Usefulness of Bone SPECT/CT for Predicting Avascular Necrosis of the Femoral Head in Children with Slipped Capital Femoral Epiphysis or Femoral Neck Fracture

Objective@#This study aimed to investigate the usefulness of bone single-positron emission tomography/computed tomography (SPECT/CT) of the hip in predicting the later occurrence of avascular necrosis (AVN) after slipped capital femoral epiphysis (SCFE) or femoral neck fracture in pediatric patients. The quantitative parameters of SPECT/CT useful in predicting AVN were identified. @*Materials and Methods@#Twenty-one (male:female, 10:11) consecutive patients aged 1 year after the surgery. The SPECT/CT parameters were compared between patients who developed AVN and those who did not. The accuracy of SPECT/CT parameters for predicting AVN was assessed. @*Results@#Six patients developed AVN. There was a significant difference in the ratio of the mean SUV among patients who developed AVN (mean ± SD, 0.8 ± 0.3) and those who did not (1.1 ± 0.2, p = 0.018). However, there were no significant differences in the ratios of the maximum and minimum SUV between the groups (all p = 0.205). For the maximum, mean, and minimum SUVs, no significant differences were observed between the groups (p = 0.519, 0.733, and 0.470, respectively). The cutoff mean SUV ratio of 0.87 yielded a 66.7% sensitivity and 93.2% specificity for predicting AVN. @*Conclusion@#Quantitative bone SPECT/CT is useful for evaluating femoral head viability in pediatric patients with SCFE or femoral neck fractures. Clinicians should consider the high possibility of later AVN development in patients with a decreased mean SUV ratio.

MRI Findings in Parkinson’s Disease: Radiologic Assessment of Nigrostriatal Degeneration

Parkinson’s disease (PD) is a movement disorder that develops due to degenerative loss of dopaminergic cells in the substantia nigra of the midbrain. Recent advances in MRI techniques have demonstrated various imaging findings that can reflect the underlying pathophysiological processes occurring in Parkinson’s disease. Many imaging studies have shown that such findings can assist in the diagnosis of Parkinson’s disease and its differentiation from atypical parkinsonism. In this review, we present MRI techniques that can be used in clinical assessment, such as nigrosome imaging and neuromelanin imaging, and we provide the detailed imaging features of Parkinson’s disease reflecting nigrostriatal degeneration.

Clinical Perspectives of Parkinson's Disease for Ophthalmologists, Otorhinolaryngologists, Cardiologists, Dentists, Gastroenterologists, Urologists, Physiatrists, and Psychiatrists

Parkinson's disease (PD) is a multisystemic disorder characterized by various non-motor symptoms (NMS) in addition to motor dysfunction. NMS include sleep, ocular, olfactory, throat, cardiovascular, gastrointestinal, genitourinary, or musculoskeletal disorders. A range of NMS, particularly hyposmia, sleep disturbances, constipation, and depression, can even appear prior to the motor symptoms of PD. Because NMS can affect multiple organs and result in major disabilities, the recognition and multidisciplinary and collaborative management of NMS by physicians is essential for patients with PD. Therefore, the aim of this review article is to provide an overview of the organs that are affected by NMS in PD together with a brief review of pathophysiology and treatment options.

Perspectives in TSPO PET Imaging for Neurologic Diseases / 대한핵의학회잡지

The translocator protein (18 kDa) (TSPO) is a mitochondrial transmembrane protein, which has brought attention as a neuroinflammatory biomarker. Positron emission tomography (PET) imaging studies have been done for several decades, since neuroinflammation has been implicated as an important pathophysiology of several common neurologic disorders. However, despite numerous previous studies with positive findings, its clinical significance is not yet clear. Various attempts to overcome the limitations are ongoing, in order to bring acceptance for use in clinics.

Combination of In Vivo ¹²³IFP-CIT SPECT and Microdialysis Reveals an Antipsychotic Drug Haloperidol-induced Synaptic Dopamine Availability in the Rat Midbrain and Striatum

