In diagnosing and treating certain medical conditions, it is often desirable to perform a biopsy, in which a specimen or sample of tissue is removed for pathological examination, tests and analysis. As is known, obtaining a tissue sample by biopsy and the subsequent examination are typically employed in the diagnosis of cancers and other malignant tumors, or to confirm that a suspected lesion or tumor is not malignant. Examination of tissue samples taken by biopsy is of particular significance in the diagnosis and treatment of breast cancer.
Magnetic resonance imaging (MRI) is often used to locate the site within a breast where a potentially cancerous lesion or tumor is located. Interventional MRI is the magnetic resonance imaging technique (often involving real time imaging) that allows a surgeon to perform MRI-guided tissue biopsy or surgery. One application of interventional MRI is to guide a surgeon during a biopsy or surgical operation on one or both of the breasts of a female patient.
Interventional MRI procedures typically require a magnetic resonance signal detection coil which has large openings so that the surgeon can have access to the surgical site through the coil with the biopsy device or other surgical devices. The MRI device may also include compression plates to compress the breast. Compression plates contain needle guide holes to allow for proper placement of a needle during a needle biopsy or larger windows configured to hold guide blocks. Guide blocks have block bodies with needle guide holes or with larger openings to allow access for larger biopsy devices. The guide blocks assist the physician with proper placement and stabilization of the biopsy device during a biopsy procedure.
The compression plates are secured to the housing of the signal detection coil. Markers, such as Vitamin E Capsules, which are highly visible under MRI device are placed on the compression plates and the position of the markers relative to the suspect tissue is measured using the magnetic resonance images. The proper window of the compression plate is then determined by finding the window in the compression plate which is closest to the desired entry point.
For larger biopsy devices the guide blocks are usually cube-shaped and contain about nine circular openings spaced in three rows of three. Due to the configuration of the openings in the guide block and the large size of some biopsy devices it is often difficult to precisely reach the desired tissue location. Present guide blocks for larger biopsy devices do not allow for access to every area of tissue directly behind the block. Thus, there is need in the art for improved guide blocks which allow access to all areas of tissue directly behind the block.