Virtually all patients in this study received a CT scan following surgery in order that a radiologist could individually determine how well the screws had been placed. Every person’s backbone is a bit exclusive, Dr. Nottmeier says, and unexpected variations in bone form and density could make screw positioning in the spine more challenging, especially in patients who’ve had previous spine medical procedures. Almost half of the individuals in the Mayo study had a previous backbone surgery. This system we can have the very best view feasible of the vertebrae as we work, Dr. Nottmeier says. Based on the success of the technique, the picture guidance system is currently found in all spinal screw operations at Mayo Clinic’s campus in Florida. Two different picture guided systems were used in this study: the Stealth Treon, manufactured by Medtronic of Littleton, Mass., and the BrainLAB Vector Vision, from BrainLAB in Westchester, Ill.All of the authors made a decision to send the manuscript for publication and attest to the precision and completeness of the data and analyses and for adherence to the study protocol, which is available at NEJM.org. Statistical Analysis The analysis of the principal end point of hematologic response included all patients who received at least one dosage of imetelstat. The evaluation of the duration of response included all individuals who had a reply. The evaluation of molecular response included sufferers who received at least one dosage of imetelstat and who got a JAK2 V617F, MPL W515L, MPL W515K, or CALR mutant allele burden at baseline.