Magnetic Resonance Spectroscopy of the Head and Neck

Case report: intracranial lesions in a patient with anxiety and depression: tumor recurrence or radiation encephalopathy?

Purpose

Radiation encephalopathy (REP) is one of the most common complications of radiotherapy for malignant tumors of the head and neck. Symptoms usually appear months to years following radiotherapy, with headache, insomnia, and memory loss as the main clinical features. We report a patient who was admitted to the hospital with anxiety and depressive disorder and was eventually diagnosed with REP.

Patients and methods

A 48-year-old patient who had undergone over 2 years of radiotherapy for nasopharyngeal carcinoma was admitted to the Department of Psychosomatic Medicine of our hospital because of recurrent fear, low mood, and waking up from dreams. Magnetic resonance imaging (MRI) revealed a mass in the left temporal lobe with a large peripheral edema. After multidisciplinary consultation, the possibility of tumor recurrence could not be excluded.

Results

Resection of the lesioned brain tissue to obtain pathological tissue showed glial cell proliferation and small focal areas of degeneration and necrosis, which indicated that the lesions were inflammatory. Postoperative MRI showed no abnormal signal, and the patient's condition improved.

Conclusion

Nasopharyngeal carcinoma patients with a history of radiotherapy and symptoms of increased intracranial pressure and neurological damage should be examined for REP. Furthermore, patients may experience anxiety and depressive disorders as a result of temporal lobe damage caused by REP.

Recent advances in head and neck surgical oncology

In recent years, the field of head and neck oncology has witnessed a remarkable transformation with unprecedented advances that have revolutionized the management of complex tumors in this region. As an intricate subspecialty within oncology, head and neck surgical procedures demand detailed knowledge of the complex anatomy meticulous precision in surgical technique, and expertise to preserve vital functions while ensuring optimal oncological outcomes. With the relentless pursuit of improved patient outcomes, the integration of innovative technologies has significantly enhanced the surgical armamentarium. Robotics, endoscopic platforms, and image-guided navigation have revolutionized the surgical approach, enabling precise tumor resection and sparing healthy tissues. Furthermore, the application of advanced imaging modalities and molecular biomarker profiling has opened new avenues for personalized treatment strategies. From targeted therapies and immunotherapies to adaptive radiation techniques, clinicians are now equipped with an array of tailored options, ushering in a new era of personalized care for patients with head and neck malignancies. This article delves into the unfolding narratives of clinical triumphs, exploring the transformative potential of emerging therapies and the collaborative efforts propelling head and neck surgical oncology toward a future of hope and healing.

Functional Magnetic Resonance Spectroscopy of Lactate in Alzheimer Disease: A Comprehensive Review of Alzheimer Disease Pathology and the Role of Lactate

ABSTRACT

Functional 1H magnetic resonance spectroscopy (fMRS) is a derivative of dynamic MRS imaging. This modality links physiologic metabolic responses with available activity and measures absolute or relative concentrations of various metabolites. According to clinical evidence, the mitochondrial glycolysis pathway is disrupted in many nervous system disorders, especially Alzheimer disease, resulting in the activation of anaerobic glycolysis and an increased rate of lactate production. Our study evaluates fMRS with J-editing as a cutting-edge technique to detect lactate in Alzheimer disease. In this modality, functional activation is highlighted by signal subtractions of lipids and macromolecules, which yields a much higher signal-to-noise ratio and enables better detection of trace levels of lactate compared with other modalities. However, until now, clinical evidence is not conclusive regarding the widespread use of this diagnostic method. The complex machinery of cellular and noncellular modulators in lactate metabolism has obscured the potential roles fMRS imaging can have in dementia diagnosis. Recent developments in MRI imaging such as the advent of 7 Tesla machines and new image reconstruction methods, coupled with a renewed interest in the molecular and cellular basis of Alzheimer disease, have reinvigorated the drive to establish new clinical options for the early detection of Alzheimer disease. Based on the latter, lactate has the potential to be investigated as a novel diagnostic and prognostic marker for Alzheimer disease.

Simultaneous multislice diffusion-weighted imaging versus standard diffusion-weighted imaging in whole-body PET/MRI

OBJECTIVE

To compare standard (STD-DWI) single-shot echo-planar imaging DWI and simultaneous multislice (SMS) DWI during whole-body positron emission tomography (PET)/MRI regarding acquisition time, image quality, and lesion detection.

