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Biomedical subjects

Carlo Bartolozzi

Publications and source records attributed to Carlo Bartolozzi.

At least 19 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↗
PubMed2006

Mangafodipir trisodium-enhanced MR imaging of pancreatic disease.

Our study aimed to assess the diagnostic capabilities of mangafodipir trisodium-enhanced MRI for the evaluation of pancreatic disease. Sixty-three patients suspected of having pancreatic disease underwent MRI with a 1.5-T device. After the acquisition of axial and coronal T2-weighted sequences, the MR protocol included T1-weighted fat-suppressed breath-hold SPGR images obtained before and 30 min after the infusion of Mn-DPDP (Teslascan). The detection of a focal pancreatic lesion and its intensity were evaluated in consensus by two observers, who also attempted to characterize each lesion as benign or malignant. The reviewers were blinded to patient identification and all clinical, laboratory and previous imaging findings. MR imaging results were correlated with surgery (n=37), laparoscopy (n=1), biopsy (n=2) and imaging follow-up (n=22). Sixty-two subjects were effectively included in our analysis because one patient was lost to follow-up; final malignant and benign diagnoses were determined in 22 (35%) and 29 (47%) of the patients, respectively. The level of confidence in the diagnosis of the pancreatic lesion was significantly increased by the administration of Mn-DPDP as demonstrated by ROC analysis of unenhanced and post-contrast image sets (P=0.009). Overall, on the basis of observers' readings, MR assessment of pancreatic disease resulted in 57 correct diagnoses (accuracy, 92%) and five (8%) incorrect diagnoses. The sensitivity, specificity, positive predictive value and negative predictive value of the reviewers for the detection of pancreatic lesions and for the differentiation between benign and malignant masses were 91% (95% CI: 84 and 98%), 93% (95% CI: 86 and 99%), 87% (95% CI: 79 and 95%) and 95% (95% CI: 89 and 100%), respectively. Mn-DPDP-enhanced MRI is an effective diagnostic tool for evaluating pancreatic disease.

Adult↗
PubMed2006

Imaging and invasive techniques for diagnosis and treatment of surgical infections.

BACKGROUND: Advances in imaging techniques have caused a radical change in the radiologic approach to the diagnosis and treatment of surgical infections. METHOD: Review of the pertinent English-language literature. RESULTS: Ultrasonography (US) is a useful modality for the initial evaluation of intra-abdominal infection, whereas computed tomography (CT) often represents the modality of choice for definitive identification of the cause and extent of the infection. Both US and CT can be used to guide diagnostic fluid aspiration or drainage catheter placement. Fluoroscopy may be useful for diagnostic and interventional procedures in the biliary and urinary tracts, whereas magnetic resonance imaging plays a leading role in evaluating bone and soft tissue structures and the pancreatobiliary tree. CONCLUSION: The choice of imaging study must be individualized to the particular circumstances of the clinical situation, particularly whether image-guided therapy may be required in addition to diagnosis. Computed tomography is the most versatile for most clinical circumstances.

Diagnostic Imaging↗
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

Silent cerebral ischemia detected with diffusion-weighted imaging in patients treated with protected and unprotected carotid artery stenting.

BACKGROUND AND PURPOSE: Percutaneous transluminal angioplasty with stent (CAS) is an alternative method to endarterectomy in the revascularization of carotid artery stenosis. Protected CAS is currently used to prevent distal embolization. Diffusion-weighted MRI (DWI) is the most sensitive tool to evaluate silent cerebral ischemia. The purpose of this research was to assess the incidence of cerebral embolic lesions during CAS and to evaluate whether cerebral protection devices can reduce the number of silent cerebral ischemia with respect to unprotected CAS. METHODS: Fifty-two patients with high-grade internal stenosis underwent CAS; 30 patients (group a) were treated with a cerebral protection device, and 22 (group b) were treated without it. All of the patients were evaluated preoperatively and postoperatively with fluid-attenuated inversion recovery and DWI sequences to depict the number of new embolic silent cerebral lesions. RESULTS: Embolic silent cerebral lesions occurred in 30% of CAS. Cerebral protection devices reduce the number of new lesions significantly reducing the consistent lesions ipsilateral to the treated vessel. Inconsistent lesions do not differ in both groups of patients. Clinical, radiological, and procedural variables do not correlate with the appearance of new cerebral lesions. CONCLUSIONS: Embolic cerebral lesions detected with DWI are more frequent with unprotected CAS, although they are present also with the use of cerebral protection devices. Probably a part of silent cerebral lesions arise from the procedural maneuver in the aortic arch.

