy (cART), 7 HIV-1/HCV-positive non-treated, 14 HCV-positive before antiviral therapy and 18 control subjects were enrolled in the study. PWI was performed with a 1.5T MR unit using dynamic susceptibility contrast (DSC) method. Cerebral blood volume (CBV) measurements relative to cerebellum (rCBV) were evaluated in the posterior cingulated region (PCG), basal ganglia (BG), temporoparietal (TPC) and frontal cortices (FC), as well as in white matter of frontoparietal areas. Correlations of rCBV values with immunologic data and liver histology activity index (HAI) were analyzed. RESULTS: Significantly lower rCBV values were found in the right TPC and left FC as well as in PCG in HIV-1-positive naïve (p = 0.009; p = 0.020; p = 0.012), HIV-1 cART treated (p = 0.007; p = 0.009; p = 0.033), HIV-1/HCV-positive (p = 0.007; p = 0.027; p = 0.045) and HCV-positive patients (p = 0.010; p = 0.005; p = 0.045) compared to controls. HIV-1-positive cART treated and HIV-1/HCV-positive patients demonstrated lower rCBV values in the right FC (p = 0.009; p = 0.032, respectively) and the left TPC (p = 0.036; p = 0.005, respectively), while HCV-positive subjects revealed lower rCBV values in the left TPC region (p = 0.003). We found significantly elevated rCBV values in BG in HCV-positive patients (p = 0.0002; p<0.0001) compared to controls as well as to all HIV-1-positive subjects. There were no significant correlations of rCBV values and CD4 T cell count or HAI score. CONCLUSIONS: PWI examination enables the assessment of HIV-related as well as HCV-related early cerebral dysfunction in asymptomatic subjects. HCV-infected patients seem to reveal the most pronounced perfusion changes.

Assessment of metabolic changes within normal appearing gray and white matter in children with growth hormone deficiency: magnetic resonance spectroscopy and hormonal correlation.

OBJECTIVE: The pathogenesis of idiopathic growth hormone deficiency (GHD) in children, including possible cerebral metabolic alterations, remains unclear. The aim of the study was to evaluate metabolic changes within the normal appearing brain in children with GHD using MR spectroscopy (MRS) and to correlate MRS measurements with hormonal concentrations and with pituitary gland size. METHODS: Seventy children with GHD (mean age 7.8 yrs) and 11 healthy controls (mean age 8.4 yrs) were enrolled in the study. The MRS examinations were performed on a 1.5T scanner. Voxels were located in the posterior cingulate gyrus (PCG) and the left parietal white matter (PWM). The NAA/Cr, Cho/Cr and mI/Cr ratios were analyzed. The metabolite ratios, pituitary gland size and hormonal concentrations: growth hormone (GH) in two stimulation tests and GH during the night, as well as IGF-1 (insulin-like growth factor) and IGFBP3 (insulin-like growth factor-binding protein) levels were also correlated. RESULTS: There was a significant (p < 0.05) decrease of the NAA/Cr ratios in PCG and PWM in children with GHD compared to the normal subjects. Other metabolite ratios showed no significant differences. We also found significant positive correlations between NAA/Cr ratio in PWM and IGFBP3 level, as well as with GH concentration in a stimulation test with glucagon. CONCLUSIONS: The reduction of NAA/Cr ratios may suggest loss of neuronal activity within normal appearing gray and white matters in children with GHD. MRS could be a sensitive marker of cerebral metabolic disturbances associated with GHD and maybe used as an additional indicator for therapy with recombinant GH.

Multislice computed tomography angiography as an imaging modality of choice in patients with suspicion of pulmonary embolism - own experiences and modern imaging techniques.

