The Value of 18 F-FDG PET/CT in Evaluating Disease Severity and Prognosis in Idiopathic Pulmonary Fibrosis Patients

Background@#Several parameters are useful for assessing disease severity in idiopathic pulmonary fibrosis (IPF); however, the role of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) is not well-defined. We aimed to evaluate the value of 18 F-FDG PET/CT for assessing disease severity and prognosis in IPF patients. @*Methods@#Clinical data of 89 IPF patients (mean age: 68.1 years, male: 94%) who underwent18 F-FDG PET/CT for evaluation of lung nodules or cancer staging were retrospectively reviewed. Mean and maximal standardized uptake values (SUV mean , SUV max , respectively) were measured in the fibrotic area. Adjusted SUV, including SUV ratio (SUVR, defined as SUV max -to-liver SUV mean ratio), tissue fraction-corrected SUV mean (SUV meanTF ), and SUVR (SUVRTF ), and tissue-to-blood ratio (SUV max /SUV mean venous; TBR blood ) were obtained. Death was defined as the primary outcome, and associations between other clinical parameters (lung function, exercise capacity, C-reactive protein [CRP] level) were also investigated. @*Results@#All SUV parameters were inversely correlated with the forced vital capacity, diffusing capacity for carbon monoxide, and positively correlated with CRP level and the gender-agephysiology index. The SUV mean , SUV max , and SUV meanTF were associated with changes in lung function at six months. The SUVR (hazard ratio [HR], 1.738; 95% confidence interval [CI], 1.011–2.991), SUVR TF (HR, 1.441; 95% CI, 1.000–2.098), and TBR blood (HR, 1.377; 95% CI, 1.038–1.827) were significant predictors for mortality in patients with IPF in the univariate analysis, but not in the multivariate analysis. @*Conclusion@#18 F-FDG PET/CT may provide additional information on the disease severity and prognosis in IPF patients, and the SUVR may be superior to other SUV parameters.

Predicting Vascularized Bone Graft Viability Using 1-Week Postoperative Bone SPECT/CT After Maxillofacial Reconstructive Surgery / 대한핵의학회잡지

Purpose@#We aimed to evaluate the performance of hybrid bone single-photon emission computed tomography (SPECT)/computed tomography (CT) in predicting bone graft viability after maxillary or mandibular reconstructive surgery with vascularized bone grafts. @*Methods@#We retrospectively reviewed 46 bone planar scintigraphy and SPECT/CT images of 45 adult patients taken at 1 week (5–8 days) after maxillary or mandibular reconstructive surgery with vascularized bone grafts. By visual analysis, two nuclear medicine physicians scored the uptake degrees of each bone graft segment compared with the calvarium uptake on planar bone scintigraphy and SPECT/CT, respectively (0 = absence of uptake, 1 = less uptake, 2 = similar uptake, and 3 = more uptake). The imaging results were compared with clinical follow-up for assessing bone graft viability. @*Results@#During follow-up, five bone graft segments were surgically removed and confirmed as nonviable—one had a score of 0, although the other four had a score of 1–3 on planar bone scintigraphy. All five bone graft segments were scored 0 on SPECT/CT and eventually confirmed as nonviable. All other graft segments with a score of > 1 on SPECT/CT were viable and uneventful.The anatomical CT information on SPECT/CT images was helpful in discriminating bone graft uptake from adjacent bone or soft tissue uptake. @*Conclusions@#The absence of tracer uptake by the vascularized bone graft on bone SPECT/CT at 1 week after maxillary or mandibular reconstructive surgery can predict graft failure. Bone SPECT/CT can be used to predict vascularized bone graft viability postoperatively.

