ABSTRACT
To measure radiation exposures rate in low-risk patients having stress-only and stress-rest myocardial perfusion imaging. This was a prospective study conducted from January 2012 till November 2012 upon patients with low pre-test probability for coronary artery disease [CAD]. A stress MPI [stress-only if MPI is normal and no resting study] followed by a resting MPI study [same day] if stress study was positive or equivocal. Exposure rates [in milli-Roentgen/hour, mR/hr] from injected patients at 1 meter distance were measured at 10 minutes, 1 hour and at time of releasing patients in both groups. Total 369 patients were included and 104 [28%] patients had stress-only and 265 [72%] had stress-resting studies. Mean administered [99m]Tc-MIBI dose in Stress-only and Stress-rest groups was 8 +/- 1 mCi and 24 +/- 03 mCi respectively [p<0.05]. Exposure rates[in mR/hr] within 10 min, 1 hour and at release time in Stress-only and stress-rest groups were 0.394, 0.294, 0.194and 1.540, 1.431, 1.207 respectively [p<0.05]. Mean stay of patients in laboratory was 90 +/- 39 minute in Stress-only and 156 +/- 53 minute in Stress-Rest group [p <0.0001]. There was a significantly widening gap between exposure rates from patients with Stress-only and stress-rest protocols as 26:74%, 21:79% and 16:84% at 10 min, 1 hour and at time of release respectively. We conclude that adopting a Stress-only MPI protocol in low risk patients ensures significantly lower radiation doses to patients and technologists. A worldwide paradigm shift in nuclear cardiology practice would safe mankind from unjustified radiation exposure
ABSTRACT
Paraganglioma are tumors originating from paraganglial system and may be associated with parasympathetic [head, neck and anterior mediastinum tumors] or sympathetic [adrenal or extraadrenal or posterior mediastinal tumor] system. Majority of sympathetic paraganglioma and minority of parasympathetic tumor are functional and [131I or [132]I labeled MIBG [Meta Iodio Benzyl Guanidine] is a well established tool with good sensitivity and exceedingly high specificity. We are presenting a case report of a large extradrenal paraganglioma with extensive bony metastases and raised serum Chromogranin-A level. In this case [131]-MIBG was not only helpful in revealing the true burden of functional disease but also showed an overwhelming therapeutic response proven on post-therapy MIBG scan and normalization of serum Chromogranin-A level. This case report is followed by a mini-review about pathology, genetic mutation, diagnosis and treatment of focused on extraadrenal paragangliomas
ABSTRACT
Obesity is generally considered as a risk factor for coronary artery disease [CAD] and cardiac deaths but some reports suggest better survival in obese with CAD. The objective of this study was to find out predictive value of body mass index [BMI] and waist circumference [WC] for CAD and its outcome using gated myocardial perfusion imaging [GMPI]. This was a prospective study conducted at Nuclear Cardiology Department of Karachi Institute of Heart Diseases [KIHD], Karachi, Pakistan from August 2011 till May 2013. 400 patients who qualified study criteria were included and were divided in [a] to Obese [BMI30 Kg/m[2]] and Non-obese [BMI<30 Kg/ m[2]] and [b] Low-WC group [male<90 cm and female < 80 cm] and High-WC group [male 90 cm and female 80 cm]. Rest and stress GMPI using Tc-99m MIBI was performed in all patients and abnormal GMPI was followed by coronary angiogram. These patients were followed for 12-18 months regarding fatal and non-fatal events. Non-Obese group included 281 patients [Male: Female = 131:150] with a mean age of 58 +/- 12 years and mean WC 100 +/- 15 cm. Obese group included 119 patients [Male: Female = 36:83] with a mean age of 55 +/- 11 years and mean WC 101 +/- 13 cm. Normal GMPI was found in 172 non-obese and 85 obese patients [p<0.05]. GMPI was abnormal in 109 non-obese and 34 obese patients [p<0.05]. WC was not found independent predictor of abnormal GMPI but high WC was found to a significant predictor of CAD in non-obese females [Odd ratio 8.04; 1.041 - 62.127]. At 18 months event-free survival in normal GMPI group for non- fatal MI was 99.4% in non-obese group and 94.1% for obese [significant P value]. For fatal MI, event-free survival was 99.4% in non-obese and 100% for obese [non-significant P value]. In patients with abnormal GMPI event-free survival for non-fatal events was 95.4% in non-obese group and 82.3% in obese group [significant P value]. While event-free survival for fatal MI was 96.3% in non-obese group and 98.1% for obese [significant P value]. We conclude that CAD was found less prevalent in obese group and High-WC predicted CAD in non-obese females only and was not found an independent predictor. A normal GMPI predicted very high event free survival for fatal events in obese and non-obese but significantly lower for non-fatal events in obese group. Obese group with abnormal GMPI had lower risk for cardiac deaths but higher risk for non-fatal events than non-obese patients with abnormal scans
ABSTRACT
Solitary metastasis involving sternum in breast cancer is very uncommon and less is known about the possible mechanism. Similarly, clinical significance of this uncommon presentation is elusive. We are presenting a case of breast cancer with isolated sternal metastasis on radionuclide bone scan which was also documented on chest CT study. In this mini-review we will be discussing the possible mechanisms for isolated sternal metastasis in breast cancer, its clinical significance and therapeutic approaches used