Significant Association of Serum Albumin With the Severity of Coronary Microvascular Dysfunction Using Dynamic CZT-SPECT.

OBJECTIVE: Both low serum albumin (SA) concentration and coronary microvascular dysfunction (CMD) are risk factors for the development of heart failure (HF). We hypothesized that SA concentration is associated with myocardial flow reserve (MFR) and implicated in pathophysiological mechanism of HF. METHODS: We retrospectively studied 454 patients undergoing dynamic cardiac cadmium-zinc-telluride myocardial perfusion imaging from April 2018 to February 2020. The population was categorized into three groups according to SA level (g/dL): Group 1: >4, Group 2: 3.5-4, and Group 3: <3.5. Myocardial blood flow (MBF) and myocardial flow reserve (MFR, defined as stress/rest MBF ratio) were compared. RESULTS: The mean age of the whole cohort was 66.2 years, and 65.2% were men. As SA decreased, stress MBF (mL min-1 g-1) and MFR decreased (MBF: 3.29 ± 1.03, MFR: 3.46 ± 1.33 in Group 1, MBF: 2.95 ± 1.13, MFR: 2.51 ± 0.93 in Group 2, and MBF: 2.64 ± 1.16, MFR: 1.90 ± 0.50 in Group 3), whereas rest MBF (mL min-1 g-1) increased (MBF: 1.05 ± 0.42 in Group 1, 1.27 ± 0.56 in Group 2, and 1.41 ± 0.61 in Group 3). After adjusting for covariates, compared with Group 1, the odds ratios for impaired MFR (defined as MFR < 2.5) were 3.57 (95% CI: 2.32-5.48) for Group 2 and 34.9 (95% CI: 13.23-92.14) for Group 3. The results would be similar if only regional MFR were assessed. The risk prediction for CMD using SA was acceptable, with an AUC of 0.76. CONCLUSION: Low SA concentration was associated with the severity of CMD in both global and regional MFR as well as MBF.

Integration of quantitative absolute myocardial blood flow estimates from dynamic CZT-SPECT improves the detection of coronary artery disease.

BACKGROUND: Balanced ischemia with multi-vessel coronary artery disease (CAD) is difficult to diagnose with semiquantitative single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Dynamic cardiac SPECT provides quantitative estimations of stenosis severity and ischemic burden by assessing myocardial flow reserve (MFR) and myocardial blood flow (MBF). The aim of this study was to evaluate the incremental value of dynamic SPECT in multi-vessel coronary artery disease (CAD). METHODS: Patients with suspected CAD who underwent dynamic ECG-gated dipyridamole MPI and coronary angiography within 6 months were retrospectively reviewed. The performance of summed stress, rest and difference scores (SSS, SRS, SDS), post-stress and resting MBF (MBFs, MBFr) and MFR were compared at both patient level and vessel level. RESULTS: In 32 patients with 39 stenotic vessels, 12 had three-vessel disease (38%). Globally increased SSS and impaired MBF values were significantly associated with significant CAD at the patient level, but SDS and MFR were not. Regional increases in SSS and reductions in both MBFs and MBFr were significantly associated with stenotic vessels. The best cutoff value of global MBFs to predict CAD was 3.5 ml·g-1·min-1 (area under the curve, AUC = .84, P = .002). The best cutoff value of regional MBFs to detect significant stenosis was 3.6 ml·g-1·min-1 (AUC = .74, P < .001). However, the best possible cut-off values of MFR were not found. Sex-difference in both global and regional MBFr but MBFs was found, which might result in the non-significance in MFR. CONCLUSIONS: This study validated a clinically available method to quantify MFR using dynamic CZT-SPECT. This method improved the detectability of multi-vessel CAD, and absolute MBFs was superior to MFR and other semiquantitative MPI parameters.

Clinical significance of quantitative assessment of glucose utilization in patients with ischemic cardiomyopathy.

