Fiber density index in the evaluation of the spinal cord in patients with multiple sclerosis.

PURPOSE: The aims of this study were to determine fractional anisotropy (FA) and the fibre density index (FDi) in the cervical spinal cord of patients with multiple sclerosis (MS) by using diffusion-tensor magnetic resonance imaging (DT-MRI) to identify possible differences between MS patients and controls. MATERIALS AND METHODS: We studied 27 patients with MS - nine with primary progressive (PPMS), nine with secondary progressive (SPMS) and nine with relapsing-remitting (RRMS) disease - and 18 healthy individuals as controls. Conventional and DTI sequences with diffusion gradients applied in 32 directions were obtained. The results were compared between healthy controls and patients, between healthy controls and individual forms of MS and between the three forms of MS. Statistical analysis was performed by analysis of variance (ANOVA) and Student's t test. RESULTS: The FDi in the three subgroups of patients and in controls showed a statistically significant difference. Using the t test, we found results from both PPMS and SPMS groups were different from controls. The correlation between FA and FDi was significant both in healthy controls and in MS patients evaluated as a single group. CONSLUCIONS: Despite the small group of patients, these findings suggest that FDi associated with FA is a sensitive parameter for assessing spinal cord damage in patients with MS.

Functional MRI during the execution of a motor task in patients with multiple sclerosis and fatigue.

PURPOSE: This study was undertaken to assess cortical activation during execution of a motor task in patients with multiple sclerosis (MS) and fatigue. MATERIALS AND METHODS: We enrolled 24 right-handed patients affected by relapsing-remitting MS and mild disability (12 with and 12 without fatigue) and 15 healthy volunteers. Magnetic resonance imaging (MRI) examination (1.5 T) was performed with conventional sequences and an echoplanar imaging (EPI) sequence for functional MRI (fMRI). The motor task consisted of sequential finger tapping performed with the right hand. Statistical maps of motor activation were obtained. Comparison between the two subgroups of patients and between patients and controls was performed with analysis of variance (ANOVA) statistical analysis (p<0.05). RESULTS: Compared with controls, patients without fatigue showed greater activation of the primary sensorimotor cortex bilaterally, of the right supplementary motor cortex, of the left premotor cortex, of the left cerebellum and of the superior parietal lobule bilaterally. Compared with patients without fatigue, patients with fatigue demonstrated greater activation of the right premotor area, of the putamen and the dorsolateral prefrontal cortex. CONCLUSIONS: Patients with fatigue have greater activation of the motor-attentional network when performing a simple motor task.

Evaluation of white matter damage in patients with Alzheimer's disease and in patients with mild cognitive impairment by using diffusion tensor imaging.

PURPOSE: The objective of this study was to evaluate white matter tissue damage in patients with Alzheimer's disease (AD) and in patients with mild cognitive impairment (MCI) using diffusion tensor imaging (DTI). MATERIALS AND METHODS: Forty-seven subjects were evaluated: 14 patients with AD, 15 with MCI and 18 healthy volunteers. All subjects were studied using conventional magnetic resonance imaging (MRI) and DTI (32 directions) with a 1.5 T magnet. Fractional anisotropy (FA) was measured in the following regions: frontal, occipital, parietal and temporal white matter and in the genu and splenium of the corpus callosum. The results were compared between the different groups and correlated with the Mini-Mental State Evaluation (MMSE) scores. RESULTS: A statistically significant difference was obtained between controls and MCI patients (p < 0.007) and between controls and AD patients (p < 0.05) with regard to FA of the white matter in the splenium. A statistically significant difference was obtained between controls and AD patients with regard to FA in the genu (p < 0.016). Moreover, there was a statistically significant difference between controls and AD patients considering the genu (p < 0.016) and the frontal white matter on the right side (p < 0.024). The MMSE scores correlated with the FA values measured in the genu, the splenium and frontal white matter on the right side. No significant differences were identified between patients with AD and those with MCI. CONCLUSIONS: DTI could be of value in the early detection of white-matter damage in patients with MCI and AD. The DTI values correlate with the neuropsychological tests.

