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Biomedical subjects

D Caramella

Publications and source records attributed to D Caramella.

At least 73 records · Page 4Linked to original sources
PubMed1993

Acute spinal trauma: prognostic value of MRI appearances at 0.5 T.

Thirty-two patients with post-traumatic myelopathy were examined with a 0.5 T MRI system within 4 days of injury and the MRI findings analysed with respect to the immediate and residual functional deficit and (in 20 patients) the MRI appearances of the spinal cord in the chronic phase. In the acute phase a normal spinal cord was associated with only slight clinical deficit in four patients. Signal abnormalities in the spinal cord at the site of trauma were identified on T2-weighted spin-echo or T2*-weighted gradient-recalled echo images in 28 patients. The 12 most functionally impaired patients showed focal low signal suggestive of intramedullary haemorrhage: the other 16 had homogeneous high signal consistent with diffuse oedema. Swelling of the spinal cord and mild persistent cord compression following reduction were noted in 17 and 26 patients respectively. All patients were treated conservatively other than undergoing surgical decompression. Four died of complications. No patient with low signal in the spinal cord on initial MRI showed significant clinical improvement. Five whose spinal cord was hyperintense remained unchanged, whereas nine made a significant recovery, as did all patients with normal-appearing spinal cords. Cord compression on the initial examination was not relevant to clinical outcome. Intramedullary scars were identified at follow-up in 18 patients and were more extensive in those with haemorrhagic acute lesions. Haemorrhagic contusion of the spinal cord can be demonstrated in the acute phase with midfield MRI and is a valuable predictor of the functional outcome in patients with traumatic myelopathy.

Acute Disease↗
PubMed1993

Percutaneous injection of ethanol to treat autonomous thyroid nodules.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of sonographically guided percutaneous injection of ethanol for treating autonomous thyroid nodules in order to assess that technique's feasibility as an alternative to traditional ablative (radionuclide and surgical) therapies. SUBJECTS AND METHODS: Thirty-two patients with autonomous thyroid nodules were included in the study: seven had thyrotoxicosis, and 25 were in the pretoxic clinical phase. Ethanol was injected percutaneously on an outpatient basis once or twice a week for a total of three to 10 injections per nodule, mainly depending on the nodule's size. Scintigrams obtained 3 months after the end of treatment were used to assess response to this therapy. The follow-up period was from 3 to 30 months. RESULTS: Thyroid scintigraphy 3 months after percutaneous injection of ethanol showed complete recovery of function in extranodular tissue in 26 patients (81%), partial recovery in five patients (16%), and no recovery in one patient (3%). In all patients, the volume of the nodules decreased by more than 50% after treatment. In three of five patients in whom scintigraphy showed only partial recovery of function in extranodular tissue, a second percutaneous injection of ethanol was given after 15 months. The therapy was well tolerated, and after a total of 216 injections, no patient had permanent side effects. CONCLUSIONS: Our experience shows that percutaneous injection of ethanol is a practical alternative to traditional treatments for autonomous thyroid nodules and that it is an option for treating pretoxic adenoma.

Adult↗
PubMed1993

Cine-MR imaging of aqueductal CSF flow in normal pressure hydrocephalus syndrome before and after CSF shunt.

Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction.

Adolescent↗
PubMed1993

[Computer-assisted interactive didactic system in radiology].

A computer-assisted didactic interactive system for radiology is described; it was implemented on a widely available, cost-effective personal computer with advanced graphic features. A set of suitable CT images was selected and digitized with a specific software that also allowed to process the acquired images. After adding graphic and textual comments, the images were ready to be put in the tutorial. A second software tool was used to manage the image display and to control the correct sequence of the interactive steps of the tutorial. A series of computer-driven multiple-choice questions was prepared to provide the user with a tool improving his/her knowledge of the topics covered by the system, in a simple and unconventional way. The tutorial was designed so that both the absolute number and the percentage of correct answers can be displayed and the critical evaluation of incorrect answers is automatically performed; in the end, the system goes back to the first screen and the tutorial can be run again. The system performance is good with standard hardware; it can be markedly improved with the integration of peripherals--i.e. hard disk. In the next future, the commercial availability of more advanced storage media (videodisks and optical disks) will dramatically improve the archiving capacity and will reduce access times.

