Odd Sites of Parathyroid Adenomas: 18F-fluorocholine PET/CT Pointing to the Right Place.

Primary hyperparathyroidism is mostly caused by parathyroid adenoma(s) which are generally localized using routine imaging modalities such as neck ultrasonography and 99mTc-SestaMIBI scintigraphy. However, these can miss ectopic parathyroid adenomas due to their limited sensitivities. These ectopic lesions can later lead to failure of surgical excision and necessitate the need for a re-exploration. 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) can help in the localization of these ectopic adenomas due to its superior detection rates and spatial resolution. Herein, we report a case of ectopic parathyroid adenomas that were localized on FCH PET/CT.

Micropump integrated white blood cell separation platform for detection of chronic granulomatous disease.

White blood cells (WBCs) are robust defenders during antigenic challenges and prime immune cell functioning indicators. High-purity WBC separation is vital for various clinical assays and disease diagnosis. Red blood cells (RBCs) are a major hindrance in WBC separation, constituting 1000 times the WBC population. The study showcases a low-cost micropump integrated microfluidic platform to provide highly purified WBCs for point-of-care testing. An integrated user-friendly microfluidic platform was designed to separate WBCs from finger-prick blood (⁓5 µL), employing an inertial focusing technique. We achieved an efficient WBC separation with 86% WBC purity and 99.99% RBC removal rate in less than 1 min. In addition, the microdevice allows lab-on-chip colorimetric evaluation of chronic granulomatous disease (CGD), a rare genetic disorder affecting globally. The assay duration, straight from separation to disease detection, requires only 20 min. Hence, the proposed microfluidic platform can further be implemented to streamline various clinical procedures involving WBCs in healthcare industries.

Gold nanoparticle assisted colorimetric biosensors for rapid polyethylene terephthalate (PET) sensing for sustainable environment to monitor microplastics.

The extremely widespread and ubiquitous nature of plastics, estimated to boost its global production by 26 billion tons till 2050. The large chunks of plastic waste that decomposed down to micro- or nano plastics (MNPs) leads to various ill effects on biological entities. The conventional PET detection methods lack rapid detection of microplastics due to variances in microplastic features, long-drawn-out sample pre-processing procedures and complex instrumentation. Therefore, an instantaneous colorimetric evaluation of microplastic will ensures the simplicity of conducting assays on field. Several nanoparticle-based biosensors that detects proteins, nucleic acids, metabolites operate on either cluster or disperse state of nanoparticle. However, gold nanoparticle (AuNPs) emerges an ideal scaffold for sensory element in lateral flow biosensors due to their simple surface functionalization, unique optoelectronic properties and varied colour spectrum depending on morphologies and aggregation state. In this paper an effort has been made in the form of a hypothesis using in silico tools as a basis to detect polyethylene terephthalate (PET) - most abundant type of microplastic using gold nanoparticle based lateral flow biosensor. We retrieved sequences of PET-binding synthetic peptides and modelled their 3-D structure using I-Tasser server. The best protein model for each peptide sequences are docked with PET monomers - BHET, MHET and other PET polymeric ligands, to evaluate their binding affinities. The synthetic peptide SP 1 (WPAWKTHPILRM) docked with BHET and (MHET)4 exhibits 1.5-fold increases in binding affinity as compared to reference PET anchor peptide Dermaseptin SI (DSI). The GROMACS molecular dynamics simulation studies of synthetic peptide SP 1 - BHET & - (MHET)4 complexes for 50 ns further confirmed the stable binding. RMSF, RMSD, hydrogen bonds, Rg and SASA analysis provides useful structural insights of the SP 1 complexes as compared to reference DSI. Furthermore, SP 1 functionalized AuNP-based colorimetric device was described in detail for detection of PET.

A reaction network scheme for hidden Markov model parameter learning.

With a view towards artificial cells, molecular communication systems, molecular multiagent systems and federated learning, we propose a novel reaction network scheme (termed the Baum-Welch (BW) reaction network) that learns parameters for hidden Markov models (HMMs). All variables including inputs and outputs are encoded by separate species. Each reaction in the scheme changes only one molecule of one species to one molecule of another. The reverse change is also accessible but via a different set of enzymes, in a design reminiscent of futile cycles in biochemical pathways. We show that every positive fixed point of the BW algorithm for HMMs is a fixed point of the reaction network scheme, and vice versa. Furthermore, we prove that the 'expectation' step and the 'maximization' step of the reaction network separately converge exponentially fast and compute the same values as the E-step and the M-step of the BW algorithm. We simulate example sequences, and show that our reaction network learns the same parameters for the HMM as the BW algorithm, and that the log-likelihood increases continuously along the trajectory of the reaction network.

Comparison of 99mTc-methyl diphosphonate bone scintigraphy and 68Ga-DOTANOC PET/computed tomography in articular manifestation of rheumatoid arthritis.