BACKGROUND: The aim of this study was to prospectively quantify the rate of myocardial glucose uptake (MRGlu) in myocardium with different perfusion-metabolism patterns and determine its prognostic value in patients with ischemic cardiomyopathy. METHODS AND RESULTS: 79 patients with ischemic cardiomyopathy were prospectively enrolled for dynamic cardiac FDG PET, and then followed for at least 6 months. Perfusion-metabolism patterns were determined based on visual score analysis of 201Tl SPECT and FDG PET. MRGlu was analyzed using the Patlak kinetic model. The primary end-point was cardiovascular mortality. Significantly higher MRGlu was observed in viable compared with non-viable areas. Negative correlations were found between MRGlu in transmural match and a history of hyperlipidemia, statin usage, and triglyceride levels. Diabetic patients receiving dipeptidyl peptidase-4 inhibitors (DPP4i) had a significantly lower MRGlu in transmural match, mismatch, and reverse mismatch. Patients with MRGlu in transmural match ≥ 23.40 or reverse mismatch ≥ 36.90 had a worse outcome. CONCLUSIONS: Myocardial glucose utilization was influenced by substrates and medications, including statins and DPP4i. MRGlu could discriminate between viable and non-viable myocardium, and MRGlu in transmural match and reverse mismatch may be prognostic predictors of cardiovascular death in patients with ischemic cardiomyopathy.

The clinical usefulness of phase analysis in detecting coronary artery disease using dipyridamole thallium-201-gated myocardial perfusion imaging with a cadmium-zinc-telluride camera.

BACKGROUND: Previous studies have demonstrated left ventricular mechanical dyssynchrony (LVMD) in patients with severe coronary artery disease (CAD) with ≥ 70% stenosis. The aim of this study was to evaluate the clinical usefulness of stress/rest LVMD in the diagnosis of CAD with ≥ 50% stenosis using dipyridamole thallium-201 (Tl-201) myocardial perfusion imaging (MPI) with a cadmium-zinc-telluride camera. METHODS AND RESULTS: A total of 476 patients without known CAD who underwent dipyridamole Tl-201 MPI and coronary angiography within 6 months were retrospectively reviewed. LVMD parameters including phase standard deviation and phase histogram bandwidth, phase skewness and phase kurtosis, as well as myocardial perfusion and myocardial stunning were assessed in post-stress and rest MPI. Relationships between the presence of CAD on coronary angiography and single photon emission computerized tomography (SPECT) parameters were evaluated. The presence of perfusion abnormalities was the best diagnostic tool in detecting CAD. Although less left ventricular synchrony was observed post-stress in the CAD group compared to the non-CAD group, no significant dyssynchrony was noted. CONCLUSIONS: The addition of phase analysis to help diagnose CAD in Tl-201-gated SPECT with dipyridamole stress may have limited value in patients with CAD with ≥ 50% stenosis.

The clinical value and safety of ECG-gated dipyridamole myocardial perfusion imaging in patients with aortic stenosis.

The role of vasodilator myocardial perfusion imaging (MPI) for aortic stenosis (AS) is controversial due to safety and accuracy concerns. In addition, its utility after aortic valve (AV) interventions remains unclear. Patients with AS who underwent thallium-201-gated dipyridamole MPI using a cadmium-zinc-telluride camera were retrospectively reviewed and divided into three groups: mild AS, moderate-to-severe AS, and prior AV interventions. Patients with coronary artery disease with ≥50% stenosis, severe arrhythmia, left ventricular ejection fraction (LVEF) <40%, left bundle branch block or no follow-up were excluded. Relationships between the severity of AS, clinical characteristics, hemodynamic response, serious adverse events (SAE) and MPI parameters were analyzed. None of the 47 patients had SAE, including significant hypotension or LVEF reduction. The moderate-to-severe AS group had higher summed stress scores (SSSs) and depressed LVEF than the mild AS group, however there were no differences after AV interventions. SSS was positively correlated with AV mean pressure gradient, post-stress lung-heart ratio (LHRs), and post-stress end-diastolic volume (EDVs) (P < 0.05). In multivariate analysis, LHRs and EDVs were independent contributors to SSS. Dipyridamole-induced ischemia and LV dysfunction is common, and dipyridamole stress could be a safe diagnostic tool in evaluation and follow-up in patients with AS.