Computer-Assisted Instruction↗
PubMed1992

Neural network synthesis of spin echo multiecho sequences.

Spin echo multiecho sequences are not frequently used in clinical practice, because they allow the observation of one single slice, imaged at different echo times, for each acquisition. To limit examination time, multislice sequences that include only images derived from one or two echoes are usually acquired. Nevertheless, the strong T2 dependence of multiecho sequences can be used effectively to enhance the contrast between tissues with different T2 and to gather useful diagnostic information. Artificial neural networks can offer new interesting facilities to the radiologist. In fact, the learning capabilities of neural networks allow them to extract the prototypical behavior of a system from a set of examples. After learning, artificial neural networks can emulate the system behavior even in the presence of new inputs, as far as these are not too different from those included in the training set. A conveniently trained neural network can synthesize a multiecho sequence for each slice of a multislice sequence, requiring only two images for each slice to achieve reliable results. When compared with a true multiecho sequence, the images generated by the network preserve the contrast characteristics of the original ones and have a better signal-to-noise (SNR) ratio. In this paper we report the results achieved by using a neural network to reconstruct synthetic spin echo multiecho images of the brain.

Image Processing, Computer-Assisted↗
PubMed1992

[Percutaneous alcoholization of a small hepatocarcinoma].

Twenty-nine small hepatocellular carcinomas (sHCCs) less than 5 cm in diameter were treated with percutaneous ethanol injection (PEI) under US guidance in 24 cirrhotic patients. The nodules were treated on an outpatient basis with 6-18 ethanol injections; the total amount of alcohol delivered to each lesion was 10-103 ml. Twenty-seven of the 29 HCCs (93.1%) showed no evidence viable neoplastic tissue at a dynamic CT scan combined with multiple fine-needle biopsies performed one month after the end of treatment; in 10 cases MR confirmed the presence of necrosis showing marked hypointensity of the lesions in T2-weighted images. None of the 27 necrotized sHCCs recurred locally during a 4-44 months' follow-up period (mean 18 months). Two lesions larger than 4 cm showed incomplete response to treatment. No complications occurred after a total number of 264 alcohol injections. The 1-year survival rate in the 16 patients with a follow-up longer than 12 months was 93.7%. PEI proved to be a safe and effective treatment for sHCCs. In particular, PEI can be viewed as a reliable alternative to surgery in the management of nodules less than 3 cm in diameter, considering the operative hazards and the high risk of new lesions occurring in resected livers.

Administration, Cutaneous↗
PubMed1992

[Digital radiology with storage phosphors in cephalometric study in orthodontics].

Conventional radiology is continually modified with the development of digital systems which can be used for several types of radiologic examinations. Our study was aimed at evaluating the advantages of these new technologies in the orthodontic field, where the problems associated with image quality and radiation protection are major especially in young patients; the latter goal is achievable by dramatically reducing radiation dose and by avoiding repeating the exam. In our study, we compared lateral teleradiographs of the skull for cephalometric analysis obtained using conventional and digital diagnostic methods. The preliminary results demonstrated that the two imaging techniques did not differ relative to bone structure representation, even though the digital system provided better visualization of soft tissue structures. Computed radiography also allowed a marked reduction in the number of repeats and reduced radiation dose. The current disadvantages of this imaging method are the high initial cost of the equipment, reduced work rate, and the need of frequent technical assistance.

Adolescent↗
PubMed1992

MR imaging with STIR technique and air insufflation for local staging of bladder neoplasms.

