End-Triassic mass extinction started by intrusive CAMP activity.

The end-Triassic extinction is one of the Phanerozoic's largest mass extinctions. This extinction is typically attributed to climate change associated with degassing of basalt flows from the central Atlantic magmatic province (CAMP). However, recent work suggests that the earliest known CAMP basalts occur above the extinction horizon and that climatic and biotic changes began before the earliest known CAMP eruptions. Here we present new high-precision U-Pb ages from CAMP mafic intrusive units, showing that magmatic activity was occurring ∼100 Kyr ago before the earliest known eruptions. We correlate the early magmatic activity with the onset of changes to the climatic and biotic records. We also report ages from sills in an organic rich sedimentary basin in Brazil that intrude synchronously with the extinction suggesting that degassing of these organics contributed to the climate change which drove the extinction. Our results indicate that the intrusive record from large igneous provinces may be more important for linking to mass extinctions than the eruptive record.

Extensive 200-million-year-Old continental flood basalts of the central atlantic magmatic province

The Central Atlantic Magmatic Province (CAMP) is defined by tholeiitic basalts that crop out in once-contiguous parts of North America, Europe, Africa, and South America and is associated with the breakup of Pangea. 40Ar/39Ar and paleomagnetic data indicate that CAMP magmatism extended over an area of 2.5 million square kilometers in north and central Brazil, and the total aerial extent of the magmatism exceeded 7 million square kilometers in a few million years, with peak activity at 200 million years ago. The magmatism coincided closely in time with a major mass extinction at the Triassic-Jurassic boundary.

Mucopolysaccharidosis: thickening of dura mater at the craniocervical junction and other CT/MRI findings.

Cranial CT and/or MRI imaging of 8 patients with mucopolysaccharidosis (MPS) was retrospectively evaluated. Two patients had MPS IH, 1 had MPS IS, 1 had MPS IVA and 4 had MPS IV. CT and MRI showed thickening of dura mater at the cranio-cervical junction, causing narrowing of the subarachnoid space, in all the patients examined. Spinal cord compression was detected in 4 patients. Other findings were: white matter alterations, mild to severe hydrocephalus, skull dysplasia and odontoid dysplasia. White matter alterations were evident as large areas and as multiple dispersed spots of prolonged T1 and T2 value. Reduced gray/white matter contrast was demonstrated on T2-weighted MRI images. It is important to examine the cranio-cervical junction carefully for thickening of dura mater in all patients with mucopolysaccharidosis examined by CT or MRI, because of the generally progressive clinical course of MPS. In patients with symptomatic cord compression, surgical intervention should be considered.

Vein of Galen aneurysm: MRI with a fast gradient refocusing pulse sequence.

A case of vein of Galen aneurysm, studied with a fast gradient refocusing pulse MRI sequence, is presented. Fast MRI sequences allowed the acquisition of additional hemodynamic information that was not available with either routine MRI or angiography.

[High-resolution computerized tomography. Staging of lobular lesions in cystic fibrosis]. / Tomografia computerizzata ad alta risoluzione. Stadiazione delle lesioni lobulari nella fibrosi cistica.

Forty-four patients affected with cystic fibrosis (CF) were examined by means of high-resolution Computed Tomography (HRCT) of the chest; the sensitivity of this technique was evaluated in identifying small pulmonary structure alterations, and its role outlined. In all cases, HRCT scans allowed early lobular shape anomalies to be detected and secondary pulmonary lobular lesions to be correlated with disease evolution. A classification for lobular lesions was proposed: Stage I - Thickening of the bronchovascular bundle and/or intralobular septa and/or middle interstitial compartment. Unessential changes in lobular ventilation. Preservation of lobular shape. Stage II - Intralobular emphysema. Acinar filling with normal ventilation (A) or diffuse hypoventilation of the lobule (B). Preservation of lobular shape. Stage III - Lobular consolidations. Preservation of lobular shape. Stage IV - Patch distribution of lesions characterized by derangement of lobular structures. Changes in normal lobular shape. The identification of these lesions confirms HRCT as the most sensitive technique for the early visualization and localization of signs of CF bronchopneumonopathy. A broader experience coming from the systematic use of HRCT in chronic inflammatory lung diseases would increase our knowledge of pathogenetic processes and allow therapeutic perspectives to be improved.