Clinical significance of quantitative assessment of right ventricular glucose metabolism in patients with heart failure with reduced ejection fraction.

PURPOSE: Dynamic 18F-fluorodeoxyglucose (FDG) PET can be used to quantitatively assess the rate of myocardial glucose uptake (MRGlu). The aim of this study was to evaluate the clinical significance and prognostic value of right ventricular (RV) MRGlu in patients with coronary artery disease and heart failure with reduced ejection fraction. METHODS: Patients with left ventricular ejection fraction (LVEF) ≤ 40% were consecutively enrolled for FDG PET between November 2012 and May 2017. Global LV and RV MRGlu (µmol/min/100 g) were analyzed. Outcome events were independently assessed using electronic medical records to determine hospitalization for revascularization, new-onset ischemic events, heart failure, cardiovascular, and all-cause death. Differences between LV and RV MRGlu and associations with clinical characteristics and echocardiographic data were evaluated. Associations among FDG PET findings and outcomes were analyzed using Kaplan-Meier survival analysis. RESULTS: Seventy-five patients (mean age 62.2 ± 12.7 years, male 85.3%, LVEF 19.3 ± 8.6%) were included for analysis. The mean glucose utilization ratio of RV-to-LV (RV/LV MRGlu) was 89.5 ± 264.9% (r = 0.77, p < 0.001). Positive correlations between RV MRGlu and maximal tricuspid regurgitation peak gradient (r = 0.28, p = 0.033) and peak tricuspid regurgitation jet velocity (r = 0.29, p = 0.021) were noted. LVEF was positively correlated with LV MRGlu (r = 0.27, p = 0.018), but negatively correlated with end-diastolic volume (r = - 0.37, p = 0.001), end-systolic volume (r = - 0.54, p < 0.001), and RV/LV MRGlu (r = - 0.40, p < 0.001). However, RV MRGlu was not well correlated with LVEF. Forty-three patients received revascularization procedures after FDG PET, and 13 patients died in a mean follow-up period of 496 ± 453 days (1-1788 days), including nine cardiovascular deaths. Higher RV and LV MRGlu values, LVEF ≤ 16% and LV end-diastolic volume ≥ 209 ml of gated-PET were associated with poor overall survival and cardiac outcomes. CONCLUSIONS: In patients with coronary artery disease and ischemic cardiomyopathy, RV glucose utilization was positively correlated with RV pressure overload, but not LVEF. Global LV and RV MRGlu, LVEF, and LV end-diastolic volume showed significant prognostic value.

Mechanical dyssynchrony and diastolic dysfunction are common in LVH: a pilot correlation study using Doppler echocardiography and CZT gated-SPECT MPI.

Hypertrophic cardiomyopathy (HCM) is an often under-diagnosed cause of left ventricular hypertrophy (LVH). It affects 1/500 of the population, is the most commonly inherited cardiovascular disorder, and can present in apical, concentric, or septal forms. Although most patients are asymptomatic, sudden cardiac death can be the initial presentation of HCM. By retrospectively enrolling patients suspected of having three different types of HCM in the absence of epicardial coronary stenosis, we aimed to examine systolic and diastolic dysfunction and perfusion abnormalities using both Doppler echocardiography and state-of-the-art gated single-photon emission computerized tomography (SPECT) myocardial perfusion imaging (MPI) with a cadmium-zinc-telluride camera and thallium-201. Both regional perfusion and gated SPECT parameters were collected in addition to diastolic parameters from Doppler echocardiography. The results showed that mild ischemia was common in patients suspected of having HCM, with a mean summed stress score of 4.7 ± 4.9 (score 0-4 in 17-segment model). The patients with HCM were associated with discernible left ventricular mechanical dyssynchrony, especially those with the apical form. In addition, diastolic dysfunction was prevalent and early to late ventricular filling velocity ratios were significantly different between groups. By combining gated-MPI and Doppler data, the trivial functional changes in HCM may be identified.

Clinical value of radionuclide shuntography by qualitative methods in hydrocephalic adult patients with suspected ventriculoperitoneal shunt malfunction.

