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UMRAM researchers has recently published an article titled as “A z-gradient array for simultaneous multi-slice excitation with a single band RF pulse”. It is shown that multiple slices can be excited with a single band RF pulse using a custom designed z-gradient array. In recent years, imaging multiple slices at the same time, multi-slice MRI, has become popular due to reduced imaging time or increased SNR. In the conventional techniques, excitation of multiple slices cause increase in the peak voltage, peak power, specific absorption rate (SAR). Therefore, design of multi-slice RF pulses are limited by RF power amplifier limitations or safety limits related to SAR. In this study, a z-gradient array is used to create spatially oscillating magnetic fields such that multiple locations can be excited with a conventional single band RF pulse; therefore, increase in the peak power, peak voltage, SAR or RF pulse durations can be avoided. Novel z-gradient hardware including 9 channel z-gradient array, Tx/Rx RF coils, 9 power amplifiers and control circuits are introduced. Design techniques and performance evaluations for various target specifications are also analyzed. At last, MR experiments has been conducted to validate the proposed technique and multiple slices are successfully excited with a single band RF pulse using the z-gradient array coil.

In a recent publication from UMRAM researchers, it is shown that simultaneous use of linear and nonlinear gradients provides better B1+ inhomogeneity correction than using only linear or only nonlinear gradients. In high field scanners (3T or above), perfectly spatially homogeneous radio frequency (RF) pulse cannot be achieved inside the body because wavelength becomes comparable with the object dimension. In literature, spoke excitation, which uses RF pulses together with the commercial linear gradient fields, can provide more homogeneous excitation by correcting the B1+ inhomogeneity. In this study, it is shown that when there are additional nonlinear gradient fields driven by independent amplifiers, degree of freedom in the excitations problem is increased. Formulations and design techniques are formulated in the study. In an example experiment, transmit inhomogeneity is decreased 46% while it can only be decreased 20% with the original hardware of the scanner in the same scenario. 

UMRAM researchers published a novel work in MRM journal in
collaborating with UNAM team. This study presents an inductively
coupled ultra-thin, flexible, and passive RF resonator for MRI marking
and guiding purposes with clinical feasibility. Standard
microfabrication processing was used to fabricate the resonant marker.
The proposed marker consists of two metal traces in the shape of a
square with an edge length of 8 mm, with upper and lower traces
connected to each other by a metalized via. A 3T MRI fiducial marking
procedure was tested in phantom and ex vivo, and then the marker's
performance was evaluated in an MRI experiment using humans. The
ultra-thin and flexible structure of this wireless flexible RF
resonant marker offers effective and safe MR visualization with high
feasibility for anatomic marking and guiding in various regions of the
body.


Umram researchers published a new study for implant safety research under MRI. The project introduces a new in vivo testing method and system for active implantable medical devices. The computer simulations and phantom experiments poorly represent potential temperature increases and Animal experiments could be a better model but heating experiments conducted immediately after the surgery suffer from alterations of the thermoregulatory and tissue properties during acute testing conditions. In this study, a new temperature sensor implant (TSI) system was demonstrated. It resembles an active implantable medical device but it measures the most potential heating locations during MRI. The battery operated device allows low power wireless data transfer. Therefore, it can be used for subacute and acute MRI animal heating tests.            

"Aziz Sancar Science, Service and Encouragement Awards"  by the Turkish Health Institutions Presidency (TÜSEB) that is organized for the first time this year has been rewarded to six scientists who works in the field of Biological and Medicinal Sciences. One of the incentive awards of this very important prize has been given to Associate Professor Oktay Algın of UMRAM for his studies on interventional procedures and investigations on closed surgeries such as stroke, brain bubble (aneurysm), vein stenting.  We are honored to have him as a researcher in UMRAM and wish him every success in the future for his valuable studies.

UMRAM researchers have recently examined the effects of sub-second time interval adaptation on visual apparent motion. They found that both auditory and visual time interval adaptation can alter ERPs elicited by apparent motion. However, the after-effects by each modality were in the opposite direction and found as distinct changes in the spatiotemporal profile of the neural activity. Accordingly, these findings suggest that distributed sensory processes play an important role in sub-second time interval adaptation. Click here for further information and the journal article.

A new article of which the neuroimaging studies had been carried out in UMRAM has been published in International Electronic Journal of Elementary Education. The article is produced from  the doctoral thesis by Dr. Gül Kuruyer which is entitled "The Effect of Enriched Reading Program on the Cognitive Processes of Students with Reading Strength and Their Neural Structures" and supervised by Prof. Dr. Kader Karlı Oguz and Prof. Dr. Hayati Akyol. Arzu Ceylan Has contributed to the investigation during the collection and analysis of data related to neuroimaging. 

The main purpose of the current study is to explain the effect of an enrichment reading program on the cognitive processes and neural structures of children experiencing reading difficulties. The current study was carried out in line with a single-subject research method and the between-subjects multiple probe design belonging to this method. This research focuses on a group of eight students with reading difficulties. Within the context of the study, memory capacities, attention spans, reading-related functional MRI activation and white matter pathways of the students were determined before and after the application of the enrichment reading program. This determination process was carried out in two stages. Neuro-imaging was performed in the first stage and in the second stage the students’ cognitive processes and neural structures were investigated in terms of focusing attention and memory capacities by using the following tools: Stroop Test TBAG Form, Auditory Verbal Digit Span Test-Form B, Cancellation Test and Number Order Learning Test. The results obtained show that the enrichment reading program resulted in an improvement in the reading profiles of the students having reading difficulties in terms of their cognitive processes and neural structures.

When the studies dealing with white matter and activation are examined, it is seen that they have mostly focused on adults and compared neural structures of good and poor readers. Within the context of the current study, since each student’s state before the implementation of the reading program was accepted as a unique starting point, it has been possible to investigate and explain the effect of the enrichment reading program on the students’ neural structures in an individualized way. When we examine the results reported by neuro-imaging studies focusing on reading and reading, we see that there is some degree of consistency, but also differentiation between the findings. The reason for this can be age, gender, or the complex and multi-faceted structure of reading.The full article can be found here: 

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