PubMed Health⌕ Search

Biomedical subjects

M Midiri

Publications and source records attributed to M Midiri.

At least 37 records · Page 2Linked to original sources
PubMed2000

Abdominal wall hernias: imaging with spiral CT.

Computed tomography is an accurate method of identifying the various types of abdominal wall hernias, especially if they are clinically occult, and of distinguishing them from other diseases such as hematomas, abscesses and neoplasia. In this study we examined the CT images of 94 patients affected by abdominal wall hernias observed over a period of 6 years. Computed tomography clearly demonstrates the anatomical site of the hernial sac, the content and any occlusive bowel complications due to incarceration or strangulation. Clinical diagnosis of external hernias is particularly difficult in obese patients or in those with laparotic scars. In these cases abdominal imaging is essential for a correct preoperative diagnosis and to determine the most effective treatment.

Aged↗
PubMed2000

Small renal masses: assessment of lesion characterization and vascularity on dynamic contrast-enhanced MR imaging with fat suppression.

OBJECTIVE: The aim of our study was to characterize renal lesions equal to or smaller than 3.0 cm using dynamic contrast-enhanced MR imaging with fat suppression by means of quantitative analysis of signal intensity. MATERIALS AND METHODS: We retrospectively reviewed the MR imaging examinations of 35 patients (20 with renal cell carcinoma, eight with angiomyolipoma, and seven with complicated cysts) who were studied with spin-echo and dynamic fat-suppressed gradient-recalled echo MR sequences, before and after the administration of gadopentetate dimeglumine. Every 30 sec after contrast injection, we measured the lesion percentage of enhancement and the ratio of contrast (lesion-renal cortex signal intensity difference) to noise. RESULTS: Ten renal cell carcinomas were classified as hypervascular (enhancement greater than that of renal cortex) and 10 as hypovascular. The percentage of enhancement of hypervascular carcinomas was similar to that of renal cortex until 150 sec and greater in the late sequences (180-210 sec, p < 0.01). Hypovascular carcinomas had a lower percentage of enhancement than hypervascular carcinomas (60-210 sec, p < 0.005). Angiomyolipomas, after an early enhancement peak, showed values similar to those of hypovascular carcinomas. Complicated cysts had very low enhancement (p < 0.001). The baseline contrast-to-noise ratio was negative for all lesions (hypointensity with respect to renal cortex). After gadolinium injection, the contrast-to-noise ratio of hypervascular carcinomas rose, becoming positive after 150 sec. Until 60 sec, the contrast-to-noise ratio of hypovascular carcinomas declined slightly, whereas that of angiomyolipomas and cysts fell sharply; then the three curves remained stable (60-210 sec, p < 0.05 for all matches except angiomyolipomas versus cysts). CONCLUSION: Quantitative analysis of signal intensity variations during dynamic contrast-enhanced MR imaging with fat suppression can be useful in the characterization of small renal lesions.

Adult↗
PubMed2000

[Aortic intramural hematoma: aspects with spiral computerized tomography].

PURPOSE: To evaluate the signs of aortic intramural hematoma with helical CT and the diagnostic role of this technique in patients with this condition. MATERIAL AND METHODS: We reviewed the CT findings of 396 patients submitted to emergency examinations for suspected aortic dissection from 1995 to 1999. Only 18 patients (6 women and 12 men) had CT signs of aortic intramural hematoma. Helical CT studies were carried out with the following parameters: slice thickness 10 mm, reconstruction index 10, feed 1.5 mm, conventional algorithm with minimum values of 130 kV and 125 mA. All patients were examined with dynamic contrast-enhanced CT, before and after a power injection of 130 mL ionic contrast material. We studied: hematoma localization and longitudinal extension; thickness and density of aortic wall; presence and location of intimal calcifications; integrity of intimal wall; hemomediastinum and/or hemothorax. RESULTS: Aortic wall thickening appeared as a high density crescent-shaped area at baseline CT and had low density on enhanced images in all patients. Thickening was eccentric in 14/18 patients and concentric in 4/18 only; it always exceeded 4 mm. We found some intimal calcifications in 8 patients and hemothorax and/or hemomediastinum in 9 patients. A patient with type A hematoma died of cardiac tamponade a few hours after CT diagnosis. Six patients (5 type B and 1 type A) underwent anti-hypertensive treatment and radiological follow-up. Eleven patients (6 type A and 5 type B) underwent prosthesis replacement and 5 of them (3 type A and 2 type B) died of postoperative complications. In the 5 type B patients surgery was performed because of treatment-resistant pain and of the onset of ischemic complications to abdominal organs caused by involvement of the main collateral branches of the aorta. One patient with type A hematoma was submitted to drug treatment because it was judged unresectable. DISCUSSION AND CONCLUSIONS: Intramural hematoma of the aorta is a distinct pathological entity, which should not be confused with aortic dissection. The imaging techniques (TEE, CT, MRI) have an important role in the final diagnosis of aortic hematoma. Presently Helical CT and MR angiography are the main tools in the early diagnosis of this condition before the development of complications. In our experience helical CT, before and after the administration of contrast material, was accurate in identifying the hematoma localization and extension.

