The first number on a breast nodule exam report card is the longitudinal diameter and the second number is the transverse diameter. The longitudinal to transverse ratio is generally a measurement taken during a breast ultrasound exam of a breast lump that is found. When a patient has a breast ultrasound, he or she is usually lying flat. So a breast nodule is the equivalent of a lump measured from the top down in terms of the breast in the flat position as the longitudinal diameter and the transverse diameter as the transverse diameter. The aspect ratio shows the longitudinal and transverse diameter of the lump. It is an important reference for identifying whether a lump is benign or malignant. The aspect ratio less than 1 is mostly benign tumors. Transverse ratio greater than 1 is partly malignant tumor, because the tumor is invasive growth and the transverse ratio is more than one. As a reference basis for diagnosis of benign and malignant tumors, the aspect ratio cannot absolutely represent malignant or benign tumors. It is recommended that patients with breast nodules consult a regular hospital in a timely manner for treatment under the guidance of a doctor.