Aged↗
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↗
PubMed2005

Early-stage hepatocellular carcinoma in patients with cirrhosis: long-term results of percutaneous image-guided radiofrequency ablation.

PURPOSE: To perform a prospective, intention-to-treat clinical trial to determine the long-term survival rates of patients with hepatic cirrhosis and early-stage hepatocellular carcinoma (HCC) in whom percutaneous image-guided radiofrequency (RF) ablation was used as the sole first-line anticancer treatment. MATERIALS AND METHODS: The study was performed with approval of the ethics committee, and written informed consent was obtained for all patients. From June 1, 1996, to January 1, 2003, 206 patients (143 men, 63 women; age range, 51-81 years; mean age, 67 years +/- 7) who were excluded from surgery and who had Child class A or B cirrhosis with either a single HCC less than or equal to 5 cm in diameter or multiple (as many as three) HCCs less than or equal to 3 cm in diameter each were enrolled. RF ablation was performed in 187 (91%) of 206 patients; 19 (9%) were excluded from RF treatment because of unfavorable tumor location. Follow-up ranged from 3 to 78 months (mean, 24 months +/- 21) and included measurement of alpha-fetoprotein level, ultrasonography at 3-month intervals, and spiral computed tomography at 6-month intervals. Patients were observed for recurrence of the treated tumor and for the emergence of new HCC tumors. Survival probabilities were estimated with the Kaplan-Meier method, and differences between survival curves were evaluated with the log-rank test. RESULTS: At the end of the study, 145 patients were alive, and 61 were dead. In the intention-to-treat analysis, overall survival rates were 97% at 1 year, 67% at 3 years, and 41% at 5 years. Median survival was 49 months. In the 187 patients treated with RF ablation, overall survival rates were 97% at 1 year, 71% at 3 years, and 48% at 5 years. Median survival was 57 months. The difference between the two survival curves was not statistically significant (P=.5094). Survival of patients treated with RF ablation was dependent on Child class (P=.0006) and tumor multiplicity (P=.0133). Patients who had Child class A cirrhosis with solitary HCC (n=116) had 1-, 3-, and 5-year survival rates of 100%, 89% and 61%; median survival was 65 months. The 1-, 3-, and 5-year recurrence rates were 14%, 49%, and 81% for the emergence of new tumors and 4%, 10%, and 10% for local tumor progression. CONCLUSION: RF ablation is an effective first-line treatment for cirrhotic patients with early-stage HCC who were excluded from surgery.

Aged↗
PubMed2005

Clinical management of hepatic malignancies: ferucarbotran-enhanced magnetic resonance imaging versus contrast-enhanced spiral computed tomography.

