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Biomedical subjects

A Boubaker

Publications and source records attributed to A Boubaker.

At least 19 recordsLinked to original sources
PubMed2006

[Aneurysmal bone cyst of the cranial base treated by partial resection and calcitonin injection. A case report].

STUDY DESIGN: First published report of a cranial aneurysmal bone cyst (ABC) treated successfully with intralesional injection of calcitonin. OBJECTIVES: To describe a safe and effective treatment method for ABCs of the cranial base. SUMMARY OF BACKGROUND DATA: ABC is a rare form of dystrophic pseudotumor. Less than 100 cases involving the skull have been reported in the literature, most of them localised in the cranial vault. Cranial base locations are rare and difficult to treat. We selected this treatment after a very rapid recurrence of the lesion following a partial resection. Method. - After a partial resection of a 10 cm petro-occipital ABC that encased the vertebral artery and the lower cranial nerves, an Ommaya reservoir was implanted with a catheter tip inside the ABC. Repeated intralesional injections of calcitonin were performed through the reservoir. RESULTS: Shrinkage of the cyst occurred with disappearance of its heterogeneous cystic content and ossification of its walls. There was no complication and the lesion remains quiescent at a 3 year follow-up. CONCLUSION: We reviewed the pertinent literature concerning percutaneous treatment of ABC. The percutaneous intralesionnal injection of calcitonin was reported in the literature only in 3 publications reporting 9 cases that did not involve the skull. This treatment seems safe and effective, worthy in cranial base ABCs that are difficult to resect completely.

Adolescent↗
PubMed2005

[Antenatally detected hydronephrosis: practical approach for the pediatrician].

Approximately 1% of the fetuses present some dilatation of their urinary tract in utero. More than 50% of these antenatally detected hydronephrosis will disappear spontaneously after birth. The other 50% comprises ureteropelvic junction obstruction, vesico-ureteral reflux and primary megaureters. Postnatal radiological evaluation (renal ultrasonography and VCUG) is performed in every infant with a significantly dilated renal pelvis (> 8 mm between 20 and 30 weeks or > 10 mm after 30 weeks in utero). Renal nuclear scan should be done in every child with significant/worsening post-natal hydronephrosis. Antibioprophylaxis will be started from birth to prevent urinary tract infection. Medical or surgical approach will be chosen in the light of the uroradiological exam results and the clinical progress.

Female↗
PubMed2003

Nuclear medicine procedures and neuroblastoma in childhood. Their value in the diagnosis, staging and assessment of response to therapy.

Neuroblastoma is a frequent tumor of childhood and remains a leading cause of death despite treatment intensification. Many clinical, biological and genetic factors have been identified and are associated with prognosis and outcome after treatment. Initial staging plays a major role for determining the therapeutic strategy. Radioiodinated metaiodobenzylguanidine (MIBG) scintigraphy is a highly sensitive and specific method for diagnosing, staging and also monitoring response to therapy. In children with high-risk neuroblastoma, relapse may occur any time after remission has been obtained. (123)I-MIBG scintigraphy is a reliable method to follow-up those children and allows early detection of recurrence. As far as outcome is concerned, MIBG scintigraphy has not proven to have any prognostic value. Other radiolabeled tracers, such as pentetreotide, monoclonal antibodies, and sestamibi have been compared with MIBG. Up to now, no method has demonstrated a reliable prognostic value, even though neuroblastoma that express somatostatin receptor seem to have a better clinical outcome and survival rate. Positron emission tomography (PET) with (18)F-fluorodeoxyglucose has been used successfully in staging and monitoring response to treatment of MIBG negative tumors. (11)C-hydroxyephedrine has shown promising results in staging neuroblastoma, but is not as widely available as MIBG. With respect to biological and genetic factors, nuclear medicine procedures play a major role in initial diagnosis and staging of neuroblastoma. At the moment, MIBG scintigraphy is certainly the most sensitive and specific method for initial staging of the disease, as well as monitoring the response to treatment and detecting early relapse.

3-Iodobenzylguanidine↗
PubMed2001

F+0 renography in neonates and infants younger than 6 months: an accurate method to diagnose severe obstructive uropathy.

