Search PubMed⌕ Search

Biomedical subjects

Giovanni Simonetti

Publications and source records attributed to Giovanni Simonetti.

At least 37 records · Page 2Linked to original sources
PubMed2004

Is SPECT/CT with a hybrid camera useful to improve scintigraphic imaging interpretation?

OBJECTIVES: To assess the usefulness of a hybrid imaging system (single-photon emission computed tomography/computed tomography, SPECT/CT) for functional anatomical mapping (FAM) using various radiotracers and the additional value of fused SPECT/CT images compared with SPECT alone. METHODS: Eighty-one consecutive patients studied for various clinical situations were evaluated: 10 with 111In-pentetreotide, four with 123I-meta-iodobenzylguanidine (I-MIBG), five with 99mTc-labelled red blood cells, two with 99mTc-antigranulocyte antibodies, four with 99mTc-nanocolloids, 10 with 67Ga, seven with 99mTc-methylene diphosphonate (99mTc-MDP), nine with 99mTc-sestamibi, 21 with 99mTc-tetrofosmin, two with 201Tl, three with 99mTc-ethylcysteinate dimer (ECD), one with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) and three with 123I-N-w-fluoropropyl-2-beta-carbomethoxy-3-beta-(4-iodophenyl) nortropanel (FPCIT). The acquisition of both anatomical (CT) and functional (SPECT) data was performed during a single session. SPECT data were first interpreted alone and then re-evaluated with the addition of FAM. RESULTS: Transmission anatomical maps allowed for the precise anatomical localization of SPECT images in 79 of the 81 cases. SPECT/CT had a significant impact on the results in 33 (40.7%) of the 81 patients: FAM provided the correct localization of SPECT findings in 23 cases, allowed the definition of the functional significance of CT lesions in two and enabled the exclusion of disease in sites of physiological tracer uptake in eight. CONCLUSIONS: SPECT/CT with this hybrid system is a feasible technique yielding co-registered dual-modality images. FAM allows a more precise interpretation of scintigraphic studies in several cases and fused images can improve the diagnostic accuracy of SPECT in various clinical situations.

Brain Diseases↗
PubMed2004

Kyphoplasty: a new opportunity for rehabilitation of neurologic disabilities.

Using percutaneous kyphoplasty, we treated a patient with a diagnosis of Guillain-Barré syndrome who complained of an unremitting pain in the spine, refractory to the conventional medical therapy, elicited by pressure over the spinous process, and in absence of neurologic deficits. The method provided swift midline back pain relief associated with an evident augmentation in the stability and in the vertebral body's height. The injection of polymethylmethacrylate was effective and safe, no cement leakages were observed, and no complications such as pulmonary embolism, toxicity, or infection were observed. Due to the rapid pain relief, a rehabilitation program was promptly undertaken with a good improvement of the disability score (FIM scale score). Kyphoplasty is a new method for treatment of vertebral collapses consequent to osteoporosis, aggressive hemangiomas, myelomas, and metastases, and it may aid in rehabilitation of the underlying systemic neurologic disorder if the pain is interfering with those therapies.

Aged↗
PubMed2004

Sensitivity of MRI versus mammography for detecting foci of multifocal, multicentric breast cancer in Fatty and dense breasts using the whole-breast pathologic examination as a gold standard.

OBJECTIVE: Our aim was to compare the effectiveness of mammography and MRI in the detection of multifocal, multicentric breast cancer. SUBJECTS AND METHODS: Ninety patients with planned mastectomies (nine bilateral) underwent mammography and dynamic gadolinium-enhanced MRI. Off-site reviewers aware of the entry criterion (planned mastectomy) evaluated both examinations for the presence of malignant foci, recording the density pattern on mammography. The gold standard was pathologic examination of the whole excised breast (slice thickness, 5 mm). RESULTS: Of 99 breasts, pathologic findings revealed 52 unifocal, 29 multifocal, and 18 multicentric cancers for a total of 188 malignant foci (158 invasive and 30 in situ). Overall sensitivity was 66% (124/188) for mammography and 81% (152/188) for MRI (p < 0.001); 72% (113/158) and 89% (140/158) for invasive foci (p < 0.001); and 37% (11/30) and 40% (12/30) for in situ foci (p > 0.05, not significant), respectively. Mammography and MRI missed 64 and 36 malignant foci, respectively, with median diameters of 8 and 5 mm (p = 0.033) and an invasive-noninvasive ratio of 2.4:1 (45:19) and 1.0:1 (18:18) (p = 0.043), respectively. The overall positive predictive value (PPV) was 76% (124/164) for mammography and 68% (152/222) for MRI (not significant). In breasts with an almost entirely fatty pattern, sensitivity was 75% for mammography and 80% for MRI (not significant), and the PPV was 73% and 65% (not significant), respectively. In breasts with fibroglandular or dense pattern, the sensitivity was 60% and 81% (p < 0.001), and the PPV was 78% and 71% (not significant), respectively. CONCLUSION: MRI was more sensitive than mammography for the detection of multiple malignant foci in fibroglandular or dense breasts. Mammography missed larger and more invasive cancer foci than MRI. A relatively low PPV was a problem for both techniques.