Interferon beta-1a slows progression of brain atrophy in relapsing-remitting multiple sclerosis predominantly by reducing gray matter atrophy.

BACKGROUND: Brain atrophy, as assessed by magnetic resonance imaging (MRI), has been correlated with disability in patients with multiple sclerosis (MS). Recent evidence indicates that both white matter (WM) and gray matter (GM) are subject to atrophy in patients with MS. Although neurological deficiencies in MS are primarily due to loss of WM, the clinical significance of GM atrophy has not been fully explored in MS. METHODS: We have undertaken a three-year, open-label study, comparing 26 patients who elected to receive intramuscular interferon beta-1a (IFN beta-1a) therapy, with 28 patients who elected not to receive therapy. Both groups had quantitative cranial MRI scans at study entry and after three years, and standardized clinical assessments every six months. Brain parenchymal fraction (BPF), GM fraction (GMF), and WM fraction (WMF) percent changes were calculated, and T2- and T1-lesion volumes (LVs) assessed. RESULTS: After three years, mean percent (%) change in BPF favored the IFN beta-1a treatment group (IFN beta-1a -1.3% versus the control group -2.5%, P=0.009), as did the mean percent change in GMF (+0.2 versus -1.4%, P=0.014), and the mean percent change in T1-LV (-9.3 versus +91.6%, P=0.011). At the end of the study, there was a significant within-patient decrease in BPF for both groups (P=0.02 for the IFN beta-1a treatment group, and P<0.001 for the control group), a significant within-patient decrease in WMF for the IFN beta-1a treatment group (P=0.01), and a significant decrease in GMF for the control group (P=0.013) when compared with baseline. CONCLUSION: Over a three-year period, treatment with IFN beta-1a significantly slowed the progression of whole-brain and GM atrophy, and of T1-hypointense LV accumulation, when compared with the control group.

Functional MRI in the assessment of cortical activation in subjects with Parkinson's disease.

PURPOSE: The purpose of this study was to evaluate cortical activation patterns in patients with Parkinson's disease during a relatively complex motor task. MATERIALS AND METHODS: Seven patients (six men and one woman) with lateralised akinetic-rigid Parkinson's disease underwent functional magnetic resonance imaging (MRI) of the brain with a 1.5-T magnet. Finger tapping was chosen as a motor task. The control group included 11 volunteers (six men and five women) with no neurological disease. RESULTS: Patients showed hyperactivity of the ipsilateral and contralateral motor cortex associated with bilateral over-activation of the parietal cortex during movement of the affected hand. In some cases, there was a lack of activation of the pre-motor and supplementary motor areas whereas, when present, activation in these areas was greater during movement of the healthy hand. Finally, activation of the occipital cortex was found in all patients as a result of their tendency to control movement visually. CONCLUSIONS: Results of this study confirm a re-organisation of cortical circuits due to subcortical damage in patient's with Parkinson's disease.

Persistent aura without infarction: decription of the first case studied with both brain SPECT and perfusion MRI.

To the best of our knowledge, persistent visual symptoms, lasting months or years without evidence of infarction, a rare complication of migraine with aura, has been reported in only 20 patients. We report the case of a 43-year-old woman with a 31-year history of migraine with typical visual aura. At presentation, she experienced a visual aura in her right hemifield followed by a pulsating headache. The visual symptoms persisted. There were no abnormal findings on neurological and ophthalmological examinations, EEG, visual evoked potentials (VEPs), brain computed tomography and magnetic resonance imaging (MRI). Both brain single photon emission computed tomography (SPECT) and brain perfusion MRI revealed decreased left fronto-parieto-occipital and right occipital blood perfusion. A perfusion MRI, performed 7 months after symptom onset and almost complete extinction of symptoms, was normal. As previously reported, we demonstrated a cortical hypoperfusion by SPECT in a case of persistent visual aura. For the first time this finding was confirmed by perfusion MRI.

