PubMed Health⌕ Search

Biomedical subjects

S Colagrande

Publications and source records attributed to S Colagrande.

At least 19 recordsLinked to original sources
PubMed2006

Magnetic resonance diffusion-weighted imaging: extraneurological applications.

Diffusion-weighted (Dw) imaging has for a number of years been a diagnostic tool in the field of neuroradiology, yet only since the end of the 1990s, with the introduction of echoplanar imaging (EPI) and the use of sequences capable of performing diffusion studies during a single breath hold, has it found diagnostic applications at the level of the abdomen. The inherent sensitivity to motion and the magnetic susceptibility of Dw sequences nonetheless still create problems in the study of the abdomen due to artefacts caused by the heartbeat and intestinal peristalsis, as well as the presence of various parenchymal-gas interfaces. With regard to focal liver lesions, a review of the literature reveals that Dw imaging is able to differentiate lesions with high water content (cysts and angiomas) from solid lesions. With regard to the latter, although there are differences between benign forms [focal nodular hyperplasia (FNH), adenoma] and malignant forms [metastasis, hepatocellular carcinoma (HCC)] in their apparent diffusion coefficient (ADC) in the average values for histological type, there is a significant overlap in values when lesions are assessed individually, with the consequent problem of their correct identification. One promising aspect is the possibility of quantifying the degree of fibrosis in patients with chronic liver disease and cirrhosis given that the deposit of collagen fibres "restricts" the motion of water molecules and therefore reduces ADC values. However, even in this field, studies can only be considered preliminary and far from real clinical applications. The retroperitoneum is less affected by motion artefacts and similarly deserves the attention of Dw imaging. Here it is possible to differentiate mucin-producing tumours of the pancreas from pseudocystic forms on the basis of ADC values even though the limited spatial resolution of Dw imaging does not enable the identification of small lesions. Dw imaging may be applied to the study of the kidney to differentiate hydronephrosis from pyonephrosis and with regard to tumours, solid from pseudocystic forms. In addition, given that renal parenchyma has significantly variable ADC values on the basis of the anatomic section and physiological conditions, the possibility of assessing functional alterations is currently being studied. Indeed, a good correlation has been found between ADC values and glomerular filtration rate. With regard to musculoskeletal applications, the absence of motion artefacts in the regions studied has enabled the development of sequences less sensitive to magnetic susceptibility and with greater spatial resolution than EPI. Attempts have therefore been made to use Dw imaging in the characterization of soft-tissue tumours although the findings so far have been disputed. Greater agreement has been found regarding sensitivity of the technique in assessing response of these tumours to chemotherapy: tumour necrosis is thought to increase ADC whereas the persistence of vital neoplastic tissue tends to lower it. One of the most promising applications of Dw imaging is without doubt the assessment of vertebral collapse where a high ADC has been shown to be associated with an osteoporotic cause and a low ADC with a neoplastic cause. Nonetheless, even here, a moderate overlap between ADC values of the two types has been encountered. Dw imaging has also been used in the assessment of bone marrow cellularity: areas of tightly packed cells show a higher ADC value than hypocellular areas. In particular, no significant difference in ADC is noted between normal hypercellular bone marrow and hypercellular bone marrow secondary to lymphomatous infiltration whereas this difference is significant between hypocellular, normocellular and haematopoietic hypercellular bone marrow. With regard to the study of joints, the limited structure dimensions, particularly cartilage, creates technical difficulties related to spatial resolution and an adequate signal-to-noise ratio, problems that can only be solved by further technological developments. Lastly, a significant difference in ADC values between degenerative and inflammatory effusion has been found, a fact that may be explained as the result of the activity of hyaluronidase present in inflammatory forms, which causes a reduction in the concentration of hyaluronic acid with a consequent decrease in viscosity.

Abdomen↗
PubMed2000

Parathyroid glands: combination of (99m)Tc MIBI scintigraphy and US for demonstration of parathyroid glands and nodules.

PURPOSE: To determine the appropriate choice of imaging techniques for localization of nodular lesions of parathyroid glands. MATERIALS AND METHODS: First, computed tomographic (CT), magnetic resonance (MR), ultrasonographic (US), and technetium 99m methoxyisobutyl-isonitrile (MIBI) scintigraphic images in 49 patients with primary hyperparathyroidism were retrospectively evaluated. A single-blind, prospective study that included 16 patients with primary hyperparathyroidism was then conducted. MR, US, scintigraphic, and color Doppler US images of the neck were obtained and analyzed. RESULTS: In the retrospective study, CT, MR imaging, and US had low sensitivity (13%, 17%, and 27%, respectively) and specificity (39%, 65%, and 65%, respectively). Scintigraphy had 57% sensitivity and 85% specificity. In the prospective study, the use of latest-generation MR and US equipment and the participation of experienced operators led to improved sensitivity and specificity for these techniques. The combination of US and scintigraphy resulted in improved sensitivity (96%), specificity (83%), and positive and negative predictive values (88% and 94%, respectively), relative to the results obtained with either method alone. Doppler US was of little help in the setting of small glands. CONCLUSIONS: The combination of (99m)Tc MIBI scintigraphy and US performed by well-trained operators with up-to-date instruments appeared to be the best diagnostic tool for the preoperative diagnosis of parathyroid disease.

