An infant in whom contrast-enhanced fluid attenuated inversion recovery (FLAIR) MRI was useful for the diagnosis of meningitis and devising a treatment strategy.

A 3-month-old male was brought to our hospital due to fever, poor sucking, and a bulging anterior fontanel. His general condition was poor. Analysis of the cerebrospinal fluid (CSF) showed increases in the cell count (8/µl) and the polymorphonuclear leukocyte count (2/µl) but normal sugar (66 mg/dl) and protein (28 mg/dl) levels. A CSF smear showed no bacterial cells. The administration of antibacterial drugs was initiated, and head MRI was performed on the next day. Plain images revealed no abnormalities. However, contrast-enhanced fluid-attenuated inversion recovery (FLAIR) MRI showed clear contrast enhancement along the brain surface in the meninges of the left and right frontal and left parietal lobes and fluid retention accompanied by contrast enhancement in a part of the adjacent subdural space. These findings could be confirmed only by contrast-enhanced FLAIR MRI. A diagnosis of bacterial meningitis with an unknown cause was made, and the administration of 2 antibacterial drugs was continued. MRI on day 8 of the illness showed the disappearance of contrast enhancement, and plain FLAIR also facilitated a diagnosis of a subdural hygroma. The treatment was effective. At present, the patient is 1 year and 6 months old without sequelae. The diagnosis of bacterial meningitis in infants is difficult based on only symptoms. In its early stage with few abnormal findings in the CSF, diagnosis is sometimes difficult. Antibacterial drug administration should be immediately initiated. However, definite findings are necessary for the continuation of large amounts of antibacterial drugs. Contrast-enhanced FLAIR allows the sensitive visualization of meningeal inflammation and is useful as a complementary diagnostic method for meningitis. In addition, this technique can reveal marked inflammatory lesions such as a subdural hygroma in the early stage, providing information useful for making a diagnosis of bacterial meningitis.

Mobile spinal enterogenous cyst resulting in intermittent paraplegia in a child: case report.

The authors report the case of a mobile spinal enterogenous cyst in a 2-year-old boy, who was admitted to the hospital several times for intermittent paraplegia. Magnetic resonance imaging and CT revealed an isolated cyst in the lumbar spinal canal. The symptoms were caused by transient myelopathy of the conus medullaris and radiculopathy of the cauda equina due to the changing size and location of the cyst. The cyst was surgically extirpated, after which the symptoms resolved. The histopathological diagnosis was enterogenous cyst. The clinical history of intraspinal enterogenous cyst is usually progressive. Mobility and changes in size are rare pathophysiological findings. The authors speculate that the cyst wall did not adhere to the surrounding structures and had ruptured and quickly reformed. Enterogenous cyst should be considered in the differential diagnosis of spinal intradural cysts in children with radiculomyelopathy.

[A case of DiGeorge syndrome with left internal carotid artery absence probably causing one-and-a-half syndrome].

We experienced a case of DiGeorge syndrome with left internal carotid artery absence probably causing one-and-a-half syndrome. MR angiogram demonstrated the apparent absence of the left internal carotid artery and consequently abnormal blood supply to the left middle cerebral artery, which was derived from the basilar artery via the left posterior communicating artery. The patient alsoshowed both an extremely narrow carotid canal on the left side and a very fine vessel extending to the terminal of the left internal carotid artery. Therefore, we regarded this abnormality as severe hypoplasia of left internal carotid artery and supposed that this hypoplasia had originated in maldevelopment of the third aortic arch based on the coexisting lower bifurcation of the right common carotid artery. Since the lesion of one-and-a-half syndrome is restricted to the pontine tegmentum, we speculated that it had resulted from ischemia of the basilar artery area during the embryonic period associated with the absence of the internal carotid artery. To our knowledge, DiGeorge syndrome has never been reported as a complication of internal carotid artery absence. The patient did not demonstrate either chromosome 22q11.2 deletion or TBX1 gene mutation, which is considered the gene responsible for 22q11.2 deletion syndrome. Therefore, the etiology of DiGeorge syndrome in this case remains unclear.

Three-dimensional numerical simulation of blood flow in the aortic arch during cardiopulmonary bypass.

OBJECTIVE: To better understand the mechanism of stroke during cardiopulmonary bypass, it is necessary to obtain information on the location of turbulence, wall pressure, and flow distribution within the aortic arch. METHODS: Blood flow was numerically simulated using the finite element method in the following representative case: a curved arterial cannula was inserted into the anterior wall of the distal ascending aorta 2 cm below the orifice of brachiocephalic artery. Perfusion was performed, with a bypass flow index of 2.5l min(-1) m(-2). Computational grids, consisting of 1,493,297 tetrahedral elements, were generated. RESULTS: The highest wall pressure (3104.8 Pa) was observed at the superior-posterior wall of the aorta below the orifice of the brachiocephalic artery where jet flow impingement occurred. The maximum wall shear stress was 25.1 Pa. High velocity vortex started below the orifice of the brachiocephalic artery. The turbulent flows continued along the posterior wall and then mainly flowed off into the left subclavian artery. Therefore, in the present case, an embolic event in the territory of the left subclavian artery could occur if a plaque was present at the superior-posterior wall of the aorta below the orifice of the brachiocephalic artery. The flow rates in each of the branches were 132, 613, 175, and 821 ml/min for the right subclavian, right common carotid, left common carotid, and left subclavian artery, respectively. CONCLUSION: This study confirmed that blood flow during cardiopulmonary bypass can be simulated and visualized. Computational fluid dynamics could be applied in the future to assess an individual's risk of stroke. Further multiple representative cases need to be simulated.

Computational flow dynamics in abdominal aortic aneurysm using multislice computed tomography.

Following the introduction of a new multislice computed tomography (MSCT) scanner, it has become possible to produce high-speed CT angiography (CTA), the preferred method for imaging in emergent abdominal vascular conditions. Unlike catheter angiography, multislice CTA not only depicts the vessels but also allows perfusion in adjacent organs to be assessed. To make the most effective diagnostic use of multi-detector row CTA and three-dimensional image post-processing, radiologists must be familiar with the optimal CTA protocols and the typical CT findings in various emergent vascular conditions using computational flow dynamics (CFD). This article describes a technical approach to estimating the blood flow state of human abdominal aortic aneurysms (AAA) in more detail by constructing realistic three-dimensional (3D) vessel models using CFD methods, focusing on pre- and postoperative cases.