Nuclear Medicine & Radiation Therapy

Goal of this work is to assess importance and usefulness of Magnetic Resonance Spectroscopy (MRS) in Patients suffering from non-Hodgkin's lymphoma (NHL), submitted to bone marrow transplant (BMT) and other hematological disorders.

Objectives: To determine the sensitivity and specificity of MPS when compared to CCA in detecting coronary artery disease and compare it with published data. To compare myocardial perfusion findings (MPS) with conventional coronary angiography (CCA) results according to their territory.
Methods: The study included men and women >35 years of age who have undergone MPS and CCA within seven months due to suspected CAD with no interval major cardiac event or intervention between 2013 and 2014 at Royal Hospital, Oman.
Results: A total of 95 patients were included in the study. The sensitivity and specificity of MPS for detection of coronary artery stenosis (>=70%) were 95.45% and 47.06% respectively and for detection of coronary artery stenosis (>= 50%) were 82.76% and 43.24% respectively. The sensitivities and specificities of MPS for detection of Left anterior descending (LAD), Right coronary artery (RCA) and left circumflex (LCX) territory stenosis (>=70%) were (59.38% and 68.25%), (73.08% and 63.77%), and (42.31% and 81.16%) respectively. The agreement between MPs and CCA for coronary artery stenosis >=70% according to territory, the kappa value ranged 0.24- 0.30, p<0.0001.
Conclusion: The sensitivity and specificity of MPS at Royal Hospital for detecting critical stenosis was comparable with published data, 95.45% vs. (81%-93%), 47.09% vs. (38%-70%), respectively. There was a fair agreement in results between territory based MPS and CCA for coronary artery disease.

Objective: To understand value of early rapid, quality-assurance (QA), post-therapy whole-body scan (Tx-WBS) in patients receiving peptide receptor radionuclide therapy (PRRT) in outpatient setting.
Methods: Sixteen patients with metastatic neuroendocrine tumors received PRRT and underwent Tx-WBS after each cycle. Early imaging (3 hour post-injection) was favored. Planar-images obtained on dual-headed gamma camera (speed 30 cm/min) were visually assessed and qualitatively compared with pre-therapy diagnostic scans. Retention% and lesion/spleen (L/S) ratios were calculated.
Results: Fifty three Tx-WBS were analyzed. No cutaneous contamination, extravasation or unexpected tracer distribution was observed. 46/53 (87%) Tx-WBS in 14/16 (88%) patients demonstrated uptake in metastatic lesions. No significant correlation was seen between L/S ratios and response on follow-up imaging. Qualitative assessment of follow-up images during four-cycles of PRRT provided preliminary estimate of disease course in 11/16 patients; with unexpected findings in 2.
Conclusion: In daily practice, especially in outpatient setting, an early QA post-PRRT scan proved effective for validating successful treatment and allowing preliminary disease monitoring, at no additional cost.

Objectives: Magnetic Resonance Image Fusion is used to highlight tissue characteristics unrevealed by the individual sequences. We have applied a fusion algorithm merging isotropic sequences T2 Constructive Interference in a Steady State-CISS and contrast-enhanced (CE) T1 to obtain multiplanar (MPR) composed images (CESS) of skull base tumors and the surrounding cranial nerves (CN). We hypothesize that CESS images may complement standard Diffusion-Tensor Tractography and depict the deviated trajectories of CN impaired by space occupying lesions within the subaracnoid cisterns.
We describe the fundamentals of this technique and present the cases of several patients in which the information garnered was coincident with CN tractographies and neurosurgical results.
Methods: A retrospective and observational study of six patients (three vestibular schwannomas, two petro-clival meningiomas and one difuse epidermoid) was performed, comparing CESS with CN tractographies and intraoperative findings. Isotropic T2-CISS, pos-Gadolinium T1 images and Diffusion-Tensor (DT) tractographies were obtained preoperatively. MPR fused CESS was processed with the MR vendor’s proprietary software.
Results: All fused imaging sets resulted correctly aligned. The location of the CN on CESS was seen has a fiber of low contrast and increased thickness at the tumor margin, coincident with CN tractographies and surgical results.
Conclusion: We speculate that image fusion (CESS) complements CN tractography evaluation and aid in the operative planning.

In scintigraphy, extra-bone uptake always arouses curiosity in certain clinical situations with a risk of misdiagnosis. We report here a case of extra-osseous fixation giving an atypical image simulating a hyper fixing kidney stone. These images caught our attention for a literary review and discussion.