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Technetium-99m pyrophosphate (Tc-99m PYP) cardiac imaging is a simple, widely available, noninvasive method to identify patients with transthyretin-type cardiac amyloidosis (ATTR), and it has remarkably high diagnostic accuracy with very high sensitivity and specificity. Visual scores of 0, 1, 2, and 3 indicate non-myocardial uptake, uptake less than rib, equal to rib, and greater than rib uptake, respectively. Semiquantitative assessment using the heart-to-contralateral lung ratio of more than 1.5 at 1 hour accurately distinguishes ATTR from the cardiac amyloid light chain subtype. However, there are several incidental non-cardiac findings that can be seen in planar images, rotating single-photon emission computed tomography (SPECT) images, maximum intensity projection images, or computed tomography images acquired for attenuation correction. These findings may lead to the early detection of a noncardiac condition that may require additional treatment. The intent of this review is to demonstrate several incidental noncardiac abnormalities that have an impact on patient management and follow-up.
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BACKGROUND: There is variable cardiac uptake observed on oncological ¹8F-fludeoxyglucose ([¹8F]FDG) positron emission/computed tomography (PET/CT). The main purpose of this study is to evaluate patterns of overnight fasting myocardial [¹8F]FDG uptake in oncological PET/CT and analyse the relationship between myocardial [¹8F]FDG uptake and myocardial ischaemia on stress single-photon emission CT (SPECT) myocardial perfusion imaging (MPI). MATERIAL AND METHODS: A total of 362 subjects underwent both oncological PET/CT and stress SPECT MPI within 3 months of each other. Subjects with focal-mass-like [¹8F]FDG myocardial uptake raising the suspicion of cardiac metastasis and subjects with coronary artery disease (CAD) were excluded. The myocardial [18F]FDG uptake was classified into four patterns. RESULTS: Abnormal SPECT MPI was noted in 91 (25%) patients; 220 (61%) patients had completely absent [18F]FDG uptake, 80 (22%) had diffuse [¹8F]FDG uptake, 39 (11%) had focal on diffuse [¹8F]FDG uptake, and 23 (6%) had focal or regional myocardial [¹8F]FDG uptake, the regional [¹8F]FDG myocardial uptake was the most predictive of myocardial ischaemia on SPECT MPI, and there were positive associations between age, sex, hypertension, tobacco smoking, hypercholesterolemia, and left ventricular ejection, a fair agreement was noted between the focal or regional FDG uptake and presence of ischaemia on SPECT, K = 0.394 (95% CI 0.164 to 0.189). CONCLUSIONS: Based on the presented findings, the physiological myocardial [¹8F]FDG uptake in fasting oncology patients is variable. The regional myocardial [¹8F]FDG uptake pattern is the most frequent pattern associated with myocardial ischaemia on stress SPECT MPI, however, the agreement between regional FDG uptake and presence of ischaemia on SPECT is fair.
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Doença da Artéria Coronariana , Isquemia Miocárdica , Imagem de Perfusão do Miocárdio , Neoplasias , Fluordesoxiglucose F18 , Humanos , Isquemia Miocárdica/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
INTRODUCTION: Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of pulmonary hypertension. Diagnosis of CTEPH can be established using various imaging techniques, including ventilation-perfusion scintigraphy (VQ) and multidetector computed tomography pulmonary angiography (CTPA). The aim of this study was to determine the frequency of direct pulmonary vascular, parenchymal lung, and cardiac abnormalities on CTPA in patients with CTEPH and to compare the diagnostic accuracy of both VQ scan CTPA in detecting CTEPH. METHODS: We retrospectively included 54 patients who had been referred for pulmonary hypertension service (20 males, 34 females). All patients had VQ scan and CTPA within 15 days and underwent pulmonary artery endarterectomy (PEA) thereafter. VQ scans were reported according to modified PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) criteria. CTPA was considered as diagnostic for CTEPH if it showed presence of thrombus, webs, stenosis, or perfusion lung abnormalities. RESULTS: The mean age of the study population was 41±10 years. The mean pulmonary artery pressure was 53±13 mmHg. Fifty-three out of 54 patients in the study population had high probability VQ scan and one patient had intermediate probability. CTPA was suggestive of CTEPH in all patients. The most frequent CTPA findings in the central pulmonary arteries and peripheral arteries were presence of thrombotic materials, abnormal vessel tapering and abrupt vessels-cut off (76% vs 65%, 67% vs 48%, and 48% vs 22%), respectively. The mosaic lung perfusion was present in 78% of the patients, and various cardiac morphology abnormalities were present and most common was abnormal right to left ventricle ratio (69%). CONCLUSION: Our findings indicate that both VQ scan and CTPA are highly sensitive for the detection of CTEPH confirmed by PEA. Most CTEPH patients had several pulmonary vascular, parenchymal lung and cardiac abnormalities. There was no sign with 100% sensitivity on CTPA for CTEPH detection.