This study compares ferucarbotran-enhanced magnetic resonance (MR) imaging with spiral computed tomography (CT) in the clinical management of patients with suspected hepatic malignancy. One hundred fifty-nine patients with suspected liver malignancy were included in a prospective, multicenter, phase IIIB clinical trial. Patients were examined with baseline plus contrast-enhanced spiral CT and with baseline plus ferucarbotran-enhanced MR imaging. For each patient, four maps of liver lesions were constructed by a trusted blind party on the basis of (a) baseline plus contrast-enhanced spiral CT, (b) baseline MR imaging, (c) baseline plus ferucarbotran-enhanced MR imaging, and (d) final diagnosis. Three blinded experts evaluated the treatment options for each map. The concordance of the treatment choice based on imaging with the treatment choice based on final diagnosis was verified. The final therapeutic decision was radical therapy for 85 patients, palliative therapy for 49 patients, and no treatment for 25 patients who had a final diagnosis of benign lesion. Proper treatment allocation was achieved in 121 (76%) of 159 patients when the evaluation was based on liver maps obtained from spiral CT, in 97 (61%) of 159 patients when the evaluation was based on liver maps obtained from baseline MR imaging, and in 136 (85%) of 159 patients when the evaluation was based on liver maps obtained from baseline plus ferucarbotran-enhanced MR imaging. MR imaging with ferucabotran was significantly superior to spiral CT for correct treatment allocation (P = 0.0167). Ferucarbotran-enhanced MR imaging is superior to spiral CT in clinical management of patients with suspected hepatic malignancy.

Adult↗
PubMed2005

Type II lumbar endoleaks: hemodynamic differentiation by contrast-enhanced ultrasound scanning and influence on aneurysm enlargement after endovascular aneurysm repair.

OBJECTIVE: The objective of this study was to differentiate type II lumbar endoleaks on the basis of dynamic features identified by contrast-enhanced ultrasound scanning (CUS) and to evaluate the role of this differentiation in detecting abdominal aortic aneurysm (AAA) enlargement > or =1 mL/mo. METHODS: Eighteen male patients (mean age, 71.8 years) with type II lumbar endoleak suspected at CUS underwent computed tomography angiography (CTA) and digital subtraction angiography (DSA). On CTA, AAA volumes and endoleak visualization and volume were assessed. At CUS, performed after a bolus of 1.5 to 2.4 mL of a second generation blood pool contrast agent, the following parameters were evaluated: presence of contrast material within the aneurysmal sac (endoleak), delay of endoleak detection (wash-in) and disappearance (washout) from the beginning of contrast injection, visualization of inflow and outflow vessels, and presence of cavity filling. Statistical analysis was performed regarding endoleak features at CUS, endoleak detection at CTA, and rate of AAA enlargement. RESULTS: DSA confirmed all the endoleaks. Mean +/- standard deviation wash-in and washout times were 121.9 +/- 132.6 and 337.2 +/- 193.7 seconds, respectively; a significant relation was observed between these two parameters (P < .01, analysis of variance). By Youden plots, endoleaks were classified as hyperdynamic when wash-in was <100 seconds (n = 10, 55.5%) and/or washout was <520 seconds (n = 13, 72.2%). A slower washout was associated with nonvisualized outflow (66.7%) and/or inflow arteries (66.7%) ( P < .05). Eight endoleaks (44.4%) were missed at CTA; it occurred in hypodynamic endoleaks, absence of detectable inflow or outflow vessels, and absence of cavity filling at CUS (P < .05). Overall mean AAA volume increase rate was 1.1 +/- 1.7 mL/mo. By multiple logistic regression model, the washout time > or = 520 seconds was the only independent predictor of AAA volume increase > or = 1 mL/mo (8 patients, 44.4%). CONCLUSION: Type II lumbar endoleaks show different hemodynamic features at CUS, which might influence the rate of aneurysm enlargement, addressing the need for treatment.

Aged↗
PubMed2005

Imaging diagnosis.

The diagnosis of hepatocellular carcinoma (HCC) is based on imaging examinations in combination with clinical and laboratory findings. Despite technological advances, imaging cirrhotic patients remains a challenging issue because nonmalignant hepatocellular lesions, such as dysplastic nodules, mimic a small HCC. One of the key pathologic factors for differential diagnosis that is reflected in imaging appearances is the vascular supply to the lesion. It is accepted that imaging techniques may establish the diagnosis of HCC in nodules larger than 2 cm showing characteristic arterial hypervascularization. In lesions ranging from 1 to 2 cm, biopsy is still recommended, although a negative response can never be used to rule out malignancy completely. Although ultrasonography is widely accepted for HCC surveillance, spiral computed tomography (CT) or dynamic magnetic resonance imaging is required for diagnostic confirmation and intrahepatic tumor staging. These examinations have replaced invasive procedures, such as lipiodol CT, but remain relatively insensitive for the detection of tiny HCC lesions and tumor vascular invasion into peripheral portal vein branches.

