Bone Scan Research Articles

Diffuse Uptake of 68Ga-Pentixafor in the Breasts During the Ovulatory Phase in a Patient With SAPHO Syndrome.

We report a case of a woman with SAPHO syndrome who exhibited increased tracer uptake in the sternal angle on a 99mTc-MDP bone scan. This patient was enrolled in a 68Ga-pentixafor PET/CT trial for inflammatory diseases. The PET/CT showed no abnormal tracer uptake in the sternal angle. Unexpectedly, diffuse uptake of 68Ga-pentixafor was observed in both breasts, which might be due to hormonal stimulation because the woman underwent the 68Ga-pentixafor PET/CT scan during the ovulatory phase.

Prognostic Significance of Total Body Surface Area in Rhabdomyolysis Assessed by Bone Scan

Prognostic Significance of Total Body Surface Area in Rhabdomyolysis Assessed by Bone Scan

Flourine-18 Prostate-Specific Membrane Antigen-1007 Positron Emission Tomography Imaging in Staging of Primary and Secondary Prostate Cancer—A Retrospective Observational Cohort Study

Background: Detection of metastatic disease is important to inform prostate cancer management. Objectives: Evaluate local and distant staging by initial 18F-PSMA-1007 PET in primary and secondary prostate cancer. Design, Setting, and Participants: We retrospectively identified a consecutive series of 18F-PSMA-1007 PET scans from the date of introduction of 18F-PSMA-1007 PET in September 2019 until April 2022 at a single UK tertiary referral center. Our protocol was registered in advance (OSF registration ID: KTE3R). Results: We identified 1335 PSMA-PET scans, from 1220 men. Across 623 initial scans for primary staging, we observed PSMA-PET avidity in 97.6% cases positive for local disease, 29.5% for nodal disease, and 26.5% for metastatic disease. PSMA-PET identified a 13.2% absolute increase in nodal lesions compared with MRI and a 24.0% absolute increase in metastatic lesions compared with MRI marrow. The sensitivity for detection of local disease among 79 patients who had radical prostatectomy was 96.2% for PSMA-PET vs 89.4% for multiparametric MRI. Across 612 scans for secondary staging, we observed PSMA-PET positive avidity in 51.2% of cases for local recurrence, 46.6% for nodal disease, and 43.0% for metastatic disease. When evaluated by the PSA range for patients receiving secondary staging, using the PSA values of 0.2 to 0.49, 0.5 to 0.99, 1 to 1.99, and ≥ 2 ng/mL, PSMA-PET scans were positive in 57.8%, 75.0%, 83.8%, and 95.5% of cases, respectively. PSMA-PET identified a 26.2% absolute increase in metastatic lesions compared with MRI marrow or other skeletal MRI (n = 61) and a 14.7% absolute increase in metastatic lesions compared with the bone scan (n = 42). Conclusion: 18F-PSMA-1007 PET identifies a higher number of nodal and metastatic lesions compared with conventional cross-sectional imaging. However, the high number of indeterminate lesions and stage migration necessitates discussion of 18F-PSMA-1007 PET imaging within a multidisciplinary team and places a higher burden on these teams.

Transthyretin amyloidosis prevalence and characteristics in Korean patients with heart failure with preserved or mildly reduced ejection fractions

The diagnosis and awareness of transthyretin amyloidosis cardiomyopathy (ATTR-CM) in heart failure with left ventricular ejection fraction (LVEF) > 40% remains under-recognized. This study aimed to investigate the prevalence and characteristics of ATTR-CM in patients with heart failure with LVEF > 40%. Patients with LVEF > 40% and maximal left ventricular wall thickness (MWT) > 10 mm who underwent bone scintigraphy were retrospectively investigated. Patients with a definite cause of heart failure were excluded. ATTR-CM was diagnosed when grade 2 or 3 myocardial uptake was observed on scintigraphy. Among 97 patients (male, 62.5%; median age, 69 years), 13 (13.4%) were diagnosed with ATTR-CM (wild type, 69.2%; hereditary type, 30.8%). Age or biomarker levels did not differ significantly; however, all patients with ATTR-CM were male. The ATTR-CM group had a significantly higher prevalence of polyneuropathy or carpal tunnel syndrome than the non-ATTR-CM group, accompanied by a longer PR interval, thicker MWT, larger left atrial volume index, and higher E/e′. Accordingly, ATTR was present in a substantial number, particularly among men. Clinicians should suspect ATTR when a male patient exhibits neurologic symptoms, diastolic dysfunction, and a long PR interval.

