Clinical implication of F-18 FDG PET/CT in patients with secondary hemophagocytic lymphohistiocytosis

The contribution that F-18 fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18 FDG) PET/CT makes to the diagnosis of malignancy in patients with hemophagocytic lymphohistiocytosis (HLH) is still uncertain. The aim of this study was to evaluate the diagnostic performance of F-18 FDG PET/CT for the detection of underlying malignancy, to investigate the correlation between PET and laboratory parameters, and to identify prognosis-related factors in patients with secondary HLH. We enrolled 14 patients who were diagnosed with HLH and referred for F-18 FDG PET/CT to exclude malignancy. The diagnostic performance of F-18 FDG PET/CT for malignancy detection was assessed. The correlations between PET and laboratory parameters were determined. The prognostic significance of the following factors was evaluated: PET and laboratory parameters, age in years, presence of underlying malignancy, and fever and splenomegaly. Six of the 14 patients had malignancies (four with lymphoma, one with multiple myeloma, and one with colonic malignancy). Sensitivity, specificity, and diagnostic accuracy of F-18 FDG PET/CT for malignancy detection were 83, 62.5, and 71.4 %, respectively. F-18 FDG uptake in the bone marrow and spleen was positively correlated with neutrophil count and C-reactive protein. All of the PET parameters, but none of the clinical or laboratory parameters, were significantly associated with patient outcome, as determined by univariate analysis. Given the small sample size, F-18 FDG PET/CT was useful for detecting underlying malignancy, and PET parameters correlated with laboratory parameters that reflected inflammatory status. F-18 FDG PET/CT might provide prognostic information for the management of patients with secondary HLH.     

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diophosphate bone scan to detect bone metastases in patients with non-small cell lung cancer

Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.     

Relationship between Tl-201, Tc-99m (Sn) pyrophosphate and F-18 2-deoxyglucose uptake in ischemically injured dog myocardium

We have previously demonstrated that enhanced glucose utilization in reperfused myocardium as assessed by F-18 2-deoxyglucose (FDG) and positron tomography predicts functional recovery. In this study, we compared segmental uptake of F-18 FDG with that of Tl-201 and Tc-99m (Sn) pyrophosphate (Tc-99m PPi) as conventional markers of tissue viability in seven dogs after a 3-hour intracoronary balloon occlusion and 20 hours of reperfusion. Myocardial blood flow was determined with microspheres. Regional retention fractions were calculated from tracer tissue concentrations, the arterial input function, and blood flow. Ischemic injury was assessed by triphenyltetrazolium chloride (TTC) staining and histologic analysis. At 24 hours, blood flow was 22% lower in reperfused than in control myocardium (p less than 0.05). Uptake of Tl-201 was related linearly to blood flow (r = 0.92), while glucose utilization and Tc-99m PPi were 2.9 (p less than 0.01) and 4.7 (p less than 0.05) times higher in reperfused than in control myocardium. Retention fractions of Tc-99m PPi increased with the degree of ischemic injury, while F-18 FDG uptake was highest in segments with mild cell injury. Thus, in ischemically injured myocardium, Tl-201 primarily reflects blood flow. F-18 FDG as a marker of glucose utilization identifies ischemically injured but viable tissue. The admixture of necrotic cells can be determined with Tc-99m PPi. Our results indicate that a dual tracer approach might best characterize the presence and extent of reversibly and of irreversibly injured tissue in a given myocardial region.     

