Magnetic resonance imaging of liver tumors.
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Contrast Media↗
Biomedical subjects
Carlo Bartolozzi
Publications and source records attributed to Carlo Bartolozzi.
Percutaneous radiofrequency ablation of hepatic colorectal metastases: technique, indications, results, and new promises.
Surgical resection is the standard of care for colorectal metastases isolated to the liver. However, only 10-25% of the patients are eligible for resection because of extent and location of the disease in the liver or concurrent medical conditions. Image-guided radiofrequency (RF) ablation is a minimally invasive technique that is emerging as a viable alternate treatment of nonsurgical patients with limited hepatic metastatic disease. Several series have shown that RF ablation can result in complete tumor eradication in properly selected candidates and have provided indirect evidence that the treatment improves survival. In a recent multicenter trial including 423 patients, overall survival of RF-ablation treated patients reached 47% at 3 years and 24% at 5 years. RF ablation technology is undergoing continuous improvement, and its clinical application has been successfully expanded to the treatment of colorectal metastases to the lung. Randomized trials comparing RF ablation with either surgical resection or chemotherapy protocols, however, are still missing. In this article, we review technique, indications, clinical results, and future prospects of RF ablation in the therapeutic management of metastatic colorectal cancer patients.
Catheter Ablation↗
Abdominal aortic aneurysm: contrast-enhanced US for missed endoleaks after endoluminal repair.
PURPOSE: To evaluate contrast material-enhanced ultrasonography (US) for depiction of endoleaks after endovascular abdominal aortic aneurysm repair (or endovascular aneurysm repair [EVAR]) in patients with aneurysm enlargement and no evidence of endoleak. MATERIALS AND METHODS: From November 1998 to February 2003, 112 patients underwent EVAR. At follow-up, duplex US and biphasic multi-detector row computed tomographic (CT) angiography were performed. In 10 patients (group A), evident aneurysm enlargement was observed, with no evidence of complications, at both CT angiography and duplex US. Group A patients, 10 men (mean age, 69.6 years +/- 10 [standard deviation]), underwent US after intravenous bolus injection of a second-generation contrast agent, with continuous low-mechanical index (0.01-0.04) real-time tissue harmonic imaging. Group B patients, 10 men (mean age, 71.3 years +/- 8.2) with aneurysm shrinkage and no evidence of complications, and group C patients, 10 men (mean age, 73.2 years +/- 6) with CT angiographic evidence of endoleak, underwent contrast-enhanced US. Digital subtraction angiography (DSA) was performed in groups A and C. Endoleak detection and characterization were assessed with imaging modalities used in groups A-C; at contrast-enhanced US, time of detection of endoleak, persistence of sac enhancement, and morphology of enhancement were evaluated. RESULTS: In group A, contrast-enhanced US depicted one type I, six type II, one type III, and two undefined endoleaks that were not detected at CT angiography. All leakages were characterized by slow and delayed echo enhancement detected at longer than 150 seconds after contrast agent administration. DSA results confirmed findings in all patients; percutaneous treatment was performed. In group B, contrast-enhanced US did not show echo enhancement; in group C, results with this modality confirmed findings at CT angiography and DSA. CONCLUSION: Contrast-enhanced US depicts endoleaks after EVAR, particularly when depiction fails with other imaging modalities.
Aged↗
Clinical impact of Resovist-enhanced MRI: results of an Italian multicenter trial.
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Contrast Media↗
Role of the chest radiograph in the preoperative assessment of the pulmonary function in patients with cirrhosis candidates to liver transplant.
PURPOSE: To appraise the role of chest radiography (CXR) in the clinical assessment of pulmonary complications occurring as a result of liver disease of any cause, a standardised reading of CXR was compared both with the results of lung function studies and with the severity of liver disease in 60 consecutive patients with cirrhosis candidates to liver transplant. MATERIALS AND METHODS: CXR were scored for signs of cardiomegaly, enlargement of central and or peripheral vessels, hyperkinetic circulatory and/or intravascular volume states, abnormally increased interstitial lung markings, and pleural effusion by three independent observers. RESULTS: The CXR score of this complete vascular-interstitial deficiency showed a high interobserver reproducibility and was significantly increased in those patients with a more decompensated liver cirrhosis. Moreover, a larger number of CXR signs of vascular and interstitial deficiency was present in those patients who had a more severe cirrhosis (Child-Pugh class 3). Functional indices of pulmonary gas exchange and diffusing capacity were worse in patients with end-stage liver cirrhosis, and for some indices the correlation was statistically significant. The comparison between lung function and CXR score showed that on average lung function impairment was significantly less severe in patients with lower CXR scores. CONCLUSIONS: In conclusion, the information derived from a standardised reading of CXR is valuable in the clinical assessment of the pulmonary damage induced by liver cirrhosis as it allows discrimination of classes of severity of liver disease and of lung function impairment. When integrated with physiologic measurements and, if necessary, with high resolution tomographic studies, chest radiography helps to discriminate patients with advanced liver cirrhosis and progressing towards a hepatopulmonary syndrome, who need a proper therapeutic management.
