METHOD FOR DESIGNING AND MANUFACTURING CUSTOMIZED BOWTIE FILTERS FOR BETTER IMAGE QUALITY AND LOWER PATIENT DOSE
Publication Date: 2017-Apr-27
The IP.com Prior Art Database
A technique for designing a bowtie filter based on characterizing anatomy to be imaged using CT scan, and for manufacturing a pre-patient collimator "bowtie" filter that is customized to a patient's specific body type and anatomy. A custom design for a bowtie filter is generated according to a patient's anatomy, desired dose and IQ performance. A bowtie filter is manufactured using additive manufacturing or conventional manufacturing techniques, and installed in the CT scanning systems for conducting the CT scan.
The present disclosure relates generally to computed tomography (CT) scanning systems, and more particularly to designing and manufacturing bowtie filters according to patient anatomy for use in CT scanning systems.
Currently available CT scanning systems generally use a standard of up to 3 selectable bowtie filters, chosen for a specific type of CT scan or anatomy to be imaged. The choice from 3 bowtie filters is not always optimal with respect to image quality (IQ), or with respect to a dose for a scan. For example, in certain type of anatomy, such as extremities or pediatrics, each of the 3 bowtie filter choices may represent a compromise in dose or in IQ, however, one must be used due to lack of availability of other options. Therefore, in many instances, the scans are conducted in sub-optimal conditions due the availability of a limited type of bowtie filters.
Therefore, it would be desirable to provide more optimal bowtie filtering solutions for use in CT scans.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts a schematic illustrating the positioning of the bowtie filter in a CT scanning system.
This invention proposes a method that characterizes anatomy to be imaged using CT scan, and utilizes manufacturing methods to produce a pre-patient collimator "bowtie" filter that is customized to a patient's specific body type and anatomy. Specifically, the present invention provides techniques for designing and manufacturing a custom produced bowtie filter according to a patient’s anatomy, desired dose and IQ performance. The invention comprises manufacturing an additive bowtie filter to provide better than prevalent standard of selectable bowtie filters. The bowtie filter is designed according to patient size (waist, chest, height, etc.), weight, body composition (Body Mass Index or BMI, fat %, etc.), and the Specific Scan Area. The designed bowtie filter is manufactured, installed and calibrated into conventional CT scanning systems, and yields desired IQ and dose performance.
FIG. 1 depicts a schematic illustrating the positioning of the bowtie filter custom-designed and manufactured according to a patient, installed for performing a CT scan in a CT scanning system.
The bowtie filter is designed based on the desired characteristics of the CT scan. A patient anatomy is characterized based on pre-determined factors such as anatomy to be imaged, size, weight, body composition, and other similar physical parameters. A filter design software tool utilizes this data to determine an optimal filter profile and material composition. The determination is based on theoretical and/or experimental correlation data between scan types, anatomical locations, and selected scan parameters. The design tool may also design for limited scan field of views for organ specific scans using know techniques. Th...