Rivastigmine superior to aspirin plus nimodipine in subcortical vascular dementia: an open, 16-month, comparative study.

Recent data indicate that patients with vascular dementia (VaD) show a cholinergic deficit. Having obtained good results in a previous study comparing rivastigmine, an inhibitor of acetylcholinesterase (AChE) and butyrylcholine-sterase (BuChE), vs. aspirin, we aimed to compare the efficacy and tolerability of rivastigmine vs. aspirin plus nimodipine. Patients with a diagnosis of dementia and probable VaD received rivastigmine 3-6 mg/day (n = 32) or aspirin plus nimodipine (n = 32) in an open study for 16 months. Patients treated with rivastigmine showed superior benefits, compared with those receiving aspirin plus nimodipine, in attention, executive function, instrumental activities of daily living, and behavioural and psychotic disturbances. Side-effects in both groups were tolerable and there were no study withdrawals. The benefits observed with rivastigmine may reflect its inhibitory effects on AChE and BuChE, and the drug's affinity for frontal brain areas.

Corticobasal degeneration: structural and functional MRI and single-photon emission computed tomography.

We studied seven patients with corticobasal degeneration (CBD) from a clinical and imaging perspective. We describe the main morphological features of CBD and, using functional MRI, try to define the possible role of the parietal lobe in simple and complex learned motor sequences. We showed decreased activation of the parietal lobe contralateral to the more affected arm, when movements, simple or complex, are performed with that hand. Moreover we found that functional imaging can demonstrate parietal and motor cortex dysfunction before structural, and even single-photon emission computed tomography changes become evident.

Correlation of sexual dysfunction and brain magnetic resonance imaging in multiple sclerosis.

Sixty-two patients (40 women and 22 men) with multiple sclerosis (MS) were examined with 1.5 tesla magnetic resonance imaging (MRI) of the brain. Information on sexual and sphincteric disturbances has been collected, and data on disability, independence, cognitive performances and psychological functioning have been assessed. Calculations of T1- and T2-lesion load (LL) of total brain, frontal lobes and pons have been performed using a reproducible semiautomated technique. Whole brain, frontal and pontine atrophies were estimated using a normalized measure, the brain parenchymal fraction (BPF), obtained with a computerized interactive program. When comparing patients with and without sexual dysfunction (SD), there were no differences in total brain, frontal and pontine T1- and T2-LL, as well as in measures of whole brain and frontal atrophy. The only significant difference was in the pontine BPF (P = 0.026). In linear multiple regression analysis, SD was associated with depression (R = 0.56, P < 0.001) and, after adjusting for depression and anxiety, with bladder dysfunction (R = 0.43, P = 0.003) and pontine BPF (R = 0.56, P < 0.001). No association between SD and any of the measures of T1- and T2-LL was found. The findings showed a relationship between SD and pontine atrophy, confirmed the correlation of SD with bladder dysfunction and highlighted the role of psychological factors in determining SD.

Depressive symptoms and MRI changes in multiple sclerosis.

To determine whether changes in specific regions of the brain can contribute to the development of depression in patients with multiple sclerosis (MS). We prospectively studied 90 patients with clinically definite MS. Disability, independence, cognitive performances, and depressive and anxiety symptoms have been assessed at baseline and 2 years later. At these two time-points, patients underwent a 1.5-T magnetic resonance examination of the brain including T1- and T2-weighted images. Calculation of regional and total lesion loads (LL) have been performed by a semiautomatic technique; total and regional brain volumes have been calculated by a fully automatic highly reproducible computerized interactive program. Measurements of LL did not show any significant difference between depressed and non-depressed patients. Brain atrophy was significantly more conspicuous in the left frontal lobe (P=0.039), in both frontal lobes (P=0.046) and showed a trend towards a difference in the right frontal lobe (P=0.056), in the right temporal lobe (P=0.057) and in both temporal lobes (P=0.072) of depressed patients. Disability, independence and cognitive performances were similar in depressed and non-depressed patients (P=NS). Spearman correlation analysis and multiple-regression analysis demonstrated that the severity of the depressive symptoms score was associated both with the disability score and the right temporal brain volume. Destructive lesions in the right temporal lobe can contribute to the severity of depression in patients with MS but the influence of the severity of neurological impairment should be taken into account.

