Diagnostic utility of hybrid single photon emission computed tomography/computed tomography imaging in patients with Takotsubo syndrome.

PURPOSE: Clinical symptoms and electrocardiographic changes in patients with Takotsubo syndrome can be similar to patients with myocardial infarction. The aim of the study was to assess the impact of SPECT/CT imaging on the diagnosis and management of Takotsubo syndrome (TTS). METHODS: Gated single photon emission computed tomography (SPECT)/CT after injection 99Tc-MIBI in resting conditions was performed in 27 patients with TTS using dual-head Symbia T6SPECT/CT hybrid device. CT data were used for attenuation correction of SPECT images and to assess the risk of coronary artery disease on the basis of coronary artery calcium score. RESULTS: Abnormal myocardial perfusion was found in 20/27 patients. The mean defect size was 9.8 cm, the extent 11.7%, mean total perfusion defect was 10.36%, mean summed rest score (SRS) 6.71.Left ventricle ejection fraction was lower in patients with SRS at least 4 than in patients with SRS less than 4. Perfusion defect size, total perfusion defect, number of akinetic segments in echocardiography and number of segments with perfusion defect in SPECT were higher in the group with SRS at least 4. The applied attenuation correction algorithms did not change the result of our SPECT study. CONCLUSION: In the majority of patients with TTS perfusion in SPECT was normal or only minor perfusion defect was observed. Application of CT attenuation correction did not change the final result of myocardial perfusion imaging; therefore, the CT component of the SPECT/CT study performed for attenuation correction is not useful for TTS diagnosis.

Takotsubo cardiomyopathy: FDG myocardial uptake pattern in fasting patients. Comparison of PET/CT, SPECT, and ECHO results.

BACKGROUND: The aim of this study was to assess the accumulation pattern of 18F-FDG in fasting patients with takotsubo cardiomyopathy (TTC) and to correlate the results with perfusion scintigraphy and echocardiography. METHODS: 18 consecutive patients with TTC were identified by clinical symptoms, cardiac catheterization, and echocardiography. Coronary angiography (CA) and transthoracic echocardiography (TTE) were performed on the day of the onset of symptoms. An assessment of myocardial perfusion (99mTc-MIBI) and glucose metabolism (18F-FDG) was performed within 18 days. RESULTS: SPECT showed no regional perfusion abnormalities in 10/18 patients, and a mild perfusion defect was found in 8/18 patients. Perfusion abnormalities were limited to apical and para-apical regions. In 8/18 cases, there was an increased selective apical 18F-FDG accumulation. In 10/18 cases, in spite of the fastened 18F-FDG protocol, slightly inhomogeneous 18F-FDG uptake was present in the entire myocardium: with relatively reduced uptake of 18F-FDG in the apical region and LV mid-segments. CONCLUSION: This study demonstrated the heterogeneous nature of myocardial 18F-FDG accumulation in patients with TTC. Selective, preferential apical 18F-FDG uptake in almost half of the patients confirms an existing disorder of glucose metabolism, similar to that observed in stunned or hibernated myocardium.

Assessment of the myocardial FDG-PET image quality with the use of maximal Standardized Uptake Value myocardial to background index. Application of the results in regard to semiquantitative assessment of myocardial viability with cardiac dedicated softwar.

BACKGROUND: The objective of this study was to semiquantitatively assess the degree of myocardial fluorodeoxyglucose (FDG) uptake in glucose-loaded myocardial viability positron emission tomography/computed tomography (PET/CT) scans, to calculate the myocardial to background index, and correlate the index with image quality assessed on the basis of visual qualitative assessment. MATERIAL AND METHODS: The myocardial FDG-PET/CT study was carried out in 69 non-diabetic patients, who had known coronary artery disease, by intravenous injection of 250 ± 70 MBq (range: 180-320 MBq) FDG. Images were interpreted visually and patients were divided into three groups according to the grade of myocardial uptake: optimal, suboptimal, and uninterpretable. Semiquantitative analysis was performed by calculating the standardized uptake value (SUVmax) for myocardium and background (blood pool) activity, and expressed as the myocardial to background (M/B) activity ratio. RESULTS: On the basis of visual (qualitative) analysis, 60/69 (86.96%) patients showed optimal quality of FDG cardiac uptake, 3/69 (4.35%) were suboptimal, and uninterpretable FDG PET scan results were found in 6/69 (8.70%) patients. The M/B index was found to be significantly higher in images of optimal vs. suboptimal quality (6.87 ± 3.99 vs. 1.65 ± 0.78 respectively; p < 0.0001). CONCLUSIONS: The index ratio of 2.2, which is consistent with the upper borderline value for visually uninterpretable images, was considered the cut-off value for scans of optimal and non-optimal quality.