OBJECTIVE: Tc-99m methyl diphosphonate (MDP) bone scintigraphy is used to assess disease activity in rheumatoid arthritis (RA). Somatostatin receptor (SSTR) expression in RA has been reported previously. SSTR-based PET/computed tomography (CT) may be superior to bone scintigraphy to know disease extent and in locating inflammatory joints that can be further targeted with peptide receptor radionuclide therapy thereby opening up new theranostic avenues. Based on these facts, the present study was designed to compare Tc-99m MDP bone scintigraphy and Ga-68 DOTANOC PET/CT in patients with RA. MATERIALS AND METHODS: Patients with a clinical diagnosis of RA were injected with 111-185 MBq of Ga-68 DOTANOC and 740 MBq of Tc-99m MDP intravenously. Images were acquired 30-45 min postinjection for Ga-68 DOTANOC on dedicated PET/CT scanners. Triple-phase bone scans were acquired on a dual-head gamma camera. PET/CT and MDP scan images were visually assessed by two experienced nuclear medicine physicians. RESULTS: Nineteen patients (16 women and 3 men) with a clinical diagnosis of RA were included in the study. Clinically, 196 joints in these 19 patients were diagnosed positive for RA. Of these 196 joints, Tc-99m MDP uptake was seen in 157 joints (80%). On Ga-68 DOTANOC scan, tracer uptake was seen in 151 of 196 joints (77%) with a lesion to background ratio of at least 2 in most of the joints. CONCLUSION: Ga-68 DOTANOC is equally good as an MDP scan for detection of RA with the added advantage of being used as a theranostic modality. However, further evaluation with a larger sample size and joint-to-joint comparison is warranted.

Comparison of Lutetium-177 tin colloid and Rhenium-188 tin colloid radiosynovectomy in chronic knee arthritis.

OBJECTIVE: To assess the role of Lutetium-177(Lu-177) tin colloid for radiosynovectomy and compare it with Rhenium-188 (Re-188) tin colloid radiosynovectomy for alleviation of pain in patients with chronic inflammatory arthritis of knee. METHODS: Patients of chronic inflammatory arthritis of the knee underwent pretherapeutic evaluation in a form of knee ultrasonogram, bone scan and clinical evaluation. Fifty-seven recruited patients were allocated at random to receive either intraarticular injections of Lu-177 tin colloid or Re-188 tin colloid. Eventually, 27 patients received Re-188 tin colloid and 30 patients received Lu-177 tin colloid. The joint was then immobilized for 2 days. Response evaluation was done using knee ultrasound, bone scan and clinical findings. RESULT: Of 30, 20 patients responded to radiosynovectomy in the Lu-177 tin colloid group compared to 21/27 patients in the Re-188 tin colloid group. CONCLUSION: Lu-177 tin colloid is an effective alternative to Re-188 tin colloid for radiosynovectomy in patients with chronic inflammatory knee arthritis.

Adrenocortical Carcinoma with Inferior Vena Cava Thrombus on 18F-FDG-PET-Computed Tomography.

Adrenocortical carcinoma (ACC) is a rare and highly aggressive malignant neoplasm which can produce intravascular extension into the inferior vena cava (IVC) and can rarely extend into the right atrium. We describe the 18F Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography findings of a 57-year-old man diagnosed with ACC with IVC thrombus extending up to the right atrium.

Adenoid Cystic Carcinoma of Trachea: Findings on 18F FDG Positron Emission Tomography-Computed Tomography.

Adenoid cystic carcinoma (ACC) of the trachea is the second most common tumor of trachea after squamous cell carcinomas. It arises from the submucosal layer and predominantly has a rapid locoregional spread. We describe the 18F FDG positron emission tomography-computed tomography findings of a 51-year-old woman, a biopsy-proven case of ACC of trachea who underwent the scan for initial staging.

Prostate-Specific Membrane Antigen Expression in Adrenocortical Carcinoma on 68Ga-Prostate-Specific Membrane Antigen PET/CT.

We present here a case of metastatic adrenocortical carcinoma with bilateral lung nodules. The patient had been treated with mitotane therapy initially and then was later referred for chemotherapy. There was progression of disease noted on the F-FDG PET/CT. Ga prostate-specific membrane antigen (PSMA) PET/CT was planned to explore the possibility of future treatment with Lu-DKFZ-PSMA-617. It revealed peripheral increased uptake of Ga-HBED-CC-PSMA equal to liver uptake.

18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Tuberculosis: Spectrum of Manifestations.

The objective of this article is to provide an illustrative tutorial highlighting the utility of 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) imaging to detect spectrum of manifestations in patients with tuberculosis (TB). FDG-PET/CT is a powerful tool for early diagnosis, measuring the extent of disease (staging), and consequently for evaluation of response to therapy in patients with TB.

Development and Validation of the Suprathreshold Stochastic Resonance-Based Image Processing Method for the Detection of Abdomino-pelvic Tumor on PET/CT Scans.