Aged↗
PubMed2000

[Pre- and postoperative study of the bile ducts with spiral computerized tomography].

PURPOSE: To investigate the capabilities of Helical CT in imaging the biliary tract after administration of an oral cholecystographic contrast agent. MATERIAL AND METHODS: Forty-five adult patients and one 8-year-old child were examined with Helical CT 12 hours after the oral administration of hyopanoic acid (3 g). All the examinations were performed with the following parameters: thickness 5 mm, pitch factor 1.5, standard reconstruction algorithm, acquisition time 20-30 s, image index 2.5 mm, 130 kV, 125 mA. In 37 cases CT was performed in patients candidate to laparoscopic cholecystectomy, in 8 cases to assess the positioning of surgical clips in patients with postcholecystectomy syndrome and in 1 case (the 8-year-old child) to confirm the US diagnosis of choledochal cystic dilatation. Helical CT images were reconstructed with a Volume Rendering (VR) software. RESULTS: The extrahepatic biliary tract was visualized in all the cases with CT and VR. II grade biliary ducts were visualized in 87% (CT) and 91% (VR), III grade ducts in 76% (CT) and 78% (VR), IV grade ducts in 28% and 35%, respectively. No statistically significant difference was found between CT and VR in the visualization of the biliary structures (p > 0.05), while three-dimensional VR reconstructions improved the evaluation of the anatomical relations in the biliary tract in comparison with CT both in normal cases and in patients with congenital abnormalities of the biliary tract. Also, three-dimensional VR reconstructions were superior in assessing the correct positioning of surgical clips in patients with postcholecystectomy syndrome (p < 0.05). DISCUSSION AND CONCLUSIONS: Cholecysto-cholangio-CT with VR reconstructions is a reliable imaging technique for the biliary tract in patients candidate to laparoscopic cholecystectomy, to diagnose choledochal cystic dilatation and to assess the positioning of surgical clips.

Administration, Oral↗
PubMed2000

[Acquired immunodeficiency syndrome and pulmonary Mycobacterium xenopi infection. Role of computerized tomography].

INTRODUCTION: Mycobacterium xenopi is one of the most common agents responsible for nontubercular mycobacterial pulmonary disease on AIDS patients. These lesions have been studied with conventional radiography, while CT has been used in patients with aspecific mycobacterioses or non-AIDS pulmonary conditions from Mycobacterium xenopi. PURPOSE: We investigated the yield of CT in the study of lung lesions from Mycobacterium xenopi in AIDS patients. MATERIAL AND METHODS: We examined 12 AIDS patients with pulmonary lesions from Mycobacterium xenopi, patients age ranged 30 to 46 years. All patients had CD4 blood levels lower than 250 cells/mL and Mycobacterium xenopi in the sputum. All patients underwent a standard chest radiograph and a CT examination. CT images were evaluated by three radiologists independently and the definitive diagnosis was made in the presence of a fourth radiologist. RESULTS: Chest CT showed parenchymal consolidation in 66% of cases, associated with bilateral basal bands in 16% of cases. Consolidation was unilateral in 41% of cases and most frequently involved the right lower lobe. Bilateral reticular interstitial involvement was seen in the patients (41%). Micronodules in 1 patient (8%) and mediastinal adenopathy in 33% of cases. Two patients had pre-xisting emphysema and 1 had bronchiectasis. DISCUSSION AND CONCLUSIONS: The frequency of lung disease from Mycobacoerium xenopi has increased because of the spreading of the HIV infection. Such lung lesions in AIDS patients are aspecific in appearance and localization, which the clinical radiologist needs to consider to address treatment planning. The frequent finding of parenchymal consolidation and the absence of cavitary lesions may be referred to the poor capability of AIDS to produce an adequate inflammatory response. The lung lesions tend to distribute in the lower lobes unilaterally. Adenopathy was also a frequent finding. CT plays a fundamental role in studying the chest of these patients because it permits to locate lung lesions with higher accuracy than conventional radiography and to detect adenopathies, micronodules reticular interstitial involvement and bronchiectases.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Magnetic resonance imaging of the pituitary gland in patients with secondary hypogonadism due to transfusional hemochromatosis.