Learned movements in a left-handed pianist: an f-MRI evaluation.

The spatial arrangement of neuronal sources for digit movement is non somatotopic, and is structured as extensively arranged through different regional cortex. We have functionally examined the cerebro-cortical activation during simple and complex motor sequences, before and after learning sessions, in healthy volunteers, both considering left- and right-dominant hand use, and left non dominant hand use, skillfulness and educational level. We discuss the results with a review on the topic.

Effects of IV methylprednisolone on brain atrophy in relapsing-remitting MS.

BACKGROUND: IV methylprednisolone (IVMP) has been used to treat relapses in patients with relapsing-remitting (RR) MS, but its effect on disease progression is not known. Furthermore, there are no data on the impact of IVMP on T1 black holes or whole-brain atrophy. OBJECTIVE: To determine the effect of IVMP on MRI measures of the destructive pathology in patients with RR-MS and secondarily to determine the effect of IVMP on disability progression in patients with RR-MS. METHODS: The authors conducted a randomized, controlled, single-blind, phase II clinical trial of IVMP in patients with RR-MS. Eighty-eight patients with RR-MS with baseline Expanded Disability Status Scale (EDSS) scores of < or =5.5 were randomly assigned to regular pulses of IVMP (1 g/day for 5 days with an oral prednisone taper) or IVMP at the same dose schedule only for relapses (IVMP for relapses) and followed without other disease-modifying drug therapy for 5 years. Pulsed IVMP was given every 4 months for 3 years and then every 6 months for the subsequent 2 years. Patients had quantitative cranial MRI scans at study entry and after 5 years and standardized clinical assessments every 4 to 6 months. RESULTS: Eighty-one of 88 patients completed the trial as planned, and treatment was well tolerated. Baseline demographic, clinical, and MRI measures were well matched in the two study arms. Patients on the pulsed IVMP arm received more MP than patients on the control arm of the study (p < 0.0001). Mean change in T1 black hole volume favored pulsed IVMP therapy (+1.3 vs +5.2 mL; p < 0.0001), as did mean change in brain parenchymal volume (+2.6 vs -74.5 mL; p = 0.003). There was no significant difference between treatment arms in the change in T2 volume or annual relapse rate during the study. However, there was significantly more EDSS score worsening in the control group, receiving IVMP only for relapses. There was a 32.2% reduction (p

Depression and anxiety in multiple sclerosis. A clinical and MRI study in 95 subjects.