Clinical Implications of Radiopharmaceutical Uptake in the Skull as a New Marker of CKD-MBD: Findings of Bone Scintigraphy

Clinical Implications of Radiopharmaceutical Uptake in the Skull as a New Marker of CKD-MBD: Findings of Bone Scintigraphy

Is LVH a must in an amyloid heart?

Abstract Background Transthyretin amyloidosis (ATTR), an infiltrative cardiomyopathy, is characterized by the infiltration of transthyretin-derived amyloid fibrils into the cardiac extracellular space, which causes morphological and functional heart damage. Because of the vast range of symptoms that can accompany ATTR cardiac amyloidosis, the illness remains unknown. However, misdiagnosis or delayed diagnosis due to inconsistencies between clinical findings and the severity of the underlying disease hampers treatment methods. Aim and objectives This article investigates the intricate relationship between ATTR amyloidosis pathogenesis and clinical signs to understand better the challenges and advancements in early discovery, treatment, and prognosis of this concealed sickness. Methods & Results Between November 2022 and April 2024, we conducted a prospective analysis on a cohort of 71 patients diagnosed with ATTR cardiac amyloidosis utilizing PYP imaging at our institution (Al Hada Armed Force Hospital, Taif, Saudi Arabia). The Medical Ethics Review Committee of the hospital accepted this project (2023-720). During our study, we faced two cases without LVH and both cases have grade II-III cardiac uptake. 1st case A 66-year-old male patient who is a known case of ischemic cardiomyopathy with EF 35% since 2018, he underwent PCI in 2018. The patient is following the cardio clinic since 2018 and on every visit he was asymptomatic, The Patient in 2021 experienced new shortness of breath within six minutes’ walk distance less than 400 meters. The patient experienced erectile dysfunction and underwent intervention for his carpal tunnel syndrome. ECG showed old Q in anterior leads. Echo showed the same EF 35% and old wall motion abnormalities. Diagnostic coronary angiography showed patent stents and no residual ischemia. When we revised his old echo study that was done in 2017, we found EF 55%, concentric LVH. PYP bone scintigraphy was decided and showed grade II-III cardiac uptake. 2nd case A 53-year-old hypothyroid female patient and she has metastatic left breast cancer. During her workup bone scan, grade III cardiac uptake was accidentally discovered using an HMDP isotope. The patient was referred to the cardio clinic where the patient denied any cardiac or non-cardiac symptoms. All her labs, ECG and Echo were within normal range. CMR showed diffuse subendocardial LGE suggestive of infiltrative disease. Conclusion Based on unique pathological features of CA that would present as morphological LVH with /without ECG evidence of LVH. We hypothesized that LVH would occur in the later stages of the disease or may be decreased due to other pathology as coronary artery disease. Clinical suspicion remains the cornerstone for early diagnosis and workup.

Radiological Diagnosis and Advances in Imaging of Vertebral Compression Fractures.

Vertebral compression fractures (VCFs) affect 1.4 million patients every year, especially among the globally aging population, leading to increased morbidity and mortality. Often characterized with symptoms of sudden onset back pain, decreased vertebral height, progressive kyphosis, and limited mobility, VCFs can significantly impact a patient's quality of life and are a significant public health concern. Imaging modalities in radiology, including radiographs, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) studies and bone scans, play crucial and evolving roles in the diagnosis, assessment, and management of VCFs. An understanding of anatomy, and the extent to which each imaging modality serves to elucidate that anatomy, is crucial in understanding and providing guidance on fracture severity, classification, associated soft tissue injuries, underlying pathologies, and bone mineral density, ultimately guiding treatment decisions, monitoring treatment response, and predicting prognosis and long-term outcomes. This article thus explores the important role of radiology in illuminating the underlying anatomy and pathophysiology, classification, diagnosis, treatment, and management of patients with VCFs. Continued research and advancements in imaging technologies will further enhance our understanding of VCFs and pave the way for personalized and effective management strategies.

Modified trochanteric triplane osteotomy for chronic moderate to severe slipped capital femoral epiphysis - a preliminary report.