Adipose Tissue↗
PubMed2004

Virtual endoscopy in odontogenic sinus disease. Study technique and main pathological findings.

The use of CT scans in dental pathology is an established technique. The potential applications of Dentascan are further enhanced by the use of virtual navigation software, resulting in endoscopy-like imaging of the maxillary sinus, thus optimising both the diagnostic and therapeutic approach to sinus pathology of dental origin. The aim of this paper is to illustrate the technical-methodological aspects of maxillary sinus virtual endoscopy with Dentascan software and to document the most important and frequent diseases.

Endoscopy, Digestive System↗
PubMed2003

Treatment of intermetatarsal Morton's neuroma with alcohol injection under US guide: 10-month follow-up.

Morton's neuroma (MN) is a frequent cause of metatarsalgia. The aim of our study was to evaluate the efficacy of neuroma alcohol-sclerosing therapy (NAST) under US guide in MN after a 10-month follow-up. Forty intermetatarsal neuromas underwent alcohol-sclerosing therapy after sonographic evaluation of their dimensions and echotexture. After subcutaneous anesthesia, a sclerosing solution composed of anesthetic (carbocaine-adrenaline 70%) and ethylic alcohol (30%) was injected inside the mass under US guidance. The procedure was repeated at intervals of 15 days until the resolution of the symptoms. A total or partial symptomatic relief was obtained in 36 cases (90%). No procedure-related complications were observed. Transitory plantar pain, due to the flogistic reaction induced by the sclerosing solution, occurred in 6 cases (15%). The 10-month follow-up revealed a 20-30% mass volume reduction and an adiposus-like change in echotexture. In the 4 cases (10%) of therapeutic failure, the preliminary sonography demonstrated a hypoechoic echotexture with a strong US beam attenuation corresponding to a highly fibrous neuroma after surgical resection. The NAST is a feasible and cost-efficient procedure with high rates of therapeutic success.

Adult↗
PubMed2003

Endovascular treatment of giant splenic aneurysm that developed after liver transplantation.

Splenic artery aneurysms (SAAs) are not uncommon in patients with portal hypertension. They are usually diagnosed in preliminary examinations prior to orthotopic liver transplantation (OLT) and are treated surgically at the time of transplantation. In our case, the patient developed a giant SAA after liver transplantation. This was detected incidentally upon routine ultrasound follow-up, and the diagnosis was confirmed on magnetic resonance (MR) angiography. The patient was treated by endovascular embolization because it is believed that this minimally invasive approach is beneficial in an immunocompromised patient following OLT. After coil embolization, to achieve complete and immediate blood flow exclusion of the sac, it was decided to inject some glue ( N-butyl-2-cyanoacrylate) directly into the aneurysm. The aneurysm was successfully obliterated. To the best of our knowledge the use of cyanoacrylate glue in an SSA has never been reported.

Aneurysm↗
PubMed2003

Selective uterine artery embolization in the management of uterine myomas.

