Relationship of body mass index and related anthropometric measurements on the image quality of thallium-201 and technetium-99m sestamibi myocardial perfusion imaging

The study aims to determine the relationship of body mass index (BMI) and related anthropometric measurements on the image quality of Tl-201 and Tc-99m sestamibi myocardial perfusion scans (MPS). A total of 163 scans were analyzed. A blinded experienced physician performed visual analysis on the scans image quality on two different occasions. Quantitative parameter used was the heart-to-lung ratio (HLR). Regression analysis was done to determine the association of HLR with BMI and myocardial tracer uptake, ROC curves were generated to establish BMI and HLR cut-off points. Increasing BMI was associated with visually poorer images in the Tl-201 MPS group (p 0.003) but not for the Tc-99m MPS group (p 0.065). It was also associated with decrease HLR and myocardial tracer upatake for both tracers (p <0.001). ROC curves revealed BMI cut-off points of 28 (Tl-201 p 0.000; Tc99m sestamibi p 0.004) for both procedures; HR cut-off values of 3.0 for Tl-201 )p 0.295) and 2.5 for Tc-99m sestamibi (p 0.875). the image quality of Tl-201 scans begins to deteriorate at a BMI of 28 and HLR of 3.0 with myocardial count density reduction (less than or equal to 6000 counts) translating to visually poorer images. On the other hand , image quality of Tc-99m sestamibi scans also tend to deteriorate similarly at a BMI of 28. However, in contrast to Tl-201, the lower HLR cut-off of 2.5 suggests a relatively higher myocardial count density (greater than or equal to 9000 counts) rendering the image quality to be still satisfactory for subjective assessment.

Resolving hypoplastic dilemma: Lung perfusion scintigraphy in a case of congenital cystic adenomatoid malformation (CCAM)

Congenital cystic adenomatoid malformation is a rare bronchopulmonary malformation resulting from an arrest in lung development between 4th and 7th week of fetal life. It typically presents as respiratory distress in the neonatal period and recurrent pulmonary infections in adults; and is sometimes associated with other congenital abnormalities [especially CCAM Type II]. Chest roentgenograms and CT scan are the usual modalities of choice in its initial evaluation and histopathology done post-operatively establishes the diagnosis. Ventilation-Perfusion [VQ] scintigraphy is of paramount importance in the routine assessment of CCAM patients but is often disregarded. This paper presents the incremental value of doing a lung perfusion scintigraphy and aims to emphasize the significance of performing a VQ scan in such cases.

Myocardial perfusion scintigraphy in tetralogy of fallot prior to total correction of a non-patent shunt

This paper presents a clinical situation in which a Technetium 99m sestamibi myocardial perfusion scintigraphy (MPS) with dipyridamole was used as part of the preoperative evaluation in a 15 year old female with Tetralogy of Fallot. MPS revealed no evident inducible myocardial ischemia, depressed LV wall function and RVH but with good RV function. There are many different techniques for imaging and studying patients with Tetralogy of Fallot (TOF). Echocardiography, ventriculography and invasive angiography remain the mainstay in its evaluation. However, the presence of coronary anomalies in these patients is very common and has negative effect on myocardial perfusion, either preoperatively or postoperatively. Hence, MPS plays an essential role in providing complete assessment in this group of patients.