Lauren V. Zollinger

Comparison of 18F-fluorodeoxyglucose and 18F- fluorothymidine PET in differentiating radiation necrosis from recurrent glioma

Purpose The objective was to compare 18F-fluorodeoxyglucose (FDG) and 18F-fluorothymidine (FLT) PET in differentiating radiation necrosis from recurrent glioma. Materials and Methods Visual and quantitative analyses were derived from static FDG PET and static and dynamic FLT PET in 15 patients with suspected recurrence of treated grade 2 glioma or worse with a new focus of Gd contrast enhancement on MRI. For FDG PET, SUVmax and the ratio of lesion SUVmax to the SUVmean of contralateral white matter were measured. For FLT PET, SUVmax and Patlak-derived metabolic flux parameter Kimax were measured for the same locus. A 5-point visual confidence scale was applied to FDG PET and FLT PET. Receiver operating curve analysis was applied to visual and quantitative results. Differences between recurrent tumor and radiation necrosis were tested by Kruskal-Wallis analysis. On the basis of follow-up Gd-enhanced MRI, lesion-specific recurrent tumor was defined as a definitive increase in size of the lesion, and radiation necrosis was defined as stability or regression. Results For FDG SUVmax, the FDG ratio of lesion–white matter, and FLT Kimax, there was a significant difference between mean values for recurrent tumor and radiation necrosis. Recurrent tumor was best identified by the FDG ratio of lesion–contralateral normal white matter (area under the curve of 0.98, confidence interval of 0.91 to 1.00, sensitivity of 100%, and specificity of 75% for an optimized cutoff value of 1.82). Conclusions Both quantitative and visual determinations allow accurate differentiation between recurrent glioma and radiation necrosis by both FDG and FLT PET. In this small series, FLT PET offers no advantage over FDG PET.

Using Diffusion Tensor Imaging and Immunofluorescent assay to evaluate the pathology of Multiple Sclerosis

To determine the ability of the principal diffusion tensor imaging (DTI) indices to predict the underlying histopathology evaluated with immunofluorescent assay (IFA).

Diffusion tensor imaging of ex vivo cervical spinal cord specimens: the immediate and long term effects of fixation on diffusivity

Diffusion tensor imaging (DTI) is an emerging noninvasive method for evaluating tissue microstructure, but is highly susceptible to in vivo motion artifact. Ex vivo experiments on fixed tissues are needed to improve DTI techniques, which require fixed tissue specimens. Several efforts have been made to study the effect of fixation on both human and mouse tissue, with varying results. Four human cervical cords and three segments of pig cervical spinal cord specimens were imaged both before and after tissue fixation using 3D multishot diffusion weighted imaging (ms‐DWEPI). Fixation caused a significant decrease in the longitudinal diffusivity whereas the relative anisotropy (RA) and radial diffusivity remained unaffected. Additionally, once adequately preserved, the diffusivity parameters of fixed tissue remain constant over time. Fixation has important effects on the diffusivity of tissue specimens. These findings have important implications for the determination of tissue microstructure and function using DTI technologies. Anat Rec, 2009.

Quantification of diffusivities of the human cervical spinal cord using a 2D single-shot interleaved multisection inner volume diffusion-weighted echo-planar imaging technique.

BACKGROUND AND PURPOSE: DTI is a highly sensitive technique, which can detect pathology not otherwise noted with conventional imaging methods. This paper provides the atlas of reliable normative in vivo DTI parameters in the cervical spinal cord and its potential applications toward quantifying pathology. MATERIALS AND METHODS: In our study, we created a reference of normal diffusivities of the cervical spinal cord by using a 2D ss-IMIV-DWEPI technique from 14 healthy volunteers and compared parameters with those in 8 patients with CSM. The 2D ss-IMIV-DWEPI technique was applied in each subject to acquire diffusion-weighted images. FA, λ∥, and λ⊥ were calculated. A reference of normal DTI indices from 12 regions of interest was created and compared with DTI indices of 8 patients. RESULTS: A map of reference diffusivity values was obtained from healthy controls. We found statistically significant differences in diffusivities between healthy volunteers and patients with CSM with different severities of disease, by using FA, λ∥, and λ⊥ values. CONCLUSIONS: DTI using 2D ss-IMIV-DWPEI is sensitive to spinal cord pathology. This technique can be used to detect and quantify the degree of pathology within the cervical spinal cord from multiple disease states.

