Perfusion abnormalities in hemimegalencephaly.

INTRODUCTION: Cerebrovascular changes are rarely discussed in patients with hemimegalencephaly. These alterations have previously been associated with epileptical activity. CASE: We report the case of a 36-week gestation neonate presenting with total right hemimegalencephaly, as demonstrated by a magnetic resonance imaging (MRI) performed in the first days of life. Perfusion-weighted imaging displayed a clear hypervascularization of the right hemisphere. Diffusion-tensor imaging showed an arrangement of white matter fibers concentrically around the ventricle on the right hemisphere. AngioMRI showed an obvious asymmetry in the size of the middle cerebral arteries, with the right middle cerebral artery being prominent. The baby was free of clinical seizures during his first week of life. An electroencephalogram at that time displayed an asymmetric background activity, but no electrical seizures. CONCLUSION: Perfusion anomalies in hemimegalencephaly may not necessarily be related to epileptical activity, but may be related to vessel alterations.

Detection of ingested cocaine-filled packets--diagnostic value of unenhanced CT.

PURPOSE: Emergency departments are facing nowadays an increasing number of illegal drug-related health problems, associated with medicolegal and/or social consequences. Body stuffers are street cocaine dealers, who either store wrapped packets of drugs in their rectum or hastily swallow them, prompted by fear of police's arrest. These packets can be life threatening in case of leakage. We evaluate the diagnostic value of unenhanced multidetector CT (MDCT) for detection of cocaine-filled packets (CFP) ingested by body stuffers in a phantom model. MATERIALS AND METHODS: Our phantom simulated normal bowel contents in which a varying number of true and false CFP were randomly mixed. Both only differ in radiological density. During 18 different reading sessions, four radiologists independently evaluated the presence and number of true and false CFP. Interobserver agreement, sensitivity, specificity, positive and negative predictive value were calculated. RESULTS: Interobserver agreement for detection of any packets, for visualization of true, and false CFP was good (kappa=0.63, 0.74 and 0.58, respectively). Sensitivity, specificity, positive and negative predictive value for detection of any packets was 95.6%, 100%, 100% and 62.5%, respectively; for visualization of the true CFP 86.5%, 100%, 100% and 77.6%, respectively; and for the false packets 98.1%, 65%, 88.6% and 87.5%, respectively. CONCLUSION: Unenhanced MDCT without bowel preparation is a fast, reliable and easily reproducible imaging modality for the immediate detection of ingested CFP, thus facilitating medicolegal management of body stuffers.

An image quality comparison of standard and dual-side read CR systems for pediatric radiology.

An objective analysis of image quality parameters was performed for a computed radiography (CR) system using both standard single-side and prototype dual-side read plates. The pre-sampled modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) for the systems were determined at three different beam qualities representative of pediatric chest radiography, at an entrance detector air kerma of 5 microGy. The NPS and DQE measurements were realized under clinically relevant x-ray spectra for pediatric radiology, including x-ray scatter radiations. Compared to the standard single-side read system, the MTF for the dual-side read system is reduced, but this is offset by a significant decrease in image noise, resulting in a marked increase in DQE (+40%) in the low spatial frequency range. Thus, for the same image quality, the new technology permits the CR system to be used at a reduced dose level.

Influence of cassette type on the DQE of CR systems.

In our recent paper by Monnin et al. [Med. Phys. 33, 411-420 (2006)], an objective analysis of the relative performance of a computed radiography (CR) system using both standard single-side (ST-VI) and prototype dual-side read (ST-BD) plates was reported. The presampled modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) for the systems were determined at three different beam qualities representative of paediatric chest radiography, at an entrance detector air kerma of 5 microGy. Experiments demonstrated that, compared to the standard single-side read system, the MTF for the dual-side read system was slightly reduced, but a significant decrease in image noise resulted in a marked increase in DQE (+40%) in the low spatial frequency range. However, the DQE improvement for the ST-BD plate decreased with increasing spatial frequency, and, at spatial frequencies above 2.2 mm(-1), the DQE of the dual-side read system was lower than that of the single-side one.

[Patient dose optimization in pediatric computerized tomography]. / Optimisation des doses en tomographie computérisée pédiatrique.