False-negative Hepatobiliary Scintigraphy for Biliary Atresia / 대한핵의학회잡지

We present the case of a patient with biliary and duodenal atresia who showed false-negative hepatobiliary scintigraphy results. The patient was born at 37 weeks and 2 days of gestation. Her mother had undergone amnioreduction after detection of a double-bubble ultrasound sign in the fetal abdomen. At 2 days of age, total serum bilirubin level was elevated. On hepatobiliary scintigraphy 4 days later, the gallbladder was visualized from 30 min and it showed duodeno-gastric reflux at 240 min. After 24 h, the radiotracer was almost washed out in the hepatic parenchyma, but there was retention in the gastroduodenal junction. Because the biliary to duodenal transit was visible, biliary atresia seemed unlikely. Abdominal ultrasonography at 7 days of age showed a small dysmorphic gallbladder, but triangular cord sign was not definite. Magnetic resonance cholangiography revealed atretic gallbladder. Although cystic and common bile ducts were visible, the proximal common hepatic bile duct was not visible. The next day, serum total bilirubin levels remained elevated (17.1 mg/dl) with direct bilirubin level of 1.2 mg/dl. Kasai portoenterostomy with duodeno-duodenostomy was performed at 10 days of age. Histopathological evaluation showed a fibrous obliteration of the common bile duct, consistent with that of biliary atresia.

False-negative Hepatobiliary Scintigraphy for Biliary Atresia / 대한핵의학회잡지

We present the case of a patient with biliary and duodenal atresia who showed false-negative hepatobiliary scintigraphy results. The patient was born at 37 weeks and 2 days of gestation. Her mother had undergone amnioreduction after detection of a double-bubble ultrasound sign in the fetal abdomen. At 2 days of age, total serum bilirubin level was elevated. On hepatobiliary scintigraphy 4 days later, the gallbladder was visualized from 30 min and it showed duodeno-gastric reflux at 240 min. After 24 h, the radiotracer was almost washed out in the hepatic parenchyma, but there was retention in the gastroduodenal junction. Because the biliary to duodenal transit was visible, biliary atresia seemed unlikely. Abdominal ultrasonography at 7 days of age showed a small dysmorphic gallbladder, but triangular cord sign was not definite. Magnetic resonance cholangiography revealed atretic gallbladder. Although cystic and common bile ducts were visible, the proximal common hepatic bile duct was not visible. The next day, serum total bilirubin levels remained elevated (17.1 mg/dl) with direct bilirubin level of 1.2 mg/dl. Kasai portoenterostomy with duodeno-duodenostomy was performed at 10 days of age. Histopathological evaluation showed a fibrous obliteration of the common bile duct, consistent with that of biliary atresia.

Successful Localization Using ⁶⁸Ga-DOTATOC PET/CT of a Phosphaturic Mesenchymal Tumor Causing Osteomalacia in a Patient with Concurrent Follicular Lymphoma / 대한핵의학회잡지

Diagnosing tumor-induced osteomalacia is often challenging because conventional imaging modalities may fail to locate the responsible tumor. This report describes the ability of ⁶⁸Ga-DOTATOC PET/CT to successfully distinguish between the responsible phosphaturic mesenchymal tumor and concurrent lymphoma lesions. A 52-year-old man with bone pain for several years was diagnosed with a vitamin D-resistant hypophosphatemic osteomalacia. Whole body ¹⁸F-FDG PET/CT revealed multiple enlarged hypermetabolic lymph nodes in his bilateral cervical, axillary, mediastinal, abdominal, pelvic, and inguinal regions. Core needle biopsy of the right cervical lymph node confirmed the diagnosis of follicular lymphoma. However, lymphoma was not considered the cause of osteomalacia. ⁶⁸Ga-DOTATOC PET/CT before chemotherapy showed a small nodule with intensely increased uptake in the right inguinal region, which was distinguished from the other enlarged lymph nodes. The nodule was surgically removed and histopathologically consistent with phosphaturic mesenchymal tumor. After surgery, the patient's serum phosphorus and alkaline phosphatase levels normalized without nutritional supplement.

A Comparison of the Accuracy of Different Single Plasma Sample Methods for Measuring Glomerular Filtration Rate Using ⁵¹Cr-EDTA in Children / 대한핵의학회잡지

