Chronic T Cell Encephalitis Responsive to Immunotherapy.

Chronic encephalitis manifesting as an epilepsy syndrome most commonly presents as Rasmussen's syndrome, usually characterized by epilepsia partialis continua, hemiparesis, and progressive cortical deficits such as aphasia, hemianopia, and cognitive decline. It is characterized by progressive hemispheric cortical atrophy on imaging and is usually seen in childhood. Adult-onset of the syndrome is rare, and only a few cases have been reported with bilateral symptoms. We present a patient with pseudobulbar affect and frontal lobe dysfunction who developed multifocal myoclonic jerks, right hemibody focal motor seizures, and right hemiparesis with bilateral cerebellar signs. Magnetic resonance imaging showed progressive hemispheric atrophy and bilateral features in Positron emission tomography-computed tomography (PET CT). Brain biopsy revealed chronic T-cell infiltrate. We discuss this case as the patient had several features that were atypical for Rasmussen's encephalitis (or syndrome).

Near-lossless compression of PET/CT images using singular value decomposition.

AIMS AND OBJECTIVES: The aim of the study is to compare the single matrix approach and slice-by-slice approach for computing singular value decomposition (SVD) to achieve near-lossless compression of PET/CT images. MATERIALS AND METHODS: The parameters used for comparison were SVD computation time, percentage compression and percentage difference between ROI counts on compressed and original images. SVD of 49 F-18-FDG PET/CT studies (33 370 PET/CT images) was computed using both approaches. The smaller singular values contributing insignificant information to the image were truncated, and then, the compressed image was reconstructed. A mask (101 × 101pixels) was used to extract the ROI counts from compressed and original images. Two nuclear medicine physicians compared compressed images with their corresponding original images for loss of clinical details and the presence of generated artifacts. Structural Similarity Index Measure, blur, brightness, contrast per pixel and global contrast factor were used for objective assessment of image quality. Wilcoxon test was applied to find a statistically significant difference between the parameters used for comparison at alpha = 0.05. RESULTS: Nuclear medicine physicians found compressed image identical to the corresponding original image. The values of comparation parameters were significantly larger for the single matrix approach in comparison with the slice-by-slice approach. The maximum percentage error between the compressed image and original image was less than 5%. CONCLUSIONS: Up to 64 % and 44% near-lossless compression of PET and CT images were achieved, respectively using the slice-by-slice approach, and up to 58 and 53% near-lossless compression of PET and CT images were achieved respectively using the single matrix approach.

Compression of 99mTc Methylene Diphosphonate Bone Scan Images using Discrete Cosine Transformation.

Aims and Objectives: The objective of this study was to find the optimum value of threshold for compression of 99mTc-methylene diphosphonate (MDP) bone scan images using discrete cosine transformation (DCT). Materials and Methods: DCT was applied to 51 99mTc-MDP bone scan images and then the image of logarithmic value of DCT coefficients was inspected to determine the threshold. After inspecting the number of images of DCT coefficients, we estimated the appropriate value of the threshold to be 10. After the application of threshold = 10, compressed image was reconstructed by applying the inverse DCT. Compression factor was calculated by dividing the nonzero element after thresholding to the nonzero element before thresholding DCT coefficients. Nuclear medicine physicians compared the compressed images with its input images and labeled them as acceptable or unacceptable. During comparison of input and compressed images, we considered points such as smoothening, blocking artifacts, body contour, gap between closely placed lesions, and detectability of lesion. Results: Forty-four compressed images (out of 51 images) obtained at threshold 10 were acceptable to Nuclear Medicine Physician (NMP). Compressed images were less noisy compared to its input image. Compression factor was found to be 13.03 ± (minimum = 2.71, maximum = 42.92). Conclusion: The optimum value of threshold for compression of 99mTc-MDP bone scan images was found to be 10, and the average compression factor achieved was equal to 13.03 (92.30%).

Diagnostic added value of interictal magnetic source imaging in presurgical evaluation of persons with epilepsy: A prospective blinded study.