UNLABELLED: We studied the response to F+0 renography and the relative and absolute individual kidney function in neonates and < 6-mo-old infants before and after surgery for unilateral ureteropelvic junction obstruction (UJO). METHODS: The results obtained at diagnosis and after pyeloplasty for 9 children (8 boys, 1 girl; age range, 0.8-5.9 mo; mean age +/- SD, 2.4 +/- 1.5 mo) with proven unilateral UJO (i.e., affected kidney [AK]) and an unremarkable contralateral kidney (i.e., normal kidney [NK]) were evaluated and compared with a control group of 10 children (6 boys, 4 girls; age range, 0.8-2.8 mo; mean age, 1.5 +/- 0.7 mo) selected because of symmetric renal function, absence of vesicoureteral reflux or infection, and an initially dilated but not obstructed renal pelvis as proven by follow-up. Renography was performed for 20 min after injection of (123)I-hippuran (OIH) (0.5-1.0 MBq/kg) immediately followed by furosemide (1 mg/kg). The relative and absolute renal functions and the response to furosemide were measured on background-subtracted and depth-corrected renograms. The response to furosemide was quantified by an elimination index (EI), defined as the ratio of the 3- to 20-min activities: An EI > or = 3 was considered definitively normal and an EI < or = 1 definitively abnormal. If EI was equivocal (1 < EI < 3), the response to gravity-assisted drainage was used to differentiate AKs from NKs. Absolute separate renal function was measured by an accumulation index (AI), defined as the percentage of (123)I-OIH (%ID) extracted by the kidney 30-90 s after maximal cardiac activity. RESULTS: All AKs had definitively abnormal EIs at diagnosis (mean, 0.56 +/- 0.12) and were significantly lower than the EIs of the NKs (mean, 3.24 +/- 1.88) and of the 20 control kidneys (mean, 3.81 +/- 1.97; P < 0.001). The EIs of the AKs significantly improved (mean, 2.81 +/- 0.64; P < 0.05) after pyeloplasty. At diagnosis, the AIs of the AKs were significantly lower (mean, 6.31 +/- 2.33 %ID) than the AIs of the NKs (mean, 9.43 +/- 1.12 %ID) and of the control kidneys (mean, 9.05 +/- 1.17 %ID; P < 0.05). The AIs of the AKs increased at follow-up (mean, 7.81 +/- 2.23 %ID) but remained lower than those of the NKs (mean, 10.75 +/- 1.35 %ID; P < 0.05). CONCLUSION: In neonates and infants younger than 6 mo, (123)I-OIH renography with early furosemide injection (F+0) allowed us to reliably diagnose AKs and to determine if parenchymal function was normal or impaired and if it improved after surgery.

Case-Control Studies↗
PubMed2000

Combination of clinical and V/Q scan assessment for the diagnosis of pulmonary embolism: a 2-year outcome prospective study.

With the aim of evaluating the efficiency of our diagnostic approach in patients with suspected acute pulmonary embolism (PE), we prospectively studied 143 patients investigated by means of a ventilation/perfusion (V/Q) lung scan. A pre-test clinical probability of PE (Pclin) was assigned to all patients by the clinicians and scans were interpreted blinded to clinical assessment. A 2-year follow-up of our patients was systematically performed and possible in 134 cases. Distribution of clinical probabilities was high Pclin in 22.5%, intermediate Pclin in 24% and low Pclin in 53.5%, whereas the distribution of scan categories was high Pscan in 14%, intermediate Pscan in 18%, low Pscan in 57% and normal Pscan in 11%. The final prevalence of PE was 24.5%. High Pscan and normal Pscan were always conclusive (19 and 15 cases respectively). Low Pscan associated with low Pclin could exclude PE in 43/45 cases (96%). None of the patients in whom the diagnosis of PE was discarded had a major event related to PE during the 2-year follow-up. Overall, the combined assessment of clinical and scintigraphic probabilities allowed confirmation or exclusion of PE in 80% of subjects (107/134) and proved to be a valuable tool for selecting patients who needed pulmonary angiography, which was required in 20% of our patients (27/134).

Adult↗
PubMed2000

[Investigation of the urinary tract in children in nuclear medicine].

The early detection of urologic abnormalities by antenatal sonography has resulted in the investigation of many infants and neonates for suspicion of either obstructive uropathy or reflux nephropathy. Nuclear medicine techniques allow to assess renal parenchyma integrity, to detect pyelonephritic scars and to measure absolute and relative renal function; these methods are easy to perform and reproducible, without any sedation, repeated venous punctures or bladder catheterization. Furthermore, the use of dynamic tubular tracers and frusemide test is a very usefull method which can differentiate between upper and/or lower urinary tract obstruction and determine the degree of obstruction (severe or incomplete) in order to plan for surgery or conservative treatment. The detection of vesicoureteric reflux may be difficult as it is an intermittent phenomenon: the use of the indirect radionuclide cystography (IRC), that is to say after completion of a dynamic renography, allows to detect reflux with a high sensitivity because images can be recorded continuously until the child voids, without any bladder catheterization and at low radiation dosis. In case of discordant results between micturating cysto-urethrography and IRC or of concomittant obstructive uropathy, the direct radionuclide cystography (DRC) is indicated for appropriate treatment. Nuclear medicine techniques do not give morphological information about the urinary tract and should be considered as complementary to radiological investigations in first evaluation of children with recurrent urinary tract infections or hydronephrosis.

