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Domenico Lepori

Publications and source records attributed to Domenico Lepori.

10 recordsLinked to original sources
PubMed2005

Objective assessment of image quality in conventional and digital mammography taking into account dynamic range.

The goal of this work is to develop a method to objectively compare the performance of a digital and a screen-film mammography system in terms of image quality. The method takes into account the dynamic range of the image detector, the detection of high and low contrast structures, the visualisation of the images and the observer response. A test object, designed to represent a compressed breast, was constructed from various tissue equivalent materials ranging from purely adipose to purely glandular composition. Different areas within the test object permitted the evaluation of low and high contrast detection, spatial resolution and image noise. All the images (digital and conventional) were captured using a CCD camera to include the visualisation process in the image quality assessment. A mathematical model observer (non-prewhitening matched filter), that calculates the detectability of high and low contrast structures using spatial resolution, noise and contrast, was used to compare the two technologies. Our results show that for a given patient dose, the detection of high and low contrast structures is significantly better for the digital system than for the conventional screen-film system studied. The method of using a test object with a large tissue composition range combined with a camera to compare conventional and digital imaging modalities can be applied to other radiological imaging techniques. In particular it could be used to optimise the process of radiographic reading of soft copy images.

Breast↗
PubMed2005

Acute brain perfusion disorders in children assessed by quantitative perfusion computed tomography in the emergency setting.

OBJECTIVE: Perfusion computed tomography (CT) is a simple imaging technique that allows accurate quantitative assessment of brain perfusion. Perfusion CT is an ideal imaging technique to be used in the emergency setting and has thus gained recognition in the early management of adult acute stroke patients. Perfusion CT can be applied to children successfully by using adequate imaging protocols. The goal of this article is to provide a pictorial essay of the perfusion CT features of diseases that affect brain perfusion as depicted in a population of children who were evaluated in the emergency CT unit of our institution. METHODS: During the period of September 2001 to October 2002, all the children, who were evaluated in the emergency CT unit of our institution and who were prescribed with a cerebral CT and an intravenous administration of iodinated contrast material, underwent a perfusion-CT examination. Perfusion-CT maps were reviewed in the patients diagnosed as abnormal on the basis of follow-up clinical/radiological examinations and correlated with the results of these tests. RESULTS: Brain perfusion-CT examinations have been performed in 77 children. Fifty-three patients were considered as normal, based on normal conventional cerebral CT and normal clinical/radiological follow-up. Perfusion-CT results showed major abnormalities in 14 cases among the 24 remaining patients, related to brain ischemia in 2, head trauma in 9, brain infection in 2, and sickle cell disease in 1. These abnormalities consisted in low regional cerebral blood flow and volume values, and in high mean transit time values. They demonstrated typical anatomical distribution, depending on the considered pathological condition. CONCLUSIONS: Perfusion CT provides quantitative assessment of child brain perfusion disorders. Its ability to be easily performed upon admission makes it an ideal emergency tool that advantageously competes with other imaging techniques such as perfusion-weighted magnetic resonance imaging, despite its limited spatial coverage. Its usefulness with respect to the impact on treatment and outcome, however, remains to be established in further studies.

Adolescent↗
PubMed2004

Severe hypertension and massive proteinuria in a newborn with renal artery stenosis.

Renal vein thrombosis and the congenital nephrotic syndrome have been associated with nephrotic-range proteinuria/nephrotic syndrome and hypertension in the newborn period. We describe a newborn with severe hypertension and proteinuria secondary to unilateral renal artery stenosis. Proteinuria completely disappeared with blood pressure control (with sodium nitroprusside and an angiotensin-converting enzyme inhibitor). Although renin was not measured, we speculate that proteinuria might have been induced by a high renin state, and was controlled by the angiotensin-converting enzyme inhibitor.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2004

Closure of large intrathoracic airway defects using extrathoracic muscle flaps.