Bone scintigraphy using Tc-99m DPD and F18-FDG in a patient with SAPHO syndrome

Synovitis (inflammatory arthritis), acne (pustulosa), palmoplantar pustulosis, hyperostosis and osteitis (bland osteomyelitis) are symptoms forming the acronym SAPHO. We present the case of a 48-year old man with sterno-costo-clavicular hyperostosis and typical pustulosis palmaris. We performed Tc-99m DPD serial bone scanning to monitor the course of disease and to assess therapeutic efficiency. Control bone scans in 2001 showed minor compromises of the ribs and diminished disease activity on collarbones and the sternum after medication with non-steroidal anti-inflammatory drugs (NSAIDs) and bisphosphonates. F-18 FDG PET presented synovial inflammation in the left sterno-clavicular joint but no relevant tracer uptake on clavicles or breastbones. In case of diagnostic doubts F-18 FDG PET could be recommended in order to discriminate bland osteomyelitis from bacterial osteomyelitis or from bone malignancy when SAPHO-syndrome is assumed.     

The utility of 99mTc depreotide compared with F-18 fluorodeoxyglucose positron emission tomography and surgical staging in patients with suspected non-small cell lung cancer

STUDY OBJECTIVES: The findings from conventional imaging modalities, such as chest CT, are frequently unreliable in patients with lung cancer. This study was designed to compare the relative diagnostic accuracies and utility of the two most widely used functional imaging examinations, F-18-2-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) and (99m)Tc depreotide scintigraphy, for the diagnosis and staging of lung cancer. DESIGN: Prospective, experimental investigation. SETTING: Academic medical center. PATIENTS: One hundred sixty-six subjects with suspected lung cancer were enrolled in the study. INTERVENTIONS: Whole-body and single-photon emission CT imaging of the chest was performed after IV administration of (99m)Tc depreotide. Attenuation-corrected FDG PET imaging was performed after IV administration of FDG. Image findings were compared with the biopsy results or clinical follow-up. Measurements and results: In 157 subjects with evaluable lung lesions, the sensitivities and specificities for detecting malignant disease (95% confidence intervals) of FDG PET are 96% (90 to 98%) and 71% (54 to 85%), and of (99m)Tc depreotide are 94% (88 to 98%) and 51% (34 to 68%). In the 139 subjects with available complete staging data, FDG PET correctly staged 76 of 139 patients (55%), and (99m)Tc depreotide correctly staged 63 of 139 patients (45%). CONCLUSIONS: The sensitivity for detection of lung cancer in the primary lesion is equally high for FDG PET and (99m)Tc depreotide. The specificity is superior for FDG PET. The staging accuracy of FDG PET and (99m)Tc depreotide is similar, but when read with the chest CT neither scintigraphic examination is sufficiently accurate to stage patients with non-small cell lung cancer.     

Diagnosis of Paget's disease of the pelvis using F-18 FDG PET/CT

Sclerotic lesions of the right iliac bone were discovered incidentally in a 52-year-old Korean woman. In this case, imaging of the right iliac bone showed intense osteoblastic activity on the bone scan and very mild F-18-fluoro-2-deoxyglucose (FDG) uptake on positron emission tomography (PET). Since Paget's disease is rare in Koreans, we aimed to rule out other bone diseases such as osteoblastic metastasis or osteomyelitis. These results allowed us to exclude chronic osteomyelitis or malignancy and clarify the diagnosis of Paget's disease of the iliac bone. This case illustrates how F-18 FDG PET/CT can be a useful tool in the differential diagnosis of various bone diseases.     

Discordant findings of skeletal metastasis between tc 99M MDP bone scans and F18 FDG PET/CT imaging for advanced breast and lung cancers--two case reports and literature review

Traditionally, Tc 99m methyl diphosphate (MDP) bone scintigraphy provides high-sensitivity detection of skeletal metastasis from breast and lung cancers in regular follow-up. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), based on the glucose metabolism of malignant cells, plays a role in describing tumor growth, proliferation of neoplasm and the extent of metastasis. In general, concordant findings of skeletal metastasis are seen on both types of image, especially in cases of breast and lung cancer. However, there were extremely discordant findings of skeletal metastasis between bone scans and F 18 FDG PET/CT imaging in two cases among 300 consecutive F 18 FDG PET/CT follow-up exams of patients with malignancies, during the past year, in our center. Both cases, one of breast cancer and one of lung cancer, had negative bone scintigraphic findings, but a diffusely high grade of F 18 FDG avid marrow infiltration in the axial spine, leading to the diagnosis of stage IV disease in both cases. Owing to variant genetic aberrance of malignance, F 18 FDG PET/CT reveals direct evidence of diffuse, rapid neoplasm metabolism in the bone marrow of the spine, but not of secondary osteoblastic reactions in vivo . F 18 FDG PET/CT should always be employed in the follow-up of patients with malignancies.     