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Rosai-Dorfman-Destombes disease (RDD) is a rare histocytic disorder with a broad spectrum of clinical presentations. The disease typically presents with lymphadenopathy but may involve multiple systems. Usually, RDD lesions demonstrate intense 18F-Fluorodeoxyglucose (FDG) uptake in positron emission tomography/computed tomography (PET/CT) imaging due to the inflammation and infiltration with high metabolic process of the disease. Here, we describe a rare case of 37-year-old man who presented with multiple systemic symptoms, including fever, weight loss and bilateral cervical, and inguinal lymphadenopathy who underwent FDG PET/CT for detection of disease extension. This case highlights the role of FDG PET/CT in establishing the disease extent in newly diagnosed RDD and guiding the therapeutic recommendations and for follow-up to monitor the disease response to therapy. To the best of our knowledge, this is the first case report from Saudi Arabia highlighting the role of FDG PET/CT in newly diagnosed RDD.
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OBJECTIVE: This study examined the diagnostic accuracy of myocardial perfusion scintigraphy (MPS) in end-stage renal disease (ESRD) patients and the incidence and clinical and biochemical predictors of myocardial perfusion abnormalities. METHODS: We evaluated 500 asymptomatic ESRD patients on hemodialysis referred for MPS for cardiac risk stratification before renal transplant surgery. Patients with abnormal MPS and an additional few patients without abnormal MPS underwent invasive coronary angiography (ICA). RESULTS: Sixty-nine patients (13%) showed abnormal MPS (reversible or fixed defect). The majority of patients had cardiovascular risk factors. There were statistically significant differences in age, male gender, hypertension, diabetes, hypercholesterolemia, and left ventricular ejection fraction (LVEF) (P < 0.05 for each) between patients with normal and abnormal MPS. Multivariate regression analysis showed that age (≥ 62 years) and low LVEF (≤ 47%) were independent predictors for abnormal MPS. ICA was performed in 112 subjects; the sensitivity, specificity, positive predictive value, and negative predictive value of MPA to detect CAD is 72%, 70%, 79%, and 61%, respectively. CONCLUSIONS: In ESRD, the incidence of myocardial perfusion defects is 13%. In addition to other traditional CAD risk factors, such as diabetes and hypertension, age, and LVEF are the strongest predictors of MPS abnormalities. Initial risk stratification can be cost-effective for identifying high-risk patients who will benefit from more imaging with CAD risk factors and LVEF. In ESRD patients, MPS diagnostic performance is relatively poor. To further evaluate the utility of MPS in diagnosis and risk stratification in ESRD, more data is therefore required.