BACKGROUND: Prospective assessment of pedicled extrathoracic muscle flaps for the closure of large intrathoracic airway defects after noncircumferential resection in situations where an end-to-end reconstruction seemed risky (defects of > 4-cm length, desmoplastic reactions after previous infection or radiochemotherapy). METHODS: From 1996 to 2001, 13 intrathoracic muscle transpositions (6 latissimus dorsi and 7 serratus anterior muscle flaps) were performed to close defects of the intrathoracic airways after noncircumferential resection for tumor (n = 5), large tracheoesophageal fistula (n = 2), delayed tracheal injury (n = 1) and bronchopleural fistula (n = 5). In 2 patients, the extent of the tracheal defect required reinforcement of the reconstruction by use of a rib segment embedded into the muscle flap followed by temporary tracheal stenting. Patient follow-up was by clinical examination bronchoscopy and biopsy, pulmonary function tests, and dynamic virtual bronchoscopy by computed tomographic (CT) scan during inspiration and expiration. RESULTS: The airway defects ranged from 2 x 1 cm to 8 x 4 cm and involved up to 50% of the airway circumference. They were all successfully closed using muscle flaps with no mortality and all patients were extubated within 24 hours. Bronchoscopy revealed epithelialization of the reconstructions without dehiscence, stenosis, or recurrence of fistulas. The flow-volume loop was preserved in all patients and dynamic virtual bronchoscopy revealed no significant difference in the endoluminal cross surface areas of the airway between inspiration and expiration above (45 +/- 21 mm(2)), at the site (76 +/- 23 mm(2)) and below the reconstruction (65 +/- 40 mm(2)). CONCLUSIONS: Intrathoracic airway defects of up to 50% of the circumference may be repaired using extrathoracic muscle flaps when an end-to-end reconstruction is not feasible.

Adolescent↗
PubMed2004

Brain perfusion in children: evolution with age assessed by quantitative perfusion computed tomography.

OBJECTIVE: The objective of this study was to assess the age-related variations of brain perfusion through quantitative cerebral perfusion computed tomography (CT) results in children without brain abnormality. METHODS: Brain perfusion CT examinations were performed in 77 children, aged 7 days to 18 years. These patients were admitted at our institution for both noncontrast and contrast-enhanced cerebral CT. Only children whose conventional cerebral CT and clinical/radiologic follow-up, including additional investigations, were normal were taken into account for this study (53 of 77). RESULTS: The average regional rCBF amounts to 40 (mL/100 g per minute) for the first 6 months of life, peaks at approximately 130 (mL/100 g per minute) at approximately 2 to 4 years of age, and finally stabilizes at approximately 50 (mL/100 g per minute) at approximately 7 to 8 years of age, with a small increase of rCBF values at approximately 12 years of age. The rCBF in the gray matter averages 3 times that in the white matter, except for the first 6 months of life. The global CBF represents 10% to 20% of the global cardiac output for the first 6 months of life, peaks at approximately 55% by 2 to 4 years of age, and finally stabilizes at approximately 15% by 7 to 8 years of age. Specific age-related evolution patterns were identified in the different anatomic areas of the cerebral parenchyma, which could be related to the development of neuroanatomic structures and to the emergence of corresponding cognitive functions. CONCLUSIONS: Quantitative perfusion CT characterization of brain perfusion shows specific age variations. Brain perfusion of each cortical area evolves according to a specific time course, in close correlation with the psychomotor development.

Adolescent↗
PubMed2003

[Quality assurance in organized screening of breast cancer].

Quality assurance is an essential process which should be applied for any organised breast cancer screening program since mammography it the only test available for an early diagnosis. It should also assess the quality of diagnostic and treatment processes in order to ascertain that the quality of the screening program would not be altered by the procedures which take place after the screening. Quality assurance must be applied to each component of the screening process: equipment, radiographers (technicians) as well as radiologists. It is a multidisciplinary approach following a well defined protocol, which should be supervised by a coordination unit, the Breast Cancer Screening Foundation in Canton of Vaud. Performances of the Vaud program show clearly at what extend multiple reading method improves the quality of screening. It seems that there is no inconvenient to involve radiologists who wish to participate without any selection to the reading process provided that there is in place a team of 2nd and 3rd readers who benefit of an appropriate training and experience.

