CT Scan Data Analysis in Malformations of Cortical Development.

Malformations of cortical development (MCDs) are a diverse group of disorders that result from abnormal neuronal migration, proliferation, and differentiation during brain development. Head computed tomography (CT) has limited use in the diagnosis of MCDs and should be reserved for selected cases with specific indications or when magnetic resonance imaging is not available or contraindicated. CT can detect brain calcifications associated with MCDs, thus helping in the differential diagnosis between acquired and genetic MCDs or in the identification of different genetic patterns. Moreover, CT can provide high-resolution images of the skull and bones, thus identifying associated malformations, such as craniosynostosis, inner and middle ear malformations, and vertebral anomalies. In this chapter, we review the CT scan technique, data analysis, and indications in the investigation of MCDs.

Electrocardiographic, biochemical, and scintigraphic evidence for the cardioprotective effect of paricalcitol and vitamin D3 on doxorubicin-induced acute cardiotoxicity in rats.

AIM: We aimed to investigate the possible cardioprotective effects of paricalcitol (PR), its vitamin D receptor agonist, and vitamin D3 (VIT-D3) on an experimental model of doxorubicin (DX) cardiotoxicity by 99mTc-PYP scintigraphy, electrocardiographic (ECG) and biochemical methods. METHOD: Forty-two male Wistar/Albino rats (250‒300 g; aged 10‒12 weeks) were randomly separated into six groups, namely into control (CN), doxorubicin (DX), paricalcitol (PR), vitamin D3 (VIT-D3), paricalcitol + doxorubicin (PR+DX), and vitamin D3 + doxorubicin (VIT-D3+DX) groups. Cardiotoxicity was induced by three doses of DX (18 mg/kg, i.p.) at 24-hour intervals on days 18, 19 and 20. PR (0.5 ug/ kg, i.p) and VIT-D3 (5,000 IU/kg, i.p) were injected for 20 days before and after the application of DX (18 mg/kg, i.p.). On day 21 of the experiment, biochemical parameters [tumor necrosis factor TNF-alpha (TNF-α); interleukin-6 (IL-6), nitric oxide (NO), and cardiac troponin T (cTnT)], as well as ECG and scintigraphic (99mTc-PYP) features were assessed. RESULTS: Compared to CN, DX significantly raised TNF-α, IL-6, and NO in heart tissue, cTnT in serum, 99mTc-PYP uptake in the myocardium, and ECG parameters, specifically QRS complex duration, QT interval duration, and ST-segment amplitude, while also reducing heart rate (p<0.001). Pretreatment with PR and VIT-D3 mitigated these abnormalities produced by DX in the heart (p<0.001). CONCLUSION: Results show that vitamin D receptor agonist paricalcitol and vitamin D protect against DX-induced cardiotoxicity through anti-inflammatory and antioxidant effects (Fig. 4, Ref. 59). Text in PDF www.elis.sk Keywords: paricalcitol, doxorubicin, vitamin D, ECG, 99mTc-PYP scintigraphy, cardiotoxicity, inflammation.

Unsupervised OCT image despeckling with ground-truth- and repeated-scanning-free features.

Optical coherence tomography (OCT) can resolve biological three-dimensional tissue structures, but it is inevitably plagued by speckle noise that degrades image quality and obscures biological structure. Recently unsupervised deep learning methods are becoming more popular in OCT despeckling but they still have to use unpaired noisy-clean images or paired noisy-noisy images. To address the above problem, we propose what we believe to be a novel unsupervised deep learning method for OCT despeckling, termed Double-free Net, which eliminates the need for ground truth data and repeated scanning by sub-sampling noisy images and synthesizing noisier images. In comparison to existing unsupervised methods, Double-free Net obtains superior denoising performance when trained on datasets comprising retinal and human tissue images without clean images. The efficacy of Double-free Net in denoising holds significant promise for diagnostic applications in retinal pathologies and enhances the accuracy of retinal layer segmentation. Results demonstrate that Double-free Net outperforms state-of-the-art methods and exhibits strong convenience and adaptability across different OCT images.

Gastrointestinal radionuclide imaging in pediatric age group.