Adult↗
Vascular injuries after percutaneous renal procedures: treatment by transcatheter embolization.
Percutaneous renal procedures have become the standard technique for diagnosis and treatment of a number of renal pathologies. Hemorrhage and vascular lesions are the most serious complications. We report our experience with 15 patients treated by hyperselective vascular embolization. Fifteen patients (10 men and 5 women; mean age 55 years) had severe perioperative hemorrhage after percutaneous renal procedures, due to arterial renal major injury. All patients underwent duplex US, CT, and renal arteriography demonstrating the presence of arteriovenous fistulas (n=2), renal hematoma (n=3), pseudoaneurysms (n=3), and hematoma with pseudoaneurysm (n=7). Four patients showed transient renal dysfunction, with an increase in serum creatinine levels. One patient had a solitary transplanted kidney. Hyperselective arterial embolization was performed successfully by means of coils (n=14), associated with gelfoam in 4 cases; homologous blood clot was used in 1 patient. No major complications occurred, and renal function rapidly normalized in the 4 patients with transient renal failure. Imaging follow-up confirmed the successful devascularization of the lesion. Renal arterial hemorrhage following percutaneous procedures is a rare but severe complication. Hyperselective renal artery embolization, with particles and/or coils, represents the first-choice treatment option, being safe and effective in stopping the bleeding.
Angiography, Digital Subtraction↗
Detection of colorectal liver metastases: a prospective multicenter trial comparing unenhanced MRI, MnDPDP-enhanced MRI, and spiral CT.
The aim of this study was to compare unenhanced MRI, MnDPDP-enhanced MRI, and spiral CT in the detection of hepatic colorectal metastases. Forty-four patients with hepatic colorectal metastases were examined with unenhanced and MnDPDP-enhanced MRI and with unenhanced and contrast-enhanced spiral CT. The MR examination protocol included baseline T1-weighted spin-echo (SE), T1-weighted gradient-recalled-echo (GRE), and T2-weighted fast-SE sequences; and T1-weighted SE and T1-weighted GRE sequences obtained 30-60 min after administration of 0.5 micromol/kg (0.5 ml/kg) mangafodipir trisodium (MnDPDP). Images were interpreted by three blinded readers. Findings at CT and MRI were compared with those at intraoperative US, which were used as term of reference. Intraoperative US detected 128 metastases. In a lesion-by-lesion analysis, the overall detection rate was 71% (91 of 128) for spiral CT, 72% (92 of 128) for unenhanced MRI, and 90% (115 of 128) for MnDPDP-enhanced MRI. MnDPDP-enhanced MRI was more sensitive than either unenhanced MRI ( p<0.0001) or spiral CT ( p=0.0007). In a patient-by-patient analysis, agreement with gold standard was higher for MnDPDP-enhanced MRI (33 of 44 cases) than for spiral CT (22 of 44 cases, p=0.0023) and unenhanced MRI (21 of 44 cases, p=0.0013). MnDPDP-enhanced MRI is superior to unenhanced MRI and spiral CT in the detection of hepatic colorectal metastases.
Adult↗
Small hepatocellular carcinoma in cirrhosis: randomized comparison of radio-frequency thermal ablation versus percutaneous ethanol injection.
PURPOSE: To compare the effectiveness of radio-frequency (RF) thermal ablation with that of percutaneous ethanol injection (PEI) for the treatment of small hepatocellular carcinoma (HCC) in patients with cirrhosis. MATERIALS AND METHODS: A series of 102 patients with hepatic cirrhosis and either single HCC 5 cm in diameter or smaller or as many as three HCCs each 3 cm or smaller (overall number of lesions, 142) randomly received either RF ablation (n = 52) or PEI (n = 50) as the sole first-line anticancer treatment. Mean follow-up was 22.9 months +/- 9.4 (SD) in the RF group and 22.4 months +/- 8.6 in the PEI group. Prognostic value of treatment techniques was assessed with univariate and multivariate Cox proportional hazards regression models. RESULTS: One- and 2-year survival rates were 100% and 98% in the RF group and 96% and 88% in the PEI group, respectively (univariate relative risk [RR] = 0.20; 95% CI: 0.02, 1.69; P =.138). One- and 2-year local recurrence-free survival rates were 98% and 96% in the RF group and 83% and 62% in the PEI group, respectively (univariate RR = 0.17; 95% CI: 0.06, 0.51; P =.002). One- and 2-year event-free survival rates were 86% and 64% for the RF group and 77% and 43% for the PEI group, respectively (univariate RR = 0.48; 95% CI: 0.27, 0.85; P =.012). RF treatment was confirmed as an independent prognostic factor for local recurrence-free survival rates with multivariate analysis (adjusted RR = 0.20; 95% CI: 0.05, 0.73; P =.015). CONCLUSION: RF ablation is superior to PEI with respect to local recurrence-free survival rates.
