For the first time, researchers show that noninvasive, T2-weighted MRI can detect pre-fibrotic stages of the bone marrow cancer myelofibrosis in mice. Katya Ravid, professor of medicine and biochemistry at Boston University School of Medicine, MA, and colleagues report their findings in the Blood Cancer Journal.
Myelofibrosis is a serious bone marrow disorder that disrupts your body’s normal production of blood cells. The result is extensive scarring in your bone marrow, leading to severe anemia, weakness, fatigue and often an enlarged liver and spleen. This condition can occur at any age, but it typically develops after the age of 50 years.
The exact causes of myelofibrosis are unknown, but research suggests that it may arise from non-inherited mutations in the JAK2, MPL, CALR, and TET2 genes in blood stem cells. Other genes may also be involved.
There are few number of population studies that are available to estimate the prevalence of myelofibrosis. A review of textbooks and magazine articles suggests it may affect 0.3-1.5 out of every 100,000 people in Europe, Australia, and North America.
When myelofibrosis arises without having had any other condition it is called primary myelofibrosis (PMF). However, the condition can also occur as a result of other blood disorders, said the authors.
The condition gradually changes the structure of the bone marrow, which in the latest stage shows excessive deposits of reticulin fibers and cross-linked collagen. This gradually reduces the normal development of blood cells, which leads to bone marrow failure.
The current standard way of diagnosing myelofibrosis is through an invasive biopsy and tissue analysis of the bone marrow to assess the state of the cell population and reticulin deposits. In their research, the authors explain the previous studies have investigated the use of magnetic resonance imaging (MRI) to detect myelofibrosis, but to their knowledge, none had investigated the extent to which it could detect a pre-fibrotic state of the disease.
For their study, they devised and tested an approach using “T2-weighted magnetic resonance imaging” to see if they could detect bone marrow fibrosis in a mouse model of the disease. They also asked, “if the modality can capture early and late stages of the pathology.” The researchers found that they could detect a pre-fibrotic state of myelofibrosis with a clear and bright MRI signal, as well as more advanced states.
One of the features of pre-fibrotic myelofibrosis is an abundance of a type of large bone marrow cell called megakaryocytes. The researchers see that these are responsible for the bright MRI signal.
They conclude that their study is the first to evaluate a “T2-weighted MRI in a mouse model of myelofibrosis, with examination of potential sources of the MRI signal.” They also suggest perhaps such MRIs might be used to guide decisions on if and where biopsy should be performed.