Management of chronic moderate and severe slipped capital femoral epiphysis (SCFE) remains controversial. We propose that the modified trochanteric triplane osteotomy(MTTO) with a 1300 angled blade plate, without removal of bone wedge, is effective for addressing moderate and severe chronic SCFE. A retrospective review was performed on patients who underwent MTTO for moderate to severe chronic SCFE, with at least two years follow-up. Radiological outcomes assessed were osteotomy union, alpha angle, neck shaft angle, mechanical axis deviation and limb length discrepancy(LLD). Functional outcomes were assessed using modified Harris hip score, lower extremity functional scale (LEFS) and SF-36 questionnaire. A total of 11 patients (13 hips) underwent MTTO for chronic SCFE, with a mean age of 12.9 ± 2.1 years. The pre-operative median modified Harris Hip Score was 73. 12 had severe slip and one had moderate slip. All the osteotomies went on to unite by two months. At an average of 37 months follow up, the mean neck shaft angle was 1290, mean alpha angle was 69.70, and mean LLD was 1.05cm. There was significant improvement in the post-operative modified Harris hip score (p < 0.001), the median post-operative modified Harris hip score was 96, and the median LEFS was 78. One case had bone scan evidence of AVN, but did well with bisphosphonate therapy and one case had a superficial infection. MTTO is a safe and effective option for addressing deformities in chronic moderate and severe SCFE. However, a residual proximal femoral Cam deformity persists after this procedure which may need to be treated with a simultaneous or a staged osteochondroplasty.

Prostate-specific membrane antigen PET versus [99mTc]Tc-MDP bone scan for diagnosing bone metastasis in prostate cancer: a head-to-head comparative meta-analysis.

To evaluate the diagnostic performance of PSMA PET/CT, including [68Ga]Ga-PSMA-11 and [18F]DCFPyL, in comparison with the [99mTc]Tc-MDP bone scan (BS) in identifying bone metastases among prostate cancer patients. A search was performed in the PubMed and Embase databases to locate pertinent publications from inception to February 12, 2024. The studies included were those that examined the diagnostic effectiveness of PSMA PET/CT (covering [68Ga]Ga-PSMA-11 and [18F]DCFPyL) compared to [99mTc]Tc-MDP BS in identifying bone metastases among prostate cancer patients. The quality of the selected studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) checklist. The meta-analysis included nine articles involving 702 patients. The sensitivity of PSMA PET/CT was higher compared to [99mTc]Tc-MDP BS (0.98 vs. 0.85, P < 0.01), while the specificity of PSMA PET/CT was also higher than [99mTc]Tc-MDP BS (0.97 vs. 0.70,P < 0.01). In subgroup analysis, the sensitivity of [68Ga]Ga-PSMA-11 PET/CT was higher compared to [99mTc]Tc-MDP BS (0.98 vs. 0.86), while the specificity of [68Ga]Ga-PSMA-11 PET/CT was also higher than [99mTc]Tc-MDP BS (0.98 vs. 0.65). Our meta-analysis demonstrates that PSMA PET/CT exhibits superior sensitivity and specificity in comparison with [99mTc]Tc-MDP BS for identifying bone metastases in prostate cancer patients. Further research with head-to-head design is necessary to validate these results and evaluate the clinical effectiveness of these imaging methods. https://www.crd.york.ac.uk/prospero/, identifier PROSPERO CRD42024545112.

Enhancing bone scan image quality: an improved self-supervised denoising approach.

Bone scans play an important role in skeletal lesion assessment, but gamma cameras exhibit challenges with low sensitivity and high noise levels. Deep learning (DL) has emerged as a promising solution to enhance image quality without increasing radiation exposure or scan time. However, existing self-supervised denoising methods, such as Noise2Noise (N2N), may introduce deviations from the clinical standard in bone scans. This study proposes an improved self-supervised denoising technique to minimize discrepancies between DL-based denoising and full scan images. &#xD;Retrospective analysis of 351 whole-body bone scan data sets was conducted. In this study, we used N2N and Noise2FullCount (N2F) denoising models, along with an interpolated version of N2N (iN2N). Denoising networks were separately trained for each reduced scan time from 5 to 50%, and also trained for mixed training datasets, which include all shortened scans. We performed quantitative analysis and clinical evaluation by nuclear medicine experts.&#xD;The denoising networks effectively generated images resembling full scans, with N2F revealing distinctive patterns for different scan times, N2N producing smooth textures with slight blurring, and iN2N closely mirroring full scan patterns. Quantitative analysis showed that denoising improved with longer input times and mixed count training outperformed fixed count training. Traditional denoising methods lagged behind DL-based denoising. N2N demonstrated limitations in long-scan images. Clinical evaluation favored N2N and iN2N in resolution, noise, blurriness, and findings, showcasing their potential for enhanced diagnostic performance in quarter-time scans.&#xD;The improved self-supervised denoising technique presented in this study offers a viable solution to enhance bone scan image quality, minimizing deviations from clinical standards. The method's effectiveness was demonstrated quantitatively and clinically, showing promise for quarter-time scans without compromising diagnostic performance. This approach holds potential for improving bone scan interpretations, aiding in more accurate clinical diagnoses.