The development of CT applications might become a public health problem if no effort is made on the justification and the optimisation of the examinations. This paper presents some hints to assure that the risk-benefit compromise remains in favour of the patient, especially when one deals with the examinations of young patients. In this context a particular attention has to be made on the justification of the examination. When performing the acquisition one needs to optimise the extension of the volume investigated together with the number of acquisition sequences used. Finally, the use of automatic exposure systems, now available on all the units, and the use of the Diagnostic Reference Levels (DRL) should allow help radiologists to control the exposure of their patients.

[Undifferentiated sarcoma of the liver: a rare tumor of childhood]. / Le sarcome indifférencié du foie: une tumeur rare chez l'enfant.

UNLABELLED: Undifferentiated sarcoma of the liver is a rare primary tumor of childhood: only about 150 cases have been reported in the literature. CASE-REPORT: A 10 year-old girl was admitted because of diarrhea and weight loss. Sonography, then CT-scan and MRI showed a large tumor of the liver. COMMENTS: In the differential diagnosis of primary liver tumors in children, one should think about undifferentiated sarcoma of the liver, especially if imaging shows haemorrhagic foci and if sonography and CT/MRI display a discordant appearance. Survival has improved in the last decade due to agressive surgery and intensive chemotherapy.

Evaluating bone marrow metastasis of neuroblastoma with iodine-123-MIBG scintigraphy and MRI.

Of 10 patients with neuroblastoma who had both 123I-MIBG scintigraphy and MRI at diagnosis, four presented with bone marrow metastasis that was diagnosed by both imaging modalities and confirmed by bone marrow biopsy and smears. This report focuses on the follow up of the four patients with bone marrow metastasis. MIBG scintigraphy and MRI were concordant in two patients, a case of normalization and a case of relapse in the seventh dorsal vertebra confirmed by surgical biopsy. The last two patients presented a normalized MIBG scan for marrow infiltration after chemotherapy but persistent abnormal MRI signal of several vertebrae, suggesting marrow infiltration, up to 27 mo after the end of chemotherapy in one case. In the second patient, MRI bone marrow aspect returned to normal 4 mo after the end of chemotherapy. Bone marrow biopsy remained negative in these two MIBG-negative patients. These cases suggest that in presence of complete normalization of the MIBG scan after chemotherapy, the persistence of a hypointense signal on bone marrow on T1WI does not necessarily indicate persistence of disease but may be due to delayed normalization. Therefore, attention must be paid to the delay of signal normalization on MRI (which can be as long as more than 2 yr after the end of chemotherapy) in order to avoid false-positive interpretation.

Lemierre's syndrome in children: high-resolution CT and color Doppler sonography patterns.

Lemierre's syndrome is an anaerobic sepsis occurring after oropharyngeal infection in healthy teenagers and young adults. We report two cases of adolescent girls suffering from Lemierre's syndrome studied with cervical color Doppler ultrasonography (CDUS), cervicothoracic helical CT, and high-resolution CT (HRCT) scanning. In both patients, HRCT allowed a good depiction of multiple cavitated pulmonary nodules of various sizes suggestive of this entity and was able to detect small or peripheral nodules. CDUS helped to pinpoint the extent of thromboses of the internal jugular vein demonstrated by CT. CDUS and HRCT should be performed as early as possible to confirm and treat this life-threatening condition.

Development of a cavernous malformation of the brain.

We report the appearance of a cavernous malformation associated with a developmental venous anomaly in a young boy 3 years after radiation therapy for a posterior fossa medulloblastoma. The presence of a stenosis of the venous drainage of the anomaly led us to postulate that venous restrictive disease, induced by radiation therapy, resulted in increased venous pressure and caused the formation of the cavernous malformation.

Echography of pulmonary sequestration.

Pulmonary sequestration is a rare congenital disorder in which a portion of normal lung tissue lacks normal connections with the tracheo-bronchial tree and the pulmonary arteries. We report on three cases of left lower lobe extrapleural sequestrations that have been studied with ultrasound since 1980. In the two more recent cases demonstration of the feeding vessel originating directly in the abdominal aorta by real-time ultrasound permitted very rapid non-invasive diagnosis of the malformation. We recommend that a search should be made for such an aberrant vessel with real-time ultrasound whenever a pulmonary sequestration is suspected.

An uncommon G375C substitution in a newborn with achondroplasia.

We report a G-to-T de novo transversion mutation causing the substitution of a glycine with a cysteine (G375C) in a newborn with achondroplasia. This rare observation confirms allelic heterogeneity.

A new case of Pfeiffer syndrome with mutation in FGFR2.