PURPOSE: Among the different methods of measuring glomerular filtration rate (GFR) using 51Cr-ethylenediaminetetraacetic acid clearance, the two-plasma-sample method (TPSM) is widely used, and highly accurate. The single-plasma-sample method (SPSM) is occasionally used for simplicity, at the expense of accuracy. Our aims were (1) to investigate the correlation and (2) to compare the accuracy of six known SPSMs in pediatric patients in reference to TPSM.METHODS: We retrospectively reviewed 122 pediatric cases (65 boys, age 7.3 ± 4.6 years) and analyzed 307 GFR measurements. SPSMs included Groth and Aasted at 120 min, Hamat 120 min, Christensen and Groth at 120 and 240 min, and Jacobsson at 120 and 240 min. Reference GFR (GFRref) was defined using TPSM GFR corrected by the Jodal and Brochner-Mortensen equation. GFRref < 30 mL min−1 1.73 m−2 were excluded. The standard error of the estimate (SEE) and the number of cases with differences > 10% (N10%) were used to evaluate accuracy.RESULTS: SPSMs generally correlated well with GFRref (r = 0.92~0.99) and were relatively accurate (SEE = 9.21~15.60). Groth and Aasted showed the smallest SEE, while Jacobsson at 240 min showed the smallest N10% for all GFRref ranges. As for the decreased GFRref, Ham was most accurate followed by Jacobsson at 240 min.CONCLUSIONS: Jacobsson at 240 min provided good accuracy in all GFRref ranges and was well correlated with TPSM. Jacobsson at 240 min might be the most appropriate method to substitute for TPSM in pediatric patients. Ham could be an alternative in patients with impaired renal function.

Successful Localization Using ⁶⁸Ga-DOTATOC PET/CT of a Phosphaturic Mesenchymal Tumor Causing Osteomalacia in a Patient with Concurrent Follicular Lymphoma / 대한핵의학회잡지

Diagnosing tumor-induced osteomalacia is often challenging because conventional imaging modalities may fail to locate the responsible tumor. This report describes the ability of ⁶⁸Ga-DOTATOC PET/CT to successfully distinguish between the responsible phosphaturic mesenchymal tumor and concurrent lymphoma lesions. A 52-year-old man with bone pain for several years was diagnosed with a vitamin D-resistant hypophosphatemic osteomalacia. Whole body ¹⁸F-FDG PET/CT revealed multiple enlarged hypermetabolic lymph nodes in his bilateral cervical, axillary, mediastinal, abdominal, pelvic, and inguinal regions. Core needle biopsy of the right cervical lymph node confirmed the diagnosis of follicular lymphoma. However, lymphoma was not considered the cause of osteomalacia. ⁶⁸Ga-DOTATOC PET/CT before chemotherapy showed a small nodule with intensely increased uptake in the right inguinal region, which was distinguished from the other enlarged lymph nodes. The nodule was surgically removed and histopathologically consistent with phosphaturic mesenchymal tumor. After surgery, the patient's serum phosphorus and alkaline phosphatase levels normalized without nutritional supplement.

A Comparison of the Accuracy of Different Single Plasma Sample Methods for Measuring Glomerular Filtration Rate Using ⁵¹Cr-EDTA in Children / 대한핵의학회잡지

PURPOSE@#Among the different methods of measuring glomerular filtration rate (GFR) using 51Cr-ethylenediaminetetraacetic acid clearance, the two-plasma-sample method (TPSM) is widely used, and highly accurate. The single-plasma-sample method (SPSM) is occasionally used for simplicity, at the expense of accuracy. Our aims were (1) to investigate the correlation and (2) to compare the accuracy of six known SPSMs in pediatric patients in reference to TPSM.@*METHODS@#We retrospectively reviewed 122 pediatric cases (65 boys, age 7.3 ± 4.6 years) and analyzed 307 GFR measurements. SPSMs included Groth and Aasted at 120 min, Hamat 120 min, Christensen and Groth at 120 and 240 min, and Jacobsson at 120 and 240 min. Reference GFR (GFRref) was defined using TPSM GFR corrected by the Jodal and Brochner-Mortensen equation. GFRref 10% (N10%) were used to evaluate accuracy.@*RESULTS@#SPSMs generally correlated well with GFRref (r = 0.92~0.99) and were relatively accurate (SEE = 9.21~15.60). Groth and Aasted showed the smallest SEE, while Jacobsson at 240 min showed the smallest N10% for all GFRref ranges. As for the decreased GFRref, Ham was most accurate followed by Jacobsson at 240 min.@*CONCLUSIONS@#Jacobsson at 240 min provided good accuracy in all GFRref ranges and was well correlated with TPSM. Jacobsson at 240 min might be the most appropriate method to substitute for TPSM in pediatric patients. Ham could be an alternative in patients with impaired renal function.