Fifty-six patients with bladder carcinoma were studied with MR imaging for the assessment of the local stage, using the inversion recovery pulse sequence with fat suppression (STIR) with air in the bladder. With this technique images of the inner and the outer parts of the bladder wall were obtained, showing high contrast between the latter and the tumor (tumor/muscle contrast 89.9%). Four tumor stages were recognized: superficial neoplasms (Tis, Ta, and T1), partial wall infiltrating neoplasms (T2); total wall infiltrating neoplasms (T3a, T3b), and neoplasms involving other pelvic organs (T4). MR imaging was compared with histopathologic diagnosis obtained at transurethral resection or cystectomy. True-positive diagnosis was obtained in 80.4%; false-positive in 14.3% of cases; false-negative in 5.3%. Despite the relatively high incidence of overstaged neoplasms, STIR technique combined with air in the bladder allowed a good accuracy in local staging.

Adult↗
PubMed1992

[The echographic aspects of prostatic carcinoma before and after radiation treatment].

The authors evaluated the US patterns of 50 prostatic carcinomas before and after radiation therapy, analyzing the correlation of US patterns with histologic (bioptic) findings and with treatment outcome. Before radiation therapy, 28 tumors were hypoechoic, 8 were isoechoic and 14 mixed. In 18 of 28 hypoechoic carcinomas, the lesion showed a progressive increase in echogenicity, becoming completely isoechoic 9-18 months after the end of treatment. In this group of patients the final response to treatment was complete in 17 cases and partial in 1; during the follow-up (24-90 months, mean 48 months) neither local recurrences nor distant metastases were observed. In 10 of 28 hypoechoic carcinomas, a hypoechoic area of variable size was still clearly recognizable within the lesion after a minimum period of 18 months since the end of treatment. Nine of these patients underwent histology and persistent carcinomas were found in 8 of them; one patient developed distant metastases. In the group of isoechoic and mixed carcinomas, no significant differences were observed in the US patterns relative to treatment outcome. Persistent prostatic carcinoma after radiation therapy seems not to affect its US pattern. If the tumor is hypoechoic before treatment, the persistence of a hypoechoic area within the lesion 18 months after the end of treatment must be regarded as a possible therapeutic failure and histologically verified. On the contrary, the evolution of the lesion toward isoechogenicity is usually related to a favorable outcome. If the tumor is isoechoic or mixed before treatment, a reliable US evaluation is not possible and the correct assessment of the response to treatment can only be made with multiple biopsies.

Adenocarcinoma↗
PubMed1992

Assessment of liver iron overload in thalassemic patients by MR imaging.

The use of MR imaging has been proposed for the assessment of the hepatic iron overload in transfusion-dependent thalassemic patients treated with desferrioxamine. The aim of the study was to correlate serum ferritin levels and MR signal intensity of the liver parenchyma. Results on 12 patients showed that the ratios between the signal intensity of liver parenchyma and muscle and fat are promising parameters for predicting iron overload.

Adolescent↗
PubMed1991

[The incidence of disk changes in volleyball players. The magnetic resonance findings].

In order to evaluate the to potential hazards related to athletic functional overload on the intervertebral disk we studied with MRI the incidence of intervertebral disk abnormalities in a group of 45 volunteers who had been playing professional volleyball for 3-7 years. As a control group we examined with MRI 30 professional swimmers as well. Among the volley-ball players the incidence of intervertebral disk alterations was 44.4%; they were represented by 8 cases of disk degeneration, 11 cases of bulging and 9 disk herniations (in 8 patients the simultaneous presence of more than one lesion was observed). In the control group the incidence of such lesions was 20%. The obtained results were correlated with the clinical findings and the age of the athletes. Among the 26 athletes with back pain only 13 had positive findings at MRI, while among the 19 asymptomatic athletes 7 showed lesions detectable with MRI. As for age, we observed that the younger athletes (17-19 years) had positive MRI findings in 38.5% of cases, while the players in the age group ranging from 23 to 26 years, had positive MRI findings in 56.2% of cases. The analysis of the different types of training of the volley-ball players and the control group, showed that 19 volley-ball players who followed appropriate training procedures had positive MRI findings in 21.1% of cases (in the control group the percentage was 20%). Among the 26 athletes who were trained with exercises that caused significant functional overload, 16 had intervertebral disk lesions at MRI (61.5%). Moreover, our data showed that the correlation of the incidence of disk lesions with the type of training (and relative varying degree of overload) is definitely more important than the one existing with the age of volley-ball players and the overall period of their athletic activity. MRI proved to be a useful technique for the early assessment of the intervertebral disk damage caused by an incorrect training in young athletes, even when asymptomatic.