We report on a sporadic case of Pfeiffer syndrome in a male newborn with complex craniosynostosis, broad thumbs and great toes and early demise. SSCP and direct sequencing revealed a missense mutation at position 1037 of the exon B (or IIIc) of the FGFR2 gene (codon 342) resulting in a cysteine to serine modification (TGC-TCC). Genotype-phenotype correlations between the FGFRs mutations and the different craniosynostotic syndromes are discussed.

Hepatic trauma in children: long-term follow-up.

The purpose of this report is to assess the role of long-term clinical and hepatic ultrasound (US) follow-up in children who sustained blunt liver trauma. Forty-three children with blunt hepatic injury were prospectively studied between 1976 and 1994 in our institution. Four patients died (9%). Fourteen children (52%) were operated upon and 13 (48%) were treated conservatively. Twenty-seven patients were recalled for a long-term echography (US) with a mean time span of 6 years after trauma. The physical examination and the liver tests were normal in all patients. The US aspect of the liver was abnormal in 22% of our cases, showing hypoechogenic areas and anomalies of the biliary tract in four patients (11%). Cholelithiasis secondary to hemobilia was demonstrated in 2 patients. Cholecystectomy was performed in one patient because of posttraumatic strictures of the biliary tract. All patients with US anomalies of the liver and biliary tract were clinically asymptomatic and had normal liver tests. We recommend a follow-up US in children having sustained blunt hepatic injury about 6 months after the trauma. If no cholelithiasis or alteration of the biliary tract is present, no other follow-up procedure seems necessary.

[Cardiac rhabdomyomatosis and Bourneville's tuberous sclerosis in the fetus. Apropos of 2 cases]. / Rhabdomyomatose cardiaque et sclérose tubéreuse de Bourneville chez le foetus. A propos de 2 cas.

Two cases of cardiac rhabdomyoma discovered fortuitously at foetal ultrasonography gave rise to no obstructive cardiac signs or arrhythmias either in the antenatal or postnatal periods. These multiple tumours often observed in Bourneville's tuberous sclerosis orientated the clinical investigations to the diagnosis of this disease from the outset. MRI demonstrated cortical tubers and subependymal nodules in both cases. A retinal hamartoma was present in one case. No renal involvement could be detected by ultrasonic examination. No neurological or cardiovascular symptoms appeared during follow-up (20 and 4 months after birth). Investigations in the parents were negative, these two cases being sporadic forms of Bourneville's tuberous sclerosis. The functional prognosis is related to the neurological outcome. Doppler echocardiography would appear to be the best method of following up cardiac rhabdomyomas, and enabled the demonstration of partial regression of the largest tumour in one of these two cases. Cardiac MRI is also an excellent diagnostic tool. As it is usually performed at the same time as cerebral MRI, essential in the follow-up of Bourneville's tuberous sclerosis, it does not represent additional discomfort to the patient.

[Pulmonary arteriovenous fistula: a rare cause of progressive asymptomatic cyanosis in neonates]. / Fistule artérioveineuse pulmonaire: une cause rare de cyanose progressive et muette chez le nourrisson.

A six month old girl with no significant medical history was admitted to hospital for progressive cyanosis of recent onset refractory to oxygen therapy. There were no detectable cardiac murmurs. Chest X-ray showed an irregular left posterior parahilar infiltration. Echocardiography showed dilatation of the left atrium and ventricle but no cardiac malformation. The diagnosis of pulmonary arteriovenous fistula was suspected. Chest CT scan, magnetic resonance imaging and pulmonary angiography demonstrated the arteriovenous fistula in the lower lobe of the left lung. It was much bigger than the appearances of the chest X-ray suggested. After the left lower lobectomy, the cyanosis completely disappeared. Progressive cyanosis refractory to oxygen therapy without any apparent cardiac or pulmonary disease is strongly suggestive of pulmonary arteriovenous fistula. Surgical treatment is curative whereas the spontaneous outcome of this condition may be lethal.

[Spontaneous intracranial hypotension syndrome]. / Syndrome d'hypotension intracrânienne spontanée.