BACKGROUND AND PURPOSE: In presurgical evaluation for epilepsy surgery, information is sourced from various imaging modalities to accurately localize the epileptogenic zone. Magnetoencephalography (MEG) is a newer noninvasive technique for localization. However, there is limited literature to evaluate if MEG provides additional advantage over the conventional imaging modalities in clinical decision making. The objective of this study was to assess the diagnostic added value of MEG in decision making before epilepsy surgery. METHOD: This was a prospective observational study. Patients underwent 3 h of recording in a MEG scanner, and the resulting localizations were compared with other complimentary investigations. Added value of MEG (considered separately from high-density electroencephalography) was defined as the frequency of cases in which (i) the information provided by magnetic source imaging (MSI) avoided implantation of intracranial electrodes and the patient was directly cleared for surgery, and (ii) MSI indicated additional substrates for implantation of intracranial electrodes. Postoperative seizure freedom was used as the diagnostic reference by which to measure the localizing accuracy of MSI. RESULTS: A total of 102 patients underwent epilepsy surgery. MEG provided nonredundant information, which contributed to deciding the course of surgery in 33% of the patients, and prevented intracranial recordings in 19%. A total of 76% of the patients underwent surgical resection in sublobes concordant with MSI localization, and the diagnostic odds ratio for good (Engel I) outcome in these patients was 2.3 (95% confidence interval 0.68, 7.86; p = 0.183) after long-term follow-up of 36 months. CONCLUSION: Magnetic source imaging yields additional useful information which can significantly alter as well as improve the surgical strategy for persons with epilepsy.

Comparison of noise estimation methods used in denoising 99mTc-sestamibi parathyroid images using wavelet transform.

The objective of this study was to compare the performance of variance, median absolute deviation, and the square of median absolute deviation methods of noise estimation in denoising of 99mTc-sestamibi parathyroid images using wavelet transform. Sixty-eight 99mTc-sestamibi parathyroid images including 33 images acquired at zoom 1.0 and 35 acquired at zoom 2.0 were denoised using the wavethresh package in R. The image decomposition and reconstruction method discrete wavelet transform, wavelet filter db4, shrinkage method hard, and thresholding policy universal were used. The noise estimation in the process was made using var, mad and madmad functions, which use variance, mean absolute deviation, and the square of mean absolute deviation, respectively. The quality of denoised images was assessed both qualitatively and quantitatively. A nonparametric two-sample Kolmogorov-Smirnov test was applied to find whether the difference in image quality produced by these three noise estimation methods was significant at 95% confidence. Noise estimation using madmad function produced the best quality denoised image. Further, the quality of the denoised image using madmad function was significantly better than the quality of the denoised image obtained with var or mad function (P = 1). The estimation of noise using madmad functions in wavelet transforms provides the best-denoised image for both zoom 1.0 and zoom 2.0 99mTc-sestamibi parathyroid images.

Comparative contribution of magnetoencephalography (MEG) and single-photon emission computed tomography (SPECT) in pre-operative localization for epilepsy surgery: A prospective blinded study.

PURPOSE: The aim of this study was to compare the diagnostic value and accuracy of ictal SPECT and inter-ictal magnetoencephalography (MEG) in localizing the site for surgery in persons with drug resistant epilepsy. METHOD: This was a prospective observational study. Patients expected to undergo epilepsy surgery were enrolled consecutively and the localization results from different imaging modalities were discussed in an epilepsy surgery meet. Odds ratio of good outcome (Engel I) were calculated in patients who underwent surgery in concordance with MEG and SPECT findings. Post-surgical seizure freedom lasting at least 36 months or more was considered the gold standard for determining the diagnostic output of SPECT and MEG. RESULTS: MEG and SPECT were performed in 101 and 57 patients respectively. In 45 patients SPECT could not be done due to delay in injection or technical factors. The accuracy of MEG and SPECT in localizing the epileptogenic zone was found to be 74.26 % and 78.57 % respectively. The diagnostic odds ratio for Engel I surgical outcome was reported as 2.43 and 5.0 for MEG and SPECT respectively. The diagnostic odds ratio for MEG in whom SPECT was non-informative was found to be 6.57 [95 % CI 1.1, 39.24], although it was not significantly associated with good surgical outcome. MEG was useful in indicating sites for SEEG implantation. CONCLUSION: SPECT was found to be non-informative for most patients, but reported better diagnostic output than MEG. MEG may be a useful alternative for patients in whom SPECT cannot be done or was non-localizing.

