OBJECTIVE:A high transient ischemic dilatation ratio (TID) for the left ventricle (LV) from a gated myocardial perfusion imaging (G-MPI) study is widely believed to be associated with significant coronary artery disease (CAD). We have investigated the relationship between TID and CAD for our male Saudi Arabian patient population. METHODS:In this retrospective study, all male Saudi Arabian patients who underwent a two-day G-MPI study using Tc99m MIBI during the year 2011 having a TID ⩾ 1.20 were included. Quantitative perfusion and gated parameters were obtained using Cedar Sinai's AutoQuant software version 3.0, 2003, Means of summed stress scores, summed rest scores and summed difference scores (SSS, SRS, SDS, respectively), stress and rest ejection fraction (EF) were calculated. Visual interpretation was performed to classify the perfusion as normal, fixed, mixed (fixed and reversible defects), single reversible or multiple reversible defects. Coronary angiograms were assessed as normal with no CAD, single vessel, two-vessel or three-vessel disease. Correlations between the TID and other parameters were studied using analysis of variance (ANOVA) with IBM-SPSS version 20. RESULTS:A total of 52 male patients had a high TID of ⩾1.20 (mean 1.30 ± 0.13). Ten patients had a SSS of 0-3 and 16 were classified as normal by visual assessment. Stress EF (mean 50.4 ± 12%) was lower than the rest EF (mean 56.6 ± 12.8%) with the difference being statistically significant (Students paired t-test, p = 0.001). Angiography results were available in 44 patients, 3 having a normal angiogram, 24 having three vessel disease, 7 having two vessel disease and 10 having one vessel disease. Five patients with normal perfusion and SSS = 0-3 had CAD as seen on a coronary angiography. CAD on coronary angiography showed a significant correlation with perfusion abnormalities as assessed by visual interpretation (p = 0.002). TID showed a significantly correlation with both perfusion abnormalities (p = 0.009), as assessed by visual interpretation, and with Summed difference scores, SDS (p = 0.000). CONCLUSION:A high TID on G-MPI was a very sensitive indicator of significant CAD. In patients with normal perfusion and high TID further workup is warranted.

Objective: To perform a comparison between post-stress and rest gated single-photon emission computer tomography (SPECT) myocardial perfusion imaging (MPI) studies to assess post-stress stunning and the variables underlying this phenomenon. Subjects and Methods: This was a prospective study of 318 consecutive adult patients undergoing stress and rest gated SPECT using a 2-day 99mTc-tetrofosmin protocol. Bruce protocol treadmill stress (n = 93) or i.v. dipyridamole pharmacologic stress (n = 225) were used as stressors. Ejection fractions (EF) and left ventricular (LV) end-diastolic (EDV) and end-systolic volumes (ESV) were calculated using the Cedars Sinai Quantitative Gated SPECT software. Perfusion defects were visually scored using a 20-segment model to obtain summed stress scores. Statistical analysis was performed by applying paired t test and multi-regression. Statistically significant (p < 0.05) paired differences between post-stress and rest EF and ESV and type of stressing were noted. Results: Analysis of patient groups based on the type of stress showed significantly low EF on post-stress studies for both treadmill and dipyridamole stressing and also significantly high ESV on post-stress studies for dipyridamole. Multi-regression analysis using differences in post-stress and rest EF, EDV and ESV as dependent and summed stress scores, type of stress, delay time, previous myocardial infarction and size of LV as independent variables showed statistically significant associations between high summed stress scores (>13) and size of post-stress LV for EDV and ESV differences. High volumes were noted on post-stress studies. The magnitudes of the observed differences were well within the reproducibility of LV volume calculations. Conclusions: Patients showing stunning had significant ischemia or a dilated LV. The stunning manifested as high EDV and ESV differences. The magnitude of the differences observed in EF and LV volumes were not clinically significant.

Background When reporting bone scans, it is important to distinguish between normal variants and skeletal pathology involving the sternum. There are only limited reports dealing with age-related normal variants of the sternum on bone scintigraphy.Methods We have studied the age-related variants of sternal uptake on bone scintigraphy. In a prospective study, 152 consecutive patients (66 males and 86 females) undergoing whole-body bone scanning, and who had no symptoms associated with the sternum, were evaluated for patterns of normal sternal uptake. Three hours after intravenous injection of Tc-99m-methylene diphosphonate (Tc-99m-MDP), whole-body bone scans in the anterior and posterior projections were acquired. Patterns of sternal uptake, including the sites and distribution of increased and decreased uptake, were analysed using age-related groups.Results Three patterns of tracer uptake in the sternum were recognized: a uniform pattern was most common in children ( <= 12 years); a heterogeneous uptake pattern was frequently seen in adolescents, young adult and adult groups; and a segmented pattern was commonly seen in the geriatric group (> 60 years). A predominant focal finding was a hot spot at the angle of Louis. In addition, there were focal spots of decreased tracer uptake in the lower sternum, just above the xiphoid process, and spots of increased tracer uptake in the body of the sternum. Such focal spots were not seen in subjects of less than 12 years of age.Conclusion Evolutionary changes of the sternum appear to exist throughout life. There are age-related normal variants of sternal uptake on bone scintigraphy. Nucl Med Commun 26:253-257 (c) 2005 Lippincott Williams & Wilkins.

The archiving and retrieval of patient studies in a nuclear medicine department is routine and performed for patient study review and comparisons, research and legalities. The storage requirements are modest at around 2–5 Gbytes per month. The process and review (P & R) workstations in nuclear medicine have the necessary software and hardware to perform this function. However, advances in storage media capacity (fixed and removable) coupled with the age of the department's P&R workstations often leads to the use of outdated, expensive and limited capacity storage media with no on-line access to the archived data. Our department's GE Genie P&R workstations archive to magnetic optical disks that are expensive (£100), limited capacity (630 Mbytes) and have a slow transfer rate. (The patients’ files are also stored in a propriety database preventing their transfer to another vendors system by removable media.) In order to overcome these problems an in-house archival system was developed. All programs were written in C, C++ with the use of free DICOM source code from the OFFIS group. Patient files are transferred automatically from our GE Millennium acquisition gamma cameras computers through DICOM to a P4 personnel computer (PC) operating under Microsoft Windows XP. The PC has a 120 Gbytes fixed disk hard drive. On receiving the patient study a DICOM file is stored on the hard drive and a database entry automatically created with appropriate fields to record patient demographics and acquisition parameters. The hard drive at present contains over 2 years of patients’ data (60 Gbytes) allowing for on-line access for patient retrieval through DICOM to the P&R workstations. The studies are also stored on CDRs for permanent storage backup. The removable media contain DICOM storage files that can be read by any vendor. This has resulted in an archive system that uses current and easily upgradeable components to keep abreast of current technologies. The system is automatic and allows for on-line access to our patient studies in a cost effective manner.