Adolescent↗
PubMed1991

[The continent perineal colostomy after abdominoperineal resection of the rectum. A digital defecographic study].

For 10 years, in the Surgery Dept. of the University of Pisa, perineal colostomies have been performed on patients who had undergone abdominoperineal rectal amputation. The gracilis muscles of the thighs, transposed to the perineum, are used for building a continent muscular apparatus. Seventeen of 40 patients operated with this procedure have been submitted to defecographic studies, by means of digital fluoroscopic image acquisition. This modality allowed the visualization of anastomotic colon morphology as well as of the functionality of the transposed gracilis muscles during the various phases of defecography. The muscle surrounding the colostomy acts as a sphincter and relaxes only during evacuation; the one positioned as a sling acts as the normal puborectalis muscle. In two patients a perineocele was documented, causing problems in the evacuation phase, which were solved after surgical intervention.

Colostomy↗
PubMed1991

[Problems and errors of magnetic resonance in the diagnosis of renal masses].

Since the impact of MRI on the diagnostic evaluation of renal masses is affected by the intrinsic complexity of the modality, the problems related to the specific knowledge, on the part of the radiologist, of the examination itself to make a correct diagnosis are carefully analyzed. The problems related to the technical features of the equipment are presented as well, with a special emphasis on the still inadequate spatial resolution of MRI, and on its long acquisition time and unfavorable signal-to-noise ratio. On the other hand, its good contrast resolution is mentioned, which will be further improved by the new gradient-echo sequence (GRE) and by the use of paramagnetic contrast media. As for diagnostic problems, the results are analyzed of a series of 62 patients showing US "solid" renal mass. MRI allowed lesion detection in 59/62 cases, with 95.1% sensitivity. False negatives were due solely to the poor image quality determined by motion artifacts. MRI did not provide significant information in the structural evaluation of the lesions when tissue characterization was concerned, but was helpful in the correct assessment of necrotic foci (thus allowing the calculation of viable neoplastic mass) and in the detection of collateral vessels. Finally, the spatial relationships of the mass could be easily assessed by MRI, thanks to both its multiplanarity and to its good capabilities in the visualization of vascular involvement.

Diagnostic Errors↗
PubMed1990

Neurological damage in patients irradiated twice on the spinal cord: a morphologic and electrophysiological study.

We reviewed the files of 950 patients treated for Hodgkin's disease since 1966 and were able to find five patients treated with radiochemotherapy and irradiated twice on volumes including a cord segment, at various time intervals, and surviving until now. Seven patients with comparable clinical and therapeutic features, but not reirradiated on the cord, were chosen as a control group and were examined with the same diagnostic procedures. The cumulative cord dose in the reirradiated patients was recalculated and ranged from 50 to 70 Gy. All these patients and the control cases were followed up for more than 10 years and presented no or only minor neurological symptoms. We compare the results of both magnetic resonance imaging (MRI) and electrophysiological studies (spinal and scalp recorded somatosensory evoked potentials--SEPs) in an attempt to define the characteristics of the subclinical damage present in these patients. While no cord abnormality was demonstrated with MRI, electrophysiological studies evidenced a clear difference between cases and controls, as far as the D10-P1 conduction time and SEPs average amplitude are concerned. Advantages and drawbacks of a wider use of electrophysiological methods in research work on cord radiation damage are presented, along with the possible implications of the results obtained for the understanding of the pathogenesis and of the dose dependence of radiation myelitis (RM).