Improving technetium-99m methylene diphosphonate bone scan images using histogram specification technique.

In this study, we have proposed and validated that histogram of a good-quality bone scan image can enhance a poor-quality bone scan image. The histograms of two good-quality technetium-99m methyl diphosphonate bone scan images IA and IB recommended by nuclear medicine physicians (NMPs) were used to enhance 87 poor-quality bone scan images. Processed images and their corresponding input images were compared visually by two NMPs with scoring and also quantitatively using entropy, Structural similarity index measure, edge-based contrast measure, and absolute brightness mean error. Barnard's unconditional test was applied with a null hypothesis that the histogram of both IA and IB produces similar output image at α =0.05. The mean values of quantitative metrices of the processed images obtained using IA and IB were compared using Kolmogorov-Smirnov test. Histogram of a good-quality bone scan image can enhance a poor-quality bone scan image. Visually, histogram of IB improved statistically significantly higher proportion (P < 0.0001) of images (86/87) as compared to histogram of IA (51/87). Quantitatively, IB performed better than IA, and the Chi-square distance of input and IB was smaller than that of IA. In addition, a statistically significant (P < 0.05) difference in all the quantitative metrics among the outputs obtained using IA and IB was observed. In our study, reference histogram of good-quality bone scan images transformed the majority of poor-quality bone scan images (98.85%) into visually good-quality images acceptable by NMPs.

Role of an Intensity-Transformation Function in Enhancement of Bone Scintigraphy Images.

Bone scintigraphy images might exceed the dynamic range (the ratio between the highest and the lowest displayable brightness) of the monitor. In such a case, a high-intensity area accompanied by loss of detail in other structures in the displayed image make the clinical interpretation challenging. We have investigated the role of an intensity-transformation (IT) function in enhancement of these types of images. Methods: Forty high-dynamic-range bone scintigraphy images were processed using an IT function. The IT function has 2 parameters: threshold and slope. With the threshold kept equal to the mean count of the image, the slope was varied from 1 to 20. A software program developed in-house was used to process the images. Twenty output images corresponding to one input image were visually inspected by 2 experienced nuclear medicine physicians to select images of diagnostic quality, and from their selection was determined the standardized slope that produced the maximum number of diagnostic images. The 2 physicians also scored the quality of the input and output images (at the standardized slope) on a scale of 1-5. The Student t test was used to determine the significance of differences in mean score between the input and output images at an α significance level of 0.05. Results: Application of the IT function with standardized parameters significantly improved the quality of high-dynamic-range bone scintigraphy images (P < 0.001, with α = 0.05). A slope of 8 maximized the number of diagnostic images. Conclusion: The IT function has a significant role in enhancing high-dynamic-range bone scintigraphy images.

Progression of Chronic Pancreatitis to Pancreatic Cancer: Is There a Role of Gene Mutations as a Screening Tool?

OBJECTIVES: Early detection of pancreatic ductal adenocarcinoma still remains a challenge. Patients with chronic pancreatitis (CP) have a markedly increased risk of pancreatic cancer. Mutations in oncogenes and/or tumor suppressor genes play a role in development of pancreatic ductal adenocarcinoma. This study assessed mutations in KRAS and p53 gene in blood as a screening tool for malignant transformation in CP patients. METHODS: This was a cohort, single-center study including 294 CP patients. DNA was isolated from plasma of CP patients, and KRAS mutations were identified using polymerase chain reaction-restriction fragment length polymorphism. Patients with positive KRAS mutation were screened for malignancy using positron emission tomography or endoscopic ultrasound. Mutations in p53 gene were analyzed by sequencing. Tissue samples from CP and pancreatic cancer patients were also tested for mutations in KRAS and p53 genes. RESULTS: The plasma samples of 64 CP patients were positive for KRAS mutation, and 4 had mutation in p53 gene also. No patient positive for KRAS mutation and/or p53 mutation was found to have malignant transformation. CONCLUSION: Detection of KRAS or p53 mutation in plasma is not an effective screening tool for pancreatic cancer because accumulation of multiple mutations is required for malignant transformation in the pancreas.

