Biomedical subjects

Emanuele Neri

Publications and source records attributed to Emanuele Neri.

12 recordsLinked to original sources

PubMed2006

Time efficiency of CT colonography: 2D vs 3D visualization.

We aimed to compare the time efficiency of three visualization methods in CT colonography and to identify the colonic factors influencing the time for interpretation. Twenty CT colonographic examinations were prospectively analysed. Three reading methods were adopted: method 1, primary 2D analysis with the use of virtual endoscopy as problem solver, method 2, primary standard virtual endoscopy with semiautomatic navigation through the colon and use of 2D images as problem solver; method 3, primary virtual endoscopy with automatic navigation and the use of 2D images as problem solver. In method 1, time for 2D analysis ranged between 6 and 18min (mean 12) for evaluation of both supine and prone decubitus with a synchronization method. In method 2, time for 3D manual navigation in supine plus prone ranged between 9 and 24min (mean 17). In method 3, time for automated navigation ranged between 6 and 20min (mean 12) for evaluation of both supine and prone decubitus. A statistically significant difference was found between time efficiency of methods 1 and 2 (p=0.009, t-test, unequal variances). Methods 2 and 3 showed a tendency to significant differences (p=0.054, t-test, unequal variances). Faecal or fluid residuals were reported as major drawbacks in 3D navigations, requiring constant correlation with 2D images; tortuous folds influenced mostly the 2D analysis; diverticula were reported as influencing factor in all three methods. No differences in sensitivity and specificity were observed between the three viewing methods. The 3D semiautomatic navigation method* tended to increase the time for interpretation in almost all cases. There is, in particular, greatest time efficiency for 2D analysis as compared with 3D manual analysis. Two-dimensional and automated 3D navigation reading have comparable time efficiencies in a routine clinical setting.

Colonography, Computed Tomographic↗

PubMed2005

Immediate structural changes of porcine renal arteries after angioplasty: a histological and morphometric study.

The aim of this research was to characterize the immediate alterations induced by angioplasty and to compare the results of the application of two types of balloons. Ten porcine renal arteries were dilated with a compliant balloon, and ten with a non-compliant balloon. After angioplastic treatment arterial specimens were wax embedded for light microscopy. Sections were stained with the orcein-Van Gieson method, orcein, haematoxylin-eosin, and PAS. Image analysis was performed taking into consideration the following parameters: thickness of the entire wall, of the tunica media and of the inner elastic lamina. The major axes of the smooth muscle cells nuclei were also measured. The effects of the two types of balloon resulted in changes consisting in thinning of the entire arterial wall, reduction of the tunica media, distension of reticular fibers, presence of wide spaces between smooth muscle cells, stretching of smooth muscle cells, inner elastic lamina thickening. Both angioplasty devices used can modify the vascular wall. The identification of the tunica media structural damages might be useful in order to estimate the behavior of the vascular wall in the follow-up after angioplasty, because the entity of modifications could be predictive of restenosis that often takes place weeks or months after angioplasty.

Angioplasty, Balloon↗

PubMed2005

3-D CT and MRI co-registration in the assessment of cochlear implantation.

BACKGROUND: The aim of this study was to evaluate the feasibility of co-registering preoperative MRI and postoperative CT and to assess the position of the electrode within the cochlea. MATERIAL/METHODS: In a series of 14 patients, high-resolution MRI datasets of the cochlea obtained before implantation and multirow CT datasets obtained after implantation were co-registered using a stereoscopic display and volume-rendering platform (Dextroscope, Volume Interactions/Bracco, Singapore). Image co-registration was performed with a semi-automatic method (multipoint plus freehand fusion). RESULTS: In 2 patients the electrode was correctly inserted in the middle turn of the cochlea and the assigned rank was 4 (corresponding to the initial tract of the middle turn). In 8 patients the rank was 3, meaning that the electrode tip reached the upper portion of the basal turn. In 4 patients the rank was 2, meaning that the electrode tip reached the middle portion of the basal turn; in two of these patients, electrode kinking was observed. CONCLUSIONS: Co-registration of preoperative MRI and postoperative CT is feasible and represents a unique method to assess electrode position within the membranous labyrinth.