Adult↗
Evaluation of the proximal aortic neck enlargement following endovascular repair of abdominal aortic aneurysm: 3-years experience.
The aim of this study was to evaluate incidence, potential risk factors and effects on stent-graft migration of proximal neck dilatation after endoluminal repair of abdominal aortic aneurysm (EVAR), and the role of ultrasound (US) in detecting neck enlargement. From November 1998 to October 2001, 90 patients underwent EVAR. On follow-up, US and CT angiography (CTA) were performed, and diameters of the suprarenal and infrarenal aortic necks were monitored. Incidence of significant neck enlargement (> or =2.5 mm) and distal stent-graft migration (>10 mm) was calculated. Several factors were evaluated as predictive of neck enlargement. Ultrasound and CTA measurements were compared. The US and CTA examinations were available in 68, 39, and 11 patients at 1, 2, and 3 years follow-up (mean follow-up 15 months). Incidence of significant neck dilatation was 21.8% at the infrarenal level (13, 33, and 36% at 1, 2, and 3 years follow-up) and 13.8% at the suprarenal level (9, 18, and 27% at 1, 2, and 3 years follow-up). Significant stent-graft migration occurred in 14 of 87 patients (16%) and was associated with neck dilatation in 8 (2 suprarenal and 6 infrarenal). No risk factors were identified. Ultrasound was less accurate than CT in measuring neck diameter, in particular at the suprarenal level. Proximal aortic neck enlargement occurs in up to 30% of patients after EVAR and represents the main risk factor for stent-graft migration. The risk of infrarenal neck dilatation is higher at 2 years follow-up, whereas the suprarenal neck enlarges later. Ultrasound is not useful in monitoring neck diameter.
Aged↗
Contrast-enhanced three-dimensional magnetic resonance angiography of atherosclerotic internal carotid stenosis as the noninvasive imaging modality in revascularization decision making.
BACKGROUND AND PURPOSE: In patients with severe internal carotid artery stenoses, thromboendarterectomy significantly reduces both ischemic stroke and the risk of more ischemic attacks. Digital subtraction angiography (DSA) is the accepted preoperative test to determine whether a high-grade stenosis is present and requires surgical therapy. However, DSA has a procedural risk of stroke between 0.7% and 1%. An accurate, noninvasive imaging protocol with no risk of severe complications would significantly increase the benefit of surgical treatment. The aims of the study were (1) to evaluate the diagnostic accuracy of contrast-enhanced magnetic resonance angiography (CEMRA) in detecting and grading internal carotid artery stenoses and (2) to assess the misclassification rate of vessels suitable for revascularization by CEMRA. METHODS: Ninety-two patients with sonographic evidence of neck vessel stenosis were enrolled in the study. All patients were submitted to CEMRA and DSA. CEMRA images were evaluated for the presence of mild, moderate, or severe stenosis and occlusion. RESULTS: Sensitivity, specificity, and diagnostic accuracy were 97%, 82%, and 92.5%, respectively. Agreement with DSA was optimal at kappa=0.87. The misclassification rate of CEMRA was 3.1% because of its tendency to overestimate the stenosis. CONCLUSIONS: The high diagnostic accuracy and limited misclassification rate suggest that CEMRA can be considered a powerful tool for the preoperative, noninvasive evaluation of atherosclerotic pathology of carotid arteries.
Aged↗
Gadobenate dimeglumine-enhanced MRI of the breast: analysis of dose response and comparison with gadopentetate dimeglumine.