To determine the clinical value of radionuclide shuntography in the evaluation of adult hydrocephalic patients with suspected ventriculoperitoneal (V-P) shunt malfunction. All adult patients who underwent Tc-99m diethylenetriamine pentaacetic acid shuntographic scans at Far Eastern Memorial Hospital between August 2005 and December 2015 were included. Shuntographic results were visually evaluated in a simple qualitative manner: prompt flow that reached the peritoneum on 30-minute early images and diffuse peritoneal tracer distribution on 2-hour delayed images were interpreted as nonobstructive shunt flow. Partial dysfunction was diagnosed as scintigraphic findings between no obstruction and complete obstruction (where complete malfunction indicated no peritoneal distribution on delayed images). The results were correlated with the clinical outcomes and surgical results within 30 days. Diagnostic sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were also calculated. A total of 93 scans in 69 patients with suspected V-P shunt malfunction were analyzed. Sixty-two scans were interpreted as abnormal, including complete (n = 26, 41.9) distal obstruction, partial (n = 35, 56.5) distal dysfunction, and miscellaneous (n = 1, 1.6, cerebrospinal fluid leak). The Se and Sp were 83.0% and 55.0%, respectively, and PPV, NPV, and accuracy were all 71.0%. Twenty-five patients (28 scans) underwent surgical revision, and the results were highly concordant with the imaging findings (Se, 92.0%; Sp, 100.0%; PPV, 100.0%; NPV, 60.0%; and accuracy, 92.9%). Radionuclide shuntography provides useful information in adult patients with V-P shunt malfunction and could be used to guide further surgical intervention.

Benign incidental findings of osteopoikilosis on Tc-99m MDP bone SPECT/CT: A case report and literature review.

Osteopoikilosis is a benign but rare condition characterized by bone islands throughout the osseous tissue, which could be easily confused with bone metastasis. We present a case of a 37-year-old man presented to orthopedic outpatient clinic with right hip pain for 2 weeks. There were multiple, small punctate lesions scattered throughout the skeleton on radiograph. Subsequent Tc-99m methylene diphosphonate (MDP) bone scan with pelvic single-photon emission computed tomography (SPECT)/computed tomography (CT) showed multiple enostoses without abnormal focal MDP uptake. Therefore, clinical diagnosis was compatible with osteopoikilosis while bone metastasis was unlikely. The symptoms then improved by conservative treatments. Osteopoikilosis is usually an incidental finding on radiograph or CT, and a normal MDP confirmed the diagnosis by excluding bone metastasis. It is important for clinicians to recognize the specific image features to prevent further unnecessary interventions. In addition, bone SPECT/CT could also make the diagnosis in one step.

Conjunctival Melanoma on 18F-FDG PET/CT as a Second Primary Cancer.

Herein we present the F-FDG PET/CT findings in conjunctival melanoma as a second primary cancer in a 56-year-old Taiwanese man with a history of small lymphocytic lymphoma/chronic lymphocytic leukemia and nasal cavity carcinoma under remission. The right eye lesion slowly progressed since noted by the patient himself 2 years ago, but he refused biopsy and further treatment including surgery. Either small lymphocytic lymphoma/chronic lymphocytic leukemia or conjunctival melanoma is extremely rare in Asians, left alone in combination with a third malignancy of nasal cavity carcinoma. FDG PET/CT could effectively evaluate malignancies with multiple primary origins.

Extramedullary Soft Tissue Involvement and Discrepant Osseous Uptake on Tc-99m MDP and Ga-67 Citrate Scintigraphy in a Patient With Multiple Myeloma: A Case Report and Literature Review.