Carcinoma, Hepatocellular↗
PubMed2005

Diffusion-tensor MR imaging of corticospinal tract in amyotrophic lateral sclerosis and progressive muscular atrophy.

PURPOSE: To prospectively evaluate several diffusion-tensor magnetic resonance (MR) imaging indexes (mean diffusivity [MD], fractional anisotropy [FA], and eigenvalues) of corticospinal tract impairment in patients with progressive muscular atrophy (PMA) and patients with amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS: This study had institutional review board approval, and written informed consent was obtained from all subjects. Eight male patients with PMA (mean age, 63 years +/- 13 [standard deviation]), eighteen patients with ALS (14 men and four women; mean age, 64 years +/- 7), and twelve control subjects (four men and eight women; mean age, 65 years +/- 6) underwent diffusion-tensor MR imaging at which 25 spin-echo echo-planar imaging diffusion-weighted images (b = 1000 sec/mm2) were acquired along noncollinear directions. MD and FA were measured along the corticospinal tracts in each patient and subject. Changes in diffusion along and orthogonal to fiber bundles in patients were evaluated by using diffusion-tensor eigenvalues. Differences in diffusion-tensor imaging indexes between patients with PMA and those with ALS, as compared with these indexes in control subjects, were evaluated with Mann-Whitney testing. Correlations between diffusion-tensor imaging indexes and clinical variables were estimated with Pearson and Spearman rank correlation testing. RESULTS: As compared with MD (697.1 x 10(-6) mm2/sec +/- 28.1) and FA (0.585 +/- 0.032) in control subjects, MD was typically significantly increased (734.7 x 10(-6) mm2/sec +/- 41.2, P = .035) and FA significantly decreased (0.534 +/- 0.053, P = .037) along the corticospinal tracts in patients with ALS, while these parameters showed no significant change in patients with PMA (MD, 707.0 x 10(-6) mm2/sec +/- 44.2; FA, 0.559 +/- 0.028). Estimation of diffusion-tensor eigenvalues revealed normal diffusion along fiber tracts in all patients, while diffusion was increased orthogonal to fiber tracts only in patients with typical ALS. In patients with ALS, MD correlated with disease duration while FA correlated with disease severity. CONCLUSION: Diffusion-tensor MR imaging reveals corticospinal tract impairment in ALS but not in PMA.

Aged↗
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↗
PubMed2004

Redistribution of cerebropetal blood flow in patients with carotid artery stenosis measured non-invasively with fast cine phase contrast MR angiography.

The purpose was to evaluate the blood flow redistribution in the neck vessels of patients with internal carotid artery (ICA) stenosis. Eighty-six patients with ICA stenosis underwent contrast-enhanced magnetic resonance angiography (CEMRA) and fast 2D phase contrast (2D-PC) sequence to measure the mean blood flow (MBF) of ICA, basilar artery (BA) and middle cerebral artery (MCA). CEMRA revealed 53 severe stenoses, 45 moderate stenoses and 3 occluded vessels. Patients with a unilateral severe ICA stenosis had a significantly reduced MBF of the ICA compared to the control group; the MBF reduction of the severely stenosed ICA was less conspicuous if associated with a controlateral severe stenosis. The MBF of the BA increased significantly in the presence of the bilateral severe ICA stenosis and in the ICA occlusion. The MBF of the MCA was unchanged in the presence of various degrees of ICA stenosis. Measurement of MBF with fast PC MRA permits cerebropethal blood flow assessment and gives additional information in grading ICA stenosis. The reduced MBF of a severe ICA stenosis has to be considered with caution since it depends also on the status of the controlateral ICA and may be considered a confident parameter only in case of unilateral carotid stenosis.

Aged↗
PubMed2004

Radiofrequency ablation of lung malignancies: where do we stand?