Peptide Receptor Radionuclide and Octreotide: A Novel Approach for Metastatic Tumor-Induced Osteomalacia.

KEY MESSAGES: Octreotide can be used as an adjunctive therapy to increase phosphorus levels in patients with tumor-induced osteomalacia. Malignant phosphaturic mesenchymal tumor (PMT) may benefit from treatment with peptide receptor radionucleotide therapy. CONTEXT: The success of treatment modalities for malignant PMT is limited. Octreotide has been used to treat hypophosphatemia in patients with tumor-induced osteomalacia with equivocal results. To our knowledge, there are no reports of octreotide or peptide receptor radionuclide therapy use for malignant PMT. CASE DESCRIPTION: We report a 40-year-old man having hypophosphatemia, phosphaturia (tubular maximum of phosphorus corrected for glomerular filtration rate of <2.5 mg/dL), and somatostatin avid lesions in the right foot region with metastasis to both lungs. The patient had been subjected to resection of the primary tumor from the foot with thoracoscopic removal of the lung secondaries. Histology from all three lesions showed a spindle cell soft tissue tumor with a high mitotic index and somatostatin receptor 2 and 5 positivity. A trial of subcutaneous octreotide therapy at a dose of 100 µg thrice daily resulted in an increase in serum phosphorus levels from an average of 1.44 mg/dL to an average of 2.3 mg/dL. Finally, the affected limb was amputated, and the hypophosphatemia persisted postoperatively. In view of persistent hypophosphatemia and transient response to octreotide, the patient was administered four cycles of peptide receptor radionuclide therapy using 177Lutetium, which showed moderate improvement of serum phosphorus levels. CONCLUSION: Although octreotide use has been reported in four patients with benign PMT, to our knowledge, this is the first case of malignant PMT that has used peptide receptor radionuclide therapy in the treatment of malignant PMT. This moderately beneficial evidence is likely to guide the future use of radionuclide treatments in such tumors.

Calculating Gamma Camera Uniformity Parameters: Beyond the Vendor-specific Protocol.

OBJECTIVES: The aim of this study was to develop and verify a personal computer-based software tool for calculating uniformity indices of gamma camera. MATERIALS AND METHODS: The program was developed in MATLAB R2013b under Microsoft Windows operating system. Noise-less digital phantoms with known uniformity parameters were used to verify the accuracy of the program. Two hundred and forty-four Co-57 flood source images were acquired on Symbia T6 and Discovery nuclear medicine/computed tomography 670. The uniformity indices of these images were determined with their respective vendor's software and also by the tool developed. Bland-Altman plots were used for measuring the agreements between the developed program and the vendor's program for the calculation of uniformity indices. RESULTS: The tool for calculating uniformity indices was found to be accurate. Uniformity indices measured with the tool revealed a very good correlation with vendor's software based on Bland-Altman analysis, as almost all measurements were within the ±2 standard deviation range. CONCLUSION: The software tool for calculation of uniformity indices is accurate, and the uniformity indices calculated by it are in agreement with uniformity indices calculated by the vendor's software.

Role of various semiquantitative parameters of 18F-FDG PET/CT studies for interim treatment response evaluation in non-small-cell lung cancer.