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BACKGROUND: Cardiovascular disease (CVD) and osteoporosis are major health-care concerns worldwide. The evidence is contradictory on whether a relationship exists between low bone mineral density (BMD) determined by dual-energy absorptiometry (DXA scan) and coronary artery calcification (CAC) measured by computed tomography. Currently, there are no data on patients from Saudi Arabia. OBJECTIVE: Examine the relationship between CAC and BMD in both genders and study the influence of traditional coronary artery disease (CAD) risk factors and osteoporosis. DESIGN: Retrospective, cross-sectional, analytical. SETTING: Single tertiary care center. PATIENTS AND METHODS: We searched radiology databases for patients who underwent both DXA and CAC score scanning within six months of each other. The inclusion criterion was an absence of any history of CAD. MAIN OUTCOME MEASURE: Association between osteoporosis and CAC. SAMPLE SIZE: 195 (34 osteoporosic, 161 normal BMD or osteopenic) RESULTS: Most of the study population (57.4%) were females. The mean age of all patients was 63.6 (10.1) years. Participants with CAC scores of 0 were significantly younger than those who had CAC scores >0. The presence of diabetes mellitus, hypertension, and hypercholesterolemia was higher in patients with CAC scores >0. CAC score and other CAD risk factors were not significantly different between the osteoporotic and nonosteoporotic groups, except for body mass index. A high CAC score (>100) was present in 28%, 20%, 11%, and 30% of participants with no osteoporosis, osteoporosis of the lumbar spine, osteoporosis of the femoral neck, and participants with osteoporosis of both the lumbar spine and femoral neck, respectively (P=.762), suggesting there is no association between CAC and the presence of osteoporosis. CONCLUSIONS: Osteoporosis is not associated with higher CAC scores in Saudi Arabia and CAD risk factors are not significantly prevalent in osteoporosis. It appears that CAC and osteoporosis are independent age-related diseases that share common risk factors. LIMITATIONS: Single-center, retrospective. CONFLICT OF INTEREST: None.
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Doença da Artéria Coronariana , Osteoporose , Absorciometria de Fóton , Densidade Óssea , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/etiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Arábia Saudita/epidemiologiaRESUMO
A 69-year-old male patient who had a history of well-differentiated hepatocellular carcinoma (HCC) post right hepatectomy presented a year later with iron-deficiency anemia. His anemia work-up included upper endoscopy that revealed multiple gastric polyp a biopsy from the largest demonstrated metastatic hepatocellular carcinoma. His magnetic resonance imaging (MRI) showed a gastric "polyp" without evidence of local HCC recurrence within the liver. His subsequent dual imaging with Choline/fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) confirmed the gastric metastases and in addition revealed other sites of unexpected metastatic disease in the right adrenal and the bone that was asymptomatic. Patient was started on sorafenib and currently he is alive one-and-half-year postdetection of his metastatic disease under palliative care. This case showed that the possibility of gastric metastases should be kept in mind when confronted with anemia in HCC patient and also highlight the complementary role of molecular imaging modality along with MRI in the metastatic work-up for hepatocellular carcinoma postcurative resection.
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OBJECTIVES: A higher coronary artery calcium score (CACS) is associated with increased coronary artery plaque burden resulting in increased cardiovascular risk. Conversely, the absence of calcium indicates a low risk of cardiovascular events. However, coronary plaque calcification is a late manifestation of atherosclerosis; earlier stages of atherosclerosis present noncalcified plaques (NCPs) A recent study demonstrated that the absence of coronary artery calcification deposit does not preclude obstructive stenosis or the need for revascularization in patients with a high suspicion of coronary artery disease (CAD). Our study aimed to investigate the prevalence of NCP and the severity of coronary artery stenosis in symptomatic patients in our local population who were referred for coronary artery computed tomography angiogram (CCTA) with 0 CACS. METHODS: A total of 299 patients who had undergone CACS and CCTA, and had scored zero for coronary artery calcium. Patients included had clinically appropriate indications, mainly chest pain with variable severity with no history of CAD. The presence of CAD risk factors, such as diabetes, hypertension, and smoking, was obtained from reviewing patient charts. The CCTA analysis was performed to evaluate for coronary artery stenosis and the presence of NCP. The severity of stenosis was quantified by visual estimation and divided into 0% stenosis, 1-25% stenosis, 26-50% stenosis, and more than 50% stenosis. RESULTS: The prevalence of NCP was 6.4% (19 of the 299). Among the 19 patients with NCP, 52.6% had no identified coronary artery stenosis, 26.3% had less than 25%, and 21% had stenosis between 25 and 50%. None had stenosis greater than 50%. There was a strong association between male sex (P = 0.001), smoking (P = 0.0.004), hypertension, and NCP (P = 0.042), but no association was found between NCP and age or diabetes. CONCLUSIONS: In patients with a high clinical suspicion of CAD, the absence of coronary artery calcification does not rule out CAD; up to 6.4% of these patients have early CAD as evidenced by NCP detected by CCTA, and none have more than 50% stenosis, However, future prognostic and long-term follow-up studies are needed to determine prognostic value of NCP in patients with 0 CACS.