Pediatric gastrointestinal imaging plays a crucial role in evaluating and managing digestive system disorders in children. This comprehensive review dives into the nuances of pediatric gastrointestinal imaging techniques, focusing on three specific modalities: gastric emptying scintigraphy (GES), intestinal transit scintigraphy (ITS), and gastrointestinal bleeding scintigraphy. GES involves real-time monitoring of stomach emptying using radiotracers and gamma camera technology. While challenges exist in standardizing protocols due to age-specific meal compositions, GES remains pivotal in diagnosing motility disorders, gastroesophageal reflux, and abdominal pain in children. ITS, utilizing [67Ga], provides insights into gastrointestinal motility disorders such as Hirschsprung disease. It aids in whole-gut transit evaluation, guiding surgical interventions and improving long-term clinical outcomes. Gastrointestinal bleeding scintigraphy, employing [99mTc], assists in diagnosing conditions like Meckel's diverticulum and occult bleeding, offering continuous monitoring to pinpoint the bleeding site along the entire gastrointestinal tract. SPECT-CT improves the accuracy and the standards of care. Each technique's protocol details, clinical indications, and diagnostic capabilities are thoroughly discussed, highlighting the importance of these non-invasive, functional imaging modalities in pediatric gastroenterology.

Concordancia entre SPECT portátil y la gammagrafía convencional para detección de ganglio centinela en cáncer de mama / Concordance between freehand SPECT and conventional scintigraphy for sentinel lymph node detection in breast cancer

Introducción: La SPECT portátil puede ser una técnica de imagen útil para la planificación preoperatoria de la biopsia selectiva del ganglio centinela (BSGC) ya que permite la localización del ganglio centinela (GC) mediante imágenes tomográficas en 3D y en tiempo real y determina su profundidad, después de unos minutos de exploración. El objetivo del estudio fue evaluar la correlación entre el número de GC detectados entre las imágenes de la SPECT portátil y la linfogammagrafía (LG). Materiales y métodos: Cien pacientes con diagnóstico de cáncer de mama infiltrante y sin evidencia clínica de afectación ganglionar, se sometieron prospectivamente a una BSGC. El estudio preoperatorio incluyó imágenes de SPECT portátil a los 15 min tras la inyección y de LG a los 25 y 60-90 min (precoz y tardía). Se analizó el acuerdo observado y se realizó un estudio de concordancia entre el número de GC detectados con SPECT portátil y LG. Resultados: El acuerdo observado en la detección de GC entre SPECT portátil y LG precoz fue del 72%; entre SPECT portátil y LG tardía del 85%, y entre la LG precoz y la tardía de un 87%. En el estudio de concordancia se registró una concordancia moderada entre la SPECT portátil y la LG precoz (coeficiente kappa: 0,42); una concordancia moderada-alta entre la SPECT portátil y la LG tardía (coeficiente kappa: 0,60), y una concordancia de moderada-alta entre la LG precoz y la tardía (coeficiente kappa: 0,70), sin diferencias significativas entre ellos (valor p=0,16). Conclusión: La SPECT portátil presentó una concordancia moderada-alta con los estudios de imagen convencional y podría ser una alternativa válida para el estudio prequirúrgico de la BSGC en el cáncer de mama.(AU)

Introduction: Freehand SPECT can be a useful imaging technique for preoperative planning of sentinel lymph node biopsy (SLNB) as it allows localization of the sentinel node by 3D and real-time tomographic imaging and determines its depth after a few minutes of scanning. The aim of the study was to evaluate the correlation between the number of detected SNs between freehand SPECT images and lymphoscintigraphy (LS). Materials and methods: One hundred patients with a diagnosis of invasive breast cancer and no clinical evidence of lymph node involvement prospectively underwent SLNB. The preoperative study included freehand SPECT imaging at 15min after injection and LS imaging at 25 and 60–90min after injection (early and late). The observed agreement was analyzed and a concordance study was performed between the number of SNs detected with freehand SPECT and LS. Results: The observed agreement in the detection of SNs between freehand SPECT and early LS was 72%; between freehand SPECT and late LS was 85%; and between early and late LS was 87%. In the concordance study, there was moderate concordance between freehand SPECT and early LS (kappa coefficient: 0.42); moderate-high concordance between freehand SPECT and late LS (kappa coefficient: 0.60); and moderate-high concordance between early and late LS (kappa coefficient: 0.70), with no significant differences between them (p-value=0.16). Conclusion: Freehand SPECT showed a moderate-high concordance with conventional imaging studies and could be a valid alternative for the presurgical study of SLNB in breast cancer.(AU)

Equine skeletal scintigraphy: Comparing lesion detection ability of methylene diphosphonate and hydroxymethylene diphosphonate in the caudal cervical and proximal metacarpal/metatarsal regions.