Whole‐body MRI for staging prostate cancer: a narrative review

ObjectiveTo present a narrative review regarding the diagnostic accuracy of whole‐body magnetic resonance imaging (WBMRI) in staging patients with high‐risk prostate cancer (HRPCa) and compare it to established imaging modalities.MethodsA narrative review was carried out using PubMed using the following keywords: ‘whole body’, ‘magnetic resonance imaging’, ‘MRI’, ‘prostate cancer’, ‘risk stratification’, and ‘staging’. Articles that evaluated WBMRI as the imaging modality to stage patients with HRPCa were included, while studies that solely assessed for biochemical recurrence or metastatic disease progression were excluded.ResultsIn the evaluation of lymphatic metastases, WBMRI has demonstrated a comparable, if not improved, sensitivity and specificity compared to conventional imaging of computed tomography (CT). Furthermore, WBMRI demonstrates improved sensitivity and specificity in detecting bone metastases compared to bone scintigraphy (BS). However, with advent of prostate‐specific membrane antigen (PSMA) radioligands for positron emission tomography (PET), the diagnostic performance of WBMRI to detect metastatic disease appears inferior.ConclusionsThe diagnostic capabilities of WBMRI exceed that of conventional imaging of CT and BS in detecting metastatic disease in patients with HRPCa. However, WBMRI does not perform as well as PSMA PET/CT. Further study on cost comparisons between WBMRI and PSMA PET/CT are needed, as well as evaluations of combined PSMA PET/MRI are needed.

Diagnosis of Shin Splint: A Case Report

A 28-year-old woman presented with left leg pain, persisting for five months. The pain, localized to the anterior compartment of the leg, is exacerbated with activity. Examination revealed tenderness over the muscle bulk adjacent to the anterior tibial crest. Lower limb radiography was unremarkable, but a bone scan confirmed the diagnosis of shin splint (medial tibial stress syndrome). Despite various treatment modalities, including conservative measures and surgical fasciotomy, no treatment has shown clear superiority over others. Extracorporeal shock wave therapy (ESWT) demonstrated promising results; however, the quality of supporting studies was limited. This case highlights the challenges in managing shin splints and underscores the need for further research to determine the most effective treatment options.

The short-chain fatty acid receptors Gpr41/43 regulate bone mass by promoting adipogenic differentiation of mesenchymal stem cells.

Bone is a dynamic tissue that is constantly remodeled throughout adult life. Recently, it has been shown that bone turnover decreases shortly after food consumption. This process has been linked to the fermentation of non-digestible food ingredients such as inulin by gut microbes, which results in the production of the short-chain fatty acids (SCFAs) acetate, propionate and butyrate. SCFAs exert various metabolic functions, which in part can be explained by activation of G protein-coupled receptors (Gpr) 41 and 43. However, the potential relevance of a SCFA-Gpr41/43 signaling axis for bone metabolism has not been established. The aim of our study is to investigate the role of Gpr41/43 in bone metabolism and osteogenic differentiation of mesenchymal stem cells. For this purpose, we analyzed the skeletal phenotype of wild type controls (WT) and Gpr41/43 double knockout (Gpr41/43 dKO) mice fed either a chow or an inulin-enriched diet. In addition, we isolated bone marrow derived mesenchymal stem cells from WT and Gpr41/43 dKO mice and differentiated them into osteoblasts in the absence or presence of acetate. MicroCT scanning of femoral bones of Gpr41/43 dKO mice revealed a significant increase of trabecular bone volume and trabecular compared to WT controls. Treatment of WT bone marrow-derived osteoblasts with acetate resulted in decreased mineralization and substantial downregulation of bone formation markers such as Phex, Ptgs2 and Col1a1. Notably, this effect was strongly attenuated in differentiated osteoblasts lacking Gpr41/43. Inversely, acetate supplementation resulted in higher levels of adipocyte marker genes including Pparg, Lpl and Adipoq in bone marrow-derived cells from WT mice, an effect blunted in differentiated cells isolated from Gpr41/43 dKO mice. Overall, these data indicate that acetate regulates bone architecture via SCFA-Gpr41/43 signaling by modulating the osteogenic versus adipogenic differentiation of mesenchymal stem cells.