The aim of the present study was to investigate the relationship between involvement of specific areas of the brain and the occurrence of depression and anxiety in patients with multiple sclerosis. We studied 95 patients (62 women and 33 men, mean age 39.5 years, SD 11.2) with definite MS, 97 patients (65 women and 32 men, mean age 40.7, SD 11.9) suffering from chronic rheumatoid diseases and 110 healthy subjects (71 women and 39 men, mean age 40.1, SD 12.7). The disability, the independence, the cognitive performances, the depressive and anxiety symptoms were assessed. The diagnosis of major depression was made according to the DSM-IV. The patients with multiple sclerosis underwent a 1.5 Tesla magnetic resonance examination including T1 and T2 weighted images. Calculation of regional and total lesion loads and brain volumes were performed. The number (%) of subjects with a diagnosis of major depression was 18 (18.9) among MS cases, 16 (16.5) among controls with chronic disease (p=NS), and 4 (3.6) among healthy volunteers (p < 0.0001). The Hamilton Depression and Anxiety rating scales median scores were 5 and 18, respectively in the MS patients, 5 (p= NS) and 14 (p= NS) in the chronic rheumatoid diseases controls, and 3 (p= < 0.0001) and 6 (p= < 0.0001) in the healthy controls. Both severity of depressive symptoms and diagnosis of major depression correlated, albeit weakly, with right frontal lesion load (r=0.22, p=0.035, and r=0.23, p=0.026, respectively) and right temporal brain volume (r=0.22, p=0.005 and r=0.22, p=0.036, respectively). The severity of depression was related significantly also with total temporal brain volume (r=0.26, p=0.012), right hemisphere brain volume (r=0.25, p=0.015), disability (r=0.30, p=0.003) and independence of MS cases (r=-0.26, p=0.01). The anxiety did not correlate significantly with any of the measures of regional and total lesion loads and brain volume or with any of the considered clinical variables. The similar frequency of depression and severity of depressive symptoms in MS patients and in chronic disease patients, the significant difference in this respect with the normal controls, and the significant correlation between depression and the disability measures would suggest a psychological reaction to the impact of the disease but the relationship between depression and the alterations in the frontal and temporal lobes of the right hemisphere supports, on the contrary, the causative role of organic brain damage. The lack of any significant association between symptoms of anxiety and either MRI abnormalities or clinical variables led us to the opinion that anxiety is a reactive response to the psychosocial pressure put on the patients.

A longitudinal study of brain atrophy and cognitive disturbances in the early phase of relapsing-remitting multiple sclerosis.

OBJECTIVE: (a) To establish whether the cognitive decline of the early phase of relapsing-remitting multiple sclerosis depends on the progression of the burden of disease, or on the loss of brain parenchyma, or is influenced by both; (b) to monitor the loss of brain parenchyma in the early phase of the disease; and (c) to examine its possible relation with the progression of physical disability. METHODS: For 2 years 53 patients with clinically definite relapsing-remitting multiple sclerosis with disease duration 1-5 years and expanded disability status scale < or =5.0 at baseline were monitored. The neuropsychological performances, the psychological functioning, the neurological impairment, and the disability have been assessed at baseline and after 2 years. Patients also underwent PD/T2 and T1 weighted brain MRI. T2 and T1 lesion volumes were measured by a semiautomatic technique. Quantification of brain parenchymal volumes was obtained using a highly reproducible computerised interactive program. The relation between cognitive impairment and MRI findings has been investigated by partial correlation and stepwise multiple regression analyses excluding the effects of age, education, anxiety, depression, and total days of steroid use. RESULTS: In the 2 years of the study the mean change for T2 and T1 lesion volumes and brain parenchymal volumes were +1.7 ml (95% confidence interval (95% CI) 1.3-2.2, p=0.005, (29.8%); +0.2 ml, 95% CI 0.15-0.26, p=0.004, (25%); and -32.3 ml, 95% CI 24.2-42.3, p<0.0001, (2.7%), respectively. Overall, 14 patients (26.4%) were judged to be cognitively impaired at baseline and 28 (52.8%) at the end of the follow up. Of the 18 neuropsychological tests and subtests employed in the study, patients with multiple sclerosis failed 5.8 (SD 2.3) tests at the baseline and 8.4 (SD 2.9) (p<0.0001) tests at the end of the study. When the cognitive changes were examined in individual patients, five (9.4%) of them were considered cognitively improved, 33 (62.3%) remained stable, and 15 (28.3%) worsened over 2 years. T2 and T1 volume changes in improved, stable, and worsened patients did not show any significant difference, whereas brain parenchymal volume decrease in cognitively worsened patients was significantly greater (-66 ml (5.4%), 95% CI 37-108.9, p=0.0031). The cognitive impairment was independently predicted over 2 years only by the change of brain parenchymal volumes (R=0.51, p=0.0003). Ten patients (18.9%), who worsened by one or more points in the EDSS during the follow up period had significant decreases in brain parenchymal volumes (-99 ml (8%), 95% CI 47.6-182.3, p=0.005). At the end of the study the loss of brain parenchyma correlated significantly with change in EDSS (r= 0.59, p<0.0001). CONCLUSIONS: In the early phase of relapsing-remitting multiple sclerosis the cognitive deterioration relies more on the development of brain parenchymal volume atrophy than on the extent of burden of disease in the brain. The loss of brain parenchymal volume underlies the progressive accumulation of physical disability from the initial phase of the disease, which becomes more demonstrable only if studied with longer observation periods. Probably, the main pathological substrate of brain atrophy in the early stage of the disease is early axonal loss, which causes the progression of neurological deficits and the development of cognitive impairment. These data support the debated opinion that disease modifying therapy should be initiated as early as possible.

