Allergic fungal sinusitis is a distinct clinical entity with nonspecific symptoms that may be initially suggested by the CT findings. These findings should alert the clinician to the possibility of allergic fungal sinusitis and prompt other diagnostic studies to establish the diagnosis and treatment plan.

MR imaging is more accurate than radiography in the detection of a wide spectrum of neck injuries, and further study is warranted of its potential effect on medical decision making, clinical outcome, and cost-effectiveness.

Sphenoid sinusitis is an elusive diagnosis with significant morbidity if not diagnosed and treated promptly. We have reported an unusual case of acute sphenoiditis mimicking Gradenigo's syndrome. This resulted in virtual bilateral blindness that entirely resolved with aggressive surgical and medical treatment. It is recommended that sphenoid sinusitis be strongly considered in patients with acute headache and fever. A detailed cranial nerve examination should be performed, and CT scans of the skull base and paranasal sinuses should be obtained. Immediate surgery is strongly recommended for acute sphenoid sinusitis at the first suggestion of a complication and in those patients not promptly responding to medical therapy. It is apparent that irreversible damage to the optic nerve can occur before the development of gross intraorbital pathology. Therefore we believe that delaying surgery until the visual acuity is worse than 20/60, as advocated by some authors, may not be in the patient's best interest. Surgery should be directed at removing the purulent material, obtaining cultures, removing irreversibly diseased mucosa, and maintaining drainage of the sphenoid sinus.

The assessment of the radiation dose to internal organs or to an embryo or fetus is required on occasion for risk assessment or for comparing imaging studies. Limited resources hinder the ability to accurately assess the radiation dose received to locations outside the tissue volume actually scanned during computed tomography (CT). The purpose of this study was to assess peripheral doses and provide tabular data for dose evaluation. Validated Monte Carlo simulation techniques were used to compute the dose distribution along the length of water-equivalent cylindrical phantoms, 16 and 32 cm in diameter. For further validation, comparisons between physically measured and Monte Carlo-derived air kerma profiles were performed and showed excellent (1% to 2%) agreement. Polyenergetic x-ray spectra at 80, 100, 120, and 140 kVp with beam shaping filters were studied. Using 10(8) simulated photons input to the cylinders perpendicular to their long axis, line spread functions (LSF) of the dose distribution were determined at three depths in the cylinders (center, mid-depth, and surface). The LSF data were then used with appropriate mathematics to compute dose distributions along the long axis of the cylinder. The dose distributions resulting from helical (pitch = 1.0) scans and axial scans were approximately equivalent. Beyond about 3 cm from the edge of the CT scanned tissue volume, the fall-off of radiation dose was exponential. A series of tables normalized at 100 milliampere seconds (mAs) were produced which allow the straight-forward assessment of dose within and peripheral to the CT scanned volume. The tables should be useful for medical physicists and radiologists in the estimation of dose to sites beyond the edge of the CT scanned volume.

The normal OC1 joint in children 0 to 18 years is tightly held together by ligaments with a mean CCI of 1.28 mm in the 89 subjects tested. There is great left-right joint symmetry in both CCI and conformational anatomy. CCI and left-right symmetry do not appear to change significantly with age. It is reasonable to set a maximum CCI as a discriminator between normal and disrupted OC1 joints to indicate atlanto-occipital dislocation.

Eighty-six percent of the reported patients with choristoma have three or four of the four criteria listed to designate middle ear salivary choristoma as part of a syndrome. In the remaining four patients, all of the structures were not assessed.

Images obtained by use of MRI with standard clinical pulse sequences can document the appearance and the temporal patterns of neuronal migration in postmortem fetal specimens. With the evolution of high-resolution MRI and faster scanning techniques, these findings may serve as a template for the in utero MRI appearance of neuronal migration and thereby compliment the antenatal ultrasonic investigation of congenital anomalies.

Important aspects of fetal midface anatomy that relate to facial clefts can be observed in utero at prenatal sonography in the coronal and axial planes.