BACKGROUND: Data regarding the lesion detection ability of different radiotracers are lacking in equine bone scintigraphy. METHODS: In this prospective study, hydroxymethylene diphosphonate (HMDP) and methylene diphosphonate (MDP) were compared in horses with increased radiopharmaceutical uptake either in the caudal cervical region (CS group) or in the proximal metacarpal/metatarsal region (PMR group). Region of interest analysis was used to determine normal bone-to-soft tissue ratios, lesion-to-normal bone ratios and lesion-to-soft tissue ratios. Qualitative scoring and total count rates were recorded for each image. RESULTS: A total of 213 scintigrams were included. Within the PMR group, there were significantly higher lesion-to-normal bone ratios for MDP compared with HMDP (p = 0.02). In the CS group, normal bone-to-soft tissue ratios were significantly higher for HMDP (p = 0.01). The interobserver agreement with regard to the qualitative assessment of the scintigrams was poor. LIMITATION: Paired studies, comparing the different radiotracers in the same patient, were not feasible. CONCLUSION: This study revealed minor differences between the two radiotracers, although these have no practical implications. Both radiopharmaceuticals are well suited for detecting lesions at the investigated sites using equine bone scintigraphy.

Incidental 68Ga-DOTATATE uptake in thyroid nodules: Is guideline-directed management still appropriate?

BACKGROUND: Fluorodeoxyglucose uptake on positron emission tomography imaging has been shown to be an independent risk factor for malignancy in thyroid nodules. More recently, a new positron emission tomography radiotracer-Gallium-68 DOTATATE-has gained popularity as a sensitive method to detect neuroendocrine tumors. With greater availability of this imaging, incidental Gallium-68 DOTATATE uptake in the thyroid gland has increased. It is unclear whether current guideline-directed management of thyroid nodules remains appropriate in those that are Gallium-68 DOTATATE avid. METHODS: We retrospectively reviewed Gallium-68 DOTATATE positron emission tomography scans performed at our institution from 2012 to 2022. Patients with incidental focal Gallium-68 DOTATATE uptake in the thyroid gland were included. Fine needle aspiration biopsies were characterized via the Bethesda System for Reporting Thyroid Cytopathology. Bethesda III/IV nodules underwent molecular testing (ThyroSeq v3), and malignancy risk ≥50% was considered positive. RESULTS: In total, 1,176 Gallium-68 DOTATATE PET scans were reviewed across 837 unique patients. Fifty-three (6.3%) patients demonstrated focal Gallium-68 DOTATATE thyroid uptake. Nine patients were imaged for known medullary thyroid cancer. Forty-four patients had incidental radiotracer uptake in the thyroid and were included in our study. Patients included in the study were predominantly female sex (75%), with an average age of 62.9 ± 13.9 years and a maximum standardized uptake value in the thyroid of 7.3 ± 5.3. Frequent indications for imaging included neuroendocrine tumors of the small bowel (n = 17), lung (n = 8), and pancreas (n = 7). Thirty-three patients underwent subsequent thyroid ultrasound. Sonographic findings warranted biopsy in 24 patients, of which 3 were lost to follow-up. Cytopathology and molecular testing results are as follows: 12 Bethesda II (57.1%), 6 Bethesda III/ThyroSeq-negative (28.6%), 1 Bethesda III/ThyroSeq-positive (4.8%), 2 Bethesda V/VI (9.5%). Four nodules were resected, revealing 2 papillary thyroid cancers, 1 neoplasm with papillary-like nuclear features, and 1 follicular adenoma. There was no difference in maximum standardized uptake value between benign and malignant nodules (7.0 ± 4.6 vs 13.1 ± 5.7, P = .106). Overall, the malignancy rate among patients with sonography and appropriate follow-up was 6.7% (2/30). Among patients with cyto- or histopathology, the malignancy rate was 9.5% (2/21). There were no incidental cases of medullary thyroid cancer. CONCLUSION: The malignancy rate among thyroid nodules with incidental Gallium-68 DOTATATE uptake is comparable to rates reported among thyroid nodules in the general population. Guideline-directed management of thyroid nodules remains appropriate in those with incidental Gallium-68 DOTATATE uptake.

A Rare False-Positive Whole-Body Scan in a Patient With Differentiated Thyroid Cancer: Unilateral Conjunctival Concretions.

ABSTRACT: 131 I has been used effectively over the years in both diagnosis and therapy of differentiated thyroid cancer (DTC). Although whole-body scan with 131 I is a highly sensitive tool for detecting normal thyroid tissue and metastasis of DTC, it is not specific; therefore, false-positive images can be seen in clinical practice, and their recognition is critical for correct management. Evaluation of false-positive uptake is important because it may be confused with metastatic involvement. Here, we present a rare false-positive result of whole-body scan in a patient with DTC. To our knowledge, it is the first report on 131 I uptake of conjunctival concretions.