Extensive Invasive Extramammary Paget Disease Evaluated by F-18 FDG PET/CT: A Case Report

Extramammary Paget disease (EMPD) is a rare cutaneous, intraepithelial adenocarcinoma. Because of its rarity, little is known about the value of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in evaluating this disease. Our case report aims to increase current knowledge of FDG PET/CT in EMPD as a noninvasive imaging tool for assessing the extension of the disease and detecting distant metastases.We reported a 64-year-old Chinese man who presented with a slowly progressive, ill-margined erythematous lesion with a crusted, eroded, and scaly surface involving multiple sites of penis, scrotum, left pelvic wall, hip, groin, and thigh for >4 years, which became extensive in the past 1 year. He was referred for an FDG PET/CT examination to further evaluate the lesions. A following skin biopsy was performed to obtain a definitive histological diagnosis.FDG PET/CT imaging revealed mild FDG uptake at the extensive cutaneous lesion with subcutaneous invasion, involvement of lymph nodes, and multiple intense FDG-avid of skeletal metastases. According to the appearance of FDG PET/CT, a provisional diagnosis of advanced cutaneous malignancy was made. Histopathology findings indicated characteristic of EMPD. The patient was treated with radiation therapy and died from complications 2 months after the last dose of radiotherapy.Our case highlighted that a whole-body FDG PET/CT should be incorporated into the diagnostic algorithm of EMPD to give a comprehensive assessment of this disease.     

Bone metastasis versus bone marrow metastasis? Integration of diagnosis by 18F-fluorodeoxyglucose positron emission/computed tomography in advanced malignancy with super bone scan: Two case reports and literature review

Super scan pattern on technetium-99m methyldiphosphonate (Tc-99m MDP) bone scintigraphy is a special condition of extremely high bone uptake relative to soft tissue with absent or faint renal radioactivity visualization, which is usually seen in diffuse bone metastases or discrete endocrine entities. Here, two cases with super bone scan are presented. One was a young man diagnosed with gastric cancer. The other was a middle-aged woman with a history of breast cancer with recent recurrence. Both cases had 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) diagnosis simultaneously. Based on imaging of ¹⁸F-FDG PET/CT, diffusely incremental ¹⁸F-FDG avidity in spine/pelvis on PET and subtle erosion of cortical bone on CT were seen. The cytological results of bone marrow biopsy showed evidence of malignant metastasis. However, there were several focal discrepant findings between the ¹⁸F-FDG PET/CT and Tc-99m MDP bone scan. According to integration of both imaging findings and the result of bone marrow biopsy, we believe that the disseminated malignant spread in bone marrow is a primitive alternation in the super bone scan and that it is also as a result of neoplasm-related endocrine factors.     

F-18 FDG PET detection of a medullary thyroid carcinoma in a patient with metastatic colonic cancer; literature review

Objective

We report a case of a medullary thyroid carcinoma discovered by F-18 fluorodeoxyglucose-positron emission tomography (F-18 FDG PET).

Patient and methods

A 73-year-old man with a history of surgical removal of sigmoid colon cancer underwent F-18 FDG PET to search for distant metastases and / or local recurrence because of elevated CEA level and new episode of occlusion. F-18 FDG PET images showed increased focal FDG uptake in the right lobe of the thyroid. Thyroid ultrasound showed one thyroid nodule in each lobe.