High-resolution computed tomography in cystic fibrosis.

The sensitivity of high-resolution computed tomography (HRCT) in identifying the pulmonary lesions of cystic fibrosis (CF) was evaluated. Thirty-nine patients (16 males, 23 females; mean age 19.1 years) were examined by chest HRCT. According to Shwachman and Kulczycki criteria, the clinical score of the patients ranged from 40 to 95, thus covering most possible variations of lung disease severity. All the patients presented diffuse thickening of bronchial walls, expression of the characteristic CF bronchial inflammation. Bronchiectases were the second most common lung lesions: discrete dilatation of bronchi was observed in 87% of cases; the localization, pattern and extent of bronchiectasis were accurately detected by HRCT. Pleural thickening and hilar adenopathy were frequently identified (in 64% and 82% of the patients, respectively). Bronchoceles were seen in 64% of the patients; atelectasis (33%) and subpleural bullous dystrophic emphysema (28%) were observed less frequently. On HRCT, the localization of the disease processes within the secondary pulmonary lobule was possible in all patients. In agreement with international literature, the identification of these lesions confirms HRCT as the more sensitive technique for early visualization and location of the manifestations of CF bronchopathy. A larger range of experience coming from a systematic use of HRCT in chronic inflammatory lung diseases would increase our knowledge of pathogenetic processes and allow improvement of therapeutic perspectives.

[Mucopolysaccharidoses: evaluation of the cranium by computed tomography and magnetic resonance]. / Mucopolisaccaridosi: valutazione del cranio con tomografia computerizzata e risonanza magnetica.

Cranial CT and/or MRI examinations were performed in 8 patients affected with mucopolysaccharidosis. Two patients were affected with mucopolysaccharidosis IH,1 had mucopolysaccharidosis IS, 1 had mucopolysaccharidosis IV A and 4 presented mucopolysaccharidosis VI. CT and MRI showed white matter changes consisting of symmetric and diffuse hypodense areas on CT, large areas and multiple spots of prolonged T1 and T2 value on MRI. Reduced gray/white matter contrast was demonstrated on T2-weighted sequences. Furthermore, CT and MRI showed thickening of the dura mater at the cranio-cervical junction, which caused subarachnoid space narrowing in all patients. Spinal cord compression was detected in 4 patients. Additional findings were mild to severe hydrocephalus, skull dysplasia and odontoid dysplasia. Owing to the progressive clinical course of all mucopolysaccharidosis, the authors stress the importance of a careful study of the cranio-cervical junction in all the patients with mucopolysaccharidosis examined by CT or MRI in order to demonstrate essential thickening of the dura mater. In the patients with symptomatic cord compression, surgery should be considered.

Intraabdominal calcifications in the newborn: an unusual case with anorectal malformation and other anomalies.

Intraabdominal calcifications are an unusual radiographic finding in the newborn and can easily be misinterpreted as meconium peritonitis. The authors refer to a patient with anorectal malformation (ARM), intraluminal calcifications and other anomalies. Careful differentiation of the type of intraabdominal calcifications can suggest the possibility of other initially unsuspected anomalies.

New concepts in preoperative imaging of anorectal malformation. New concepts in imaging of ARM.

In this study of 14 patients with anorectal anomalies CT and MRI were employed for preoperative assessment. The use of a pressure enhanced water soluble enema via the colostomy proved to be an extremely efficient method for showing a fistula. MRI studies were enhanced by the use of vaseline oil and in one case this technique was used prior to surgery to provide important information by injecting through a perineal fistula. CT and axial MRI proved to be more valuable than sagittal MRI which is only useful for the length of the atretic segment. The authors consider that a combined approach using pressure enhanced water soluble enema and MRI will provide the most valuable preoperative information to plan a successful operative approach and enable an accurate prognostic evaluation of continence in these difficult and complex patients.