Novel Treatment Strategies for Low-Risk Metastatic Castration-Sensitive Prostate Cancer.

The treatment strategy for metastatic castration-sensitive prostate cancer (mCSPC) has changed significantly in recent years. Based on various guidelines, an upfront androgen receptor signaling inhibitor (ARSI) is the first choice, but in patients of Asian descent, including Japanese patients, there are a certain number of cases in which androgen deprivation therapy (ADT) and CAB are more effective. If patients can be identified who show a marked response to ADT within 12 weeks after the initiation of ADT, which is the inclusion criterion for ARSI clinical trials targeting mCSPC, it would be valuable from an economic standpoint. A total of 218 patients with pure prostate adenocarcinoma and treated with ADT at the Kanazawa University Hospital between January 2000 and December 2020 were included in this study. As a risk classification for mCSPC, in addition to the LATITUDE and CHAARTED criteria, we used the castration-sensitive prostate cancer classification proposed by Kanazawa University (Canazawa), developed by the Department of Urology of Kanazawa University. The Canazawa classification was based on three factors: Gleason pattern 5, bone scan index (BSI) ≥ 1.5, and lactate dehydrogenase (LDH) ≥ 300 IU/L. It defined patients with one factor or less as low-risk and patients with two or three factors as high-risk. The overall survival (OS) and time to castration resistance (TTCR) were estimated retrospectively using the Kaplan-Meier method, and factors associated with TTCR were identified using univariate and multivariate analyses. The median follow-up period was 40.4 months, the median OS period was 85.2 months, and the median TTCR period was 16.4 months. The Canazawa risk classification provided the clearest distinction between the OS and TTCR in mCSPC patients. Multivariate analysis revealed a decrease in PSA levels of <95% at 12 weeks after ADT initiation and was a predictor of short TTCR in low-risk, low-volume patients across all risk classifications. The Canazawa classification differentiated the prognosis of mCSPC patients more clearly. A PSA reduction rate of <95% at 12 w after starting ADT in low-risk, low-volume patients of all risk classifications was significantly shorter than the TTCR. We propose a new treatment strategy, in which patients with low-risk mCSPC are treated with ADT and switched to ARSIs based on the rate of PSA reduction at 12 w.

Determinants of bone mineral density in various regions of the skeleton among smokers and non-smokers: the role of physical activity.

The adult human skeleton is composed of cortical and cancellous bone. The proportions of these two types of bone tissue differ in various parts of the skeleton. The aim of this cross-sectional study was to quantify the determinants of bone mineral density (BMD) and bone mineral content in various regions of interest (ROIs) in smokers and never-smokers. In this study, 4,332 bone scans of three regions of interest (ROIs) were analyzed: the forearm (distal and proximal), femur, and lumbar spine. Body composition and bone parameters were measured using dual-energy X-ray absorptiometry. Smoking was measured using the Global Adult Tobacco Survey questionnaire. Body mass index (BMI) was calculated, and physical activity (PA) was characterized by the metabolic equivalent of task (MET). Among women, the interaction between PA (positive β coefficient) and smoking (negative β coefficient) was a significant predictor of BMD in the distal and proximal forearm (adj. R2 = 0.40 and R2 = 0.58; p < 0.001). The interaction of three variables-age, smoking (negative β), and MET (positive β)-was significant for total hip BMD (adj. R2 = 0.54; p < 0.001). The interaction between BMI and MET (positive β) and smoking (negative β) was significant for BMD in the lumbar spine (adj. R2 = 0.62; p < 0.001). In men, the interaction between MET (positive β) and smoking (negative β) was significant for BMD in the forearm and lumbar spine (adj. R2 = 0.44, R2 = 0.46, and R2 = 0.49; p < 0.01). Smoking alone was a significant negative predictor of total hip BMD (adj. R2 = 0.34; p < 0.001). Among both women and men, never-smokers had significantly better bone parameters than smokers. Smoking was a significant negative predictor for BMD in the various ROIs in both women and men. Physical activity was a significant positive predictor of BMD, with a strong association with bone parameters.