Adult↗
PubMed1999

Correlation between endometriosis and pelvic pain.

STUDY OBJECTIVE: To evaluate the relationship between prevalence and severity of chronic pelvic pain (CPP) and stage, site, and type of endometriosis. DESIGN: Prospective, observational study (Canadian Task Force classification II-2). SETTING: University Hospital. PATIENTS: Of 90 consecutive women with biopsy-proved endometriosis, laparoscopy was performed in 69 for pelvic pain and in 21 for infertility or clinical and ultrasonographic suspicion of ovarian endometriosis. INTERVENTION: Preoperatively, using a 10-point visual analog scale, the severity of dysmenorrhea, CPP, and deep dyspareunia was assessed. During laparoscopy all visible endometriotic lesions were recorded and treated. MEASUREMENTS AND MAIN RESULTS: Ten women (11.1%) had no pain; 72 had dysmenorrhea (mild in 13, moderate in 37, severe in 22); 55 had CPP (mild in 11, moderate in 25, severe in 19); and 39 deep dyspareunia (mild in 5, moderate in 31, severe in 3). The severity of dysmenorrhea significantly correlated with the presence and extent of pelvic adhesions (p = 0.004); the severity of CPP correlated with deep endometriosis on the uterosacral ligaments (p = 0.0001) and extent of pelvic adhesions (p = 0.02); and deep dyspareunia correlated with deep endometriosis on the uterosacral ligaments (p = 0.04). Total pain score significantly correlated with deep endometriosis on the uterosacral ligaments (p = 0.0001), peritoneal adhesions (p = 0.01), and extent of adnexal adhesions (p = 0.01). No significant correlation was found among revised American Fertility Society stage of endometriosis; presence and size of ovarian endometriomas; extent, type, and site of peritoneal lesions; and pain scores. By logistic regression analysis, the presence and intensity of total pain could be predicted simultaneously by the presence of deep endometriosis (p = 0.0001) and presence and extent of adnexal adhesions without cystic endometriosis (p = 0.01), and by the presence of ovarian endometrioma with periovarian adhesions (p = 0.03). Chronic pelvic pain was predicted by both deep endometriosis (p = 0.0001) and ovarian endometriomas with adnexal adhesions (p = 0.03). Deep dyspareunia was predicted simultaneously by deep endometriosis (p = 0.01) and an ovarian endometrioma with periovarian adhesions (p = 0. 008). Conclusion. Deep endometriosis, pelvic adhesions, and ovarian cystic endometriosis were independent predictors of pelvic pain. These data strongly suggest that it is not the size of ovarian cystic endometriosis but the association with adhesions that causes pelvic pain.

Adolescent↗
PubMed1998

[Adenocarcinoma of the duodenal bulb. A clinical case report].

A rare case of adenocarcinoma of the duodenal bulb, arising from adenoma and submitted to Whipple's procedure is presented. A diagnostic delay of about 3 months, according to literature is observed. This delay is generally due to the low incidence of the illness, aspecific symptoms and frequent endoscopic and radiologic false negative, most of all in lesions of the third and fourth duodenal portions. Diagnostic tools for these duodenal tumors are endoscopy and upper gastrointestinal barium studies (UGI). CT is useful to determine preoperatively the stage of the illness and can occasionally show the primary duodenal lesion, as in this case. Surgical approach is still controversial, except in lesions of the second duodenal portion, where Whipple operation is the procedure of choice, if the tumor is resectable, of course. In the other duodenal portions some authors suggest segmental duodenal resections instead of Whipple's procedure.

Adenocarcinoma, Mucinous↗
PubMed1997

In vivo ultrasound assessment of respiratory function of abdominal muscles in normal subjects.