PURPOSE: The aim of this study was to prospectively evaluate the role of various semiquantitative parameters obtained from fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT in interim treatment response assessment in biopsy-proven non-small-cell lung cancer (NSCLC) and to find the best parameter, if any. MATERIALS AND METHODS: Totally, 32 patients (male/female: 25/7) with biopsy proven NSCLC and a mean age of 54.71±12.65 years were enrolled in the study. Each patient underwent whole-body F-FDG PET/CT scan after injecting 5.18-7.77 MBq/kg of F-FDG intravenously at baseline and after four cycles of chemotherapy. Five parameters - that is, target-to-background ratio (TBR), maximum standardized uptake value (SUVmax), average standardized uptake value (SUVavg), whole-body metabolic tumor volume (MTVwb), and whole-body total lesion glycolysis (TLGwb) - were evaluated for both scans along with their percentage changes ([INCREMENT]). Patients were divided into two response groups as per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria: responders and nonresponders. All parameters were compared among the two response groups using appropriate statistical methods; P value of less than 0.05 was considered significant. RESULTS: All postchemotherapy parameters were found to have a significant role in the prediction of two response groups. Post-TBR had highest area under the receiver operating characteristic curve of 0.83 with a sensitivity and specificity of 75 and 82%, respectively, at a cutoff value of 4. The [INCREMENT]s, [INCREMENT]MTVwb, [INCREMENT]TLGwb, and [INCREMENT]SUVmax were significant with cutoffs of -56, -75, and -32%, respectively. [INCREMENT]MTVwb had the highest area under the receiver operating characteristic curve of 0.83 with sensitivity and specificity of 81.25%. In multivariate analysis, post-TBR and [INCREMENT]MTVwb were found to be the independent variables for prediction of interim treatment response. CONCLUSION: Our study proves that a multitude of semiquantitative parameters as documented above differ significantly between two response groups in patients with advanced stage NSCLC receiving chemotherapy. Moreover, parameters in combination (ΔMTV and post-TBR) with appropriate cutoffs can predict response groups with acceptable reliability.

Primary hyperparathyroidism may masquerade as rickets-osteomalacia in vitamin D replete children.

Primary hyperparathyroidism, typically a disease of the middle aged and the old, is less commonly seen in children. In children the disease has a bimodal age distribution with calcium sensing receptor mutation presenting in infancy as hypercalcemic crises and parathyroid adenoma or hyperplasia presenting later in childhood with bone disease. The childhood parathyroid adenomas are often familial with multiglandular disease and manifest with severe bone disease unlike adults. We report a series of four male patients with juvenile primary hyperparathyroidism, three of whom presented with bone disease masquerading as rickets-osteomalacia. One patient had asymptomatic hypercalcemia with short stature. Parathyroid adenoma was detected in all the four cases and all of them underwent resection of parathyroid adenomas confirmed on histopathology. Post-surgery all the cases had initial hypocalcaemia followed by normocalcemia. One case developed pancreatitis after surgery even after achieving normocalcemia. We conclude that parathyroid adenomas, although uncommon in children, are an important cause of skeletal disease that may initially be confused with hypovitaminosis D.

A technique for automatically extracting useful field of view and central field of view images.

INTRODUCTION: It is essential to ensure the uniform response of the single photon emission computed tomography gamma camera system before using it for the clinical studies by exposing it to uniform flood source. Vendor specific acquisition and processing protocol provide for studying flood source images along with the quantitative uniformity parameters such as integral and differential uniformity. However, a significant difficulty is that the time required to acquire a flood source image varies from 10 to 35 min depending both on the activity of Cobalt-57 flood source and the pre specified counts in the vendors protocol (usually 4000K-10,000K counts). In case the acquired total counts are less than the total prespecified counts, and then the vendor's uniformity processing protocol does not precede with the computation of the quantitative uniformity parameters. In this study, we have developed and verified a technique for reading the flood source image, remove unwanted information, and automatically extract and save the useful field of view and central field of view images for the calculation of the uniformity parameters. MATERIALS AND METHODS: This was implemented using MATLAB R2013b running on Ubuntu Operating system and was verified by subjecting it to the simulated and real flood sources images. RESULTS: The accuracy of the technique was found to be encouraging, especially in view of practical difficulties with vendor-specific protocols. CONCLUSION: It may be used as a preprocessing step while calculating uniformity parameters of the gamma camera in lesser time with fewer constraints.