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Estenose Coronária/epidemiologia , Placa Aterosclerótica/epidemiologia , Idoso , Angiografia por Tomografia Computadorizada , Estenose Coronária/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/diagnóstico por imagem , Prevalência , Medição de Risco , Fatores de Risco , Arábia Saudita/epidemiologia , Calcificação VascularRESUMO
Whole-body 18F-fluorodeoxyglucose positron emission tomography (PET) has been used extensively in the last decade for the primary staging and restaging and to assess response to therapy in these patients. We aim to discuss the diagnostic performance of PET/computed tomography in the initial staging of breast carcinoma including the locally advanced disease and to illustrate its role in restaging the disease and in the assessment of response to therapy, particularly after the neoadjuvant chemotherapy. Causes of common pitfalls during image interpretations will be also discussed.
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Constrictive pericarditis is well known but rare and commonly forgotten cause of ascites. Early diagnosis of constrictive pericarditis is difficult due to absence of typical cardiopulmonary signs and multiple vague symptoms and its insidious course. In this case report, we present, a 61-year-old male referred for liver transplantation vs transjugular intrahepatic portosystemic shunt work-up for presumptive diagnosis of nonalcoholic steatohepatitis cirrhosis and refractory ascites. Comprehensive work-up before liver transplantation including liver biopsy, liver ultrasound, and Doppler, magnetic resonance imaging was not consistent with liver cirrhosis. Echocardiographic was suggestive of constrictive pericarditis, further work-up with right heart catheterization, cardiovascular magnetic resonance and multidetector cardiac computed tomography confirmed the diagnosis of constrictive pericarditis. Patient underwent surgical pericardiectomy, he reminded stable after surgery and did not require further paracentesis and discharged in stable condition.
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BACKGROUND: Coronary artery calcification (CAC) can be visually estimated on computed tomography (CT) attenuation correction (CTAC) of positron emission tomography (PET). The visual estimation of CAC from CTAC scans performed for PET/CT is comparable to the standard CAC score scan. Myocardial perfusion imaging (MPI) with single-photon emission CT (SPECT) is commonly performed for risk stratification before oncologic surgery. OBJECTIVE: We investigated the value of visual estimation of CAC from CTAC of PET/CT as well as other factors such as coronary artery disease (CAD) risk factors and type of cancer as predictors of MPI ischemia. METHODS: Retrospectively, we identified 268 patients who underwent PET/CT and MPI for preoperative cardiac evaluation. Visual estimation of CAC was performed and classified into four categories. RESULTS: The results of visual CAC were as follows: 47.8% - zero CAC, 32.8% - mild CAC, 14.2% - moderate CAC, and 5.2% - severe CAC. The majority of patients (85.8%) had normal MPI, whereas 14.2% were abnormal. There was a strong association between ischemia on MPI and CAC seen on CTAC (P < 0.01), dyslipidemia (P < 0.01), family history of CAD (P < 0.05), smoking (P < 0.01), and type of malignancy (P < 0.01). CONCLUSION: A strong association exists between visual estimation of CAC on CTAC and MPI. Zero is highly associated with normal MPI, but moderate-to-severe CAC is associated with abnormal MPI, in addition smoking, dyslipidemia, and certain cancer are associated with ischemic MPI; subsequently, preoperative cardiac testing is warranted in these subsets of patients.
