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

Accurate identification of viable myocardium is crucial in patientqualification for medical or surgical treatment. Only personswith confirmed cardiac viability will benefit from revascularizationprocedures. It is also well known, that the amount of viablemyocardium assessed preoperatively is the best indicator oflong term cardiac event free survival after cardiac intervention.There are several diagnostic approaches used in current clinicalpractice for assessment of myocardial viability. Analysis ofwall thickness or myocardial contraction, evaluation of cardiacperfusion or metabolism can be assessed using followingmodalities: Echocardiography, Cardiac Molecular Imagingtechniques (PET, SPECT), Cardiovascular MR or CardiovascularCT. The article describes the methods and problems ofviability assessment in 18FDG PET study. PET imaging hasproved its accuracy and reproducibility for myocardial ischemiaand viability assessment. However this unique in its ability forshowing the particular substrate metabolism technique has unfortunately some disadvantages: currently achieved PETresolution is 0.4 cm. However the combined devices multislicecomputed tomography scanners with PET (PET/CT) are nowwidely used in clinical practice. This combination allows forwider morphologic assessments: coronary calcium scoring andnon-invasive coronary angiography may be added to myocardialperfusion/metabolic imaging if necessary

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.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

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

Relationship between parathyroid gland scintigraphy and its histopathology, oxyphil cell content and volume: a retrospective study

BACKGROUND: Mechanisms that are responsible for positive 99mTc-MIBI uptake in parathyroid glands are not clearly understood, some authors suggest there is a correlation between 99mTc MIBI accumulation and oxyphil cell content or parathyroid gland volume. The aim of our work was to assess the relationship between the pathological structure of parathyroids, their volume, oxyphil cell content and parathyroid 99mTc-MIBI retention. MATERIAL AND METHODS: A total of 62 hyperfunctioning parathyroid glands in 46 patients were retrospectively analyzed. Preoperative 99mTc-MIBI scintigraphy was performed according to the double-phase and subtraction protocol. After surgery all glands were evaluated histologically, oxyphil cell content was assessed and volume of each excised gland was calculated. RESULTS: Scintigraphy was positive in 41 of 62 parathyroid glands (66%). The median volume of positive glands was larger than that of negative glands (1.33 ml vs 0.7 ml, p = 0.015). Of the parathyroid lesions, there were 14 (22.6%) cases of nodular hyperplasia, 23 (37.1%) cases of diffuse hyperplasia, and 25 (40.3%) cases of adenomas. A high (≥ 25%) oxyphil cell content was found in 16 glands (25.8%) and a low ( < 25%) oxyphil cell content in 46 (74.2%) glands. Histopathology of parathyroid glands was related to the scintigraphy result (p = 0.002), but not to the 99mTc-MIBI uptake pattern (p = 0.868). The overall result of scintigraphy was not related to the oxyphil cell content (p = 0.797). 99mTc-MIBI uptake pattern wasn’t related to the oxyphil cell content (p = 0.833). In general, parathyroid lesions with low oxyphil cell content were larger than parathyroid glands with high oxyphil cell content (1.33 ml vs 0.5 ml, respectively; p = 0.01). The median volume of parathyroids containing a high number of oxyphil cells and having a prolonged 99mTc-MIBI retention was larger than those without prolonged 99mTc-MIBI retention (1.62 ml vs 0.3 ml, respectively; p = 0.008). The median volume of parathyroids with low oxyphil cells content and showing prolonged 99mTc-MIBI retention was larger than those without prolonged 99mTc-MIBI retention (1.95 ml vs 1.07 ml, respectively; p = 0.014). CONCLUSIONS: Our findings suggest that a positive scintigraphy result depends on parathyroid histopathology and gland volume and does not depend on the presence of oxyphil cells. Prolonged 99mTc-retention is not related to the parathyroid gland histopathology and the presence of oxyphil cells but to the gland volume

Porównanie badania ultrasonograficznego i scyntygraficznego w lokalizacyjnej diagnostyce przedoperacyjnej przytarczyc u chorych z pierwotną, wtórną i trzeciorzędową nadczynnością – doświadczenia własne

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 hexakis2-methoxyisobutylisonitrile scintigraphy of the neck with the use of subtraction and twophase 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.Pomimo rozwoju technik obrazowych szereg kontrowersji budzi ustalenie algorytmu postępowania diagnostycznego u chorych na nadczynność przytarczyc. Ze względu na swój niewielki rozmiar oraz zmienne położenie prawidłowe przytarczyce nie są widoczne w żadnej z obecnie stosowanych technik obrazowych, a ich uwidocznienie okazuje się możliwe dopiero wówczas, gdy ulegają powiększeniu lub wykazują cechy nadczynności. Problemy związane z decyzją o wykonaniu badania obrazowego dotyczą niemal każdego etapu diagnostyki: kwalifikacji chorych, wyboru rodzaju i techniki wykonania badania obrazowego, często również interpretacji wyników(1–4). W wielu przypadkach badanie obrazowe przed pierwszym zabiegiem operacyjnym nie jest potrzebne. Dopiero w razie nawrotu nadczynności lub nieskutecznej operacji wizualizacja przytarczyc staje się konieczna. Jednak ponieważ w ostatnich latach metodą operacyjną z wyboru stała się minimalnie inwazyjna paratyroidektomia, większość chirurgów opowiada się za wykonaniem badania lokalizacyjnego przed pierwszą operacją(5). Do rutynowo stosowanych metod diagnostyki obrazowej należą ultrasonografia, scyntygrafia, a także tomografia komputerowa i rezonans magnetyczny. Najczęściej wykorzystywanymi technikami są badanie USG i scyntygrafia(6–8). W publikowanym piśmiennictwie autorzy są zgodni w ocenie, że scyntygrafia pod względem czułości i swoistości przewyższa inne techniki obrazowe, natomiast USG jest techniką najszerzej dostępną. Jednakże algorytm stosowania poszczególnych badań obrazowych, jak również ich czułość i swoistość różnią się, w zależności od badanej populacji chorych, doświadczenia lekarzy oraz użytych protokołów badań. W niniejszej pracy porównano wyniki badania ultrasonograficznego i scyntygraficznego w do- świadczeniach własnych. Artykuł w wersji polskojęzycznej jest dostępny na stronie http://jultrason.pl/wydawnictwa/volume-17-no-6

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 twophase 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