OBJECTIVE: To evaluate the effectiveness of uterine artery embolization in women with uterine myomas in terms of the clinical results for the relief of related symptoms. DESIGN: A pilot study on 26 women affected by uterine single myoma. SETTING: Tertiary level care in an university hospital. PATIENT(S): Twenty-six patients, aged 32 to 54 years, suffering of menorrhagia, pelvic pain, and abdominal mass for single myoma, intramural localization. INTERVENTION(S): Selective uterine artery embolization performed under peridural anesthesia. MAIN OUTCOME MEASURE(S): We measured the x-ray dose to which patients were exposed. Color power Doppler ultrasound examinations were performed during the follow-up evaluations at 1 to 6 months and 1 year after the procedure. RESULT(S): Uterine artery embolization was successfully performed in 100% of cases. The mean fluoroscopy time was of 20 minutes during the procedure. The mean dose of x-ray absorbed by the ovary was estimated at 18.7 cGy and the mean dose of x-ray absorbed by the skin was 126.7 cGy. A reduction of myoma volume of 55% was found at 6 months' ultrasound examination and 75% at the 1-year examination. CONCLUSION(S): Patients are well satisfied and have short recovery times with this procedure. Uterine artery embolization may be a valid alternative to traditional surgery.

Adult↗
PubMed2003

Giant high-flow renal arteriovenous fistula treated by percutaneous embolization.

We report the case of a giant renal arteriovenous fistula after renal biopsy in a 30-year-old man with hematuria and hypertension. We performed percutaneous endovascular embolization using macrocoils to exclude the fistula. The patient made an uneventful recovery with no further hematuria and progressive reduction of blood pressure. Follow-up by digital subtraction angiography (DSA) at 6 months showed complete occlusion of the fistula with no evidence of renal parenchymal infarction. Although giant renal arteriovenous fistulas are generally treated by nephrectomy, this case shows that embolization is a reasonable alternative to surgery.

Adult↗
PubMed2003

Vascular involvement in pancreatic neoplasm: a comparison between spiral CT and DSA.

The principal criterion for resectability of pancreatic carcinoma is the assessment of vascular involvement. In a prospective evaluation the ability of Spiral CT Angiography (CTA) to detect vascular involvement in 50 patients with pancreatic carcinoma, was proved; DSA was performed later in all patients. In 20 patients, without vascular involvement, a complete concordance was obtained. Of 30 patients with vascular involvement, there was complete concordance between CTA and angiography in 22 patients and discordance in 8 patients. CTA was superior in 2 cases with periadventitial infiltration and in 5 patients with splenoportal confluence thrombosis. DSA was superior in 1 case with infiltration of the superior mesenteric vein. After surgical evaluation, sensitivity of CTA and DSA was 97% and 77%, respectively, and the negative predictive values were 95% and 74%. As compared to DSA, CTA is more rapid and less invasive and can be considered the modality of choice for preoperative work-up of pancreatic neoplasm.

Adenocarcinoma↗
PubMed2003

Virtual colonoscopy compared with conventional colonoscopy for stricturing postoperative recurrence in Crohn's disease.

BACKGROUND: The place of virtual colonoscopy (VC) in patients with Crohn's disease (CD) requiring endoscopic follow-up after surgery is unknown. The authors compared findings from VC versus conventional colonoscopy (CC) for assessing the postoperative recurrence of CD. METHODS: Sixteen patients with ileocolonic anastomosis for CD were prospectively enrolled from January 2001 to January 2002. Recurrence was assessed by CC according to Rutgeerts et al. VC was performed with a computed tomography scanner, with images examined by three radiologists who were unaware of the endoscopic findings. RESULTS: CC showed perianastomotic recurrence in 15 of 16 patients. Perianastomotic narrowing or stenosis was detected by VC in 11 of these 15 patients. There were 11 true positive, 1 true negative, 0 false-positive, and 4 false-negative findings (73% sensitivity, 100% specificity, 100% positive predictive value, 20% negative predictive value, 75% accuracy). Among the eight patients showing a rigid stenosis of the anastomosis not allowing passage of the colonoscope, VC detected narrowing or stenosis in seven patients. CONCLUSIONS: The current findings suggest that although the widespread use of VC in CD is currently not indicated because of possible false-negative findings, this technique may represent an alternative to CC in noncompliant postsurgical patients with a rigid stenosis not allowing passage of the endoscope.

Adult↗
PubMed2002

Hepatic artery pseudoaneurysm in von Willebrand's disease.

