Pakistan Journal of Nuclear Medicine (PJNM) - Jan 2012 - Volume 02 - Issue 01

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The multi modality molecular imaging has brought a new perspective into diagnostic imaging and advanced medical diagnosis considerably. Positron emission tomography (PET) is a powerful molecular imaging technique but, its inability in providing anatomical details is a major limitation for PET only systems. Combining functional imaging with anatomical imaging like computed tomography (CT) and magnetic resonance imaging (MRI) has tremendously helped in disease detection at the cellular and subcellular levels. The wide clinical adaptation of PET-CT techno logy shows the positive influence of multimodality imaging in clinical practice by providing complementary information in function and morphology. The PET technology has advanced significantly over the years alongside multidetector CT technology and now supports whole-body PET-CT imaging in less than 10 min. concurrently, the MRI modality has evolved in providing soft-tissue contrast, tumor detection, tissue characterization and some functional imaging capabilities.

Background: The nuclear medicine physician community in Pakistan has seen attrition as many (almost 15%) young trained nuclear medicine physicians have opted to change their specialty. This has important implications for future nuclear medicine physicians numbers and raises questions about professional satisfaction and perception of future prospects among them. This prompted the authors to do a formal professional satisfaction survey. The survey also included those nuclear medicine physicians who had changed their specialty. This was done in the hope of getting an insight into the reasons of this rather unprecedented exodus of nuclear rnedictne physicians from the profession.

Methods: A 12-item job satisfaction survey was designed and sent to nuclear medicine physicians of Pakistan who had completed their MSc (Nuclear Medicine) within the last 10 years. It addressed various dimensions including professional satisfaction with the job, perception of usefulness in patient management questions (as might arise in a clinico-pathological conference), perception of adequacy of training to answer commonly encountered clinical questions, future prospects, income and professional prestige. Additional data was collected in form of suggestions regarding desire of additional training and suggestions for change in the current programme. The questionnaire was sent by E-mail to 32 nuclear medicine physicians with 27 of 32 (84.4%) responders.

Results: 16 out of 27 young nuclear medicine physicians (59.3%) were not happy professionally; however most of them(81.5%) considered themselves useful in clinico-pathological conferences. 16 (59.3%) would not choose nuclear medicine again as their profession. if given a chance. All considered that the professional infrastructure is not adequate in the country. 13 (48.1 %) thought that their future is not secure while 16 (59.3%) believed that the field is not professionally satisfying and financially rewarding. 25 (92.6%) considered that the MSc (nuclear medicine) syllabus needs to be revised. 9 (33.3%) want additional training (FCPS) in nuclear medicine and 15 (55.6%) thought their MSc course provided enough skills and knowledge. 9 (33.3%) would like to start private practice. Almost half (14,51.9%) thought that they needed additional training in complementary imaging modalities.

When the data was broken up into those who had graduated within 5 years versus those who had graduated before 5 years, it appeared that there was greater satisfaction in the older group as compared to the younger participants.

Conclusion: This survey points to significant levels of dissatisfaction among the population under study about their perceptions of the parameters of professional satisfaction. This survey should alert the policy makers, administrators and educators of urgent need address these perceptions and perhaps bring the training programmes and the service milieu in line with professional and in a way that would foster satisfaction and personal growth.

Aims: The clinical diagnosis of idiopathic Parkinson's disease (IPO) and its associated parkinsonian syndromes is not simple as it can be mimicked by a variety of other conditions. Objective assessment of the dopamine transport (DAT) system by ¹²³I-Ioflupane SPECT has proven to be a highly accurate method for establishing a diaqnosis of IDP. However, the test is expensive and can only be justified if it can lead to a change in patient management. This retrospective study therefore aimed to determine the clinical impact of ¹²³I-Ioflupane SPECT scan in our Institute.

Methods: A retrospective review of the clinical impact of ¹²³I-Ioflupane imaging in a single University Hospital site over a 5-year period was undertaken. Of the total of 152 patients imaqed, follow-up information was available in 85 of the patients who presented with either a high pre-test probability of IPD (43 patients), or unlikely to have IPD (15 patients) or atypical movement disorders (27 patients).