Adolescent↗

PubMed2004

Abdominal aortic aneurysms: virtual imaging and analysis through a remote web server.

The study describes the application of a web-based software in the planning of the endovascular treatment of abdominal aortic aneurysms (AAA). The software has been developed in the framework of a 2-year research project called Aneurysm QUAntification Through an Internet Collaborative System (AQUATICS); it allows to manage remotely Virtual Reality Modeling Language (VRML) models of the abdominal aorta, derived from multirow computed tomography angiography (CTA) data sets, and to obtain measurements of diameters, angles and centerline lengths. To test the reliability of measurements, two radiologists performed a detailed analysis of multiple 3D models generated from a synthetic phantom, mimicking an AAA. The system was tested on 30 patients with AAA; CTA data sets were mailed and the time required for segmentation and measurement were collected for each case. The Bland-Altman plot analysis showed that the mean intra- and inter-observer differences in measures on phantoms were clinically acceptable. The mean time required for segmentation was 1 h (range 45-120 min). The mean time required for measurements on the web was 7 min (range 4-11 min). The AQUATICS web server may provide a rapid, standardized and accurate tool for the evaluation of AAA prior to the endovascular treatment.

Angiography↗

PubMed2003

Double-contrast MR colonography: in vivo experimental study in an animal model.

BACKGROUND: We evaluated the performance of double-contrast MR colonography in detecting colorectal tumors experimentally induced by chemical substances in the large bowel of the rat. MATERIAL/METHODS: Eight Sprague-Dawley rats developed 67 chemically induced tumors of the large bowel. The animals were imaged with a double-contrast MR technique at 0.5T, using a head coil for both signal transmission and reception. Prior to MR acquisition, room air was insufflated into the rats' large bowel. Unenhanced and contrast-enhanced T1, proton-density and T2 sequences were obtained in the axial and coronal planes. Autopsy was performed immediately after MR examination. MR images were interpreted by consensus of two observers, and the results were compared with post-mortem data. RESULTS: Sensitivity (60% vs. 93%), specificity (63% vs. 81%), positive (85% vs. 93%) and negative (30% vs. 81%) predictability, and global diagnostic accuracy (60% vs. 89%) were obtained for all tumors (n=67) and for the group of tumors larger than 1.5 cm (n=43), respectively. No tumors less than 1.5 cm were detected. CONCLUSIONS: Double-contrast MR colonography is a promising modality in detecting colorectal neoplasms larger than 1.5 cm in an animal tumor model.

Animals↗

PubMed2003

[Pancreas transplantation: multislice computed tomography follow-up].

PURPOSE: Solitary pancreas or combined kidney-pancreas transplantation is currently the only therapeutic procedure for complete resolution of diabetes mellitus type I. The aim of the present study is to investigate the role of multislice computed tomography (MSCT) in the follow-up of patients subjected to solitary pancreas or combined kidney-pancreas transplantation. MATERIALS AND METHODS: Sixteen patients who had undergone solitary pancreas (n=8) or combined kidney-pancreas (n=8) transplantation, with systemic-bladder (n=6) or portal-enteric (n=10) pancreatic drainage were evaluated with MSCT (Light Speed Plus, GE Medical System). In solitary pancreas follow-up the MSCT study included arterial and portal phases; in combined kidney-pancreas transplanted patients the urographic phase was included. The acquisition was performed with 1.25 mm collimation, 0.6 mm reconstruction interval and a pitch of 6. An MSCT scan of the thorax was included in patients suspected of having lung complications. RESULTS: In all cases MSCT allowed identification of the surgical technique performed, evaluation of the transplanted pancreas, and assessment of complications, if present. The following major complications were identified: thrombosis or stenosis of the arterial graft, pancreatic infarction, ectasia of the common iliac artery and arterial graft, dehiscence of the duodenocystostomy, infected abdominal collections, pulmonary infections. CONCLUSIONS: MSCT is able to detect complications arising in the transplanted organs and those related to immunosuppressive therapy, and confirms its usefulness in the follow-up of solitary pancreas or combined kidney-pancreas transplanted patients.

Adult↗

PubMed2002

Correlations between virtual endoscopy and otoendoscopy of the retrotympanum.