Results

The fine needle aspiration result was suspicious and calcitonin level was elevated. The subject underwent thyroidectomy without lymph node dissection. The pathology showed a 14 mm medullary thyroid carcinoma. There was no germline mutation of RET.

Conclusions

F-18 FDG PET can detect primitive or secondary malignant thyroid tumors. Thus, thyroid incidentaloma revealed by 18 FDG PET uptake always necessitates careful evaluation.     

F-18-Fluorodeoxyglucose (FDG) Positron-Emission Tomography of Echinococcus multilocularis Liver Lesions: Prospective Evaluation of its Value for Diagnosis and Follow-up during Benzimidazole Therapy

Abstract Background: Long-term benzimidazole therapy benefits patients with non-resectable alveolar echinococcosis (AE). Methods to assess early therapeutic efficacy are lacking. Recently, AE liver lesions were reported to exhibit increased F-18-fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET). To assess the value of FDG-PET for diagnosis and follow-up of AE patients. Patients/Methods: Twenty-six consecutive patients with newly diagnosed AE were enrolled. Baseline evaluation included CT and FDG-PET. Thirteen patients (11 women; median age 50 years, range 40-76) were resected, the remaining 13 (8 women; median age 60 years, range 39–72) had non-resectable disease, were started on benzimidazoles, and CT and FDG-PET were repeated at 6, 12 and 24 months of therapy. Twelve consecutive patients with newly diagnosed cystic echinococcosis (CE) of the liver were also subjected to baseline FDG-PET. Results: In 21/26 AE patients, baseline PET scans showed multifocally increased FDG uptake in the hepatic lesions' periphery, while liver lesions were FDG negative in 11/12 CE patients. Thus, sensitivity and specificity of FDG-PET for AE vs. CE were 81% and 92%, respectively. In 5 of 10 non-resectable patients with increased baseline FDG uptake, the intensity of uptake decreased (or disappeared) during benzimidazole therapy, in 3 by ≥2 grades within the initial 6 months. Conclusions: FDG-PET is a sensitive and specific adjunct in the diagnosis of suspected AE and can help in differentiating AE from CE. The rapid improvement of positive PET scans with benzimidazole therapy in some patients indicates that absent FDG uptake does not necessarily reflect parasite viability. K. D. M. Stumpe and E. C. Renner-Schneiter contributed equally to this work.     

The utility of F-18 FDG PET/CT for diagnosis and response evaluation of hepatosplenic tuberculosis

A 77-year-old woman underwent F-18 FDG PET/CT for evaluation of fever focus. Diffuse and intense hepatosplenic uptake was noted and lymphoma or tuberculosis was proposed. Liver biopsy revealed chronic granulomatous inflammation with Langerhans-type giant cells and necrosis. A follow-up PET/CT after anti-tuberculosis treatment revealed that the hepatosplenic uptake had resolved.     

F-18 FDG PET/CT in the assessment of patients with unexplained CEA rise after surgical curative resection for colorectal cancer

Purpose

We evaluated the role of quantitative assessment by maximum standardized uptake value (SUVmax) on F-18 fluorodeoxyglucose [F-18]FDG positron emission tomography/computed tomography (PET/CT) in stratifying colorectal cancer (CRC) patients with unexplained carcinoembryonic antigen (CEA) rise after surgical curative resection.

Material and methods

Forty asymptomatic patients (mean age, 64?±?12 years) with previous CRC and current serum CEA levels >5 ng/ml underwent [F-18] FDG PET/CT 13?±?3 months after complete surgical resection. The SUVmax was registered on anastomosis and peri-anastomotic tissue lesions, if present. The patients were followed for 24?±?9 months thereafter. Re-intervention, evidence of newly discovered distant metastases, and death were recognized as main events and constituted surrogate end points. The receiver-operator-curve (ROC) analysis was performed to estimate the optimal SUVmax cut-off to predict patients at high risk of main events. PET/CT results were then related to disease outcome (overall survival; OS).

