Biological characteristics of the cerebral venous system and its hemodynamic response to intracranial hypertension.

BACKGROUND: The role of the cerebral venous system (CVS) in intracranial pressure (ICP) regulation remains largely unclear. In the present study, the interaction between ICP and the cerebral venous system and its possible mechanism were investigated with respect to the biological characteristics of the cerebral venous system and its hemodynamic response under increased ICP. METHODS: We created intracranial hypertension animal model, measured and calculated the venous flow velocity and diameter of the outflow terminal of the CVS with color ultrasonic system and recorded the vascular morphology by 3-dimensional anatomical microscopy. Patients who suffered from raised ICP underwent MRI and digital subtraction angiography (DSA) examination to show the length in the vertical direction of the wall of the bridging vein representing the diameter value. Pathological autopsy was performed from bodies of patients who had died from non-cerebral causes to observe the juncture part between the venous sinuses and tributary vertical brain veins. RESULTS: Under increased ICP conditions, venous drainage through the outlet cuff segment, a unique structure between the bridge vein and sinus, was obstructed and in turn venous blood became congested. Therefore, the increased blood volume worsened the pre-existing ICP according to the well-accepted theory regarding volume-pressure relationship. This phenomenon was described as concurrent "venogenic intracranial hypertension", which is characterized by intracranial venous blood stasis responsive to and together with the original increased ICP. CONCLUSIONS: The existence of this special pathophysiological process is prevalent, rather than rare, in various intracranial disorders. This finding would definitely provide new insight into the area of cerebral venous system research.

Diagnostic value of dual-source CT in Kawasaki disease.

BACKGROUND: Doppler color echocardiography is a common method for detecting coronary artery lesions in patients with Kawasaki disease (KD). However, the diagnostic accuracy for the whole coronary artery lesions is limited. The purpose of this study was to compare the diagnostic value of dual-source computed tomography (DSCT) and Doppler color echocardiography for the assessment of coronary artery lesions caused by KD. METHODS: Sixteen patients, 12 with typical KD and 4 with atypical KD, underwent DSCT and Doppler color echocardiography. The position and internal diameter of each coronary artery lesion was measured. Correlation analysis was used to compare the diagnostic value of the two imaging modalities. RESULTS: In the typical KD group, seven patients did not have any coronary artery lesion as confirmed by both DSCT scans and Doppler color echocardiography; in four patients proximal coronary artery injuries were identified by both modalities; in one patient an aneurysm in the middle and distal segments of the coronary artery was detected by DSCT but was negative in Doppler color echocardiography. In the atypical KD group, three cases showed the same results with both modalities, while one case with coronary artery stenosis in the middle segment was identified by DSCT but not detected by Doppler color echocardiography. There was a good correlation between the two imaging modalities (Kappa value, 0.768 (>or= 0.75)). CONCLUSION: DSCT coronary artery angiography is an accurate, non-invasive, and valuable technique for detecting and following up coronary artery lesions in patients with KD.

Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot.

OBJECTIVE: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. METHODS: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. RESULTS: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. CONCLUSION: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot.

[CT multiplan reconstruction images of disorder of stapes].

OBJECTIVE: To evaluate the clinical application of multi-planar reformation (MPR) for the stapes with multi-slice spinal thin-section CT in the patients with disorder of stapes before prosthetic ossicular reconstruction and their impact on surgical decision. METHODS: Axial CT scanning of temporal bone was undergone in 50 volunteers. Multiplan reformatted images included coronal, sagittal and oblique MPR, were made. All the MPR images were compared with each other in order to show which one could reveal the whole structures of stapes better. The height of stapes was measured with the oblique MPR. CT findings were evaluated in 102 cases with disorder of stapes. Prosthetic ossicular reconstruction was made in 65 cases. RESULTS: The full stapes cannot be shown in axial, coronal and sagittal MPR images, however, it was shown in oblique MPR in all the cases. The highness of stapes was (3.3 +/- 0.4) mm in the abnormal group. There was chronic otitis media in 69 cases (90 ears) and congenital abnormalities of the stapes in 33 cases (47 ears) which included the dispart of incudostapedial joint in 5 cases (7 ears), defect of head and crus of stapes in 9 cases (13 ears), defect of one side of crus in 3 cases (4 ears) and absence of the oval window in 16 cases (23 ears). CONCLUSIONS: Coronal and oblique MPR images from Axial Spiral CT Data are essential for the pre-operative planning of prosthetic ossicular reconstruction. The ship, structure or defect of stapes can be shown in the oblique MPR images. It is important for the patient to choose the type of operation.