Multiple myeloma (MM) is a plasma cell neoplasm with skeletal destruction which could also spread to extramedullary regions. Common diagnostic imaging modalities include skeletal radiography, computed tomography (CT), magnetic resonance imaging (MRI). Recently, PET/CT is proposed as an ideal tomographic tool for diagnosis and follow-up, but impending factors includes high cost, limited availability of cameras and radiotracers. Bone scan and gallium scan are usually considered of limited clinical value. Herein, we present a 66-year-old Taiwanese man with MM, who was hospitalized to our hospital for bone pain control. Bone and gallium scintigraphies were obtained for bone pain and infection workup. However, unexpected features of discordant osseous uptake with high gallium-to-bone uptake ratio and extramedullary gallium uptake were noted which both indicated poor prognosis of MM. The patient then passed away due to rapid disease progression. In conclusion, although gallium and bone scintigraphies are considered less sensitive for MM, combined use may be a good alternative for 18F-FDG PET/CT in evaluation of disease extent and prognosis, especially in high-risk patients or with suspicion of disease progression.

Uterine cervical melanoma presenting with rapid progression detected by PET/CT.

Malignant melanoma of the uterine cervix is a rare extracutaneous melanoma which develops aggressively and is associated with a bleak prognosis. To our knowledge, no prior published reports have discussed the role of 18F-FDG positron emission tomography/computed tomography (PET/CT) in managing this disease. Our case study involved a 66-year-old woman with a malignant melanoma of the uterine cervix. The patient received PET/CT that identified metastases and lesions which had not been detected from her MRI. Serial PET/CT elucidated that the disease was initially limited to the pelvis, but then metastasized to the abdominal para-aortic lymph nodes, followed by extensive metastases to the brain, lungs, breast, supraclavicular, neck, and other abdominal lymph nodes, as observed at 6-month follow-up. PET/CT was used to complement conventional anatomic imaging modalities, and provided a novel modality for whole body screening. Visualization of the metabolic activity of indeterminate lesions may help in staging, re-staging, treatment planning, and prognostic prediction for patients with this rare disease.

F-18 FDG uptake in papillary carcinoma arising from thyroglossal duct cyst.

A 51-year-old man incidentally felt an anterior midline cervical mass since 2 months before presentation. Both neck echogram and contrast-enhanced CT exposed a cystic lesion with slightly calcified soft tissue in anterior neck and small nodules in both lobes of the thyroid gland. F-18 FDG PET/CT revealed an intense uptake over the soft-tissue component of the cystic lesion, which was located in front of the hyoid bone. The patient subsequently received Sistrunk procedure, selective neck lymph node dissection, and total thyroidectomy. Pathology revealed papillary carcinoma in thyroglossal duct cyst and microcarcinoma in both lobes of the thyroid gland.

The diagnostic and prognostic effectiveness of F-18 sodium fluoride PET-CT in detecting bone metastases for hepatocellular carcinoma patients.

BACKGROUND: The aim of this prospective study is to evaluate the diagnostic and prognostic usefulness of F-18 sodium fluoride (NaF) positron emission tomography-computed tomography (PET-CT) relative to Tc-99m methylene diphosphonate (MDP) planar bone scintigraphy with no CT (BS) for hepatocellular carcinoma (HCC) patients with suspicious bone metastasis. METHODS: Both Tc-99m MDP BS and F-18 NaF PET-CT were performed for 34 consecutive Taiwanese HCC patients (five female and 29 male; mean age, 61.0+/-12.0 years) within a time span of 1 month (mean: 11.3+/-10.4 days). The accuracies of BS and PET-CT were determined by comparing their results with the finalized clinical data in a lesion-by-lesion manner. RESULTS: According to the pathological and/or follow-up results, the accuracy for detecting metastatic bone lesions by Tc-99m MDP BS is 75.4% and that by F-18 NaF PET-CT is 95.7%, respectively. F-18 NaF PET-CT is significantly more accurate than Tc-99m MDP BS (P=0.0001). Furthermore, there is a significant correlation between the presence of F-18 NaF PET-CT-positive bone lesions and the survival time of HCC patients. On the other hand, the diagnostic results from BS are not correlated with the survival time of these HCC patients. CONCLUSION: F-18 NaF using PET-CT system has significantly better sensitivity and specificity than conventional Tc-99m MDP BS in detecting metastatic HCC bone lesions that are predominantly osteolytic. The diagnostic result of PET-CT also serves as a more effective prognostic indictor for HCC patients.