Adult↗
PubMed1989

Hematopoietic bone marrow recovery after radiation therapy: MRI evaluation.

Magnetic resonance imaging (MRI) is able to detect the increase of adipocytes in the hematopoietic bone marrow that occurs as a consequence of radiotherapy and is indicative of the loss of myeloid tissue. By monitoring this process, it is also possible to determine the recovery of the bone marrow. The amount of viable hematopoietic tissue plays a fundamental role in determining whether the patient is able to undergo further antineoplastic therapy, particularly chemotherapy. We examined 35 patients who had been treated with radiotherapy for Hodgkin's lymphoma (12), uterine cervix carcinoma (nine), ovarian dysgerminoma (six), testicular seminoma (four), and non-Hodgkin's lymphoma (four). We observed that radiation-induced modifications of the MRI pattern in the bone marrow are tightly linked to two parameters; the administered radiation dose and the length of time passed after the treatment. Bone marrow recovery was observed only when patients were treated with doses lower than 50 Gy. The earlier radiation-induced modifications of the bone marrow MRI pattern occurred 6 to 12 months after irradiation, and they were most evident 5 to 6 years after the treatment. From 2 to 9 years after radiotherapy, we observed partial recovery. Complete recovery, when it occurred, was observed only 10 to 23 years after the treatment. Our results indicate that MRI studies are likely to be useful in the assessment of radiation-induced injuries.

Bone Marrow↗
PubMed1989

Brain damage after treatment for acute lymphoblastic leukemia. A report on 34 patients with special regard to MRI findings.

In 34 patients treated for acute lymphoblastic leukemia (ALL), central nervous system (CNS) damage was assessed by clinical evaluation and brain magnetic resonance imaging (MRI). Twenty-seven of them had been off therapy from 5 to 109 months (median 64 months) while 7 had not completed the maintenance phase of their treatment. All the patients were disease-free when evaluated. None of the 3 patients who showed clinical CNS damage during the follow-up was symptomatic when submitted to MRI, while periventricular hyperintensity in T2-weighted images, suggestive of leukoencephalopathy, was present in 8 of the 34 patients. These subclinical abnormalities appear to be more frequent, transient in nature and treatment-related in patients evaluated shortly after the induction phase. Similar MRI findings seem, on the contrary, to be consequences of the disease on the CNS when appearing in long-term survivors.

Brain Damage, Chronic↗
PubMedDate not supplied

Transcatheter arterial embolization followed by percutaneous ethanol injection in the treatment of hepatocellular carcinoma.

PURPOSE: The aim of this study was to evaluate the effectiveness of transcatheter arterial embolization (TAE) followed by percutaneous ethanol injection (PEI) in the treatment of large hepatocellular carcinoma (HCC) lesions. METHODS: Fifteen patients with HCC were treated by means of TAE followed by 6-16 ethanol injections. In 10 patients, the HCC was solitary (3-8 cm); 3 patients had 1, and 2 patients had 2 daughter nodules (3 cm or smaller) in addition. In 12 of 15 main tumors and in 4 of 7 daughter nodules, a tumor capsule was observed by computed tomography or magnetic resonance imaging. RESULTS: Combined treatment with TAE and PEI resulted in complete necrosis of 12 of 15 main tumors and 7 of 7 daughter nodules on biopsy. Treatment failure (incomplete necrosis) occurred in 3 unencapsulated main tumors. The 1-year survival rate in 10 patients was 100%. CONCLUSION: The combination of TAE and PEI proved to be an effective treatment for large HCC, including those with 1-2 small daughter nodules. The presence of a tumor capsule significantly correlates (p < 0.05) with a favorable outcome of treatment.

Aged↗