BACKGROUND: Pulmonary embolism (PE) is a relatively common and potentially life threatening clinical condition with estimated prevalence to be 0.4%. Early diagnosis of PE followed by adequate treatment reduces the risk of major complications. Multislice computed tomography pulmonary angiography (CTPA) currently constitutes an imaging modality of choice in patients with suspicion of PE. Computed tomography venography (CTV) of lower limb veins and CTPA can be performed simultaneously, allowing for visualization of lower limb deep vein thrombosis (DVT). Additionally, dual energy CT scanners enable the evaluation of lung perfusion which is of high value in indirect detection of pulmonary arterial microembolisms. OBJECTIVES: The goal of the study was to assess the diagnostic value of a 64-detector CT scanner in the detection of both acute and chronic PE in patients with clinical suspicion of PE based on clinical scores. MATERIAL AND METHODS: Retrospective analysis of CTPA performed between 2010 and 2012 in 102 consecutive patients (64 women, 38 men) with clinical suspicion of PE based on clinical scores (first of all the Wells score) and elevated D-dimer level was carried out. The patients' median age was 68.9 (range between 34 and 91). The examinations were carried out with a 64-detector CT scanner, using a "pulmonary embolism" protocol. The volume of contrast agent ranged from 60 to 70 mL, depending on the patient's body mass. The contrast medium was administered with an injection rate 4.0-5.0 mL/s. The concentration of the contrast medium in the main pulmonary artery (MPA) was monitored in every case with the use of a 'smart-prep' method. Scanning was started a few seconds (4-6) after reaching a plateau by the contrast medium in MPA. Additionally, in selected patients CTV was performed and/or lung perfusion was evaluated. RESULTS: Evidence of PE was demonstrated in 32 of 102 (31.4%) analyzed patients (pts). In 19 patients, centrally localized clots were visualized. Additionally, in 32 patients, lobar, segmental and proximal subsegmental filling defects corresponding to thrombo-embolic material were demonstrated. Moreover, in 14 patients, distal subsegmental filling defects were shown. Alternative diagnoses included: heart failure-related congestion (21 pts), pneumonia (19 pts) and malignancy (5 pts). CONCLUSIONS: The multislice CTPA is an extremely useful imaging modality in patients with clinical suspicion of PE. The examination enables not only the analysis of pulmonary vessels but also evaluation of pulmonary parenchyma and mediastinum. The collimation of 0.625 mm makes it possible to detect the small foci of peripheral embolism.

Evaluation of early cerebral metabolic, perfusion and microstructural changes in HCV-positive patients: a pilot study.

BACKGROUND & AIMS: The aim of the study was to evaluate early metabolic perfusion, and microstructural cerebral changes in patients with the hepatitis C virus (HCV) infection and normal appearing brain on plain MR using advanced MR techniques, as well as to assess correlations of MR measurements with the liver histology activity index (HAI). METHODS: Fifteen HCV-positive patients and 18 control subjects underwent single voxel MR spectroscopy (MRS), perfusion weighted imaging (PWI), and diffusion tensor imaging (DTI), using a 1.5T MR unit. MRS metabolite ratios (NAA/Cr, Cho/Cr, mI/Cr) were calculated. PWI values of relative cerebral blood volume (rCBV) were assessed from 8 areas including several cortical locations, basal ganglia, and fronto-parietal white matter. DTI fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained from 14 white matter tracts. RESULTS: Compared to controls, HCV-positive patients showed significantly (p < 0.05) lower NAA/Cr ratios within frontal and parietal white matters, lower rCBV values within frontal and temporo-parietal cortices, decreased FA values, as well as increased ADC values in several white matter tracts. We also found elevated rCBV values in basal ganglia regions. The increase in mI/Cr and Cho/Cr ratio was correlated with a higher HAI score. CONCLUSIONS: The results of advanced MR techniques indicate neurotoxicity of HCV reflected by neuronal impairment within white matter, cortical hypoperfusion, and disintegrity within several white matter tracts. Hyperperfusion in basal ganglia may be an indicator of brain inflammation in HCV patients. Our findings may suggest a biologic link between HCV-related liver disease and cerebral dysfunction.

Usefulness of perfusion weighted magnetic resonance imaging with signal-intensity curves analysis in the differential diagnosis of sellar and parasellar tumors: preliminary report.