We report a case of hepatic artery pseudoaneurysm which occurred in a patient with von Willebrand's disease. The patient presented with upper abdominal pain and diagnosis was made by US and CT examinations. This case emphasizes the possible association between an established coagulation disorder and pseudoaneurysm. The patient was successfully treated by coil embolization.

Adult↗
PubMed2002

Cerebrospinal fluid changes after intravenous injection of gadolinium chelate: assessment by FLAIR MR imaging.

Fluid-attenuated inversion recovery (FLAIR) sequence is currently used in clinical practice. Some reports emphasize the possibility that, in pathologic conditions, intravenous injection of gadolinium chelates may lead to an increased signal inside the cerebrospinal fluid (CSF). The aim of this study was to evaluate the presence of CSF signal changes in pathologic conditions causing blood-brain barrier disruption or neovascularization when imaging is performed after intravenous injection of gadolinium. We obtained FLAIR sequences after gadolinium injection from 33 patients affected by different intracranial pathologies and 10 control subjects. Patients were affected by ischemic stroke in the subacute phase, from 2 to 7 days from onset of symptoms (12 patients), meningiomas (8 patients), high-grade gliomas (5 patients), previous surgical procedures for intra-axial neoplasms (5 patients), and multiple sclerosis with active plaques (3 patients). Magnetic resonance imaging was performed in patients and controls using a 1.5-T magnet, using T2- and T1-weighted FLAIR sequences. The FLAIR sequence was acquired before and 1-3 h after injection of a standard dose of gadolinium. In those patients affected by ischemic lesions, FLAIR sequences were repeated the next days and 3-4 days later. The CSF signal was visually evaluated by two readers and scored from 0 to 3 depending by the degree of enhancement. The location of CSF signal changes (close to the lesion, hemispheric, or diffuse) was also considered. The CSF signal was markedly increased after 3 h from intravenous injection of gadolinium in all the patients with stroke, in those with previous surgery, and in those with high-grade gliomas whose neoplasm's surface was in contact with the subarachnoid spaces (SAS) or ventricles; a strong enhancement was also evident inside the necrotic component of the tumor. The CSF changes were more evident close to the pathology and/or in the hemisphere involved by the pathology. Moderate CSF enhancement was observed in the SAS close to meningiomas. No signal changes were evident in all the others. In those patients with stroke imaged in the following days, CSF signal showed to be diffuse to both hemispheres the next day and returned to normal values within 2 days. In patients affected by pathologies with blood-brain barrier breakdown or neovascularization close the SAS or the ventricles, CSF changes, related to gadolinium leakage, are likely when FLAIR sequences are acquired 2-24 h after i.v. injection of the contrast. This pattern should be known in order to differentiate it from that of subarachnoid hemorrhage.

Aged↗
PubMed2002

Postoperative regression of retroperitoneal fibrosis in patients with inflammatory abdominal aortic aneurysms: evaluation with spiral computed tomography.

Partial or total regression of aortic and retroperitonel fibrosis after surgery has been reported in combination with inflammatory abdominal aortic aneurysm (AAA). In this report, we consider the most recent 21 patients with inflammatory AAA consecutively operated on at our institution. The group was composed of 19 men and 2 women, with a mean age of 66 years. In addition to preoperative CT angiographic study, abdominal ultrasound and aortoiliac angiography were also performed. There were no perioperative deaths. The perioperative morbidity rate was 9.5%. In 20 cases (95.2%), the aortic wall was subjected to histological examination with calculation of an inflammatory index. Each patient was reexamined with spiral CT angiography after surgery; postoperative results were assessed in terms of changes in maximal fibrotic-mantle thickness observed on follow-up spiral CT angiograms, expressed both in millimeters and percentage of change. Regression was analyzed for possible correlation with preoperative severity of fibrotic reaction, time of the postoperative exam, inflammatory index, and changes in the fibrotic process involving the adjacent structures. The results show that postoperative improvement was significantly more marked in cases characterized by higher preoperative inflammatory indices in the aneurysmal wall; the time course of regression was highly variable; but on the whole, improvement was more substantial during the early months after surgery, with significant slowing after the second or third year.

Aged↗
PubMed2002

Emergency endograft placement for recurrent aortocaval fistula after conventional AAA repair.