Multimodal Data-Driven Segmentation of Bone Metastasis Lesions in SPECT Bone Scans Using Deep Learning

Background: Patients with malignant tumors often develop bone metastases. SPECT bone scintigraphy is an effective tool for surveying bone metastases due to its high sensitivity, low-cost equipment, and radiopharmaceutical. However, the low spatial resolution of SPECT scans significantly hinders manual analysis by nuclear medicine physicians. Deep learning, a promising technique for automated image analysis, can extract hierarchal patterns from images without human intervention. Objective: To enhance the performance of deep learning-based segmentation models, we integrate textual data from diagnostic reports with SPECT bone scans, aiming to develop an automated analysis method that outperforms purely unimodal data-driven segmentation models. Methods: We propose a dual-path segmentation framework to extract features from bone scan images and diagnostic reports separately. In the first path, an encoder-decoder network is employed to learn hierarchical representations of features from SPECT bone scan images. In the second path, the Chinese version of the MacBERT model is utilized to develop a text encoder for extracting features from diagnostic reports. The extracted textual features are then fused with image features during the decoding stage in the first path, enhancing the overall segmentation performance. Results: Experimental evaluation conducted on real-world clinical data demonstrated the superior performance of the proposed segmentation model. Our model achieved a 0.0209 increase in the DSC (Dice Similarity Coefficient) score compared to the well-known U-Net model. Conclusions: The proposed multimodal data-driven method effectively identifies and isolates metastasis lesions in SPECT bone scans, outperforming existing classical deep learning models. This study demonstrates the value of incorporating textual data in the deep learning-based segmentation of lowresolution SPECT bone scans.

Prediction of difficult round window visibility during cochlear implantation via a reformatted CT facial recess view: A retrospective study with surgical correlation.

Cochlear implant surgery is performed commonly through the facial recess via the round window (RW) approach. This study aims to evaluate the utility of reformatting the pre-operative CT temporal bone scan into a CT facial recess view in alerting surgeons to a potentially difficult surgery with poorly visualized round window. This is a retrospective study of 41 patients (43 ears), who had undergone cochlear implant surgery. Intraoperative findings of round window position relative to 2nd genu-mastoid portion of facial nerve, and round window membrane orientation were recorded by the surgeons. Pre-operative CTs were analyzed by two radiologists in axial and a reformatted facial recess plane that simulates the surgeon's view via the facial recess. Radiological assessment markers include the facial nerve-chorda tympani nerve width (FN-CTN) measured 1.2mm inferior to the exit point of the chorda tympani nerve into the tympanic cavity, round window position relative to 2nd genu-mastoid segment of the facial nerve and RW membrane's angle from the vertical axis. The best predictor for difficult round window intraoperative visibility is the RW position relative to the 2nd genu-mastoid segment of the facial nerve lying lateral to it on CT facial recess reformatted images. A RW that lies partially to completely posterior to the posterior border of the 2nd genu-mastoid segment of the facial nerve had up to 55.6% risk of encountering difficult access, while those positioned anterior to or partially anterior to the anterior edge of the 2nd genu-mastoid segment of the facial nerve had 0% risk of difficult access (p<0.05). There are substantial agreements in the intra-rater (Kappa=0.751, p<0.001) and inter-rater reliability (Kappa= 0.698, p<0.001). There is no significant association between surgical difficulty and facial nerve-chorda tympani distance or RW angle (p>0.05). Identification of round window positions in the reformatted CT facial recess view is a useful tool in predicting potentially difficult round window access in cochlear implant surgery. RW= Round window, FN-CTN= facial nerve to chorda tympani nerve width.

Evaluation of heterotopic ossification maturity using SPECT/CT and PET/CT in preclinical model