OBJECTIVE: The purpose of this study was to evaluate the clinical efficacy and dose response relationship of three doses of gadobenate dimeglumine for MRI of the breast and to compare the results with those obtained after a dose of 0.1 mmol/kg of body weight of gadopentetate dimeglumine. SUBJECTS AND METHODS. Gadobenate dimeglumine at 0.05, 0.1, or 0.2 mmol/kg of body weight or gadopentetate dimeglumine at 0.1 mmol/kg of body weight was administered by IV bolus injection to 189 patients with known or suspected breast cancer. Coronal three-dimensional T1-weighted gradient-echo images were acquired before and at 0, 2, 4, 6, and 8 min after the administration of the dose. Images were evaluated for lesion presence, location, size, morphology, enhancement pattern, conspicuity, and type. Lesion signal intensity-time curves were acquired, and lesion matching with on-site final diagnosis was performed. A determination of global lesion detection from unenhanced to contrast-enhanced and combined images was performed, and evaluations were made of the diagnostic accuracy for lesion detection and characterization. A full safety evaluation was conducted. RESULTS: Significant dose-related increases in global lesion detection were noted for patients who received gadobenate dimeglumine (p < 0.04, all evaluations). The sensitivity for detection was comparable for 0.1 and 0.2 mmol/kg of gadobenate dimeglumine, and specificity was highest with the 0.1 mmol/kg dose. Higher detection scores and higher sensitivity values for lesion characterization were found for 0.1 mmol/kg of gadobenate dimeglumine compared with 0.1 mmol/kg of gadopentetate dimeglumine, although more variable specificity values were obtained. No differences in safety were observed, and no serious adverse events were reported. CONCLUSION: Gadobenate dimeglumine is a capable diagnostic agent for MRI of the breast. Although preliminary, our results suggest that 0.1 mmol/kg of gadobenate dimeglumine may offer advantages over doses of 0.05 and 0.2 mmol/kg of gadobenate dimeglumine and 0.1 mmol/kg of gadopentetate dimeglumine for breast lesion detection and characterization.
Adult↗
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↗
[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↗
MR evaluation of bone cysts treated with intracavital steroid injection.
The objective of this study was to evaluate the role of MR examination in showing the effects of intralesional steroid injection on bone cysts. Nineteen patients with radiologically suspected (group A, n=15) or already treated (group B, n=4) bone cysts underwent MRI (0.5 T; protocol: T2* gradient recalled echo; short tau inversion recovery or inversion recovery fast spin echo; T1 SE before and after contrast administration, 0.2 mmol/kg). All patients underwent steroid therapy for bone cysts and were followed up for 6-18 months after treatment. Evaluation of bone cyst response to therapy was based mainly on the detection of reparative tissue outlining all cystic portions at first MRI control. In group A, as early as 1 month after the first injection, the presence of a thin reparative tissue lining the cystic wall was observed. Follow-up studies revealed the progressive thickening of this reparative tissue and new bone formation. Similar features were present in the cysts of group B. Residual cystic cavities were depicted in 7 cases, with no evidence of enhancing tissue, requiring further treatment. The formation of a reparative tissue is the first feature of bone cyst recovery after intracavital steroid injection and is appreciable only on MRI. Because of the optimal visualisation of this reparative tissue and of residual cystic cavities, MRI could be proposed as a non-invasive, alternative and effective tool for evaluating the efficacy of steroid injection therapy of bone cysts.
Anti-Inflammatory Agents↗
Ultrasound imaging of focal liver lesions with a second-generation contrast agent.
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Contrast Media↗
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↗
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↗
Value of opposed-phase gradient-echo technique in distinguishing between benign and malignant vertebral lesions.
Our objective was to evaluate the possible role of opposed-phase gradient-echo (GRE) sequence in predicting the nature of vertebral lesions supposing that in the case of malignancy fat is completely replaced while in the case of benign lesion fat is still present. Eighty-six patients with vertebral lesions underwent MR examination at 0.5 T. The MR protocol included a T1-weighted spin-echo (SE) and an opposed-phase GRE using the same parameters (TR=280-320 ms, flip angle=90 degrees, slice thickness=3.5-4 mm, matrix=256x160-192, field of view=34-36 cm, no. of excitations=2-4) except for TE (10 ms in SE vs 7 ms in GRE) to obtain opposed-phased images. Qualitative (nature of lesion, detectability, degree of signal intensity (SI), marrow pattern) and quantitative (SI on opposed-phase GRE minus SI on T1-weighted SE minus SI ratio=SI on out-of-phase GRE images divided by SI on T1-weighted SE images) analysis were performed. The SI ratio values were analysed using Mann-Whitney rank-sum test and receiver operating characteristics (ROC) curve. Lesions resulted to be malignant in 45 and benign in 41 patients (23 biopsies, 20 MR follow-ups, 43 clinical and other imaging follow-ups). Based on visual inspection of opposed-phased images, visual SI was evaluated high in 38 (34 malignant, 34 benign), mild in 28 (9 malignant, 19 benign) and low in 20 (2 malignant, 18 benign) patients. Based on region-of-interest measurements, SI ratio values range was 0.36-6.2 (mean value=1.68+/-0.82) for malignant and 0.07-1.54 (mean value=0.77+/-0.44) for benign lesions. A cut-off value of 1.2 gave a sensitivity, specificity, accuracy, negative predictive value and positive predictive value, respectively, of 88.8, 80.49, 84.88, 86.4 and 83.33%. The ROC analysis of the SI ratio showed an area under ROC curve of 0.92 and a statistically significant difference between the two groups of lesions was observed ( p<0.01). The GRE opposed-phase sequence can help to predict the nature of a vertebral lesion. This fast and widely available technique together with morphological criteria can improve the accuracy of MRI.
Adolescent↗