Results

The mean SUVmax at the anastomotic site was 6.2?±?3 (range 2.6–15). At multivariate logistic regression analysis, the anastomotic SUVmax remained as the only significant contributor to the prediction of the events (p?=?0.004; OR 1.97). The ROC analysis recognized that the optimal threshold of SUVmax to differentiate patients was 5.7. A worse OS was observed in patients presenting with a SUVmax greater than 5.7 as compared to those having lesser (median survival: 16 vs. 31 months; p?=?0.002).

Conclusions

The quantitative assessment by SUVmax on [F-18]FDG PET/CT may be helpful in patients presenting with unexplained CEA rise after curative resection of CRC, by identifying those at risk of main events.     

Role of F-18 FDG positron emission tomography (PET) in the assessment of myocardial viability

Positron emission tomography (PET) is a functional imaging technique with important clinical applications in cardiology, oncology, and neurology. In cardiac imaging, its role has been extensively evaluated in the noninvasive diagnosis of coronary artery disease and in the determination of prognosis. Additionally, cardiac PET with F-18 fluorodeoxyglucose (FDG) is very helpful in selection of patients with coronary artery disease and left ventricular dysfunction who would benefit from coronary artery revascularization. Cardiac PET is arguably considered by many as a gold standard in this particular application. F-18, unlike other positron emitters, has a reasonably long physical half-life, which permits its distribution through commercial radiopharmacies. This is further facilitated by increasing popularity of FDG PET in oncology, which makes cardiac FDG PET a practical option for hospitals and outpatient centers equipped with PET scanners. In addition, gamma camera single photon emission computed tomography (SPECT) systems, routinely used in nuclear medicine departments, can be equipped with coincidence circuit or high-energy 511 KeV collimators, providing a cost-effective means of FDG cardiac imaging. Myocardial utilization of glucose as a substrate is variable, depending, among other factors, on serum levels of glucose and insulin. Therefore, patient preparation is important in obtaining good-quality images and in turn allowing for accurate interpretation of myocardial viability. There are various protocols to choose from that provide diagnostic image quality in both diabetic and nondiabetic patients. Mismatch between blood flow and FDG metabolism, an indicator of viable, jeopardized myocardium, can predict postrevascularization improvement in left ventricular function, symptomatic relief, and long-term survival.     

Scar imaging using multislice computed tomography versus metabolic imaging by F-18 FDG positron emission tomography: A pilot study

Introduction

F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) FDG PET is an established metabolic imaging technique to assess myocardial viability. Delayed iodinated contrast enhancement (DE) of myocardium on computed tomography (CT) has also been shown to be an anatomical marker of nonviable myocardium. A pilot study was undertaken to determine quantitative and qualitative agreement between metabolic viability imaging and scar imaging using FDG PET and multislice CT respectively.

Methods

Fifteen patients with coronary artery disease and left ventricular dysfunction were recruited in the study. All patients underwent same day FDG PET and DECT to evaluate myocardial viability. The images were analyzed quantitatively and qualitatively using a 17 segment model.

Results

DECT diagnosed viability in 57% (146/255) whilst PET in 51% (129/255) of segments. The per-segment agreement between DECT and FDG PET on qualitative analysis was 70% (Kappa: 0.40). The agreement in quantitative measurements between the two techniques for viability showed modest correlation [Pearson ρ: 0.63; P < 0.0001] on scatter plot and the Passing–Bablok regression analysis. Higher agreement (70 vs 77%; P = 0.051; Kappa: 0.40 vs 0.53) was obtained with quantitative compared to qualitative DECT.

Conclusions

DECT may be useful in characterizing myocardial scar, and preliminary results correlate modestly with metabolic FDG PET, both qualitatively and quantitatively. Although in our study quantitative analysis offered superior agreement compared to qualitative with DECT, further studies are needed to determine its incremental value.     