BackgroundHeterotopic ossification (HO) is the formation of bone within soft tissue where bone normally does not exist. In general, it is characterized by highly active tissue with high bone turnover and rapid bone formation. It is of an utmost importance to precisely identify and accurately diagnose the maturity of HO as early surgical intervention may result in its recurrence. The objective of this work is the experimental evaluation of HO maturity stage using advanced noninvasive nuclear medicine techniques. The use of PET radiopharmaceuticals may result in a more specific diagnosis between the phases due to their higher sensitivity and better resolution compared to bone scan. Method8-week-old Balb/c male mice underwent dual injury procedure, tenotomy and concurrent burn injury on the left side, to induce HO. The progression of HO was monitored by SPECT/CT and PET/CT weekly imaging with 99mTc-MDP, [18F]NaF and [18F]FDG for up to 16 weeks. ResultsThere was a statistically significant increase of [18F]FDG uptake from week 1 to 2 and from week 2 to 6 with p values of 0.01 and 0.005; respectively, while there was a statistically significant decrease from week 7 to 14 with a p value of 0.008. There was a statistically significant increase of [18F]NaF uptake from week 2 to 5 and statistically significant decrease between weeks 7 and 14 with p values of 0.016 and 0.003; respectively. As for 99mTc-MDP, the increase in the uptake from week 1 to 2 and from week 2 to 5 were not statistically significant with p values of 0.15 and 0.19; respectively. The decrease of uptake between week 7 and 14 was not statistically significant with a p value of 0.08. ConclusionBased on these findings, the use of noninvasive nuclear imaging modalities may assist in distinguishing between the immature and mature phases. The uptake of mainly [18F]FDG may indicate the early inflammatory phase, while the uptake of both [18F]FGD and [18F]NaF may suggest the immature phase, and an uptake of mainly [18F]NaF may indicate the maturity phase of HO.

Evaluation of jaw pathologies of patients with medication-related osteonecrosis of the jaw using a computer program to assess the bone scan index: comparison of standardized uptake values with bone SPECT/CT.

The aim of this study is to investigate the jaw pathologies of patients with medication-related osteonecrosis of the jaw (MRONJ) using a computer program to assess the bone scan index (BSI), especially comparison of standardized uptake values (SUVs) with bone single-photon emission-computed tomography/computed tomography (SPECT/CT). Sixty-three patients with MRONJ underwent bone SPECT/CT in this prospective study. BSI and high-risk hot spot as bone metastases in the patients with MRONJ were evaluated using a computer program for BSI that scanned SPECT/CT and automatically defined the data. The maximum and mean SUVs with SPECT/CT were obtained using commercially available software. Statistical analyses were performed by Pearson chi-square test, Mann-Whitney U-test, or one-way analysis of variance with Tukey's honestly significant difference test. A P value lower than 0.05 was considered statistically significant. The maximum and mean SUVs for a high-risk hot spot of the jaw with MRONJ [28.2 ± 10.2 and 11.7 ± 3.8; n = 6 (6/63 : 9.5%)] were significantly higher than those for a low-risk hot spot [18.5 ± 6.4 and 6.2 ± 1.9; n = 23 (23/63 : 36.5%)] and no-risk hot spot [14.2 ± 9.4 and 5.3 ± 5.1; n = 34 (34/63 : 54.0%)], respectively. The computer program for BSI indicated that 9.5% of the jaw with MRONJ were false positive of bone metastases. The study suggests that high-risk hot spots of the jaw with MRONJ depend on the SUVs.

The added value of 68Ga-PSMA PET/CT in anatomical staging of prostatic carcinoma in correlation with the histopathological zonal staging

BackgroundProstate cancer is well known as the commonest cancer in men and the second leading cause of cancer-related death. CT, MRI and bone scintigraphy are considered the commonly widely used imaging diagnostic tools for detection, staging and follow-up of prostate cancer. Prostate-specific membrane antigen (PSMA) is a membrane glycoprotein, that can be concentrated in prostate cancer cells up to 100 times higher than in normal cells. PSMA-targeted imaging modalities have now proven their efficacy in diagnosis, staging and follow-up of prostate cancer. The use of 68Ga PSMA PET-CT has efficiently improved the detection of loco-regional and metastatic disease. 68Ga PSMA PET-CT also has an effective role in the primary diagnosis, staging, and detecting biochemical recurrence after curative treatment and in metastasis-targeted therapy. This work aims to review the role of 68Ga PSMA PET-CT in anatomical staging of prostate cancer in correlation with histopathological staging.ResultsZonal correlation between 68Ga PSMA findings and biopsy results showed sensitivity ranging between 76.9 and 90.6% and specificity ranging from 85.7 to 100%. There was high significant correlation between the SUVmax uptake and the biopsy results, between the SUVmax uptake and the local staging as well as between the Gleason score and 68Ga PSMA PET/CT findings.Conclusions68Ga PSMA PET/CT is a highly promising imaging modality with an effective role in detection of prostate cancer showing high sensitivity and specificity in prediction of zonal histopathological results and loco-regional Gleason score staging with significant positive correlation between the SUV uptake results, Gleason score and the PSA levels.