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Cardiac amyloidosis (CA) is an important cause of restrictive cardiomyopathy and heart failure with preserved ejection fraction (HFpEF). At present, 3 bone-seeking tracers, 99mTc-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD), 99mTc-pyrophosphate (99mTc-PYP), and 99mTc-hydroxymethylene diphosphonate (99mTc-HMDP), have been evaluated for detecting CA, but they are not widely available. In contrast, methylene diphosphate (MDP) is widely available. However, only sporadic case reports have shown that MDP can accumulate in patients with CA. We report an 86-year-old man with multiple medical problems, including hypertension, hyperlipidemia, HFpEF, and a history of treated prostate cancer, who was referred for a 99mTc-MDP bone scan to rule out bone metastasis. The bone scan was negative for bone metastasis, but there was mild tracer accumulation in the heart, suggestive of CA. Subsequently, CA was diagnosed on 99mTc-PYP imaging. MDP may play a role comparable to other bone-seeking tracers in the diagnosis of CA and may be used as a noninvasive adjunct in the diagnosis of CA. Future research should compare MDP with other bone-seeking tracers for the diagnosis of CA. In addition, mechanistic studies on tracer binding to amyloid fibrils may help understand the pathophysiology of CA and facilitate the development of better and more specific tracers for CA.
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BACKGROUND: The relationship between breast arterial calcification (BAC) and angiographic coronary artery disease (CAD) is uncertain. Some studies have shown a positive association between BAC and angiographically proven CAD, while other studies have shown no association. OBJECTIVE: Examine the association between visually detected BAC on mammography and CAD found on invasive coronary angiography (ICA) in women and compare the frequency of risk factors for CAD between women with normal and abnormal ICA. DESIGN: Retrospective. SETTING: Single tertiary care center. PATIENTS AND METHODS: A review of the radiology databases was performed for female patients who underwent both ICA and mammography within six months of each other. Cases were excluded if there was a history of CAD, such as coronary artery bypass graft or prior percutaneous coronary intervention. MAIN OUTCOME MEASURES: BAC as a predictor of obstructive CAD on ICA. SAMPLE SIZE: 203 Saudi women RESULTS: The association between age at catheterization and ICA was statistically significant ( P=.01). There was no association between BAC and abnormal ICA ( P=.108). Women with abnormal ICA were older than women with a normal ICA ( P=.01). There was a higher frequency of CAD risk factors among the patients with abnormal ICA, except for smoking. In the multiple logistic regression model, ICA was associated with age, a family history of CAD, diabetes mellitus, hypertension and hypercholesterolemia. BAC-positive women were older than BAC-negative women ( P=.0001). BAC was associated with age, diabetes, hypertension, and chronic kidney disease in the multiple logistic regression model. CONCLUSIONS: BAC on mammography did not predict angiographically proven CAD. There was a strong association between BAC and age and many other conventional CAD risk factors. LIMITATIONS: Relatively small sample, single-center retrospective study. CONFLICT OF INTEREST: None.
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Mama/irrigação sanguínea , Doença da Artéria Coronariana/epidemiologia , Estenose Coronária/epidemiologia , Calcificação Vascular/epidemiologia , Fatores Etários , Idoso , Mama/diagnóstico por imagem , Cateterismo Cardíaco , Ácidos Cólicos/sangue , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Estenose Coronária/diagnóstico , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Hipertensão/epidemiologia , Modelos Logísticos , Mamografia , Pessoa de Meia-Idade , Arábia Saudita/epidemiologia , Erros Inatos do Metabolismo de Esteroides/epidemiologia , Calcificação Vascular/diagnóstico por imagemRESUMO
Renal scintigraphy of a renal graft is a non-invasive imaging used to evaluate renal graft dysfunction in relay postoperative period. We presented the case of a 42-year-old man when underwent renal transplantation and developed anuria with severe renal impairment. Renal scintigraphy yielded no visualization of the renal graft. Subsequently, the patient underwent an exploratory laparotomy. The graft was found to have normal perfusion, and a surgical biopsy suggestive of an acute perfusion injury and mild tubular necrosis. The patient recovered with conservative therapy. This case highlights a common limitation of renal scintigraphy in a post-renal-transplantation patient with severe renal impairment.