Synaptic dopamine (DA) is mainly regulated by the presynaptic DA transporter (DAT). Single-photon emission computerized tomography (SPECT) with the DAT radiotracer [¹²³I]FP-CIT assesses changes in synaptic DA availability when endogenous DA displaces [¹²³I]FP-CIT or competes for DAT. Here, we investigated the effects of haloperidol (HAL) and clozapine (CLZ) on [¹²³I]FP-CIT binding in the rat striatum and midbrain to assess the utility of [¹²³I]FP-CIT SPECT to quantify changes in synaptic DA availability. Rats underwent [¹²³I]FP-CIT SPECT after intraperitoneal administration of normal saline (vehicle), HAL (1 and 7 mg/kg), CLZ (10 and 54 mg/kg) and bupropion (BUP, a DAT blocker, 20 and 100 mg/kg). In the striatum and midbrain, percent differences in the nondisplaceable binding potential (BP(ND)) of [¹²³I]FP-CIT compared to the vehicle were calculated for the various drugs and doses. In another experiment, changes in endogenous striatal DA concentration were measured by in vivo microdialysis under the conditions used in the SPECT study. BUP dose-dependently occupied DAT at considerable levels. Compared to the vehicle, HAL decreased [¹²³I]FP-CIT BP(ND) in the striatum (−25.29% and −2.27% for 1 and 7 mg/kg, respectively) and to a greater degree in the midbrain (−58.74% and −49.64% for 1 and 7 mg/kg, respectively), whereas the CLZ-treated group showed a decrease in the midbrain (−38.60% and −40.38% for 10 and 54 mg/kg, respectively) but an increase in the striatum (18.85% and 38.64% for 10 and 54 mg/kg, respectively). Antipsychotic-induced changes in endogenous striatal DA concentrations varied across drugs and doses. The data demonstrate that [¹²³I]FP-CIT SPECT may be a useful preclinical technique for detecting increases in synaptic DA availability in the midbrain and striatum in response to HAL, with results comparable to those of in vivo microdialysis.

Perspectives in TSPO PET Imaging for Neurologic Diseases / 대한핵의학회잡지

The translocator protein (18 kDa) (TSPO) is a mitochondrial transmembrane protein, which has brought attention as a neuroinflammatory biomarker. Positron emission tomography (PET) imaging studies have been done for several decades, since neuroinflammation has been implicated as an important pathophysiology of several common neurologic disorders. However, despite numerous previous studies with positive findings, its clinical significance is not yet clear. Various attempts to overcome the limitations are ongoing, in order to bring acceptance for use in clinics.

Psychiatric Manifestation in Patients with Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder. Although its major manifestation is motor symptoms, resulting from the loss of dopaminergic neurons in the substantia nigra, psychiatric symptoms, such as depression, anxiety, hallucination, delusion, apathy and anhedonia, impulsive and compulsive behaviors, and cognitive dysfunction, may also manifest in most patients with PD. Given that the quality of life — and the need for institutionalization — is so highly dependent on the psychiatric well-being of patients with PD, psychiatric symptoms are of high clinical significance. We reviewed the prevalence, risk factors, pathophysiology, and treatment of psychiatric symptoms to get a better understanding of PD for improved management.

Quantitative Single-Photon Emission Computed Tomography/Computed Tomography for Evaluation of Salivary Gland Dysfunction in Sjögren's Syndrome Patients / 대한핵의학회잡지

PURPOSE@#The purpose of the study was to investigate the usefulness of quantitative salivary single-photon emission computed tomography/computed tomography (SPECT/CT) using Tc-99m pertechnetate in Sjögren's syndrome (SS).@*METHODS@#We retrospectively reviewed quantitative salivary SPECT/CT data from 95 xerostomic patients who were classified as either SS (n = 47, male:female = 0:47, age = 54.60 ± 13.16 y [mean ± SD]) or non-SS (n = 48, male:female = 5:43, age = 54.94 ± 14.04 y) by combination of anti-SSA/Ro antibody, labial salivary gland biopsy, unstimulated whole saliva flow rate, and Schirmer's test. Thyroid cancer patients (n = 43, male:female = 19:24, age = 46.37 ± 12.13 y) before radioactive iodine therapy served as negative controls. Quantitative SPECT/CT was performed pre-stimulatory 20 min and post-stimulatory 40 min after injection of Tc-99m pertechnetate (15 mCi). The %injected dose at 20 min and the %excretion between 20 and 40 min were calculated for parotid and submandibular glands, generating four quantitative parameters: %parotid uptake (%PU), %submandibular uptake (%SU), %parotid excretion (%PE), and %submandibular excretion (%SE). The most useful parameter for SS diagnosis was investigated.@*RESULTS@#The uptake parameters (%PU and %SU) were significantly different among the SS, non-SS, and negative controls (p = 0.005 for %PU and p 0.05 for both). The%PU and%SU were significantly lower in SS than in the negative controls and non-SS (p < 0.05 for all pair-wise comparisons). Additionally, the %SU was significantly lower in non-SS than in the negative controls (p < 0.05). Receiver-operating characteristic analysis revealed that the %SU had the greatest area-under-the curve of 0.720 (95% confidence interval = 0.618–0.807). Using the optimal cut-off value of %SU ≤ 0.07%, SS was identified with a sensitivity of 70.21% and a specificity of 70.83%.@*CONCLUSION@#Reduced submandibular uptake of Tc-99m pertechnetate at 20 min (%SU) was proved useful for the diagnosis of SS. Quantitative salivary gland SPECT/CT holds promise as an objective imaging modality for assessment of salivary dysfunction and may facilitate accurate classification of SS.