Retropharyngeal Lymph Node Metastasis From Esthesioneuroblastoma: A Review of the Therapeutic and Prognostic Implications

SUMMARY: Esthesioneuroblastoma (ENB) is a malignant neoplasm of the olfactory epithelium. Metastasis of ENBs to retropharyngeal lymph nodes is an important finding on imaging examinations that alters staging and treatment. A total of 17 cases of ENB from 3 institutions were evaluated. The CT and MR imaging findings from the cases of 4 patients with ENB with retropharyngeal metastatic disease are reviewed. The vector of spread, staging, and treatment implications are discussed.

Amyloid Deposition and Cognition in Older Adults: The Effects of Premorbid Intellect

Although amyloid deposition remains a marker of the development of Alzheimers disease, results linking amyloid and cognition have been equivocal. Twenty-five community-dwelling non-demented older adults were examined with (18)F-flutemetamol, an amyloid imaging agent, and a cognitive battery, including an estimate of premorbid intellect and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). In the first model, (18)F-flutemetamol uptake significantly correlated with the Delayed Memory Index of the RBANS (r = -.51, p = .02) and premorbid intellect (r = .43, p = .03). In the second model, the relationship between (18)F-flutemetamol and cognition was notably stronger when controlling for premorbid intellect (e.g., three of the five RBANS Indexes and its Total score significantly correlated with (18)F-flutemetamol, rs = -.41 to -.58). Associations were found between amyloid-binding (18)F-flutemetamol and cognitive functioning in non-demented older adults. These associations were greatest with delayed memory and stronger when premorbid intellect was considered, suggesting that cognitive reserve partly compensates for the symptomatic expression of amyloid pathology in community-dwelling elderly.

Congenital craniocervical anomalies pose a vulnerability to spinal cord injury without radiographic abnormality (SCIWORA)

Though the incidence of cervical spine injuries in the pediatric population is relatively low at 1.2% of trauma patients, these injuries are often associated with severe neurologic deficits [1]. Upper cervical spine injuries are more common in children less than 11 years old [1–3]. This may be explained by the unique biomechanics of the pediatric cervical spine [4] as well as the anatomy [3, 5–8]. Furthermore, the craniocervical junction (CCJ) has a dynamic complex anatomic relationship between the occiput and the atlantoaxial structures. Congenitally anomalous CCJ can lead to an acute or chronic disability related to spinal cord compression [1, 9]. Most anomalies of the CCJ are asymptomatic and occult without the presence of an underlying syndrome that may herald its presence such as Klippel-Feil, Goldenhar syndrome, or numerous additional skeletal dysplasias [10]. We present a case of spinal cord injury without radiographic abnormality (SCIWORA) secondary to minor trauma in a pediatric patient with a congenital left atlanto-occipital assimilation joint.

A Head and Neck Radiologist’s Perspective on Best Practices for the Usage of PET/CT Scans for the Diagnosis and Treatment of Head and Neck Cancers

Cancer of the head and neck accounts for 3% of all the malignant diseases within the United States; however, there is an estimated societal cost of

Inducible nitric oxide synthase in chronic active multiple sclerosis plaques: distribution, cellular expression and association with myelin damage

3.1 billion spent annually for treatment. These neoplasms can be much more debilitating than other carcinomas, especially with the involvement of exposed physical attributes. Most head and neck cancer is secondary to squamous cell carcinoma. There are over 40 000 new head and neck squamous cell carcinoma (HNSCC) cancers reported each year in the United States. Multiple available imaging modalities play