The aim of this study was to examine the anatomical landmarks of the retrotympanum using two different techniques, virtual endoscopy (VE) and fiberoptic endoscopy, and to correlate the results furnished by the two methods. Ten otosclerotic patients who were due to undergo stapedectomy were scanned using high-resolution spiral CT. Selected CT datasets were processed with Navigator 2.0 software to obtain virtual endoscopic views of the retrotympanum. Subsequently, during the surgical procedure, fiberoptic endoscopy was performed with 2.7-mm 0 degrees and 30 degrees rigid endoscopes. The ability of the two imaging methods to identify specific anatomical structures was then compared. In all cases the pyramidal eminence, pyramidal crest and sinus tympani were clearly identified in both VE images and otoendoscopy recordings, while fiberoptic endoscopy seemed to be less satisfactory than VE for studying the facial sinus, sinus of Proctor and fossula of Grivot. The two techniques proved to be equally sensitive for visualizing the ponticulus and subiculum, while the stapedius tendon could be visualized only by means of fiberoptic endoscopy. Overall, VE imaging appears promising for rendering important anatomical details of the retrotympanum, allowing identification of osseous landmarks and exploring recesses that are difficult to visualize via otoendoscopy.

Ear, Middle↗

PubMed2002

Single photon emission computed tomography in otosclerosis: diagnostic accuracy and correlation with age, sex, and sensorineural involvement.

OBJECTIVE: To evaluate the accuracy of single photon emission computed tomography (SPECT) in detecting otospongiotic foci of the labyrinthine capsule in otosclerotic patients and to correlate the metabolic patterns detected by SPECT with age, sex, and sensorineural hearing loss. PATIENTS AND METHODS: Thirty-six patients with surgically confirmed otosclerosis and a control group of 12 subjects with normal hearing; each subject underwent SPECT study of the skull with (99m)technetium-diphosphonate ((99m)Tc-medronate). Statistical analysis of the results was performed by use of the Mann-Whitney U test. RESULTS: SPECT seemed to be very sensitive in differentiating otospongiotic bone from normal bone; in the affected group, only 2 of 72 ears yielded false-negative results (sensitivity 97.2%). Moreover, in the otosclerotic patients, the mean petrosa uptake value was higher than in the control group, a difference that was statistically significant (p < 0.0001). MAIN OUTCOME MEASURES: Regarding uptake in relation to patient age, an inverse relationship was observed between increased metabolic activity and age: the mean uptake index in the younger patients was significantly higher than that in the older patients (p < 0.0001). By contrast, no statistically significant differences were found between men and women (p = 0.1519). Comparison of SPECT alterations with bone conduction thresholds revealed a statistically significant correlation (p = 0.0002 and p = 0.0010) between increased metabolic bone activity and sensorineural involvement only in the younger group of otosclerotic patients. CONCLUSIONS: Diphosphonate bone SPECT is the only functional method that allows in vivo evaluation of disease activity, and it was highly sensitive in detecting otosclerosis. SPECT can be considered useful in the diagnosis of otosclerosis that is difficult to recognize, such as cochlear otosclerosis and far-advanced otosclerosis, and it could also find a place in evaluating the efficacy of medical therapy for otosclerosis.

Adult↗

PubMed2002

Colorectal cancer: role of CT colonography in preoperative evaluation after incomplete colonoscopy.

PURPOSE: To evaluate computed tomographic (CT) colonography in patients with clinical suspicion of colorectal cancer and in whom colonoscopy was incomplete. MATERIALS AND METHODS: After incomplete colonoscopy, 34 patients underwent CT colonography before and after intravenous injection of iodinated contrast agent, in supine and prone positions. Twenty patients with no evidence of colon cancer after complete colonoscopy were included as a control group. Sensitivity and specificity of CT colonography were determined for detection of cancers, polyps, and metastases to liver. RESULTS: In 29 patients, surgery revealed 30 colorectal cancers (three synchronous cancers) and two ischemic lesions of the descending colon. Colonoscopy missed 10 colorectal cancers and three synchronous cancers; all were detected with CT colonography. Sensitivity and specificity for detection of colorectal cancer were 56% and 92%, respectively, for incomplete colonoscopy and 100% and 96%, respectively, for CT colonography (P <.01). Sensitivity and specificity of CT colonography in detection of polyps were 86% and 70%, respectively, for diameters of 5 mm or less; 100% and 80%, respectively, for 5-10-mm diameters; and 100% for diameters greater than 10 mm. Spiral CT of the liver revealed four metastases (2-5 cm); sensitivity and specificity were 100% and 43% for nonenhanced scans and 100% for contrast-enhanced scans (P <.01). CONCLUSION: In this selected group of patients, CT colonography provided complete information to properly address surgery of colorectal cancer and treatment of liver metastases.