To identify pituitary iron overload in patients with transfusional hemochromatosis causing secondary hypogonadism, we prospectively evaluated signal intensity abnormalities of the anterior lobe of the pituitary gland of 18 patients affected by transfusion-dependent thalassemia major and secondary hypogonadism. Magnetic resonance (MR) imaging is useful to assess pituitary iron overload in patients with transfusional hemochromatosis and secondary hypogonadism by detection of a significant decreased signal intensity of the anterior lobe of the pituitary gland on GRE T2*-weighted images. The decreased signal intensity of the anterior lobe of the pituitary gland on GRE T2*-weighted images was correlated to increasing serum ferritin level (r = -0.84, r2 = -0.70, P < 0.001). Indeed, the lower the signal intensity of the pituitary gland, the greater the serum ferritin level. However an exact quantification of pituitary iron overload by correlation with serum ferritin level is not allowed. No correlation was found between MR imaging results and hormonal status; however, the detection of pituitary iron overload on GRE T2*-weighted images is consistent with the hypothesis of hypogonadotrophic pituitary insufficiency due to iron-induced cellular damage.

Adolescent↗
PubMed1999

Hamartoma of the urinary bladder: case report and review of the literature.

Bladder hamartoma is a rare benign entity with only eight cases reported in the literature thus far, and whose general imaging features have not, to our knowledge, been previously discussed. The purpose of this report is to review the literature and to discuss the imaging findings in one case of bladder hamartoma where US features were those of an inhomogeneous solid mass with an unechogenic center, which was in accordance with the CT findings of a soft tissue mass with central inhomogeneous enhancement due to central necrosis.

Adult↗
PubMed1999

Right aortic arch with aberrant left innominate artery: MR imaging findings.

A rare case of a 60-year-old man with a right aortic arch and aberrant left innominate artery is presented. This case had an unusual clinical presentation. The dysphagia appeared suddenly in adulthood, whereas vascular rings, when symptomatic, usually manifest early in childhood. To our knowledge, MR imaging findings of this anomaly have never been reported. The diagnosis was made by MR imaging and confirmed by surgery. Magnetic resonance imaging can replace angiography in the assessment of the aortic arch anomalies.

Abnormalities, Multiple↗
PubMed1999

TIPS for prevention of recurrent bleeding in patients with cirrhosis: meta-analysis of randomized clinical trials.

PURPOSE: To compare the effects of transjugular intrahepatic portosystemic shunt (TIPS) creation with those of endoscopic treatment with or without propranolol administration (i.e, conventional treatment) on recurrent bleeding, encephalopathy, and mortality by using meta-analysis of 11 published randomized clinical trials. MATERIALS AND METHODS: Data from 11 relevant studies were retrieved by means of computerized and manual search. The combinability of the studies was assessed in terms of clinical and statistical criteria. Data were extracted on the basis of the intention-to-treat principle, and treatment effects were measured as risk differences between TIPS creation and conventional treatment. Pooled estimates were computed according to a random-effects model. RESULTS: A total of 750 patients were included in 11 trials. No significant heterogeneity was found for any of the outcomes. Pooled risk differences were recurrent bleeding, -31% (95% CI, -39%, -23%); encephalopathy, +16% (95% CI, +10%, +22%); death due to all causes, +2% (95% CI, -4%, +9%); and death due to bleeding, -5% (95% CI, -11%, +6%). Clinically important complications occurred in 22% of patients and were associated with both treatments. TIPS dysfunction occurred in 55% of patients. CONCLUSION: TIPS creation markedly reduces risk of rebleeding but increases risk of encephalopathy without affecting survival. Therefore, TIPS creation may not be the best first-choice therapy for prevention of recurrent variceal bleeding. Criteria for selection of candidates for TIPS creation should be assessed in future prospective studies.

Esophageal and Gastric Varices↗
PubMed1999

MR imaging of pancreatic changes in patients with transfusion-dependent beta-thalassemia major.