Ultrasonography has recently been proposed for assessing changes in thickness and motion of the diaphragm during contraction in humans. Data on ultrasound assessment of abdominal muscles in humans are scarce. We therefore investigated the changes in thickness and the relevant mechanical effects of abdominal muscles using this technique during respiratory manoeuvres in normal subjects. We evaluated the thickness of the abdominal muscle layers in six normal male subjects (aged 26-36 yrs) using a 7.5 MHz B-mode ultrasound transducer. Gastric (Pg) and mouth pressures, muscle thickness of external oblique (EO), internal oblique (IO), transversus abdominis (TA) and rectus abdominis (RA) were assessed at functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), during progressive (PEEs) and maximal expiratory efforts (MEEs) against a closed airway and during homolateral (HTR) and contralateral (CTR) trunk rotation. Abdominal muscle thickness was found to be reproducible (coefficient of variation and two-way analysis of variance). Compared to FRC, the thickness of IO, TA and RA significantly increased at RV and during MEEs, whereas EO remained unchanged; at TLC, the thickness of IO and TA significantly decreased. During PEEs, a significant relationship between increase in Pg and TA thickness was observed in all subjects, the thickness of the other abdominal muscles being inconsistently related to Pg. Finally, a significant increase in the thickness of IO and EO was found during HTR and CTR, respectively. We conclude that during maximal expiratory manoeuvres, transversus abdominis, internal oblique and rectus abdominis thickened similarly. Transversus abdominis seems to be the major contributor in generating abdominal expiratory pressure during progressive expiratory efforts. External oblique seems to be preferentially involved during trunk rotation. These results suggest the possible value of studying the abdominal muscles by ultrasonography in various respiratory disorders.

Abdominal Muscles↗
PubMed1995

Staging and follow-up of nasopharyngeal carcinoma: magnetic resonance imaging versus computerized tomography.

PURPOSE: To compare computerized tomography (CT) and magnetic resonance (MR) in relation to their accuracy in the staging of nasopharyngeal carcinoma (NPC); to compare CT and MR in postirradiation follow-up of NPC. METHODS AND MATERIALS: Staging: From 1985 to 1993, 53 patients affected with NPC were studied with MR and CT. All cases were biopsy-proved epithelial carcinoma. Plain and contrast-enhanced CT scans were performed with third-generation scanners. Magnetic resonance were obtained with 0.5 and 1.5 Tesla units in sagittal, axial, and coronal planes. Computerized tomography was chosen as reference method and findings obtained with MR were compared to those obtained with CT. FOLLOW-UP: From 1985 to 1993, 53 patients irradiated with radical intent were followed up with both CT and MR; 71 examinations were performed in all. The baseline follow-up scan was performed, in general, no sooner than 2 months after the end of radiotherapy. All patients were submitted to unlimited clinical follow-up. RESULTS: Staging: Magnetic resonance showed retropharyngeal adenopathies in 6 of 14 cases in which oropharyngeal involvement had been reported after CT; in 3 other patients, adenopathies were recognized on MR, while primary extent to parapharyngeal space had been diagnosed on CT initially. Infiltration of long muscles of the neck was revealed with MR in 14 cases. On the other hand, CT showed bone invasion in 12 patients vs. 8 on MR. Upstaging to T4 occurred in four cases on the basis of CT; no upstaging occurred after MR. FOLLOW-UP: Findings on CT were uncertain in 10 out of 53 patients, disease recurrence was excluded by MR in nine cases, whereas progressive disease was confirmed in one patient. CONCLUSION: Staging: Our series shows that either CT and MR can provide essential information in the staging of NPC. Magnetic resonance, however, seems to provide the most detailed imaging of soft tissue invasion outside the nasopharynx and of retropharyngeal node involvement. Nonetheless, its limitations in evaluating bone details suggest that CT should be always performed when the status of base of skull is uncertain on MR. General reasons and our data indicate that CT can still be considered a valuable tool in routine NPC staging. Follow up: Magnetic resonance may be the modality of choice because it seems to solve, more often than CT, the problems of differentiation between postradiation changes and recurring tumor, apart from those cases showing subtle bone erosions on initial CT scan.

Adolescent↗
PubMed1995

[The role of CT and MR in assessing the patient operated on for rectal carcinoma: the local recurrence of the disease].

Computed tomography (CT) and magnetic resonance (MR) findings in a series of 27 patients treated surgically for rectal cancer (13 rectal amputations, 8 sphincter-saving resections and 6 with the Hartmann technique) and affected with local recurrence at the time of examination (1989-1993), were retrospectively reviewed. Every detected lesion was studied relative to morphologic features (shape, outline, surrounding tissue involvement, symmetric growth toward the mid-longitudinal plane), patterns of both CT contrast enhancement and MR signal intensity with different acquisition techniques. The most typical patterns of disease recurrence were: a roundish or nodular shape (the whole group of rectal amputations), irregular outline (25 of 27 cases), infiltrative growth (23 of 27), asymmetry (25 of 27), CT enhancement > 20 HU (24 of 27), medium-high MR signal intensity on T2-weighted images (26 of 27 cases). We report on 5 cases with no positive correlation between CT enhancement and MR signal on T2-weighted images, trying to correlate this disagreement with specific histopathologic patterns.

Adenocarcinoma↗
PubMed1995

[Role of CT and RM in postoperative evaluation of the patient after rectal carcinoma surgery: postoperative anatomy and nonneoplastic sequelae].