PURPOSE: The most common pituitary tumors are adenomas, which however may be mimicked by other tumors that can show a very similar appearance in plain MRI. The aim of our study was to evaluate the usefulness of perfusion weighted MR imaging (PWI), including signal-intensity curves analysis in the differential diagnosis of sellar/parasellar tumors. METHODS: Forty-one patients with sellar/parasellar tumors (23 macroadenomas, 10 meningiomas, 5 craniopharyngiomas, 1 intrasellar hemangioblastoma, 1 intrasellar prostate cancer metastasis, 1 suprasellar glioma), underwent plain MRI followed by PWI using a 1.5T unit. In each tumor, the mean and maximum values of relative cerebral blood volume (rCBV), as well as the relative peak height (rPH) and the relative percentage of signal intensity recovery (rPSR) were calculated. RESULTS: The high perfusion tumors were: macroadenomas, meningiomas, squamous-papillary type of craniopharyngiomas, hemangioblastoma, glioma and metastasis. The low perfusion neoplasms included adamantinomatous type of craniopharyngiomas. By comparing adenomas and meningiomas, we found statistically significant differences in the mean and maximum rCBV values (p=0.026 and p=0.019, respectively), but not in rPH and rPSR. The maximum rCBV values >7.14 and the mean rCBV values >5.74 with the typical perfusion curve were very suggestive of the diagnosis of meningioma. There were differences between adenomas and other high perfusion tumors in rPH and rPSR values. CONCLUSIONS: PWI can provide additional information helpful in differential diagnosis of sellar/parasellar tumors. In our opinion PWI, as an easy to perform and fast technique should be incorporated into the MR protocol of all intracranial neoplasms including sellar/parasellar tumors.

Evaluation of metabolic changes within the normal appearing gray and white matters in neurologically asymptomatic HIV-1-positive and HCV-positive patients: magnetic resonance spectroscopy and immunologic correlation.

OBJECTIVE: The aim of the study was to evaluate early metabolic changes using proton MR spectroscopy (MRS) in asymptomatic HIV-1-positive and HCV-positive patients without abnormalities in the structural MR examination. METHODS: Sixty-five asymptomatic patients: 21 HIV-1-positive naive, 20 HIV-1-positive with combination antiretroviral therapy (cART), 9 HIV-1/HCV-positive naive, 15 HCV-positive naive and 18 normal subjects were enrolled in the study. The MRS examinations were performed with a 1.5T MR scanner. Voxels were located in the following regions: posterior cingulate gyrus (PCG), anterior cingulate gyrus (ACG), parietal white matter (PWM), left basal ganglia (BG) and frontal white matter (FWM). The NAA/Cr, Cho/Cr, mI/Cr ratios and correlations of MRS measurements with the immunologic data were analyzed. RESULTS: There was a significant decrease (p<0.05) of the NAA/Cr ratios in PCG, ACG and PWM regions in HIV-1-positive cART treated patients compared to the normal subjects. The significantly decreased NAA/Cr ratios in PWM and FWM were observed in HCV infected patients. The subjects with HIV-1/HCV co-infection revealed significantly lower NAA/Cr ratios in the ACG area. Other metabolite ratios in all analyzed regions, as well as the NAA/Cr ratios in BG showed no significant differences. The decrease of CD4n T cell count was associated with the decease of the NAA/Cr ratio in the PCG area and the increase of Cho/Cr ratio in the FWM region. CONCLUSIONS: The metabolic changes - reduction of NAA/Cr ratios are most pronounced in HIV-1-positive patients using cART. The low CD4n T cell count is a risk factor for neurocognitive impairment in HIV-1-positive patients.

Imaging of degenerative spine disease--the state of the art.

The authors review the current state of imaging of degenerative spinal disease (DSD), which is one of the most common disorders in humans. The most important definitions as well as short descriptions of the etiopathology and clinical presentation of DSD are provided first, followed by an overview of conventional and advanced imaging methods that are used in DSD. The authors then discuss in detail the imaging patterns of particular types of degenerative changes. Finally, the current imaging algorithm in DSD is presented. The imaging method of choice is magnetic resonance, including advanced techniques--especially diffusion tensor imaging. Other imaging methods (plain radiography, computed tomography, vascular studies, scintigraphy, positron emission tomography, discography) play a supplementary role ).

Application of diffusion tensor imaging (DTI) in pathological changes of the spinal cord.

We review the current knowledge concerning clinical applications of the advanced technique of magnetic resonance imaging (MRI): diffusion tensor imaging (DTI) of the spinal cord. Due to technical difficulties, DTI has rarely been used in spinal cord diseases. However, in our opinion it is potentially a very useful method in diagnosis of the different pathological processes of the spinal cord and spinal canal. We discuss the physical principles and technical aspects of DTI, as well as current and future applications. DTI seems to be a very promising method for assessment of spinal cord trauma, spinal canal tumors, degenerative myelopathy, as well as demyelinating and infectious diseases of the spinal cord. DTI enables both qualitative and quantitative (by measuring of the fractional anisotropy and apparent diffusion coefficient parameters) assessment of the spinal cord. The particular applications are illustrated by the examples provided in this article.