METHODS

Eighty-three adults (47 females, 57%), median age of 64 years (IQR 52-71), were prospectively enrolled from August 2018 to March 2020. Inclusion criteria were (a) abdominal or pelvic tumors and (b) PET/MRI referral from a clinician. Patients were excluded if whole-body acquisition of STD-DWI and SMS-DWI sequences was not completed. The evaluated sequences were axial STD-DWI at b-values 50-400-800 s/mm2 and the apparent diffusion coefficient (ADC), and axial SMS-DWI at b-values 50-300-800 s/mm2 and ADC, acquired with a 3-T PET/MRI scanner. Three radiologists rated each sequence's quality on a five-point scale. Lesion detection was quantified using the anatomic MRI sequences and PET as the reference standard. Regression models were constructed to quantify the association between all imaging outcomes/scores and sequence type.

RESULTS

The median whole-body STD-DWI acquisition time was 14.8 min (IQR 14.1-16.0) versus 7.0 min (IQR 6.7-7.2) for whole-body SMS-DWI, p < 0.001. SMS-DWI image quality scores were higher than STD-DWI in the abdomen (OR 5.31, 95% CI 2.76-10.22, p < 0.001), but lower in the cervicothoracic junction (OR 0.21, 95% CI 0.10-0.43, p < 0.001). There was no significant difference in the chest, mediastinum, pelvis, and rectum. STD-DWI detected 276/352 (78%) lesions while SMS-DWI located 296/352 (84%, OR 1.46, 95% CI 1.02-2.07, p = 0.038).

CONCLUSIONS

In cancer staging and restaging, SMS-DWI abbreviates acquisition while maintaining or improving the diagnostic yield in most anatomic regions.

KEY POINTS

• Simultaneous multislice diffusion-weighted imaging enables faster whole-body image acquisition. • Simultaneous multislice diffusion-weighted imaging maintains or improves image quality when compared to single-shot echo-planar diffusion-weighted imaging in most anatomical regions. • Simultaneous multislice diffusion-weighted imaging leads to superior lesion detection.

Guidelines for magnetic resonance imaging in pediatric head and neck pathologies: a multicentre international consensus paper

The use of standardized imaging protocols is paramount in order to facilitate comparable, reproducible images and, consequently, to optimize patient care. Standardized MR protocols are lacking when studying head and neck pathologies in the pediatric population. We propose an international, multicenter consensus paper focused on providing the best combination of acquisition time/technical requirements and image quality. Distinct protocols for different regions of the head and neck and, in some cases, for specific pathologies or clinical indications are recommended. This white paper is endorsed by several international scientific societies and it is the result of discussion, in consensus, among experts in pediatric head and neck imaging.

Advanced Magnetic Resonance Imaging of the Skull Base

Magnetic resonance (MR) imaging is a crucial tool for evaluation of the skull base, enabling characterization of complex anatomy by utilizing multiple image contrasts. Recent technical MR advances have greatly enhanced radiologists' capability to diagnose skull base pathology and help direct management. In this paper, we will summarize cutting-edge clinical and emerging research MR techniques for the skull base, including high-resolution, phase-contrast, diffusion, perfusion, vascular, zero echo-time, elastography, spectroscopy, chemical exchange saturation transfer, PET/MR, ultra-high-field, and 3D visualization. For each imaging technique, we provide a high-level summary of underlying technical principles accompanied by relevant literature review and clinical imaging examples.

A risk prediction model of post-stroke cognitive impairment based on magnetic resonance spectroscopy imaging

Objective: To explore the clinical value of a risk prediction model of post-stroke cognitive impairment (PSCI) based on proton magnetic resonance spectroscopy (¹H-MRS).Methods:A retrospective analysis was conducted on 376 stroke patients hospitalized between March 2016 and March 2019. Their relevant clinical baseline data were collected at admission. After the patients' condition was stabilized, ¹H-MRS was performed to detect the related indices of the bilateral prefrontal lobe, thalamus, basal ganglia, hippocampus, precuneus, and angular gyrus. Within 12 months of the onset of stroke, cognitive impairment tests were performed monthly. Based on score results, stroke patients were divided into two groups: PSCI and post-stroke non-PSCI (N-PSCI). Thirty-four characteristic parameters of baseline and imaging data were extracted from the PSCI and N-PSCI groups. The least absolute shrinkage and selection operator (LASSO) regression was used for optimal feature selection, and a nomogram prediction model was established. The predictive ability of the model was validated by a calibration plot and the area under the curve (AUC) of the receiver operating characteristic curve.Results: Six risk factors were identified from clinical baseline data and MRS indices based on screening by LASSO dimensionality reduction. The consistency test of the correction curve showed that the prediction probability of the PSCI nomogram had good correlation with actual diagnosis. The AUCs of internal and external validation were 0.8935 and 0.8523, respectively.Discussion: A PSCI risk prediction model based on MRS serves to assist clinicians in estimating the risk of cognitive impairment after stroke.