The CT and MRI findings in a series of 57 patients submitted to curative surgery for rectal cancer, 1989 to 1993, and locally free of disease at the time of examination, were retrospectively reviewed. Both postoperative anatomy and tissue repair features were studied relative to the different surgical approaches, i.e., rectum amputation, sphincter-saving resection, Hartmann technique. The retrospective analysis of CT and MR findings led to the identification of some signs rather typical of every predictable non-malignant postoperative event, with max accuracy when radiologic findings were correlated with clinical and laboratory findings, as well as with the results of baseline study performed about 3-6 months after surgery. Florid granulation tissue exhibited marked enhancement after i.v. contrast agent administration and high signal intensity on T2-weighted MR scans: such questionable findings as a pseudonodular pattern were often clarified on multiplanar MR images by the identification of normal anatomic structures within repairing scar tissue. The major features exhibited by fibrosis were low signal intensity on T2-weighted MR scans, laminar or spindle-like shape and some retraction of the surrounding tissues. Poor enhancement after i.v. contrast agent administration proved to be a less reliable diagnostic criterion. Abscesses were identified because of their water-like content and ring of peripheral enhancement, both easily demonstrated on CT scans. The differential diagnosis of necrotic colliquative recurrence required clinical correlation with a careful morphologic analysis of lesion outline. Non-colliquative inflammation exhibited no typical CT/MR features suggestive of diagnosis. Finally, radiation fibrosis was characterized by laminar pattern but its enhancement patterns and MR signal behavior were quite different from postoperative scar tissue: irregular enhancement spots and fairly high signal areas were often observed in these patients even months and years after radiation exposure.

Adenocarcinoma↗
PubMed1994

Myelolipoma of the adrenal gland presenting with dyspepsia and epigastric pain.

Myelolipomas are rare benign neoplasms of the adrenal glands, characterized by the presence of adipose tissue and elements of bone marrow in various degrees of differentiation. Usually asymptomatic, they are discovered incidentally or at autopsy; sometimes larger masses may cause local symptoms. We report clinical, radiologic and therapeutic aspects of a large myelolipoma of the right adrenal gland, presenting with unusual epigastric symptoms.

Abdominal Pain↗
PubMed1994

[The role of magnetic resonance in characterizing focal liver lesions].

128 Magnetic resonance (MR) investigations of single or multifocal nodular liver lesions were retrospectively reviewed. All lesions had been identified, but not characterized, with ultrasonography (US). All the studies were performed with a 0.5-T superconductive magnet (Philips Gyroscan); spin-echo (SE) T1/proton density/T2-weighted and inversion recovery (IR) pulse sequences were used routinely. Characterization was attempted considering the following variables: a) lesion outline; b) the presence of some kind of capsular or pseudocapsular ring; c-d) homogeneity of signal intensity and its difference from surrounding liver parenchyma; e) possible central scar and its signal features; f) associated lesions (multifocal nodules, ascites, locoregional adenopathies, venous thrombosis). Diagnostic confirmation was obtained by means of biopsy (63 patients), of other imaging techniques (35 patients), or of clinical follow-up over 12 months at least (30 patients). Our results confirm high MR accuracy in the diagnosis of hemangioma (48/50 cases, 96% confidence) and even higher accuracy in focal fatty liver infiltration (9/9 cases, 100% confidence), thanks to some typical MR signal patterns on appropriate acquisition techniques--i.e., SE multiecho pulse sequences and IR sequences, respectively, with liver and fat signal nulling. Primary non-malignant focal liver lesions were identified mainly on a morphological basis (smooth roundish outline with/without capsular or pseudocapsular ring; central starlet scar; "basket" or "spoked wheel" patterns): these features allowed the correct identification of 5/7 focal nodular hyperplasia cases. On the other hand, in the absence of these typical morphological features and of specific MR signal changes, adenomas were misdiagnosed in all cases but one. The study of focal lesions in cirrhotic liver disease exhibited 66.6% confidence in the diagnosis of regenerating nodules, on the basis of their iso/hypointensity relative to liver on T2-weighted pulse sequences. Such a behavior seems to be due to intracellular iron loading, to small cell size and to thin vascular network, which are typical of cirrhotic regenerating areas. The diagnosis of hepatocellular carcinoma relies on both morphostructural features and possible associated lesions: in our series, 22/25 cases (88% confidence) were correctly identified. Indeed, this result was somehow influenced by the case history of the patients and by specific serologic indexes. Finally, MRI exhibited high sensitivity in the detection of focal liver involvement in neoplastic patients. However, the intrinsic range of variability and the lack of specificity of MR signal intensity, because of different histopathologic cell types, do not usually allow an unquestionable diagnosis to be made, especially for single lesions.

Biopsy↗