Value of Tc-99m sestamibi scintigraphy in the detection of bone lesions in multiple myeloma: comparison with Tc-99m methylene diphosphonate

Technetium 99m-2-methoxyisobutylisonitrile (Tc-99m MIBI) is a lipophilic agent that accumulates preferentially within living malignant cells due to the higher transmembrane electrical potential as a consequence of the higher metabolic rate than in the surrounding normal cells. It has been effectively used to detect malignant tumors at diagnosis and follow-up and has been reported to be useful in detecting disease lesions in multiple myeloma. We studied 28 consecutive patients with multiple myeloma at diagnosis to determine the value of Tc-99m MIBI in comparison with Tc-99m methylene diphosphonate (MDP), conventional X-rays, computed tomography (CT) scan, and magnetic resonance imaging (MRI). We found 26 patients with obvious osteolytic lesions in X-rays, 22 patients with positive Tc-99m MIBI scans, and 15 patients with positive Tc-99m MDP scans. There was no coincidence of the positive lesions in the two scans, while in two patients the osteolytic areas were positive in the Tc-99m MDP scans, and in one case the osteolytic area was positive in the Tc-99m MIBI scan. The intensity of Tc-99m MIBI scans correlated with disease activity as determined by lactate dehydrogenase (LDH) (p<0.05), C-reactive protein (CRP) (p<0.01), beta2-microglobulin (p<0.05), and serum ferritin (p<0.01). We believe that Tc-99m MIBI scintigraphy can detect bone marrow lesions in myeloma patients that cannot be detected by other imaging methods and that it can be useful especially in solitary myeloma to exclude other involved sites. In addition, it could be a prognostic factor related to disease activity and multidrug resistance. We believe that a multicenter study is needed to evaluate the usefulness of this agent.     

Comparison of the diagnostic value of 3-deoxy-3-18F-fluorothymidine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the assessment of regional lymph node in thoracic esophageal squamous cell carcinoma: a pilot study

We used pathological examination as golden standard to determine whether 3-deoxy-3-(18)F-fluorothymidine positron emission tomography/computed tomography (FLT PET/CT) can detect regional lymph node metastasis in untreated thoracic esophageal squamous cell carcinoma and additionally performed (18)F-fluorodeoxyglucose (FDG) PET/CT for direct comparison with that of FLT. Twenty-two patients with thoracic esophageal squamous cell carcinoma underwent dual-tracer PET/CT examinations before surgery. The results of reviewing CT images and side-by-side FDG PET and FLT PET images for the diagnosis of locoregional lymph node metastasis were compared prospectively in relation to pathologic findings. All patients underwent esophagectomy and lymphadenectomy. Pathologic examination confirmed nodes positive for metastasis in 16 patients and 47 of 424 excised nodes. The uptake of FDG (median SUVmax, 5.4; range, 2.4-10.6) in locoregional lymph nodes metastases was significantly higher than that of FLT (median SUVmax, 2.8; range, 1.3-4.6). There were 14 false-positive nodes in FDG PET/CT and only 3 in FLT PET/CT; 8 false-negative nodes in FDG PET/CT, while there were 12 false negative nodes in FLT PET/CT. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FLT PET/CT were 74.47%, 99.20%, 96.46%, 92.11%, and 96.89%, respectively, whereas those of FDG PET/CT were 82.98%, 96.29%, 94.81%, 82.98%, and 96.29%, respectively. P-values were 0.450, 0.014, 0.313, 0.050, and 0.555, respectively. FLT uptake in regional lymph nodes of esophageal carcinoma is significantly lower compared with FDG uptake. FLT PET/CT has fewer false-positive findings and higher specificity compared with FDG PET/CT.     