Adult↗

PubMed2002

Distal renal tubular acidosis associated with isolated large vestibular aqueduct and sensorineural hearing loss.

Distal renal tubular acidosis (dRTA) is characterized by a defect in urinary acidification with various degrees of metabolic acidosis; it can be inherited either as an autosomal dominant trait or as a recessive trait. The recessive form is associated in about one third of cases with progressive sensorineural hearing loss (SNHL). We performed a neuroradiological study in 3 consecutive unrelated pediatric patients affected with sporadic dRTA and progressive SNHL that disclosed an enlarged vestibular aqueduct (VA) and endolymphatic sac (ES) in each. The presence of an enlarged VA in our patients with dRTA and SNHL could contribute to the development, or at least the progression, of the hearing impairment. We suppose that the same molecular defect present in both the kidney and the inner ear could be the cause of dRTA and of the development of the enlarged VA and ES.

Acidosis, Renal Tubular↗

PubMed2002

Scala vestibuli cochlear implantation in patients with partially ossified cochleas.

Partial cochlear obstruction is a relatively common finding in candidates for cochlear implants and frequently involves the inferior segment of the scala tympani in the basal turn of the cochlea. In such patients, the scala vestibuli is often patent and offers an alternative site for implantation. The current report describes two patients with such partial obstruction of the inferior segment of the basal cochlear turn, caused in one case by systemic vasculitis (Takayasu's disease) and in the other by obliterative otosclerosis. A scala vestibuli implantation allowed for complete insertion of the electrode array. No problems were encountered during the surgical procedures and the good post-operative hearing and communicative outcomes achieved were similar to those reported in patients without cochlear ossification. The importance of accurate pre-operative radiological study of the inner ear is underscored, to disclose the presence and define the features of the cochlear ossification and ultimately to properly plan the surgical approach.

Adult↗

PubMedDate not supplied

Large vestibular aqueduct syndrome: audiological, radiological, clinical, and genetic features.

PURPOSE: The aim of this study was to analyze the clinical, audiological, radiological, and genetic features of a group of patients affected with large vestibular aqueduct syndrome. MATERIALS AND METHODS: Seventeen patients affected with large vestibular aqueduct syndrome (LVAS), diagnosed by means of high-resolution magnetic resonance imaging of the inner ear, with 3-dimensional reconstructions of the labyrinth and by high-resolution spiral computed tomography of the temporal bone, performed only on the oldest patients, have been submitted to a complete audiological evaluation, a thyroid functional and ultrasonographic study, and a molecular study of the PDS gene. RESULTS: The clinical presentation of LVAS was very variable in our group of patients. The enlarged vestibular aqueduct was bilateral in 15 cases and unilateral in 2; it was the only malformation of the labyrinth in 12 patients, whereas it was associated with other inner ear anomalies in the other 5. The hearing loss was very variable in degree (from mild to profound), age at onset, and progression. Moreover, among the 17 patients, 10 were clinically affected by Pendred's syndrome (PS), 3 by distal renal tubular acidosis associated with large vestibular aqueduct, whereas in 3 patients the large vestibular aqueduct was not syndromal. Finally, we identified mutations in the PDS gene in 5 of 10 patients with PS. CONCLUSIONS: Our data underscore the frequent role of the large vestibular aqueduct syndrome in the pathogenesis of sensorineural hearing loss and the overall wide variability in its audiological features. It is also highlighted that LVAS is often part of some syndromal diseases, most of which are PS, which is often misdiagnosed because of the varying degree of thyroid symptoms. This study also underscores the possible role of hydro-electrolyte and acid-base endolymphatic fluid disorders in the pathogenesis of enlarged vestibular aqueduct syndrome.

Acoustic Impedance Tests↗