Results: In those patients in whom a diagnosis of IPD was suspected, the scan confirmed the disease in 79%, with a change in management in 23. In those with a low likelihood of IPD, 33% had a diagnostic ¹²³I-Ioflupane scan suggestive of IPD, with resultant change in management in 20% of patients. Of those with atypical presentation, IPD was confirmed in 48%, all of whom had a change in management.

Conclusion: In conclusion, there was a 64% agreement between the clinical diagnosis and imaging, resultinq in a change in management in 28 percent of the patients.

Aims: The present study deals with the importance of CA125 as an effective tumor marker in ovarian carcinoma and the clinical presentation observed in patients with high CA125 levels.

Methods: This Serological tests for tumour marker CA125 were performed in 585 patients with either ovarian carcinoma or some other turnouts such as kidney, uterine, cervical and testicular tumours referred to the centre for nuclear medicine Lahore for hormonal estimation. Further more, some other clinical presentations were also observed amongst the patients.

Results: The serum CA125 levels were elevated in 92% subjects with ovarian carcinoma and 8% in non ovarian tumours. Some elevated CA125 levels were observed in the patients with abdominal pain, abdominal extension, uterine fibroid, ovarian cyst, back ache and pelvic mass.

Conclusion: CA125 seems to be a reliable marker as its levels were found to be elevated in 92% ovarian tumours.

Aims: The study was aimed to determine the antithyroid activity of Dimethyl sulfoxide, a universal solvent.

Methods: The antithyroid effects of DMSO were investigated in vivo in male Wistar rats.

Results: Daily dose administration of 0.4 mL/100g to the animals significantly decreased the free triidothyronine and thyroxine levels and increased the thyroid stimulating hormone levels. The animals were afterwards dissected and thyroids were studied under microscope which revealed modifications at cellular level. Thyroid weight per 100 grams of bodv weight for the animals treated with DMSO were also found higher than control animals.

Conclusion: DMSO demosntrated moderate antithyroid activity in rats.

Aims: The protective role of calcium channel blockers on renal function has been documented in humans by use of several modalities but renal scintigraphy has however not been used for this purpose. This study was conducted to evaluate the effect of nifedipine a dihydropyridine calcium channel blocker on ^99mTc-DTPA renogram curve.

Methods: A total of 43 subjects, 20 normal and 23 hypertensive under went two ^99mTc-DTPA renal scans under same phvsioloqical conditions, with a three day interval in between, durinq which they took oral nifedipine (dose 10 mg twice daily). All the subjects had normal renal function established by routine laboratory investigations. Renograms from each kidney were generated and were used to calculate differential renal uptake and excretory function parameters of the kidneys. Paired student t-test was applied to check the statistical significance of the difference observed in the various calculated parameters, taking each kidney as an individual study organ.

Results: Quantitative renal function parameters (i.e., GFR, Peak height/mCi and uptake slope) improved significantly after use of nifedipine in both groups. GFR increased by 9.16% in hypertenslve group and 6.14% in normal group (p < 0.05). Peak height/mCi increased by 6.55% in hypertensive group and 5.8% in normal group (p < 0.05). Parenchymal uptake slope increased by 12.6% in hypertensive group and 8.6% in normal group (p < 0.05). T_max reduced by 10.6% in hypertensive group and 11.95% in normal group (p < 0.05). Statistically significant improvement in the renal excretory function parameters was observed only in hypertensive group. T_1/2max decreased by 13.4% (p < 0.05), Parenchyrnal retention index 20/3 and 30/3 improved by 9.6% (p < 0.05) 21.6% (p < 0.05) respectively in hypertensive group. However, no statistically significant change was observed in these parameters in normal group. Target-to-background ratio improved by 10.4 in hypertensive group and 11.5% in normal group (p < 0.05).