A Rare Case of Abnormal Diffuse Brain Uptake on an 123I MIBG Scan in a Patient With High-Risk Neuroblastoma.

ABSTRACT: 123I-meta-iodobenzylguanidine (123I-MIBG) is extensively used for initial staging and response evaluation in children with neuroblastoma. Physiological uptake of 123I-MIBG occurs in the salivary glands, liver, adrenal gland, myocardium, bowel, and thyroid gland. 123I-MIBG cannot cross an intact blood-brain barrier. We present the rare case of a 3-year-old boy with neuroblastoma and meningeal metastases who underwent an 123I-MIBG scan for disease restaging that showed abnormal brain uptake. Abnormal MIBG uptake in the brain can occur if there is disruption of the blood-brain barrier either secondary to metastases or after damage to blood-brain barrier.

Temporal evolution of postsurgical bone repair in a rabbit model: A [99mTc]Tc-MDP scintigraphic study.

Bone regeneration is crucial for repairing bone tissue following various injuries. Research techniques that enable the study of metabolic changes in bone tissue under different conditions are important for understanding bone repair and remodeling. This study used bone scintigraphy to evaluate osteogenesis secondary to osteotomy in a preclinical model of New Zealand rabbits. For this purpose, we conducted a longitudinal, prospective, case-control study in which scintigraphic variables were measured in both the right forearm (case-operated) and the left forearm (control - non-operated). The study sample consisted of 10 rabbits subjected to osteotomy, followed by a 12-week postoperative evaluation period, divided into six imaging stages at 1, 2, 3, 4, 8, and 12 weeks. We observed that the operated forearm showed significantly higher external radiation than the control side, using the pinhole collimator, denoting an increase in the biodistribution and tropism of the radiopharmaceutical to the operated forearm. Among the three evaluated time points, osteoblastic activity was highest in the second week and presented a significant decline in the 8th and 12th weeks, denoting regeneration and resolution of the surgical injury; the control forearm was also influenced by the inactivity imposed by the operated forearm. This fact was notably evidenced by the reduction in the metabolic activity of osteoblasts in the left forearm. Our study suggested that bone scintigraphy was sensitive enough to semi-quantitatively differentiate the metabolic activity of osteoblasts in the operated forearm in the three temporal landmarks evaluated in the study.

Gastric Emptying Studies in Pediatrics: A Cincinnati Children's Hospital Experience.

Gastric emptying studies are routinely performed in many nuclear medicine departments; however, there are many different techniques used to perform the procedure across the country. Creating consistency in clinical practice will aid gastroenterologists in diagnosing and treating illnesses associated with abnormalities related to gastric emptying. In 2017, Cincinnati Children's Hospital adopted adult standards for pediatric gastric emptying studies that included a standard meal along with imaging over the course of 4 h. Gastric emptying studies are the second-highest-volume examination performed in the nuclear medicine section at Cincinnati Children's Hospital. Accommodating this volume required changes in the scheduling template, scheduling questionnaire, and epic order sets, as well as identification of specific days and locations for gastric emptying studies. Both protocol standardization and workflow optimization are critically important in creating consistency in patient care. Gastric emptying can be evaluated with solid food, liquid food, or solid and liquid food simultaneously. The methodology of the study is initially determined by the ordering provider but may require special accommodations based on what the patient will tolerate. In coordination with the ordering and interpreting physicians, the nuclear medicine technologists at Cincinnati Children's Hospital have the decision-making ability to deviate from the provider's request as necessary, which helps expedite workflow and eliminates wasted time. Any deviation from the standardized protocol is documented by the nuclear medicine technologist and incorporated into the final report by the interpreting physician, as dietary information is meaningful to the ordering provider. Reference values associated with the standardized or modified protocol are also included in the final report.

Change in Management After Radionuclide Gastric Emptying Studies Showing Slow Emptying.

The radionuclide gastric emptying study is the gold standard for the diagnosis of gastroparesis. Methods: We performed a retrospective analysis of 510 patients to evaluate how often a diagnosis of slow gastric emptying determined by gastric emptying scintigraphy (GES) changes clinical management at our institution. Results: We found evidence of gastroparesis in 100 patients. A change in management was recommended for 62% within 1 mo of the GES. Conclusion: Our results illustrate the importance of performing GES on patients with clinically suspected gastroparesis.