Percutaneous radiofrequency (RF) ablation is a minimally invasive technique used to treat solid tumors. Because of its ability to produce large volumes of coagulation necrosis in a controlled fashion, this technique has gained acceptance as a viable therapeutic option for unresectable liver malignancies. Recently, investigation has been focused on the clinical application of RF ablation in the treatment of lung malignancies. In theory, lung tumors are well suited to RF ablation because the surrounding air in adjacent normal parenchyma provides an insulating effect, thus facilitating energy concentration within the tumor tissue. Experimental studies in rabbits have confirmed that lung RF ablation can be safely and effectively performed via a percutaneous, transthoracic approach, and have prompted the start of clinical investigation. Pilot clinical studies have shown that RF ablation enables successful treatment of relatively small lung malignancies with a high rate of complete response and acceptable morbidity, and have suggested that the technique could represent a viable alternate or complementary treatment method for patients with non-small cell lung cancer or lung metastases of favorable histotypes who are not candidates for surgical resection. This article gives an overview of lung RF ablation, discussing experimental animal findings, rationale for clinical application, technique and methodology, clinical results, and complications.

Animals↗
PubMed2004

CT-guided radiofrequency ablation of osteoid osteoma: long-term results.

The aim of the study was to assess the safety and efficacy of CT-guided percutaneous radiofrequency (RF) ablation of osteoid osteoma (OO). From 1997 to 2001, RF ablation was performed on 38 patients with OO, diagnosed clinically and by radiography, scintigraphy, contrast-enhanced MRI, and CT. Treatment was performed via percutaneous (n=29) or surgical (n=9) access, under CT guidance in all cases, with an 18-gauge straight electrode. Patients were discharged within 24 h and followed up clinically (at 1 week and every 6-12 months) and with MRI (at 6 months) and scintigraphy (after 1 year). The technical success rate was 100%. Complications occurred in two patients, consisting in local skin burns. The follow-up range was 12-66 months (mean +/- SD, 35.5+/-7.5 months). Prompt pain relief and return to normal activities were observed in 30 of 38 patients. Persistent pain occurred in eight patients; two patients refused further RF ablation and were treated surgically; RF ablation was repeated in six cases achieving successful results in five. One patient reported residual pain and is being evaluated for surgical excision. Primary and secondary clinical success rates were 78.9 (30/38 patients) and 97% (35/36 patients), respectively. CT-guided RF ablation of OO is safe and effective. Persistent lesions can be effectively re-treated. Several imaging modalities are needed for the diagnosis of OO and for the follow-up after treatment, particularly in patients with persistent symptoms.

Adolescent↗
PubMed2004

Percutaneous ablation of hepatocellular carcinoma: state-of-the-art.

Percutaneous ablation is considered the best treatment option for patients with early-stage hepatocellular carcinoma (HCC) who are not candidates for surgical resection or liver transplantation. Several methods have been developed, including intratumoral injection of ethanol or acetic acid, and thermal ablation with radiofrequency, laser, microwaves, or cryosurgery. Percutaneous ethanol injection (PEI) has been the most widely used technique. Several series have provided indirect evidence that PEI improves the natural history of HCC. Patients with Child-Pugh class A cirrhosis and either a single tumor smaller than 5 cm or as many as three lesions each smaller than 3 cm may achieve a 5-year survival of 50%. The major limitation of PEI is the high local recurrence rate, which may reach 33-43%. Radiofrequency (RF) ablation has emerged as the most powerful alternate method for percutaneous ablation. Recent studies have shown that RF ablation can achieve more effective local tumor control than PEI with fewer treatment sessions. In a randomized trial, local recurrence-free survival rates were significantly higher in patients who received RF ablation than in those treated by PEI, and treatment allocation was confirmed as an independent prognostic factor by multivariate analysis. RF ablation could therefore be considered as the percutaneous treatment of choice for patients with early-stage tumors. Further investigation is warranted to clarify whether current RF technology could offer improved results in patients with intermediate-stage HCC.

Administration, Cutaneous↗