Age Factors↗
PubMed1999

[Prognostic aspects of scintigraphy and MRI during the first 6 months of reflex sympathetic dystrophy of the distal lower limb: a preliminary prospective study of 4 cases].

PURPOSE: The appearance of scintigraphic and magnetic resonance imaging during the evolution of reflex sympathetic dystrophy of the foot is not well known and subject to controversies. The purpose of this preliminary study is to compare these two types of investigation during the first 6 months of evolution. METHODS: 4 non-selected patients with a diagnosis of acute reflex sympathetic dystrophy of the foot (no more than 2 months of evolution and more than 3 out of 6 clinical criteria suggesting a "warm" phase) were studied prospectively. A clinical evaluation, scintigraphy and magnetic resonance imaging (MRI) were performed at diagnosis and after 3 and 6 months. All available examinations (n = 22) were analyzed independently by independent observers. RESULTS: Clinically 3 of 4 patients developed or previously had another site of sympathetic dystrophy confirmed by total body scintigraphy. After 6 months 2 of 4 patients still have a "warm" dystrophy. Bone scanning showed localized or diffuse tracer uptake and MRI showed bone and soft tissue edema when the sympathetic dystrophy was and/or remained clinically "warm". MRI bone edema moved from one location to another in 3 of 4 patients during the follow-up. There was a good correlation between bone scan and MRI images. In "warm" dystrophy, MRI was positive 5 out of 7 times and scintigraphy in all cases. Bone edema and tracer uptake faded simultaneously although the latter was more diffuse and more persistent than the former. CONCLUSION: MRI as well as bone scintigraphy are suitable for the diagnosis of warm dystrophy of the foot. Both exams remain positive when the dystrophy is still "warm" after 6 months. The radiographic evolution after 6 months still has to be evaluated.

Bone Diseases↗
PubMed1999

[Cerebral stereotactic biopsy and surgery: Report of 100 cases].

OBJECTIVE: To report the results of the use of the stereotactic techniques in the management of intra cranial lesions. MATERIALS AND METHODS: Between july 1994 and march 1998, we carried out 117 stereotactic procedures of whom only 100 cases were analyzed. All the procedures were achieved after a CT scan. Patients were separated in two groups: (A) stereotactic biopsy (91 patients), (B) surgery with laser guidance (9 patients). The mean age in group A was 38 years (2-75 years) versus 27 years (11-66 years) in group B. The sex-ratio was 1.3. RESULTS: In the group A, the correct pathological diagnosis was obtained in 91.2% of cases. Glial tumors was the frequent histopathological variety of tumor (67.47%). Only one patient was operated after biopsy for a bilateral meningioma of the anterior 1/3 of the falx. There was only one death (1.09%) and 3.29% of transitory complications. In the group B, all patients were operated with laser guidance. Thirty seven per cent of patients underwent radiotherapy after the stereotactic biopsy or surgery. CONCLUSION: Stereotactic biopsy is a reliable method for the histopathological diagnosis of deep-seated brain lesions. Surgery with laser guidance is a useful alternative for the management of small deep-seated lesions or lesions located in functional areas.

Adolescent↗
PubMed1995

Immunoscintigraphy with antigranulocyte monoclonal antibodies for the diagnosis of septic loosening of hip prostheses.

To determine the value of immunoscintigraphy (IS) with antigranulocyte monoclonal antibodies (Mab) in the diagnosis of subacute or chronic infection of hip prostheses, we prospectively studied 57 patients (23 women and 34 men; age 29-92 years, mean 72.7 years) sent to our institution in the past 6 years for clinical suspicion of septic loosening of a hip prosthesis. Nineteen patients had bilateral prostheses and one of them was studied twice. A total of 78 prostheses were examined. All patients had three-phase bone scans followed by IS with technetium-99m antigranulocyte Mab BW 250/183. Intervals between bone scans and IS varied from 2 days to 4 weeks. Final diagnosis was assessed by culture in 48 cases (articular puncture or intraoperative sampling) and by clinical follow-up of at least 8 months in 30 cases. Twelve prostheses were considered septic and 66 non-septic. The overall sensitivity and specificity were 92% and 64% respectively for bone scans, 67% and 75% for IS and 67% and 84% for both modalities together. In three cases, IS was doubtful and the final clinical diagnosis was negative for infection. False-positive results were observed in the presence of massive loosening of the prosthesis or in association with metaplastic peri-articular bone formation. In three of the four false-negative results, infection was proven only after enrichment of the culture, and the bacterium was Staphylococcus epidermidis. In 12/33 (36%) positive bone scans IS allowed the diagnosis of infection to be excluded. Overall accuracy of both modalities together was 81% and the negative predictive value was 93%, which compares favourably with the results reported for other non-invasive methods.