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A 35-year-old man presented with significant weight loss of 30 kg over the previous 6 months, with newly diagnosed diabetes. Routine laboratory tests were normal, except for markedly elevated blood glucose. Computed tomography (CT) of the abdomen revealed a large severely enhanced mass replacing most of the pancreas and liver metastatic nodules and multiple paraaortic lymph node metastases, 18F-fluorodeoxygluocse positron emission tomography/computed tomography (18F-FDG PET/CT) was performed and revealed mild FDG uptake in the pancreatic mass, as well as mild uptake in the liver and lymph node metastases. A biopsy of the liver metastasis was consistent glucagonoma that was confirmed with markedly elevated serum glucagon level. Subsequently, 68Ga-DOTATATE PET/CT was performed for better tumor characterization and for assessment of the tumors' response to therapy, 68Ga-DOTATATE scan revealed intense uptake in the pancreatic mass, liver metastases, and paraaortic lymph node metastases. The patient responded well to peptide receptor radionuclide therapy. This case highlights the role of both 68Ga-DOTATATE and 18FDG-PET/CT in the diagnosis and management of a glucagonoma. 68Ga-DOTATATE is the tracer of choice for well-differentiated glucagonoma and offers very high diagnostic accuracy as compared with that of cross-sectional and other functional imaging and enables correct patient selection for peptide receptor radionuclide therapy.
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OBJECTIVES: The purpose of this study is to assess the diagnostic performance of coronary artery calcium score (CACS), computed tomography coronary angiography (CTCA), and the prevalence of coronary artery disease (CAD) as etiology of heart failure (HF) in the Middle Eastern population. BACKGROUND: CTCA has several advantages compared to invasive coronary angiography (ICA). However, studies on the diagnostic accuracy of CTCA and CACS in detecting the prevalence of CAD in patients with newly diagnosed HF are lacking in the Middle East. METHODS: This study included 204 patients with symptoms of HF and ejection fraction (EF) of <50% by echocardiography who underwent CTCA for diagnosis of CAD within 3 months. The exclusion criteria were defined as patients with a history of CAD, percutaneous coronary intervention, or coronary artery bypass grafting. All patients with obstructive CAD based on CTCA were referred for ICA. In addition, 30 patients with normal CTCA also underwent ICA for verification. RESULTS: The mean age was 48 ± 13 years, 69% (n = 141) were male and 31% (n = 73) were female, mean left ventricular EF was 31% ± 9%, and mean CACS was 58 ± 120. Based on the CTCA results, 169 patients had normal or nonobstructive CAD, whereas 35 patients had obstructive CAD. ICA was performed in all 35 patients with obstructive CAD; 30 of them were confirmed as having abnormal ICA, and only 5 had nonobstructive CAD. In addition, 30 patients with normal CTCA underwent ICA testing and were confirmed as having normal ICA. The CTCA had 100% sensitivity, 84% specificity, 86% positive predictive value, and 100% negative predictive value. Of the total population, 30 (15%) who were documented as having obstructive CAD were classified as CAD HF based on ICA. The remaining 174 (85%) patients were classified as having no CAD HF based on normal CTCA and/or ICA. The prevalence of CAD HF based on ICA was 15%. There was a strong correlation between CACS and both CTCA and ICA, with P = 0.001 and 0.0048, respectively. CONCLUSION: In patients with newly diagnosed HF, CACS and CTCA had a 100% sensitivity and negative value as well as overall excellent diagnostic accuracy. CACS = 0 excluded CAD as the etiology of HF with correlation between CACS groups and both CTCA and ICA. The prevalence of CAD as etiology of HF in the study population was 15%.
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There have been little and conflicting data regarding the relationship between coronary artery calcification score (CACS) and myocardial ischemia on positron emission tomography myocardial perfusion imaging (PET MPI). The aims of this study were to investigate the relationship between myocardial ischemia on PET MPI and CACS, the frequency and severity of CACS in patients with normal PET MPI, and to determine the optimal CACS cutoff point for abnormal PET. This retrospective study included 363 patients who underwent same-setting stress PET perfusion imaging and CACS scan because of clinically suspected coronary artery disease (CAD). Fifty-five (55%) of the 363 patients had abnormal PET perfusion. There was an association between sex, diabetes mellitus (DM), smoking, and CACS and PET perfusion abnormities with P = 0.003, 0.05, 0.005, and 0.001, respectively. However, there was no association between PET perfusion abnormalities with age, body mass index, hypertension, and hypercholesterolemia. There was association between CACS and age, sex, and DM with P = 0.000, 0.014, and 0.052, respectively, and stepwise increase in the frequency of myocardial ischemia and CACS groups. Receiver-operating characteristic analysis showed that a CACS ≥304 is the optimal cutoff for predicting perfusion abnormalities with sensitivity of 64% and specificity of 69%. In conclusion, the frequency of CAC in patients with normal PET MPI is 49%, it is highly recommended to combine CACS with PET MPI in patients without a history of CAD. PET MPI identifies myocardial ischemia and defines the need for coronary revascularization, but CAC reflects the anatomic burden of coronary atherosclerosis. Combining CACS to PET MPI allows better risk stratification and identifies high-risk patients with PET, and it may change future follow-up recommendations. CACS scan is readily available and easily acquired with modern PET-computed tomography (CT) and single-photon emission CT (SPECT)-CT with modest radiation exposure.