PURPOSE: To report a novel case in which a stent-graft was used to emergently treat an aortocaval fistula that recurred after conventional abdominal aortic aneurysm (AAA) repair. CASE REPORT: A 67-year-old man was treated urgently for ruptured AAA with surgical placement of a 16-mm Dacron interposition graft. During the procedure, an aortocaval fistula was repaired primarily. The patient was discharged in satisfactory condition but returned 20 days later with dyspnea, bilateral perimalleolar edema, and a bruit in the mesogastric region. The high flow fistula was again present just above the aortic bifurcation at the distal anastomosis of the existing graft. The patient's condition deteriorated rapidly, so a bifurcated Vanguard stent-graft was deployed in an emergency procedure. Subsequent imaging confirmed satisfactory closure of the fistula. The patient was discharged 8 days after endograft placement, and he continues to be without signs of fistula recurrence at 2 years. CONCLUSIONS: Endograft treatment of vascular lesions in the acute setting is becoming more common as our experience with the devices grows. Endovascular repair of primary aortocaval fistulas appears to be an efficacious and minimally invasive means of dealing with these lesions in AAA patients.

Aged↗
PubMed2002

Hemodynamic modifications in patients with symptomatic unilateral stenosis of the internal carotid artery: evaluation with MR imaging perfusion sequences.

BACKGROUND AND PURPOSE: Risk of developing ischemia is higher in patients with reduced cerebrovascular reactivity than in those with preserved cerebrovascular reactivity. Therefore, we assessed cerebral hemodynamic modifications in patients with unilateral stenosis of the internal carotid artery by using perfusion-weighted MR imaging to determine if these modifications underlie or anticipate ischemic signs and symptoms. METHODS: Fifteen patients with unilateral 70-90% carotid artery stenosis were studied with digital subtraction angiography and perfusion-weighted MR imaging. Their findings were compared with those of 15 age- and sex-matched control subjects. Regional cerebral blood volume (rCBV) and mean transit time (MTT) values were calculated in the middle cerebral artery and border zone territories. RESULTS: No significant difference was noted in rCBV and MTT values between the hemispheres in the symptomatic patients. There was a significant difference in MTT values in the border zones between patients and control subjects. MR images in patients and control subjects did not reveal large territorial infarcts and did reveal similar white matter lesion burdens. CONCLUSION: There is adequate compensation of unilateral stenosis when the stenosis is less than 90%. The risk of stroke is higher in patients with stenoses exceeding 70%, mostly because of decreased collateral reserve when confronted with emboli.

Aged↗
PubMed2002

A comparison between two different concentration of contrast media with multidetector CT for the study of abdominal vascular system.

PURPOSE: To evaluate two different concentrations of contrast medium (CM) and two different acquisition techniques to obtain vascular images with multislice spiral CT (msCT). MATERIALS AND METHODS: Thirty patients referred for msCT examinations of the kidney or upper abdomen underwent evaluation of the abdominal aorta during the arterial phase, after giving their consent (GE Light Speed Plus). In the first part of the study (20 patients) the enhancement values measured at six different levels of the aortoiliac axis (celiac trunk, suprarenal aorta, subrenal aorta, aortal bifurcation, right iliac and left iliac) were compared after administering two different concentrations of iodinated contrast medium (300 and 370 mgI/ml) with two different acquisition techniques (HQ and HS). The flow rate was 3 ml/sec. In the second part of the study 10 patients were examined by changing the flow rate (2 and 4 ml/sec). Both quantity and quality assessments were conducted on axial images and on vascular reconstructions. RESULTS: In the first part of the study the best results were obtained with the 370 mgI/ml concentration and with the HQ acquisition technique (pitch 3, table feed 7.5 mm/rotation, gantry rotation speed 0.5 s). The quality of reconstructions gradually improved before reaching 240 HU, above which image quality remained constant. The patients examined with a flow rate of 2 ml/sec showed a poor image quality, unlike those examined with a flow rate of 4 ml/sec where we observed the maximum threshold values and constant optimal vascular opacification, with no significant differences from the patients studied at 3 ml/sec. CONCLUSIONS: Our results indicate that, albeit on a limited number of patients, a higher concentration of CM and the use of an HQ technique allow a high quality examination to be obtained. The HS technique yields results comparable to those obtained with higher concentrations.

Abdomen↗