Breast Neoplasms↗
PubMed2002

Prospective comparison of MR enteroclysis with multidetector spiral-CT enteroclysis: interobserver agreement and sensitivity by means of "sign-by-sign" correlation.

Our objective was a prospective comparison of MR enteroclysis (MRE) with multidetector spiral-CT enteroclysis (MSCTE). Fifty patients with various suspected small bowel diseases were investigated by MSCTE and MRE. The MSCTE was performed using slices of 2.5 mm, immediately followed by MRE, obtaining T1- and T2-weighted sequences, including gadolinium-enhanced acquisition with fat saturation. Three radiologists independently evaluated MSCTE and MRE searching for 12 pathological signs. Interobserver agreement was calculated. Sensitivities and specificities resulted from comparison with pathological results ( n=29) and patient's clinical evolution ( n=21). Most pathological signs, such as bowel wall thickening (BWT), bowel wall enhancement (BWE) and lymphadenopathy (ADP), showed better interobserver agreement on MSCTE than on MRE (BWT: 0.65 vs 0.48; BWE: 0.51 vs 0.37; ADP: 0.52 vs 0.15). Sensitivity of MSCTE was higher than that of MRE in detecting BWT (88.9 vs 60%), BWE (78.6 vs 55.5%) and ADP (63.8 vs 14.3%). Wilcoxon signed-rank test revealed significantly better sensitivity of MSCTE than that of MRE for each observer ( p=0.028, p=0.046, p=0.028, respectively). Taking the given study design into account, MSCTE provides better sensitivity in detecting lesions of the small bowel than MRE, with higher interobserver agreement.

Artifacts↗
PubMed2002

Slipping rib syndrome: a place for sonography in the diagnosis of a frequently overlooked cause of abdominal or low thoracic pain.

OBJECTIVE: To describe the sonographic appearance of a poorly recognized cause of low thoracic or upper abdominal pain. METHODS: Three sonographic descriptions of slipping rib syndrome are presented. RESULTS: The 3 patients had abnormal mobility of a cartilaginous rib, which could slip over an adjacent rib during abdominal muscle contraction. CONCLUSIONS: Slipping rib syndrome should be considered in patients with histories of upper abdominal or low thoracic pain of unknown origin. We suggest that high-resolution sonography of the costal margin should be added to abdominal sonography in cases of nonspecific abdominal pain.

Abdominal Pain↗
PubMedDate not supplied

Multimodality imaging evaluation of the pediatric neck: techniques and spectrum of findings.

Neck masses are a common finding in children and can present a difficult diagnostic challenge. These masses may represent a variety of conditions having a congenital, acquired inflammatory, neoplastic, or vascular origin. The fascial spaces and compartments of the neck provide an approach to differential diagnosis, and extensive knowledge of the anatomy and contents of each cervical compartment is mandatory in the diagnosis of pediatric neck lesions. Several imaging techniques, including radiography, gray-scale and Doppler ultrasonography, conventional and three-dimensional computed tomography, magnetic resonance (MR) imaging, and MR angiography, have been proposed for the evaluation of such lesions, and each has its own advantages and limitations. The imaging findings in 120 children who had been referred or treated for cervical lesions were retrospectively reviewed, and a systematic multimodality imaging approach to pediatric neck lesions based on the involvement of anatomic compartments of the cervical region was developed to increase diagnostic efficiency. Careful attention to clinical history and physical examination findings, along with knowledge of the embryologic features and anatomy of the cervical region and a multimodality imaging approach, is very helpful in the diagnosis and management of pediatric neck lesions.

Adolescent↗