Marina-Portia Anthony

Assessment of glycosaminoglycan distribution in human lumbar intervertebral discs using chemical exchange saturation transfer at 3 T: feasibility and initial experience.

Recent studies have proposed that glycosaminoglycan chemical exchange saturation transfer (gagCEST) is associated with a loss of glycosaminoglycans (GAGs), which may be an initiating factor in intervertebral disc (IVD) degeneration. Despite its promising potential, this application has not been reported in human in vivo IVD studies because of the challenges of B0 magnetic field inhomogeneity in gagCEST. This study aimed to evaluate the feasibility of quantifying CEST values in IVDs of healthy volunteers using a clinical 3 T scanner. A single‐slice turbo spin echo sequence was used to quantify the CEST effect in various GAG phantoms and in IVDs of 12 volunteers. The phantom results indicated high correlation between gagCEST and GAG concentrations (R2 = 0.95). With optimal B0 inhomogeneity correction, in vivo CEST maps of IVDs showed robust contrast between the nucleus pulposus (NP) and the annulus fibrosus (AF) (p < 0.01), as well as higher signal in the central relative to the peripheral NP. In addition, a trend of decreasing CEST values from upper to lower disc levels was evident in NP. Our results demonstrate that in vivo gagCEST quantification in human lumbar IVDs is feasible at 3 T in combination with successful B0 inhomogeneity correction, but without significant hardware modifications. Our initial findings suggest that it would be worthwhile to perform direct correlation studies between CEST and GAGs using cadaver samples, and to extend this novel technique to studies on patients with degenerative discs to better understand its distinct imaging features relative to conventional techniques. Copyright

Quantitative assessment of the cervical spinal cord damage in neuromyelitis optica using diffusion tensor imaging at 3 Tesla.

To investigate whether quantitative MRI measures of cervical spinal cord white matter (WM) using diffusion tensor imaging (DTI) in neuromyelitis optica (NMO) differed from controls and correlated with clinical disability.

Age-related diffusion patterns in human lumbar intervertebral discs: a pilot study in asymptomatic subjects

Diffusion tensor imaging (DTI) may provide an accurate noninvasive method of detecting degenerative matrix alterations in human lumbar intervertebral discs (IVDs). This study aimed to investigate age-related degenerative changes in human lumbar IVDs using DTI. Thirty asymptomatic volunteers ranging in age from 25 to 67 years underwent single-shot diffusion weighted echo-planar imaging on a 3 T scanner. DTI-derived metrics including fractional anisotropy (FA) and mean diffusivity (MD) were analyzed by a histogram analysis method. A Mann-Whitney test was used to compare subject groups (young and elderly) with respect to the diffusion measures, and piecewise linear regression was used to characterize the change in each metric as a function of age. We found significant age-related changes in the elderly adult group, with decrease of MD (11%, P<.001) and increase of FA (20%, P<.001). Our results demonstrate that the degenerative-related changes taking place in the IVDs through aging can be quantitatively accessed by DTI-derived metrics, while the morphologic changes are difficult to be identified in conventional T(2)-weighted images. Our initial findings suggest that it would be worthwhile to validate the relationship between DTI metrics and the actual degenerative status of IVDs using extracted disc samples and to extend it to studies on patients with degenerative discs in order to further explore the clinical usefulness and relevance of DTI.

Spectrum of 18F-FDG PET/CT Appearances in Peritoneal Disease

OBJECTIVE The objective of our study was to illustrate the spectrum of appearances of peritoneal diseases on (18)F-FDG PET/CT, show the usefulness of fused FDG PET/CT as a diagnostic tool for the peritoneum, and discuss the pitfalls in FDG PET/CT interpretation of peritoneal disease. CONCLUSION Malignant and benign diseases may have peritoneal involvement, which can manifest as various imaging patterns on FDG PET/CT. Awareness of these patterns and of potential interpretation issues is important to optimize diagnostic accuracy.

Utility of FDG PET/CT in the Assessment of Myeloid Sarcoma

OBJECTIVE Myeloid sarcoma (MS) is a rare extramedullary manifestation of acute myeloid leukemia that often presents during remission or disease relapse. With awareness of this clinical entity and the appropriate clinical history, MS can be detected despite its nonspecific radiologic features. CONCLUSION This article highlights the utility of (18)F-FDG PET/CT, which has high sensitivity in detecting early MS and provides a systemic overview of tumor burden, and its potential role in monitoring of treatment response.

Ultrashort time‐to‐echo MRI of the cartilaginous endplate: Technique and association with intervertebral disc degeneration

The purpose of this study was to report the feasibility of the ultrashort time‐to‐echo (UTE) MRI technique to assess cartilaginous endplate (CEP) defects in humans in vivo and to assess their relationship with intervertebral disc (IVD) degeneration.

Hepatic radiation injury in distal esophageal carcinoma: a case report.

The liver is an organ at particular risk for toxicity after radiotherapy for distal esophageal cancer. We report the case of a 58-year-old man with distal esophageal carcinoma, who underwent follow-up FDG-PET/CT 6 weeks after completion of preoperative neoadjuvant chemoradiotherapy. The left hepatic lobe and caudate showed new, round areas of hypoenhancement on CECT and increased FDG-uptake, which resembled metastases. However an, as yet unreported, linear configuration of FDG uptake was noted and found to correlate with the anterior posterior-posterior anterior opposing field radiotherapy portal.

18F-FDG PET/CT diagnosis of vagus nerve neurolymphomatosis.