Radioiodine Remnant Ablation: A Critical Review.

Radioiodine remnant ablation (RRA) is considered a safe and effective method for eliminating residual thyroid tissue, as well as microscopic disease if at all present in thyroid bed following thyroidectomy. The rationale of RRA is that in the absence of thyroid tissue, serum thyroglobulin (Tg) measurement can be used as an excellent tumor marker. Other considerations are like the presence of significant remnant thyroid tissue makes detection and treatment of nodal or distant metastases difficult. Rarely, microscopic disease in the thyroid bed if not ablated, in the future, could be a source of anaplastic transformation. On the other hand, microscopic tumor emboli in distant sites could be the cause of distant metastasis too. The ablation of remnant tissue would in all probability eliminate these theoretical risks. It may be noted that all these are unproven contentious issues except postablation serum Tg estimation that could be a good tumor marker for detecting early biochemical recurrence in long-term follow-up strategy. Radioactive iodine is administered as a form of "adjuvant therapy" for remnant ablation. There have been several reports with regard to the administered dose for remnant ablation. The first report of a prospective randomized clinical trial was published from India by a prospective randomized study conducted at the All India Institute of Medical Sciences, New Delhi in the year 1996. The study reported that increasing the empirical (131)I initial dose to more than 50 mCi results in plateauing of the dose-response curve and thus, conventional high-dose remnant ablation needs critical evaluation. Recently, two important studies were published: One from French group and the other from UK on a similar line. Interestingly, all three studies conducted in three different geographical regions of the world showed exactly similar conclusion. The new era of low-dose remnant ablation has taken a firm scientific footing across the continents.

Prognostic factors in pediatric differentiated thyroid cancer patients with pulmonary metastases.

AIM: This study was aimed at identifying the prognostic factors predicting remission in pediatric differentiated thyroid cancer (DTC) patients presenting with pulmonary metastases. Little is known about the prognostic factors in reference to pediatric DTC patients presenting with pulmonary metastases. METHODS: Fifty-three DTC patients aged ≤21 years were diagnosed with pulmonary metastases at initial presentation. The demographic and disease characteristics were compared between the patients who achieved remission and those who did not. RESULTS: During the median follow-up of 72 months, 38 patients became disease free, 14 patients had biochemically and/or structurally persistent disease, and one patient died due to disease progression. Patient age >15 years, presence of macronodular pulmonary metastases, and surgical methods lesser than total/near-total thyroidectomy were identified as factors associated with reduced odds of remission. CONCLUSION: This study describes the disease course and depicts the disease related prognostic factors in pediatric DTC patients with pulmonary metastases.

Enhancement of positron emission tomography-computed tomography image quality using the principle of stochastic resonance.

PURPOSE: Acquisition of higher counts improves visual perception of positron emission tomography-computed tomography (PET-CT) image. Larger radiopharmaceutical doses (implies more radiation dose) are administered to acquire this count in a short time period. However, diagnostic information does not increase after a certain threshold of counts. This study was conducted to develop a post processing method based on principle of "stochastic resonance" to improve visual perception of the PET-CT image having a required threshold counts. MATERIALS AND METHODS: PET-CT images (JPEG file format) with low, medium, and high counts in the image were included in this study. The image was corrupted with the addition of Poisson noise. The amplitude of the Poisson noise was adjusted by dividing each pixel by a constant 1, 2, 4, 8, 16, and 32. The best amplitude of the noise that gave best images quality was selected based on high value of entropy of the output image, high value of structural similarity index and feature similarity index. Visual perception of the image was evaluated by two nuclear medicine physicians. RESULTS: The variation in structural and feature similarity of the image was not appreciable visually, but statistically images deteriorated as the noise amplitude increases although maintaining structural (above 70%) and feature (above 80%) similarity of input images in all cases. We obtained the best image quality at noise amplitude "4" in which 88% structural and 95% feature similarity of the input images was retained. CONCLUSION: This method of stochastic resonance can be used to improve the visual perception of the PET-CT image. This can indirectly lead to reduction of radiation dose.