Usefulness of Respiratory-Gated ¹⁸F-FDG PET/CT in Detecting Upper Abdominal Fever Focus / 대한핵의학회잡지

Respiratory-gated ¹⁸F-fluorodeoxygluocse (¹⁸F-FDG) PET/CT has been successfully used to better localize malignancies in the lung or upper abdominal organs. However, clinical usefulness of respiratory-gated ¹⁸F-FDG PET/CT in detection of fever focus has not been reported yet. A 68-year-old male patient with a history of living donor liver transplantation and biliary stenting was referred for ¹⁸F-FDG PET/CT due to fever of unknown origin (FUO). To find the accurate fever focus, respiratory-gated and non-gated ¹⁸F-FDG PET/CT was performed. Respiratory-gated PET/CT readily revealed prominent hypermetabolic lesion in the distal common bile duct (CBD) area where previous surgical graft was in situ. Maximum standardized uptake value (SUVmax) and SUVratio (SUR) were greater in the gated PET/CT (SUVmax 5.4 and SUR 3.5) than in the non-gated PET/CT (SUVmax 4.6 and SUR 3.0). Fever dramatically subsided after removal of the graft in the CBD. This case report implies that respiratory-gated ¹⁸F-FDG PET/CT can visualize upper abdominal fever focus with better contrast than the conventional non-gated method.

Evaluation of Hot Nodules of Thyroid Gland Using Tc-99m Pertechnetate: a Novel Approach Using Quantitative Single-Photon Emission Computed Tomography/Computed Tomography / 대한핵의학회잡지

Planar scintigraphy using Tc-99mpertechnetate is useful for snapshot evaluation of hot thyroid nodules, which are pathologically follicular adenoma and seldom, if ever, malignant. The autonomy of the hot nodules has been demonstrated by the presence of thyroid-stimulating hormone-dependent extra-nodular thyroid tissue besides the hot nodules. Here, we present two cases of hot thyroid nodules in patients who underwent quantitative single-photon emission computed tomography/computed tomography (SPECT/CT). In addition to the nodules, contralateral normal thyroid parenchyma was evaluated based on standardized uptake values. One patient had a traditional follicular adenoma suppressing other thyroid tissue, whereas the other patient seemed to have a nodule erupting from underlying hyperfunctioning, not suppressed, thyroid tissue. This novel approach using quantitative SPECT/CT unveils a new pathology of hot thyroid nodule that does not suppress, but coincides with hyperfunctioning thyroid tissue.

Evaluation of Hot Nodules of Thyroid Gland Using Tc-99m Pertechnetate: a Novel Approach Using Quantitative Single-Photon Emission Computed Tomography/Computed Tomography / 대한핵의학회잡지

Planar scintigraphy using Tc-99mpertechnetate is useful for snapshot evaluation of hot thyroid nodules, which are pathologically follicular adenoma and seldom, if ever, malignant. The autonomy of the hot nodules has been demonstrated by the presence of thyroid-stimulating hormone-dependent extra-nodular thyroid tissue besides the hot nodules. Here, we present two cases of hot thyroid nodules in patients who underwent quantitative single-photon emission computed tomography/computed tomography (SPECT/CT). In addition to the nodules, contralateral normal thyroid parenchyma was evaluated based on standardized uptake values. One patient had a traditional follicular adenoma suppressing other thyroid tissue, whereas the other patient seemed to have a nodule erupting from underlying hyperfunctioning, not suppressed, thyroid tissue. This novel approach using quantitative SPECT/CT unveils a new pathology of hot thyroid nodule that does not suppress, but coincides with hyperfunctioning thyroid tissue.

Quantitative Single-Photon Emission Computed Tomography/Computed Tomography for Evaluation of Salivary Gland Dysfunction in Sjögren's Syndrome Patients / 대한핵의학회잡지