An Evaluation of Gastric Emptying Scintigraphy Protocols in Health Care Institutions When Compared with the Society of Nuclear Medicine and Molecular Imaging Procedure Guidelines.

This study aimed to analyze the compliance of health care institutions with the Society of Nuclear Medicine and Molecular Imaging (SNMMI) procedure guidelines for gastric emptying scintigraphy (GES). Methods: A 19-question survey on demographics and the GES protocol was conducted using a Google form. The demographic questions covered position, number of technologists in the department, location, type of health care institution, and number of GES studies per month. The protocol questions included patient preparation, meal preparation, withholding of scheduled medications, radiopharmaceutical type, and radiopharmaceutical dose. The survey was sent to 7 nuclear medicine Facebook groups and a list of clinical affiliates provided by the Indiana University School of Medicine Nuclear Medicine Program. Descriptive statistics were compiled for most questions. A Fisher exact test with a significance level of 0.05 was used to compare the type of health care institution with compliance with the SNMMI GES protocol regarding radiolabeling time, meal preparation, and meal components, as well as to compare the type of health care institution with the number of GES studies performed per institution. Results: In total, 240 people responded to the survey. Most were nonsupervisory nuclear medicine technologists (72%) in nonacademic institutions (72%) and groups with 4 or more technologists (62%). Of the respondents, 72% followed the SNMMI guideline of adding the radiopharmaceutical before cooking, but only 37% followed the meal component guideline. There was no significant association between the type of institution or the number of GES studies and compliance with radiolabeling time or with meal preparation or components. Most respondents asked patients to withhold medications per SNMMI guidelines and used the recommended radiopharmaceutical (99mTc-sulfur colloid, 95%) at the recommended dose (18.5-37 MBq, 84%). Conclusion: Although most respondents followed most aspects of the SNMMI guidelines for GES, more than half did not use the recommended meal of liquid egg whites. Compliance did not vary between academic and nonacademic institutions or between groups performing a large or a small number of GES studies.

A statistical symptomatic evaluation on SAPHO syndrome from 56 cases of confirmed diagnosis and 352 cases of non-SAPHO involvement.

OBJECTIVE: To report a statistical evaluation of symptomatology based on 56 cases of SAPHO syndrome and 352 non-SAPHO involvement cases, to propose a symptomatic scoring system in consideration of early warning for SAPHO syndrome. METHODS: A cohort comprising 56 subjects diagnosed with SAPHO syndrome was reported, as well as 352 non-SAPHO involvement cases, including their chief complaints, skin manifestations, radiological findings, and laboratory tests. We systematically reviewed previous published five representative huge cohorts from different countries to conclude several specific features of SAPHO by comparing with our case series. The score of each specific index is based on respective incidence and comparison of two cohorts was performed. RESULT: In terms of complaint rates, all subjects of two cohorts suffered from osseous pain, which appeared in the anterior chest wall, spine, and limb which were calculated. In respect to dermatological lesions, SAPHO patients suffered from severe acne, and other patients (82.14%) accompanied with palmoplantar pustulosis. Having received radiological examinations, most SAPHO subjects rather than non-SAPHO involvement cases showed abnormal osteoarticular lesions under CT scanning and more detailed information under whole-body bone scintigraphy. Differences also emerged in elevation of inflammation values and rheumatic markers like HLA-B27. Based on our cases and huge cohorts documented, the early warning standard is set to be 5 scores. CONCLUSIONS: SAPHO syndrome case series with 56 subjects were reported and an accumulative scoring system for the early reminder on SAPHO syndrome was proposed. The threshold of this system is set to be 5 points. Key Points • Fifty-six patients diagnosed by SAPHO syndrome with detailed symptoms and radiological findings were reported. • Comparison was made between the 56 SAPHO patients and 352 non-SAPHO involvement cases. • An accumulative scoring system for the early reminder on SAPHO syndrome was proposed and the threshold of this system is set to be five points.

Knowledge and practices of radiation protection among Malaysian radiographers working in nuclear medicine: A preliminary study.

This study is aimed to determine knowledge and practices on radiation protection among radiographers in nuclear medicine department. A cross-sectional survey was conducted among radiographers in nuclear medicine departments in four health institutions in Malaysia. A set of questionnaires was distributed to 17 respondents using convenience sampling. Approximately more than 75% and 44% - 56% of the radiographers have good knowledge of radiation protection and frequent adherence to radiation protection practices, respectively. Levels of education and length of service were statistically correlated with radiation protection knowledge and practices attributes (p < 0.05), respectively. More training is necessary for knowledge and practice improvement.