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BACKGROUND: 13N-ammonia positron emission tomography-computed tomography (PET-CT) is being increasingly used as a non-invasive imaging modality for evaluating patients with known or suspected coronary artery disease (CAD), but information about the diagnostic accuracy of PET-MPI is sparse. Objectives: Our objective was to determine the accuracy of 13N-ammonia PET-CT myocardial perfusion imaging (MPI) for detecting CAD. METHODS: We retrospectively evaluated 383 patients with suspected CAD who underwent rest-stress 13N- ammonia PET-CT MPI. Invasive coronary angiography (ICA) was performed within 60 days for all patients with abnormal PET-MPI findings and for selected patients with normal PET-MPI findings. RESULTS: The mean age of the patients was 64±11 years, and the mean body mass index was 32±7 kg/m2. Stress perfusion defects were identified in 147 (34%) out of a total of 383 patients. ICA was performed in 213 patients (145 patients with abnormal PET and 68 patients with normal PET). The sensitivity of PET-MPI for detection of obstructive CAD based on ≥50% stenosis was 90%; specificity, 90%; positive predictive value, 96%; negative predictive value, 76%; and diagnostic accuracy, 80%. CONCLUSIONS: PET-MPI with 13N-ammonia affords high sensitivity and overall accuracy for detecting CAD. The addition of coronary artery calcium score (CACS) can improve CAD risk stratification.
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Chronic thromboembolism pulmonary hypertension (CTEPH) is a common cause of severe pulmonary hypertension, resulting in significant morbidity and mortality. In patients with unexplained pulmonary hypertension, a ventilation-perfusion (VQ) scan should be considered the initial diagnostic test of choice. VQ scans are widely available with excellent sensitivity, specificity, and diagnostic accuracy. However, the occurrence of a normal VQ scan in the presence of CTEPH is believed to be rare. In fact, the rate of actual false negatives in VQ scans is unknown because pulmonary digital subtraction angiography and computed tomography pulmonary angiography are rarely performed in patients with a normal VQ scan. This study reports a patient with a high clinical likelihood of CTEPH due to a hypercoagulable state, recurrent deep vein thrombosis, and prior history of acute pulmonary embolism with negative VQ scans. He subsequently underwent pulmonary digital subtraction angiography, which revealed bilateral extensive emboli with partial recanalization of the organized thrombus. The patient underwent successful pulmonary endarterectomy, with marked improvement of his symptoms postoperatively.
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Immunoglobulin 4 (IgG4)-related systemic disease (IgG4-RSD) is a systemic inflammatory disease characterized by elevation of serum IgG4. IgG4-RSD can affect any organ in the body, and the list of organs associated with this condition is growing steadily. IgG4-related cardiovascular disease affects the coronary arteries, heart valves, myocardium, pericardium, aorta, pulmonary and peripheral vessels. Echocardiography is the most commonly used non-invasive imaging method. Computed tomography angiography (CTA) can assess aortitis, periarteritis and coronary aneurysms. Coronary CTA is fast, offers high spatial resolution and a wide coverage field of view. Cardiac magnetic resonance imaging (CMR) offers a comprehensive evaluation of the cardiovascular system including cardiac function, extent of myocardial fibrosis, characterise cardiac masses with different pulse sequences and guide to further treatment. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) can provide important information about the extent of disease, the presence of active inflammation and the optimum biopsy site. In general, the role of diagnostic imaging includes establishing the diagnosis, detecting complications, guiding biopsy and documenting response to therapy.