PURPOSE: The purpose of the study was to investigate the usefulness of quantitative salivary single-photon emission computed tomography/computed tomography (SPECT/CT) using Tc-99m pertechnetate in Sjögren's syndrome (SS).METHODS: We retrospectively reviewed quantitative salivary SPECT/CT data from 95 xerostomic patients who were classified as either SS (n = 47, male:female = 0:47, age = 54.60 ± 13.16 y [mean ± SD]) or non-SS (n = 48, male:female = 5:43, age = 54.94 ± 14.04 y) by combination of anti-SSA/Ro antibody, labial salivary gland biopsy, unstimulated whole saliva flow rate, and Schirmer's test. Thyroid cancer patients (n = 43, male:female = 19:24, age = 46.37 ± 12.13 y) before radioactive iodine therapy served as negative controls. Quantitative SPECT/CT was performed pre-stimulatory 20 min and post-stimulatory 40 min after injection of Tc-99m pertechnetate (15 mCi). The %injected dose at 20 min and the %excretion between 20 and 40 min were calculated for parotid and submandibular glands, generating four quantitative parameters: %parotid uptake (%PU), %submandibular uptake (%SU), %parotid excretion (%PE), and %submandibular excretion (%SE). The most useful parameter for SS diagnosis was investigated.RESULTS: The uptake parameters (%PU and %SU) were significantly different among the SS, non-SS, and negative controls (p = 0.005 for %PU and p < 0.001 for %SU, respectively), but the excretion parameters (%PE and %SE) were not (p > 0.05 for both). The%PU and%SU were significantly lower in SS than in the negative controls and non-SS (p < 0.05 for all pair-wise comparisons). Additionally, the %SU was significantly lower in non-SS than in the negative controls (p < 0.05). Receiver-operating characteristic analysis revealed that the %SU had the greatest area-under-the curve of 0.720 (95% confidence interval = 0.618–0.807). Using the optimal cut-off value of %SU ≤ 0.07%, SS was identified with a sensitivity of 70.21% and a specificity of 70.83%.CONCLUSION: Reduced submandibular uptake of Tc-99m pertechnetate at 20 min (%SU) was proved useful for the diagnosis of SS. Quantitative salivary gland SPECT/CT holds promise as an objective imaging modality for assessment of salivary dysfunction and may facilitate accurate classification of SS.

Usefulness of Respiratory-Gated ¹⁸F-FDG PET/CT in Detecting Upper Abdominal Fever Focus / 대한핵의학회잡지

Respiratory-gated ¹⁸F-fluorodeoxygluocse (¹⁸F-FDG) PET/CT has been successfully used to better localize malignancies in the lung or upper abdominal organs. However, clinical usefulness of respiratory-gated ¹⁸F-FDG PET/CT in detection of fever focus has not been reported yet. A 68-year-old male patient with a history of living donor liver transplantation and biliary stenting was referred for ¹⁸F-FDG PET/CT due to fever of unknown origin (FUO). To find the accurate fever focus, respiratory-gated and non-gated ¹⁸F-FDG PET/CT was performed. Respiratory-gated PET/CT readily revealed prominent hypermetabolic lesion in the distal common bile duct (CBD) area where previous surgical graft was in situ. Maximum standardized uptake value (SUVmax) and SUVratio (SUR) were greater in the gated PET/CT (SUVmax 5.4 and SUR 3.5) than in the non-gated PET/CT (SUVmax 4.6 and SUR 3.0). Fever dramatically subsided after removal of the graft in the CBD. This case report implies that respiratory-gated ¹⁸F-FDG PET/CT can visualize upper abdominal fever focus with better contrast than the conventional non-gated method.

Quantitative Assessment of the Radiation Exposure during Pathologic Process in the Sentinel Lymph Node Biopsy using Radioactive Colloid / 핵의학분자영상

PURPOSE: Sentinel lymph node biopsy became the standard procedure in early breast cancer surgery. Faculty members might be exposed to a trace amount of radiation. The aim of this study is to quantify the radiation exposure and verify the safety of the procedure and the facilities, especially during pathologic process. MATERIALS AND METHODS: Sentinel lymph node biopsies with Tc-99m human serum albumin were performed as routine clinical work. Exposed radiation doses were measured in pathologic technologist, nuclear medicine technologist, and nuclear medicine physician using a thermoluminescence dosimeter (TLD) during one month. We also measured the residual radioactivities or absorbed dose rates, the exposure distance and time during procedure, the radiation dose of the waste and the ambient equivalent dose of the pathology laboratory. RESULTS: Actual exposed doses were 0.21 and 0.85 (uSv/study) for the whole body and hand of pathology technologist after 47 sentinel node pathologic preparations were performed. Whole body exposed doses of nuclear medicine physician and technologist were 0.2 and 2.3 (uSv/study). According to this data and the exposure threshold of the general population (1 mSv), at least 1100 studies were allowed in pathology technologist. The calculated exposed dose rates (micro Sv/study) from residual radioactivities data were 2.47/ 22.4 micro Sv (whole body/ hand) for the surgeon; 0.22/ 0 micro Sv for operation nurse. The ambient equivalent dose of the pathology laboratory was 0.02-0.03 mR/hr. The radiation dose of the waste was less than 100 Bq/g and nearly was not detected. CONCLUSION: Pathologic procedure relating sentinel lymph node biopsy using radioactive colloid is safe in terms of the radiation safety.