A 62-year-old woman was in remission from previously treated stage IV diffuse large B-cell lymphoma with cranial involvement. She presented with new-onset hoarseness of voice and choking; MRI of the brain showed disease recurrence in the left cavernous sinus. She was subsequently referred for F-FDG PET/CT with contrast for further evaluation of lymphomatous recurrence. F-FDG PET/CT not only revealed hypermetabolic activity in the left cavernous sinus correlating to the MRI findings but also showed an interesting manifestation explaining the patients hoarseness of voice, being neurolymphomatosis along the left vagus nerve.

Utility of 18F-FDG PET/CT in identifying terminal ileal myeloid sarcoma in an asymptomatic patient

A 63-year-old man was presented with bone pain and was found to be anemic and thrombocytopenic. There were circulating myeloblasts with dysplastic neutrophils. Repeated bone marrow aspirations showed marrow necrosis but no histological features to support the diagnosis of acute myeloid leukemia. In the absence of a definitive diagnosis at the time, a combined 18-F fluoro-deoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT) was requested to look for extramedullary neoplasms that might be associated with marrow necrosis (Images 1 and 2). Studies and case reports have demonstrated the usefulness of 18F-FDG PET in detection, assessment, and follow up of myeloid sarcoma [1–4]. 18F-FDG PET is a useful tool in detecting early MS, in early relapse, before other crosssectional imaging modalities are able to detect any morphological change or effects of its metabolic activity after treatment. The 18F-FDG uptake of MS is wide, ranging from SUVmax 2.6–9.7 (Images 3 and 4) [2]. Cases of MS involving the gastrointestinal tract are uncommon, comprising only 7% in a biopsy-proven series [5]. Although most cases of MS are clinically undetectable, gastrointestinal MS commonly presents symptomatically as small bowel obstruction, bleeding, perforation, or intussusceptions [6–8]. This patient was completely asymptomatic in the gastrointestinal tract. The 18F-FDG PET/CT finding, however, prompted a colonoscopy, which identified a solitary ulcer with an erythematous base just inside the terminal ileum. A biopsy of this ulcer showed an infiltration of atypical mononuclear cells consistent with blasts and myeloid precursors with eosinophilic granules. An immunohistochemical stain was positive for the myeloid marker, myeloperoxidase; therefore, the findings were compatible with a diagnosis of myeloid sarcoma. As bone marrow necrosis is a rare presentation of acute myeloid leukemia, the diagnosis was immediately confirmed and consolidated. The patient was subsequently offered aggressive induction chemotherapy. A bone marrow examination was repeated on day 21 after induction chemotherapy; it showed marrow fibrosis with an absence of necrosis. The patient’s hemoglobin and platelet count had improved. This case report underscores the importance of a PET/CT scan in the detection of myeloid sarcoma. References 1. Aschoff P, Häntschel M, Oksüz M, et al. Integrated FDG-PET/CT for detection, therapy monitoring and follow-up of granulocytic sarcoma. Nuklearmedizin (Nuclear Medicine) 2009;48:185–191. 2. Ueda K, Ichikawa M, Takahashi M, et al. FDG-PET is effective in the detection of granulocytic sarcoma in patients with myeloid malignancy. Leuk Res 2010;34:1239–1241. 3. Mantzarides M, Bonardel G, Fagot T, et al. Granulocytic sarcomas evaluated with F-18-fluorodeoxyglucose PET. Clin Nucl Med 2008;33:115–117. 4. Makis W, Hickeson M, Derbekyan V. Myeloid sarcoma presenting as an anterior mediastinal mass invading the pericardium: Serial imaging with F-18 FDG PET/CT. Clin Nucl Med 2010;35:706–709. 5. Neiman RS, Barcos M, Berard C, et al. Granulocytic sarcoma: A clinicopathologic study of 61 biopsy cases. Cancer 1981;48:1426–1437. 6. Sevinc A, Buyukberber S, Camci C, et al. Granulocytic sarcoma of the colon and leukemic infiltration of the liver in a patient presenting with hematochezia and jaundice. Digestion 2004;69:262–265. 7. Choi EK, Ha HK, Park SH, et al. Granulocytic sarcoma of bowel: CT findings. Radiology 2007;243:752–759. 8. Zhou W, Vasquez JC, O’Donnell MR, et al. Clinical manifestations of gastrointestinal granulocytic sarcoma requiring surgical treatment. Am Surg 2001;67:764–766. Image 1. 18F-FDG PET in maximum intensity projection, demonstrating hypermetabolic activity at the right iliac fossa (solid black arrow). In addition, there was diffuse skeletal marrow uptake due to the marrow necrosis and pathological fracture at the right anterior first rib (dotted black arrow).

PET/CT appearance of intestinal Behcet disease.

Behcet disease is a multisystem, chronic relapsing vasculitis of unknown etiology. Gastrointestinal involvement occurs in 10% to 40%, usually affecting the terminal ileum and cecum. Radiologic appearances resemble inflammatory and neoplastic diseases, with differential diagnoses including: Crohn disease, carcinoma, lymphoma, typhlitis, tuberculosis, and amebiasis. While computed tomography (CT) and magnetic resonance imaging appearances have been described, the F-18 fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/CT appearance of intestinal Behcet disease has not been previously reported. FDG-PET, coregistered with CT, was useful in this case to aid lesion detection, and for determining the extent of disease for treatment planning. The case also highlights the need for awareness of this condition as a rare benign cause for false-positive diagnosis in the assessment for malignancy, with potential avoidance of unnecessary surgery.