Prediction of left ventricular functional recovery by dobutamine echocardiography,F-18 deoxyglucose or 99mTc sestamibi nuclear imaging in patients with chronic myocardial infarction

BACKGROUND: Currently, several modalities are available to predict viability, however, studies comparing various modalities validated by functional recovery after revascularization are scarce. This study analyzed the relative merits of low-dose dobutamine echocardiography, F-18 deoxyglucose (FDG) positron emission tomography (PET) and (99m)Tc sestamibi single-photon emission computed tomography to predict functional recovery after revascularization in patients with chronic myocardial infarction. METHODS: Patients with chronic coronary occlusion (duration: 3.1 +/- 4.8 years) and impaired left ventricular function (ejection fraction: 42 +/- 13%) underwent low-dose dobutamine echocardiography (20 microg/kg/min), FDG-PET and (99m)Tc sestamibi imaging before revascularization. Revascularization was performed irrespective of any viability data. Follow-up angiography was obtained 4.8 +/- 2.5 months after revascularization. RESULTS: Viability analysis was performed in 34 patients with patent target vessel at follow-up, of whom 9 (27%) exhibited functional recovery on left ventricular angiography. For dobutamine echocardiography, improvement of >/=2 adjacent akinetic segments resulted in improved sensitivity of 89% and specificity of 80% to predict functional recovery. For glucose metabolism, FDG uptake >55% was an optimal threshold yielding a sensitivity of 89% and a specificity of 68%. With respect to perfusion, (99m)Tc sestamibi uptake >60% was the best cutoff resulting in a sensitivity and a specificity of 56 and 88%, respectively. A concordant match of FDG >55% and of (99m)Tc sestamibi >50% resulted in optimized sensitivity (78%) and specificity (80%) with dual imaging. CONCLUSIONS: Recovery of chronically dysfunctional myocardium can be predicted with high accuracy by stimulation of contractile reserve or by concordant match of preserved glucose metabolism and residual perfusion.     

Unusual adrenal metastasis and abdominal carcinomatosis secondary to Hurthle cell carcinoma of the thyroid.

Hurthle cell carcinoma (HCC) of the thyroid is an uncommon and relatively rare differentiated thyroid neoplasm. To our knowledge, no reported case of adrenal metastases with abdominal carcinomatosis secondary to HCC of the thyroid has been demonstrated by F-18 FDG PET/CT imaging. One report of adrenal uptake on I-131 whole-body scan with HCC exists. In this case report, we describe a patient with HCC who had a left adrenal metastasis with abdominal carcinomatosis that was discovered using F-18 FDG PET/CT imaging.     

A pathophysiologic study of tako-tsubo cardiomyopathy with F-18 fluorodeoxyglucose positron emission tomography.

AIMS; Our study aims to investigate the pathophysiologic mechanism underlying tako-tsubo cardiomyopathy using F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). METHODS AND RESULTS: Fifteen patients with tako-tsubo cardiomyopathy were enrolled in this study. Plasma catecholamines, cardiac troponin T (cTnT), and D-dimer were serially evaluated in all patients. Thallium-201 ((201)Tl) single-photon emission computed tomography (SPECT) and F-18 FDG PET were performed in 10 and eight patients, respectively. Emotional or physical stress occurred in 12 (80.0%) patients. ST-T segment abnormalities existed in all patients. Thirteen patients exhibited mildly elevated cTnT, although coronary angiography did not reveal significant stenosis in any patient. Endomyocardial biopsy specimens (n = 9) demonstrated contraction-band necrosis (n = 4) and mononuclear cell infiltration (n = 3). The levels of norepinephrine and epinephrine peaked on admission (744 +/- 452 and 140 +/- 166 pg/mL, respectively). There was severely reduced uptake at the apex on F-18 FDG PET image, despite slightly reduced uptake of (201)Tl. Elevation of D-dimer was observed in nine patients. CONCLUSION: The extent of metabolic defect involving apical akinetic area was more severe than perfusion abnormality. Our data suggest that sudden emotional or physical stress may cause a catecholamine-induced metabolic disorder in the myocardium, which is probably central to this syndrome.