OBJECTIVE: The aim of this study was to evaluate MR imaging changes of the pancreas in patients with transfusion-dependent beta-thalassemia major. SUBJECTS AND METHODS: Twenty patients with transfusion-dependent beta-thalassemia major were examined using MR imaging at 0.5 T, with spin-echo T1-weighted, fast spin-echo T2-weighted, and gradient-echo T2*-weighted sequences. Image analysis was performed to assess pancreas-to-fat signal intensity ratios for all pulse sequences. Pancreatic exocrine and endocrine function and serum ferritin levels were assessed. Twenty healthy volunteers underwent MR imaging with the same three sequences and served as a control group. RESULTS: The pancreas-to-fat signal intensity ratio was significantly decreased in 17 (85%) of the 20 patients on spin-echo T1-weighted images (p < .05), fast spin-echo T2-weighted images (p < .01), and gradient-echo T2*-weighted images (p < .01) when compared with the 20 volunteers in the control group. The pancreas-to-fat signal intensity ratio was significantly increased in three (15%) of the 20 patients on spin-echo T1-weighted images (p < .01) and fast spin-echo T2-weighted images (p < .05). In addition, in the 20 patients, we found a significant correlation between increased pancreas-to-fat signal intensity ratios and decreased serum trypsin levels (r = -.77, p < .01 for spin-echo T1-weighted sequences; r = -.75, p < .05 for fast spin-echo T2-weighted sequences; and r = -.74, p < .05 for gradient-echo T2*-weighted sequences). Likewise, for the 20 patients, we found a significant correlation between decreased pancreas-to-fat signal intensity ratios and increased serum ferritin levels for gradient-echo T2*-weighted images (r = -.65, p < .01). No correlation was found for the other clinical parameters evaluated. CONCLUSION: MR imaging revealed signal intensity changes in the pancreas of patients with transfusion-dependent beta-thalassemia major. Patients with a major impairment of the exocrine pancreatic function had higher signal intensity of the pancreas because of fatty replacement of the parenchyma.

Adolescent↗
PubMed1999

[Color Doppler-echo in rheumatoid arthritis with extra-articular location. Preliminary experience].

INTRODUCTION: Chronic inflammation in rheumatoid arthritis usually involves articular synovia and extends to other joint components such as bursae, tendons and sheaths. Conventional US with high frequency transducers is an accurate tool for assessing abnormal changes in evolutive rheumatoid arthritis. We investigated the role of color and power Doppler imaging in staging extra-articular involvement, monitoring local inflammatory changes and drug treatment response. MATERIAL AND METHODS: We used a color Doppler unit with a 5-10 Mhz transducer and automatic power Doppler switch to examine 23 patients with tenosynovitis of the flexor (4/23) and extensor (8/23) tendons of the hand, Achilles (6/23) and posterior tibial (3/23) tendons, and long head of biceps (2/23) in acute rheumatoid arthritis. Only minimal pressure was exerted with the probe on the patients' skin to avoid compression and collapse of blood vessels. Ten normal volunteers were also examined as a control group. RESULTS: In all 23 acute rheumatoid arthritis patients, conventional US showed tendon involvement with intra-articular fluid, thickened tendons with partial tear and markedly hypoechoic thickened sheaths. Color signals were shown in all patients. Mid-caliber vessels were visualized coursing straight from the sheath deep into the tendon. Intra-articular signals were seen in 10/12 patients only. Spectral analysis showed arterial flow, with RI ranging .40-.70. Power Doppler added no important information, but improved vessel depiction relative to color Doppler thanks to its higher accuracy in detecting flow signals. There were no color signals in the tendons of the 10 healthy volunteers in the control group. No color signals were seen in both joints and tendons in 12 patients submitted to medical treatment. CONCLUSION: Color and power Doppler can be a necessary and useful integration to high resolution US for flow mapping in rheumatoid arthritis patients with tendon and extra-articular involvement. These modes depict local circulation changes related to disease stage and treatment response.

Adult↗
PubMed1998

Nocardial adrenal abscess: CT and MR findings.

To our knowledge, four bacterial adrenal abscesses in adults have already been reported in the international literature, but an adrenal Nocardia abscess has never been described previously. In this report the CT and MR imaging appearances and the differential diagnosis of the entity are discussed. The mass could resemble a malignancy. The observation of a rapid growth and colliquation of the mass helped in distinguishing it from a malignancy. The associated pulmonary infection provided a further clue to the diagnosis. The diagnosis was confirmed by surgery.

Abscess↗