Caval thrombosis in a young athlete.

We here describe a clinical case of caval thrombosis of sudden and unexpected onset, in an athlete without signs of venous insufficiency. Pre-existing caval hypoplasia was observed through imaging examinations. Following a review of the literature, the authors interpret the pathophysiological mechanism of thrombosis as such: a combination of intense physical activity and the malformation led to an overwhelming venous flow and a consequent congestion. Caval thrombosis distal to the malformation is an absolute indication to lifelong oral anticoagulant therapy.

MRI techniques and cognitive impairment in the early phase of relapsing-remitting multiple sclerosis.

Correlation studies between various conventional and non-conventional MRI parameters and cognitive impairment in the early stages of multiple sclerosis (MS) are lacking, although it is known that a number of patients with early MS have mild cognitive impairment. Our aim was to explore whether this cognitive impairment is dependent on the extent and severity of the burden of disease, diffuse microscopic brain damage or both. We studied 63 patients with clinically definite relapsing-remitting (RR) MS, duration of disease 1-10 years and Expanded disability status scale scores < or = 5.0. Mean age was 35.4 years, mean duration of disease 5.8 years and median EDSS score 1.5. Neuropsychological performance, psychological function, neurological impairment and disability were assessed. The patients also underwent MRI, including magnetisation-transfer (MT) studies. We quantified the lesion load on T2- and T1-weighted images, the magnetisation transfer ratio (MTR) of normal-appearing brain tissue (NABT) and the brain parenchymal fraction (BPF). No significant difference was found between lesion loads in patients with and without cognitive impairment. In 15 patients (23.8%) with overall cognitive impairment, median BPF and average NABT MTR were significantly lower than those in patients without cognitive impairment (0.868 vs 0.892, P = 0.02 and 28.3 vs 29.7 P = 0.046, respectively). Multiple regression analysis models demonstrated that the only variables independently correlated with cognitive impairment were: BPF (R = 0.89, P = 0.001) and average NABT MTR (R = 0.76, P = 0.012). Our findings support the hypothesis that, cognitive decline in patients with MS, a low disability score and short duration of disease is directly associated with the extent and severity of diffuse brain damage. The loss of brain parenchyma did not correlate with the severity of microscopic damage in the NABT, indicating that the two processes could be distinct in the early stages of the disease.

Cortical-basal ganglionic degeneration: a clinical, functional and cognitive evaluation (1-year follow-up).

We decided to evaluate a patient who was diagnosed with cortical-basal ganglionic degeneration from a clinical, instrumental and neuropsychological perspective. Our aim was to employ a new instrumental tool, functional magnetic resonance, in order to evaluate his cortical damage. We then followed the pathological course for 1 year and tested the patient again: we discuss the results of our evaluation, having an overview of the literature on the topic. In particular, we focused our attention on his apraxia, trying to suggest a dynamic and anatomical model to guarantee a possible explanation of his behavior.

Olfactory dysfunction and extent of white matter abnormalities in multiple sclerosis: a clinical and MR study.