Role of concordance between ictal-subtracted SPECT and PET in predicting long-term outcomes after epilepsy surgery.

OBJECTIVE: F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and ictally subtracted single photon emission tomography (iSPECT) are important for localizing the epileptogenic focus. The following study analyzes the role of inter-concordance between FDG-PET and iSPECT in predicting long-term outcomes after epilepsy surgery. METHODS: We prospectively evaluated (January 2003-January 2008) patients undergoing surgery for temporal or extratemporal drug refractory epilepsy (DRE) who had at least a 5 years follow up. Patients with MRI and video EEG (vEEG) concordance for the seizure focus underwent iSPECT and FDG-PET. Concordance of the iSPECT and FDG-PET with each other and with the substrate (defined by MRI and vEEG) for temporal and extra-temporal epilepsies was evaluated and correlated with outcomes. RESULTS: One hundred twenty-three patients (74 males) were included in the study (mean age at time of surgery: 18.9±10.41 years). The mean age of onset of seizures was 9.87±8.37 years. The most common semiology was complex partial (45%). When both FDG-PET and iSPECT were concordant with each other, this translated into a (class I Engel at 5 years) outcome of 62% for extra-temporal epilepsies (provided they were also concordant with the lesion, as defined by MRI and vEEG). This percentage was significant (p<0.01) compared with all other situations (both FDG-PET/iSPECT not concordant to MRI/vEEG, only PET or iSPECT concordant with MRI/vEEG). This correlation was not found for the temporal epilepsies, where the MRI and vEEG were the most important prognostic parameters. In both temporal and extratemporal epilepsies the concordance of the iSPECT/FDG-PET with the MRI/vEEG correlated with a better 5-year outcome (temporal: 70% vs 25%; extra-temporal: 62% vs 33%; p<0.05). SIGNIFICANCE: Concordance between non-invasive investigations iSPECT and FDG-PET is an important predictive factor for surgical outcomes in extra-temporal epilepsy.

Ectopic insulin secreting neuroendocrine tumor of kidney with recurrent hypoglycemia: a diagnostic dilemma.

BACKGROUND: Hypoglycemia secondary to ectopic insulin secretion of non-pancreatic tumors is rare. CASE PRESENTATION: We describe a middle aged woman with recurrent hypoglycemia. On evaluation, she was detected to have hyperinsulinemic hypoglycemia and right sided renal mass lesion. 68Ga-Dotanoc and 99mTc-HYNICTOC scans confirmed the intrarenal mass to be of neuroendocrine origin. Right nephrectomy was done and it turned out to be an insulin secreting neuroendocrine tumour. Neuroendocrine nature of this tumour was further confirmed by ultra-structural examination. Her hypoglycemia did not recur after resection of this tumour. CONCLUSION: Few cases of ectopic insulin secretion have been reported though some are not proven convincingly. This case addresses all the issues raised in previous case reports and proves by clinical, laboratory, functional imaging and immunohistochemical analysis that ectopic origin of insulin by non-pancreatic tumors does occur. To our knowledge, this is the first reported case of ectopic insulinoma arising from the kidney.

Necrolytic migratory erythema associated with glucagonoma syndrome diagnosed by 68Ga-DOTANOC PET-CT.

Necrolytic migratory erythema (NME) is a rare dermatological condition which presents a diagnostic challenge. Repeated negative skin biopsies and non-detection of any pancreatic tumor in conventional imaging modalities like a computed tomography (CT) scan and ultrasonogram (USG) make the diagnosis more difficult. By the time the diagnosis is made, the patient usually presents with metastasis. We present a rare case of difficult to diagnose NME, as repeated skin biopsies and conventional imaging modalities like CT and USG could not detect the underlying glucagonoma. A (68)Ga-DOTANOC positron emission tomography PET-CT was able to detect the underlying cause of NME as glucagonoma of the pancreas and the same investigation confirmed the absence of any metastasis elsewhere in the body. The tumor was excised and patient dramatically improved, and all skin lesions disappeared.