Aged↗
PubMed1995

[Prognostic value of exercise gamma-angiography in coronary insufficiency].

The predictive value for cardiac events in stable coronary artery disease was analysed with resting and exercise radionuclide angiography and conventional exercise stress testing under medical therapy. The population comprised 93 men and 12 women, followed up for 1 to 8 years (mean 51 months). The patients were divided into two groups. Group I without cardiac events; Group II including spontaneous complications and myocardial revascularisations. The analysis was performed at 2 years and at the end of follow-up. At 2 years, 30 events (15 spontaneous complications, 15 revascularisations) were observed, and at the end of follow-up, there were 61 uncomplicated outcomes and 44 cardiac events (22 spontaneous complications, 22 revascularisations). Two independent prognostic factors distinguishing patients in Group I from those in Group II were identified at 2 years and at the end of the study: exercise EF and occurrence of exercise (on: chest pain on exercise) chest pain. Four parameters were significantly different between the two groups at 2 years: exercise EF, resting EF, difference between exercise-resting EF (all p < 0.005) and duration of exercise testing (p = 0.04). The 3 radionuclide parameters remained different between the 2 groups as well as chest pain on exercise stress testing (p = 0.03) throughout the study. The predictive value of these parameters depended on the type of cardiac event. The exercise EF was the best predictive factor of cardiac death. Pain and ST depression on exercise ECG were the best predictive factors for myocardial revascularisation. In 12 patients undergoing myocardial revascularisation, the clearest improvement was observed in exercise EF (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Prognostic value of the normalization of the exercise test under medical treatment in coronary insufficiency].

The prognostic value of exercise testing was studied in 118 patients with angiographically proven chronic coronary disease, positive ET and/or a history of myocardial infarction (MI) who were followed up for 698 years (mean 5.9 years). Medical treatment was instituted step by step and controlled by repeated ET's. ET remained positive (ST depression 1 mm) in 58 cases (group I), was alternately positive and negative in 22 cases (group II) and became normal in 38 cases (group III). The mean duration of follow-up in these three groups was 5.0, 7.6 and 6.4 years respectively. Eight patients were lost sight of. Ergometric data and outcome were similar in groups II and III, but there were differences between group I (58 patients) and groups II + III (60 patients) as regards: (a) ergometric data: total workload (22,077 +/- 9,860 vs 34,856 +/- 15,552 joules), workload causing a 1 mm ST depression (13,892 +/- 9,253 vs 31,555 +/- 15,811 joules) and maximal ST depression (2.5 +/- 0.9 vs 0.9 +/- 0.8 mm); (b) outcome: cardiac deaths (12 vs 3), myocardial revascularization (19 vs 6); but there was no significant difference as regards MI (4 vs 5), heart failure (11 vs 5) and extracardiac deaths (3 vs 4). It is concluded that the persistence of a positive ET under optimal medical treatment is a major argument in favour of myocardial revascularization.

Adult↗
PubMed1984

Thromboembolic and haemorrhagic risk in mechanical and biological aortic prostheses.

Thromboembolism, valve thrombosis and haemorrhagic events have been compared in 356 Starr-Edwards (SE) 1260, 113 Björk-Shiley (BS), and 178 aortic bioprostheses operated upon between 1968 and 1982, and reviewed by the same group with less than 2% of patients lost of follow-up. Expressed in actuarial rate at 7 years the percentage of patients free of thromboembolism event is 87% for SE, 86% for BS, 94% for bioprostheses; the linearized rate is 2.9%/patient/year for SE, 2.2 for BS, 1.9 for bioprostheses (NS). Valve thrombosis was not observed in bioprostheses; 97.9% of patients with mechanical valves were free of valve thrombosis at 6.5 years. Haemorrhagic risk was lower with bioprostheses than with mechanical valves 0.2% patient/year vs 2.33 (P less than 0.005). The most important factor influencing thromboembolic and haemorrhagic risks is the quality of anticoagulant therapy. Other contributing factors are the date of the operation and associated mitral disease.

Actuarial Analysis↗