Comparison of scintigraphy and ultrasound imaging in patients with primary, secondary and tertiary hyperparathyroidism - own experience.

BACKGROUND: The imaging techniques most commonly used in the diagnosis of hyperparathyroidisms are ultrasound and scintigraphy. The diagnostic algorithms vary, depending mainly on the population, and experience of physicians. AIM: Aim of the present research was to determine the usefulness of parathyroid scintigraphy and ultrasonography in patients diagnosed for hyperparathyroidism in own material. MATERIAL AND METHOD: In the present research, 96 operated patients with documented primary, secondary and tertiary hyperparathyroidism were retrospectively analyzed. All patients underwent a 99mTc hexakis-2-methoxyisobutylisonitrile scintigraphy of the neck with the use of subtraction and two-phase examinations. Ultrasonography of the neck was performed in all the patients in B mode 2D presentation. A total number of 172 parathyroid glands were analyzed. RESULTS: The sensitivity and specificity of scintigraphy was 68% and 60%, respectively. The sensitivity of ultrasound was 49% and specificity 85%. Both techniques allowed visualization of 76 parathyroid glands. Ultrasound revealed 19 glands that were not visible in scintigraphy. Scintigraphy showed 76 parathyroid glands that were not visualized on ultrasound. Having combined the results of scintigraphy and ultrasound, the sensitivity of 76% and specificity of 50% were obtained. Considering the ability to locate the parathyroid glands in both techniques as a positive result, the sensitivity decreased to 37% and specificity rose to 95%. CONCLUSIONS: Scintigraphy showed greater sensitivity than ultrasound in the localization of enlarged parathyroid glands. Ultrasound, in turn, was characterized by a higher specificity. The combined use of scintigraphy and ultrasonography allowed to obtain the specificity of 95%. In the light of obtained results, scintigraphy and ultrasonography are complementary and should be used together.

Scintigraphic Evaluation of Mild to Moderate Dysphagia in Motor Neuron Disease.

PURPOSE OF THE REPORT: Approximately 30% of patients with motor neuron disease (MND) present swallowing difficulties even in early disease stages. The aim of this study was to examine the usefulness of esophageal scintigraphy in detecting early stage of dysphagia in MND. METHODS: Esophageal scintigraphy (ES) including mean transit time (MTT) estimation was performed in 121 MND patients presenting various levels of upper (UMN) and lower motor neuron (LMN) degeneration. RESULTS: ES detected dysphagia in more than 80% of MND patients who had referenced swallowing difficulties. In MND patients with ES-confirmed dysphagia, the MTT was increased approximately 2-fold without significant differences between the clinical phenotypes. The MTT was significantly longer in patients with bulbar-pseudobulbar syndrome in comparison to patients with isolated pseudobulbar syndrome, which indicates a higher involvement of the LMN deficiency in developing dysphagia in MND. The esophageal passage in MND was not dependent on age, sex, disease duration, or diagnosis delay. Interestingly, ES was also able to detect dysphagia in almost 70% of MND individuals who had no swallowing complaints (subclinical dysphagia). A more benign disease course and a higher percentage of male patients characterized this group. CONCLUSIONS: Esophageal scintigraphy is a helpful screening tool in determining early swallowing impairment in a high percent of patients with MND of various clinical phenotypes.

Computer program for analysis of parathyroid scintigraphy examinations: combination of dual-tracer (subtraction) and double phase single-tracer washout techniques.