An unusual CT presentation of congenital cerebral toxoplasmosis in an 8 month-old boy with AIDS.

We report on a 8-month-old boy with AIDS, born of an asymptomatic mother with positive HTLV-III serology. He was hospitalized in the Intensive Care Unit because of anemia, fever and hepatosplenomegaly. Chest X-ray showed pneumonia and subsequent blood cultures were positive for Candida albicans. After 3 days of Amphotericin B treatment, the patient was transferred to Infectious Disease Department. After 30 days of hospitalization, the patient developed a rapid neurological impairment evolving into coma. CT scan showed a round, ring-shaped low density lesion with hyperdense and enhancing haemorrhagic centre in the left basal ganglia and a smaller hypodense lesion on the right. There was also evidence of cortical atrophy and mild ventricular dilatation. Such lesions are more commonly described in children with AIDS and congenital cytomegalic inclusion virus (CMV) encephalitis. In this case toxoplasma cysts were shown microscopically reinforcing the contention that in patients with AIDS, toxoplasma gondii infection may occur with atypical manifestation.

[Computed tomography vs. magnetic resonance in the diagnosis of anorectal anomalies]. / Tomografia Computerizzata vs Risonanza Magnetica nella diagnostica delle anomalie ano-rettali.

Anorectal malformations include a variety of anatomical anomalies which are often difficult to assess. Thirty-four patients (age range: 1 month-19 years) were studied over a 4-year period, 14 of them preoperatively and 20 postoperatively. In addition to inverted lateral plain films, a barred Iopamiro enema was performed in 13 of 14 cases by a Foley's catheter via colostomy. Endocolic pressure could thus be increased, which allowed the detection of rectal fistulas in 11 of 13 cases. Preoperative CT was performed in 9 cases, and MRI in 5. Both CT and axial MR scans provided accurate images of sphincteric muscles: they were well developed in 7 patients and poorly developed in 6; in 1 case the muscles were not identified. Sagittal MR scans only demonstrated the distance between blind pouch and perineum. Sagittal MRI also provided images of the spine (1 patient exhibited tethered cord). In the postoperative management, except for severe sacral anomalies, miscentered puborectal muscle and hypoplastic musculature were observed as the most frequent causes of fecal incontinence in patients treated with abdomino-perineal pull-through of the colon. To select the cases who needed reoperation, most frequently secondary PSARP, 17 patients were studied by CT and 7 by MRI; both techniques were employed in 4 cases. In 6 patients good development of sphincteric musculature and neo-anorectum correctly positioned within were observed. In 4 cases the neo-anorectum was correctly positioned, but sphincteric muscles were too hypoplastic to allow good continence; in 10 patients with incontinence, the neo-anorectum was seen outside sphincteric musculature: in 2 cases the latter was well developed (1 patient had had severe surgical damage to levator ani), while in 8 it appeared to be poorly developed. In our experience, postoperative CT allowed a correct evaluation to be made, whereas MRI failed to yield additional information.

[Computerized tomography in pulmonary cystic fibrosis]. / La tomografia computerizzata nella fibrosi cistica polmonare.

This study was aimed at evaluating CT sensitivity in identifying the signs of pulmonary cystic fibrosis (CF). The chests of 39 patients (16 males and 23 females, mean age 19.1 years) were examined by CT: all patients had been given a clinical score according to Schwachman and Kulckzycki criteria. Thickened bronchial walls were observed in all cases, which are typical of peribronchitis. Bronchiectases were present in 87% of cases; their extent, pattern and localization were exactly shown on CT scans. Bronchoceles were seen on CT scans in 64% of patients; less frequent was the finding of atelectases and subpleural bullous emphysema. In a great number of patients (64% and 82%, respectively) pleural thickening and hilar adenopathy were demonstrated on CT scans. In conclusion, our results confirm CT as a more sensitive method than conventional radiography to identify and locate the signs of pulmonary CF. The early identification of the lesions is of high prognostic value, since the early detection and treatment of bronchoceles may prevent permanent bronchiectasis.