BACKGROUND: The relative contribution to the olfactory dysfunction of the lesions in the specific brain regions involved in olfaction compared with the lesions scattered all over the rest of the brain has not been fully clarified yet in patients with multiple sclerosis (MS). The concurrent use of Magnetic Resonance Imaging (MRI) and a standardized test of odor identification ability now permits to study the relation between smell loss and the extent of white matter abnormalities. METHODS: We tested the olfactory function of 40 patients with definite MS and of 40 age-sex- and smoking-habit-matched healthy controls by using the Cross Cultural Smell Identification Test. We measured also the lesion load on T2-weighted images in the inferior-frontal and temporal lobes and in the rest of the brain in MS patients. Therefore, we tried to correlate measures of lesion load and smell test scores. RESULTS: A robust correlation was demonstrated between MR measures of lesion load in the white matter of the olfactory brain region and smell loss (r=-0. 739, P<0.0001). A significant relationship has been found even after taking potential confounding factors, such as sex, age, disease duration, disability, anxiety and depression, into account (r=-0.90, P<0.0001). CONCLUSIONS: Our findings show, in MS patients with stable neurological impairment and no recent disease exacerbation, a correlation between smell loss and the lesion load in the regions of the brain involved in olfaction and support the theory that the extent and severity of MRI abnormalities in specific brain regions are related to the presence of selective neurologic and neuropsychologic impairment.

[Colonoscopy with computed tomography with volume reconstruction. The results and a comparison with endoscopy and surgery]. / Colonscopia con Tomografia Computerizzata con ricostruzioni di volume. Risultati e confronto con endoscopia e chirurgia.

PURPOSE: Virtual CT colonoscopy is a novel technique whose diagnostic accuracy and clinical yield are currently investigated. Several studies have shown its capabilities in detecting colon and rectal cancers. We report the results of a preliminary experience with the volume rendering technique and compare CT colonoscopy with endoscopy and surgery. MATERIAL AND METHODS: Our series consisted of 25 patients with colon cancer confirmed at endoscopy and/or surgery. All examinations were carried out with a spiral CT scanner Philips Tomoscan AVE1. Intestinal preparation was adequate in all patients, consisting in gas insufflated immediately before acquisition, after the injection of 100 mL iodinated contrast agent. All examination were performed in prone position using axial 5 mm slices with 5 mm table feed (pitch 1) and 2 mm reconstruction index; 120 kV and 200-250 mA were used. Images were transferred to a workstation (Easy Vision, Philips, release 4.2.1.1) for processing. We acquired multiplanar (MPR) and virtual endoscopic images with volume rendering; the selected threshold was -250 to -600 Hounsfield Units. Virtual endoscopic images could be obtained in 23 of 25 cases. The results of the radiological study were compared with endoscopic and surgical findings in 25 and 17 cases, respectively. RESULTS: Endoscopy and surgery detected 46 lesions: 29 were malignant and 17 benign. Axial CT and MPR alone detected 35 lesions (76%), 29 of them malignant and 6 benign. The 11 benign lesions missed by axial CT ranged 6-8 mm in diameter. There were no false positives. CT colonoscopy alone detected 66 lesions, but 22 of them were false positive due to residual stool in the colon (21 cases) and to residual barium in the colon (1 case). Combining CT colonoscopy and axial and MPR images enabled to correct the false positive diagnoses made by CT colonoscopy alone and to decrease the false negative ratio of axial and MPR images. Forty-one of 44 lesions (93%) were detected. Thirty-seven lesions were found in the 17 surgical patients; 34 of them were correctly identified combining CT colonoscopy and axial and MPR findings, while endoscopy detected only 31 lesions. Thus, CT had 92% sensitivity, versus 83% of fiberoptic endoscopy. CONCLUSION: In this preliminary experience volume rendering CT colonoscopy exhibited high sensitivity in detecting colon cancers, but their correct evaluation and characterization can be obtained if axial and MPR studies are combined. Further investigation and technological developments are necessary to define the yield of this new technique.