Usefulness of 320-row area detector CT in neurosurgery

The introduction of 320-row area detector CT (ADCT) has led to a new era in CT. ADCT should not be thought of as conventional CT scanning with a larger number of detector rows. Since the overall width of the detector is greatly expanded, the brain can be scanned in a single rotation. This makes it possible to perform non-contrast CT scanning in a single rotation. ADCT also permits volume data to be acquired along the temporal axis by continuous scanning (4D data). Since scanning can be completed in a single rotation, sedation is not required even in patients who may be difficult to examine, such as pediatric patients and patients with impaired consciousness. Scanning can also be completed in approximately 1 second in routine 3D-CTA studies, permitting the amount of contrast medium to be reduced. In addition, volume data from the arterial phase to the venous phase (4D data) can be acquired by sequential scanning (continuous or intermittent scanning). In particular, since ADCT is superior to DSA in terms of tissue contrast, especially in the venous phase, visualization is improved and three-dimensional assessment can be performed more easily. In addition, ECG-gated continuous volume scanning allows an extensive range from the head through the carotid arteries to the heart (coronary arteries) to be examined in a single scan. Given the strong association between carotid artery stenosis and coronary artery stenosis, the ability to assess both in a single study is of great clinical value. ADCT also supports 160-row helical scanning, which permits the range from the head to the inguinal region to be scanned in approximately 6 seconds. Moreover, since ADCT allows the arteries of the entire body to be examined with no increase in the amount of contrast medium, the range from the location where the sheath is to be introduced to the lesion can be confirmed before neuroendovascular therapy. As discussed above, ADCT has many advantages. However, ADCT studies can generate a huge number of reconstructed images, sometimes reaching several thousand. It is impossible to interpret all of these images individually. In addition, sequential scanning is associated with higher X-ray exposure. It is therefore essential to select the ideal scanning method for the clinical objective, to set the optimal exposure dose, and to perform reconstruction and analysis appropriately.