PURPOSE: The detection of abdomino-pelvic tumors embedded in or nearby radioactive urine containing 18F-FDG activity is a challenging task on PET/CT scan. In this study, we propose and validate the suprathreshold stochastic resonance-based image processing method for the detection of these tumors. METHODS: The method consists of the addition of noise to the input image, and then thresholding it that creates one frame of intermediate image. One hundred such frames were generated and averaged to get the final image. The method was implemented using MATLAB R2013b on a personal computer. Noisy image was generated using random Poisson variates corresponding to each pixel of the input image. In order to verify the method, 30 sets of pre-diuretic and its corresponding post-diuretic PET/CT scan images (25 tumor images and 5 control images with no tumor) were included. For each sets of pre-diuretic image (input image), 26 images (at threshold values equal to mean counts multiplied by a constant factor ranging from 1.0 to 2.6 with increment step of 0.1) were created and visually inspected, and the image that most closely matched with the gold standard (corresponding post-diuretic image) was selected as the final output image. These images were further evaluated by two nuclear medicine physicians. RESULTS: In 22 out of 25 images, tumor was successfully detected. In five control images, no false positives were reported. Thus, the empirical probability of detection of abdomino-pelvic tumors evaluates to 0.88. CONCLUSION: The proposed method was able to detect abdomino-pelvic tumors on pre-diuretic PET/CT scan with a high probability of success and no false positives.

Comparison of 18F-Fluorocholine Positron Emission Tomography/Computed Tomography and Four-dimensional Computed Tomography in the Preoperative Localization of Parathyroid Adenomas-initial Results.

OBJECTIVE: We aimed to compare the diagnostic accuracy of 18F-Fluorocholine (FCH)-positron emission tomography/computed tomography (PET/CT) and four-dimensional (4D)- CT in detection and localization of eutopic and ectopic parathyroid adenoma (PA) in patients with hyperparathyroidism. MATERIALS AND METHODS: Five patients with primary hyperparathyroidism underwent FCH-PET/CT after 60 min of 185 MBq of intravenous 18F-FCH administration. Images were acquired from head to mediastinum at 3 min per bed position. No intravenous contrast was used. All patients underwent 4D-CT within 2 weeks of the FCH-PET/CT, with a precontrast, post contrast arterial, and venous phase with 75 ml intravenous Iohexol 350 followed by 25 ml saline chase. Histopathology was considered as the gold standard. RESULTS: Both modalities showed 100% concordance in the detection of parathyroid lesions. Both FCH-PET/CT and 4D-CT detected 7 lesions in 5 patients, with 4 patients having a single lesion, and 1 patient having three lesions. Of the 7 reported lesions, 4 were eutopic and 3 were ectopic. No additional lesions were detected by either modality in comparison to the other. All 7 specimens were resected and histopathology showed PA/hyperplasia. CONCLUSION: FCH-PET/CT and 4D-CT are equally efficacious in detection and localization of eutopic and ectopic PA. This may open up the possibility of using FCH-PET/CT in patients with negative conventional imaging who cannot undergo contrast studies.

Utility of (18)F-choline photon emission tomography/computed tomography in the diagnosis of parathyroid adenoma.

Recently, the role of (18)F-choline in the detection of parathyroid adenomas has been reported. At our institution, we are currently studying the role of this tracer in comparison to the standard methoxy-isobutyl-isonitrile.(MIBI) scan with single photon emission tomography/computed tomography. Our initial results show that (18)F-choline is at least as good as 99mTc-MIBI scan. We present here a representative case of a 45-year-old woman with multiple skeletal lytic lesions and a high parathyroid hormone.(PTH) who underwent both these imaging techniques with concordant results, further confirmed by histopathology and postoperative fall in serum PTH levels.

Metastatic superscan on (99m)Tc-methylene diphosphonate bone scintigraphy in pediatric neuroblastoma.

Excessive skeletal radioisotope uptake in relation to soft tissues along with absent or faint activity in the genitourinary tract on bone scintigraphy (BS) is known as a "superscan." However the association of pediatric solid tumor malignancy with metastatic superscan has not been reported previously. We here describe two such cases of neuroblastoma who presented with metastatic superscan on (99m)Tc-methylene diphosphonate BS. Presence of a superscan usually indicates an advanced stage of the disease. The patient prognosis is usually poor. Though extremely rare superscan can be associated with pediatric solid tumor malignancies and should be kept in mind while reporting such cases.

Radiation-Induced Esophagitis Masquerading as Disease Progression in Case of Esophageal Carcinoma: A Diagnostic Dilemma Solved on Follow-up FDG PET/CT.

Radiation esophagitis is one of the commonest complications of the radiotherapy involving esophagus. It is characterized by diffuse radiotracer uptake in the esophagus on ¹8F-FDG PET/CT. Thus, it can be often confused with the esophageal malignancy. We present the sequential ¹8F-FDG PET/CT images of a 45-year-old woman with locally advanced squamous cell carcinoma of the esophagus who developed radiation esophagitis after chemoradiotherapy. It was confused with the progression of the disease, and the dilemma was resolved by the follow-up PET/CT.