There is no controversy in the published literature that sensitivity and specificity of parathyroid scintigraphy is superior to other imaging techniques. However no uniform protocol has been established for scintigraphy. In order to analyze parathyroid scintigraphic images in the Department of Nuclear Medicine at the Medical University of Warsaw we have developed a program that allows qualitative and quantitative evaluation of recorded images and motion artifacts correction. This program offers a uniform procedure of analysis of parathyroid imaging results in diagnostic centers, accelerates the analysis of parathyroid tests performed with use of single radioactive tracer, that require the acquisition of consecutive images of the patient, without altering his body position between successive stages of registration. This program allows for automation of previously time consuming procedures and thus saves time and decreases a risk of operator's errors.

Simplified protocol of cardiac 18F-fluorodeoxyglucose positron emission tomography viability study in normoglycemic patients with known coronary artery disease.

PURPOSE: The purpose was to evaluate quality of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) myocardial scans and its correlation with background glucose (BG) after simplified 5% intravenous glucose load protocol. METHODS: An intravenous glucose load protocol was applied in 69 normoglycemic patients with confirmed coronary artery disease. The blood glucose level was measured every 15 min. RESULTS: Eighty-four percent of images were optimal, 8.7% suboptimal, and 7.3% uninterpretable. The quality of 18F-FDG-PET was BG independent and body mass index dependent (P=.0007). CONCLUSIONS: Simplified glucose load protocol is a safe and efficient method of preparation for FDG cardiac viability study in patients with normoglycemia.

Myocardial viability assessment in 18FDG PET/CT study (18FDG PET myocardial viability assessment).

Accurate identification of viable myocardium is crucial in patient qualification for medical or surgical treatment. Only persons with confirmed cardiac viability will benefit from revascularization procedures. It is also well known, that the amount of viable myocardium assessed preoperatively is the best indicator of long term cardiac event free survival after cardiac intervention.There are several diagnostic approaches used in current clinical practice for assessment of myocardial viability. Analysis of wall thickness or myocardial contraction, evaluation of cardiac perfusion or metabolism can be assessed using following modalities: Echocardiography, Cardiac Molecular Imaging techniques (PET, SPECT), Cardiovascular MR or Cardiovascular CT. The article describes the methods and problems of viability assessment in 18FDG PET study. PET imaging has proved its accuracy and reproducibility for myocardial ischemia and viability assessment. However this unique in its ability for showing the particular substrate metabolism technique has unfortunately some disadvantages: currently achieved PET resolution is 0.4 cm. However the combined devices multislice computed tomography scanners with PET (PET/CT) are now widely used in clinical practice. This combination allows for wider morphologic assessments: coronary calcium scoring and non-invasive coronary angiography may be added to myocardial perfusion/metabolic imaging if necessary.

[Usefulness of 18F-FDG PET/CT examination in the diagnosis of head and neck cancer--preliminary results]. / Ocena przydatnosci badania 18F-FDG PET/CT w diagnostyce nowotworów glowy i szyi--wyniki wstepne.

OBJECTIVES: The aim of the study was to determine the usefulness of 18-FFDG PET/CT in oncological diagnostics in laryngology. MATERIAL AND METHODS: 45 PET/CT examinations were performed in 41 patients diagnosed with head and neck cancer in Department of Otolaryngology and Nuclear Medicine Department WUM from 2008 to 2011. In 3 patients PET/CT study was conducted several times. RESULTS: In 18 patients the result of PET/CT examination was negative, in 27 ­ positive. Based on PET/CT imaging the recurrent disease was diagnosed in 9 patients, cervical lymph node metastases ­ in 12 patients, distant metastases ­ in 6 patients, possible primary tumour localization ­ in 3 patients. In 7 cases additional foci of increased FDG uptake were revealed outside the head and neck. Among 22 contrast enhanced CT scans performed earlier, in 18 cases results were confirmed. In 2 cases there was no increased FDG concentration in lesions considered suspicious due to CT, in 2 patients increased focal FDG uptake was observed despite no changes in CT scans. The mean SUVmax value in all the lesions in head and neck region was 3.0; for examinations revealing recurrent disease, nodal or distant metastases mean SUVmax was 7.9. CONCLUSIONS: 18F-FDG PET/CT is a useful diagnostic tool for staging of head and neck cancer, identifying residual and recurrent disease and detecting the occult primary tumour. It also allows the visualization of other lesions suspected for malignancy, localized outside the head and neck region.