WITHDRAWN: Predicting multidrug resistance-related protein and P-glycoprotein expression with technetium-99m tetrofosmin mammoscintigraphy.

The publisher regrets that this is an accidental duplication of an article that has already been published in The Breast, 12 (2003) 58-62, doi:10.1016/S0960-9776(02)00136-4. The duplicate article has therefore been withdrawn.

Association of amino-terminal propeptide of type III procollagen and acute myocardial rejection in male patients receiving heart transplantation.

BACKGROUND: The amino-terminal propeptides of type I and III procollagens (PINP and PIIINP) are markers reflecting the status of collagen turnover. We hypothesized that measurement of these serum procollagen propeptides could be used to non-invasively assess acute rejection in heart transplant recipients. METHODS: In heart transplant recipients, endomyocardial biopsy specimens taken at 6 and 12 months after surgery were used for study. PINP and PIIINP were measured postoperatively at 3, 6, and 12 months. RESULTS: A total of 20 male heart transplant patients and seven male control subjects were enrolled. Five patients showed rejection 6 months after transplantation (group 1), while 15 patients showed no rejection (group 2). In group 2 patients, serum PINP and PIIINP levels decreased significantly 6 months after transplantation. In contrast, elevation of serum PINP and PIIINP levels persisted in group 1 patients 6 months after transplantation. At 6 months after transplantation, group 1 patients had significantly higher PIIINP levels than group 2 patients (p=0.025) and controls (p=0.003). After immunosuppressive therapy, all group 1 patients were free of rejection 12 months after transplantation and serial serum PIIINP levels decreased significantly in these patients. CONCLUSIONS: Serum PIIINP levels represent a non-invasive method to reflect the occurrence and resolution of acute rejection.

The relation of amino-terminal propeptide of type III procollagen and severity of coronary artery disease in patients without myocardial infarction or hibernation.

OBJECTIVES: The association of cardiac fibrosis and coronary artery disease (CAD) in patients without infarction or hibernation is unclear. We investigated the relationship between serum concentrations of procollagen propeptides and severity of CAD in such patients. DESIGN AND METHODS: Forty-six patients (32 men; mean age 64 years) with chest pain were enrolled. All patients received stress thallium-201 single photon emission computed tomography (SPECT) and analysis of the serum levels of the amino-terminal propeptide of type I and III procollagen (PINP and PIIINP). RESULTS: In patients with thallium-201 perfusion defects, the number of diseased vessels was associated significantly with PIIINP (p=0.024) rather than PINP (p=0.613). Follow-up serum PINP and PIIINP levels after coronary intervention (mean 84 days) revealed no significant decrease. CONCLUSIONS: Serum PIIINP level is significantly associated with the severity of CAD in patients without myocardial infarction or hibernation.

An effective and efficient compression algorithm for ECG signals with irregular periods.

This paper presents an effective and efficient preprocessing algorithm for two-dimensional (2-D) electrocardiogram (ECG) compression to better compress irregular ECG signals by exploiting their inter- and intra-beat correlations. To better reveal the correlation structure, we first convert the ECG signal into a proper 2-D representation, or image. This involves a few steps including QRS detection and alignment, period sorting, and length equalization. The resulting 2-D ECG representation is then ready to be compressed by an appropriate image compression algorithm. We choose the state-of-the-art JPEG2000 for its high efficiency and flexibility. In this way, the proposed algorithm is shown to outperform some existing arts in the literature by simultaneously achieving high compression ratio (CR), low percent root mean squared difference (PRD), low maximum error (MaxErr), and low standard derivation of errors (StdErr). In particular, because the proposed period sorting method rearranges the detected heartbeats into a smoother image that is easier to compress, this algorithm is insensitive to irregular ECG periods. Thus either the irregular ECG signals or the QRS false-detection cases can be better compressed. This is a significant improvement over existing 2-D ECG compression methods. Moreover, this algorithm is not tied exclusively to JPEG2000. It can also be combined with other 2-D preprocessing methods or appropriate codecs to enhance the compression performance in irregular ECG cases.