News | PET-CT | March 26, 2020

High-resolution PET/CT Assesses Brain Stem Function in Patients with Hearing Impairment

Novel scanners may open door for prognostic assessment in patients receiving cochlear implants

Novel scanners may open door for prognostic assessment in patients receiving cochlear implants

Iva Speck, MD, explains research showing that novel, fully digital, high-resolution positron emission tomography/computed tomography imaging of small brain stem nuclei can provide clinicians with valuable information concerning the auditory pathway in patients with hearing impairment. The research is featured in The Journal of Nuclear Medicine (read more at http://jnm.snmjournals.org/content/current). Video courtesy of Iva Speck, University Hospital Freiburg, Germany.

March 26, 2020 — Novel, fully digital, high-resolution positron emission tomography/computed tomography (PET/CT) imaging of small brain stem nuclei can provide clinicians with valuable information concerning the auditory pathway in patients with hearing impairment, according to a new study published in the March issue of The Journal of Nuclear Medicine. Using 18F-FDG PET/CT imaging, researchers found that patients with asymmetrical hearing loss have reduced glucose metabolism in parts of the brain stem and primary auditory cortex. The latter may be influenced by cortical reorganization and thus, hopefully help to predict the chance that a cochlear implant will improve hearing.

"With the possible exception of few dedicated high-resolution research scanners, earlier PET/CT systems with lower resolution did not permit clear-cut identification and assessment of brain stem nuclei," said Iva Speck, M.D., resident of otorhinolaryngology at the University of Freiburg Medical Center in Freiberg, Germany. "Today, the use of fully digital clinical PET/CT systems permits greatly enhanced imaging and quantitative assessment of small brain stem nuclei, such as the inferior colliculus (IC), the part of the midbrain that acts as a main auditory pathway for the body."

In the study, 13 patients with asymmetric hearing loss underwent 18F-FDG PET/CT imaging. The scans were reviewed by two experienced readers who examined regional glucose metabolism in the IC and the primary auditory cortex (PAC) — a part of the brain known to undergo metabolic changes based on acoustical outside input and transformation to neuronal signals from the cochlea hair cells to the auditory nerve fibers. The readers rated the scans as to whether glucose metabolism showed no asymmetry or mild, moderate or strong asymmetry to the left or to the right for the IC and PAC separately. Statistical analyses were performed to determine the effect of the duration of hearing impairment on glucose metabolism and to compare glucose metabolism between the IC and PAC.

Regional glucose metabolism of both the IC and PAC was significantly reduced on the contralateral (opposite) side of the poorer-hearing ear, as compared to the ipsilateral (same) side. In addition, a longer duration of hearing impairment was associated with a higher metabolism on the contralateral PAC. By contrast, duration of hearing impairment did not predict regional glucose metabolism for the ipsilateral PAC or either side of the IC.

"Previous studies suggest that the association between longer duration of hearing impairment and higher glucose metabolism indicates cortical reorganization. In bilateral deaf patients this has been shown to lessen the benefits of cochlear implants," said Speck. "Prediction of a successful cochlear implant outcome might benefit from improved imaging with fully digital PET/CT systems, as large parts of the auditory system, including small brain nuclei such as the IC, can be assessed for preoperative patient characterization."

She continued, "Beyond this topic, the study's findings are of interest for other neurological research fields, like neurodegenerative diseases, which often affect brain stem nuclei early in disease course," Speck remarked. "Digital PET pushes the limits of what can be imaged and contributed to patient care by molecular imaging."

For more information: www.snmmi.org

View the YouTube video, High-Resolution PET/CT Imaging Assesses Brain Stem Function in Patients with Hearing Impairment.

Related Content

Varian received FDA clearance for its Ethos therapy in February 2020. It is an adaptive intelligence solution that uses onboard AI in the treatment system to take the cone beam CT imaging on the system, compare it to the treatment plan and deliver an entire adaptive treatment plan in a typical 15-minute treatment time slot, from patient setup through treatment delivery.

Varian received FDA clearance for its Ethos therapy in February 2020, shown here displayed for the first time at ASTRO 2019. It is an adaptive intelligence solution that uses onboard AI in the treatment system to take the cone beam CT imaging on the system, compare it to the treatment plan and deliver an entire adaptive treatment plan in a typical 15-minute treatment time slot, from patient setup through treatment delivery.

Feature | Treatment Planning | April 03, 2020 | Dave Fornell, Editor
The traditional treatment planning process takes days to create an optimized radiation therapy delivery plan, but new
Recommended best practices for nuclear imaging departments under the COVIF-19 pandemic have been issues by the ASNC and SNMMI. #COVID19 #ASNC #SNMMI #Coronavirus #SARScov2
News | Coronavirus (COVID-19) | April 03, 2020
April 3, 2020 — A new guidance document on best practices to maintain safety and minimize contamination in nuclear im
A new framework from an international team of experts aims to help protect patients and providers, and conserve protective equipment for frontline healthcare workers #COVID19 #Coronavirus #2019nCoV #Wuhanvirus #SARScov2
News | Prostate Cancer | March 30, 2020
March 30, 2020 — In the wake of the COVID-19 pan
Women are more likely to be cured of cancer by radiotherapy but the side effects are worse.

Women are more likely to be cured of cancer by radiotherapy but the side effects are worse. Image by Mark Kostich

News | Radiation Therapy | March 30, 2020
March 30, 2020 — Women undergoing radiotherapy for
Age‐standardized, delay‐adjusted overall cancer incidence rates for 2012 through 2016 are illustrated among males and females by racial/ethnic group

Age‐standardized, delay‐adjusted overall cancer incidence rates for 2012 through 2016 are illustrated among males and females by racial/ethnic group. Racial/ethnic groups are mutually exclusive. Data for the non‐Hispanic American Indian/Alaska Native (AI/AN) population are restricted to Indian Health Service Purchased/Referred Care Delivery Area (PRCDA) counties. API indicates Asian/Pacific Islander. Chart courtesy of ACS Journals 

News | Radiation Oncology | March 16, 2020
March 16, 2020 — The Ann...