Spontaneous intracranial hypotension is a rare but well known entity first described by the German neurosurgeon Schaltenbrand. We report the clinical and radiological findings of four patients (2 males, 2 females, mean age 55 years) presenting with this clinical entity and peculiar constant MRI findings. Intense postural headache was present in all patients together with a very low CSF pressure at lumbar tap although none of the patients had any history of recent lumbar puncture, spinal or cerebral surgery or cranio-cervical trauma. MRI revealed in all patients an intense meningeal enhancement and thickening which was most prominent on the dural side of the subdural space. The ventricular system was thin, presenting almost like slit ventricules. A downward shift of the cerebellar tonsils and hemorrhagic subdural collections were also observed in two patients. Biopsy of meninges performed in two patients showed fibrosis of the leptomeninges together with signs of old hemorrhage in one case. We postulate that histologic and radiologic changes are due to chronic subdural bleeding in relation with abnormal displacement of the nervous structures due to intracranial hypotension. The underlying cause of spontaneous intracranial hypotension is rarely established and the course of the disease is benign. Some authors have advocated to perform isotopic cysternography in search for a CSF leak, particularly in the spine, that could be surgically corrected. No such investigation has been conducted yet in our patients because the spontaneous evolution has been mostly favorable.

[X-ray computed tomography of the facial sinuses. Results in 198 patients with chronic sinusitis]. / TDM des sinus de la face. Résultats chez 198 patients souffrant de sinusite chronique.

The CT studies of 198 consecutive patients with chronic sinusitis were reviewed retrospectively. CT was normal in 47 patients (23.7%). In 151 patients one or many cavities showed abnormalities. In 69 cases (34.9%), the lesions affected one or two sinuses, in 35 cases (17.7%) three to six cavities were abnormal, whereas in 47 cases (23.7%), more than six cavities were abnormal. In 87 cases (57.6%), lesions were observed both in large cavities and ethmoid cells, whereas they were selectively localized in large cavities in 55 cases (36.4%), or in ethmoid cells in 9 cases (6%). Abnormalities were observed in the maxillary sinus in 137 patients (69.2%), in the ethmoid in 96 patients (48.5%), in the frontal sinus in 51 patients (25.8%), and in the sphenoid sinus in 28 patients (14.1%). The most frequent abnormality was hypertrophic mucosa, which was visible in 275 cavities. These results were compared with date of the literature.

[Priapism: review of current knowledge and presentation of a diagnostic and therapeutic algorithm]. / Priapisme: rappel des connaissances actuelles et présentation d'un algorithme diagnostique et thérapeutique.

In medicine, priapism is defined as pathological state: a prolonged, generally painful erection not accompanied by sexual desire not ending with an ejaculation. Rare before 1980, priapism became more frequent after introduction of erection-inducing drugs by intracavernosal injections for treatment of impotence. Therefore, the medical practitioner can be faced with this problem, and the authors present with an algorithm the current diagnostic and therapeutic steps based on knowledge of pathology, physiopathology and etiology of this disease.

[Magnetic resonance imaging of the normal and the pathological knee in the child]. / Imagerie par résonance magnétique du genou normal et pathologique chez l'enfant.

The results of magnetic resonance imaging (MRI) studies performed on the knee region of 60 children including 20 normally growing subjects are reported. In healthy children, MRI permitted to study the normal maturation of bone marrow and cartilaginous structures. The patients studied had bone tumors (11 patients), rheumatoid arthritis (8 patients), lesions of traumatic origin (7 patients), osteochondritis (4 patients), vascular and tissular dysplasia (3 patients), osteomyelitis (3 patients) and soft-tissue tumors (3 patients). In all patients, MRI showed clinically relevant abnormalities that were not detected by conventional X-rays or physical examination. MRI offers the ability to study disorders of bone, bone marrow, cartilage, menisci and ligaments in a noninvasive way. MRI has replaced arthrography of the knee and is the examination of choice in pediatric patients.

[The value of CT and MRI in the assessment of basal encephaloceles in children]. / Apport du CT et de l'IRM dans l'évaluation des céphalocèles basales de l'enfant.

Basal cephaloceles of the child are rare pathologies which require accurate preoperative imaging work-up. The CT and MR studies of six children with surgically proven basal cephalocele were retrospectively reviewed to evaluate the role of CT and MR in the preoperative work-up of a basal cephalocele of the child. In five patients, MR allowed to define the nature and topography of the cephalocele, and allowed an accurate depiction of the optic tract, ante- and post-hypophysis and associated agenesis of corpus callosum when present. 3-D CT allowed in one case a more precise depiction of the basal bony defect. MRI allows in a non invasive and non ionising way the best depiction of herniating meninges, brain or ventricles as well as associated cerebral anomalies.