Conclusion: Short-term use of nifedipine, even in a small dose, has significant impact on the different quantitative parameters derived from renogram curves. It improved all the quantitative renal uptake and excretory functional parameters in hypertensive subjects. In the normal group, only the parameters related to the uptake function demonstrated a significant improvement.

Aims: To evaluate the postulate that a combination of x-ray mammography (XMM) and scintimammography (SMM) using receiver operatinq characteristic (ROC) statistical technique is better than either imaging used alone in the diagnosis of early breast cancer.

Methods: A cohort of 27 patients with 30 breast tumours was studied prospectively. The patients underwent a clinical examination, XMM,j and SMM, followed by fine needle biopsy/excision biopsy. The findings on XMM and SMM were divided into five grades: (1) probably normal, (2) probably benign, (3) equivocal, (4) probably malignant and (5) definitely malignant. Sensitivity and specificity were determined and ROC curves were drawn for XMM and SMM and compared against combined XMM and SMM.

Results: The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for XMM were calculated at 77%, 82%, 77% and 82% respectively; 85%, 94%, 92% and 89% for SMM; and for combined XMM and SMM, the values were 92%, 94%, 92% and 94% respectively. ROC curves were drawn and analysis of areas under ROC curves yielded values for XMM, SMM and combined imaging (XMM+SMM) at 0.85, 0.90 and 0.93 respectively. Wilcoxon signed ranked test showed that p value for XMM and result of combination images (XMM+SMM) was close to significant at 95% confidence level (i.e. 0.06) and the p value for SMM and combination imaqes (XMM+SMM) was also close to significant at 95% confidence level (i.e. 0.062). The p value for XMM and SMM was not significant.

Conclusion: The study shows that a combination of XMM and SMM, is more accurate in the diagnosis of early breast cancer than XMM or SMM alone. The study further suggests a role for SMM in equivocal breast lesions documented on XMM.

Redionudide cystography, direct (DRC) and indirect (IRC), has been used to detect vesicoureteric reflux (VUR) for years. DRC is generally performed in female children who do not have bladder control and requires the introduction of a urinary catheter. IRC is more physiological, avoids bladder catheterization and allows estimation of renal function as well as assessment of VUR. The intermittent nature of VUR and absence of a gold standard to confirm it however make comparisons between various diagnostic techniques difficult. Further, negative finding on IRC in children with a dilated renal pelvis does not completely rule out reflux. In this report, the authors have described the detection of VUR on DRC in a 7-year-old girl with a dilated pelvicalyceal system in whom IRC was normal on two previous occasions. The case hiohliqhts the need to perform both IRC and DRC or just the latter only in patients with pelvic dilatation and strong clinical suspicion for VUR.

Among benign space occupying hepatic lesions focal nodular hyperplasia (FNH) and hepatic adenoma (HA) occur predominantly in young and middle-aged women. These are mostly discovered incidentally and differentiation is essential because of different therapeutic approaches. We present two cases of FNH and HA and briefly describe the role of nuclear medicine in their imaging.

Occasionally, bone infections may present a diagnostic or therapeutic dilemma for the clinicians. We report a case of 17-year-old male who presented with a painful swelling in the upper left leg, which was seen to be due to a lytic lesion in the upper left tibia on x-ray. The bone scan also showed increased tracer uptake at this site. However, correlative ^99mTc-MIBI scan showed no significant uptake here and hence contributed to the diagnosis by establishing a benign cause for the pathology. Subsequent MRI confirmed the lesion as focal osteomyelitis.

We present a case of metastatic neuro-endocrine carcinoma of the lower end of the oesophagus, rare as for the primary tumour site. Somatostatin Receptor scintigraphy with ^99mTc-EDDA/HYNIC-octreotate findings altered the patient's management from curative surgery to palliative chemotherapy. The patient presented with progressive dysphagia and was histopathologically diagnosed on biopsy of the mass at the lower end of the oesophagus as high-grade neuroendocrine carcinoma. Baseline investigations showed deranged liver function, but except for a thickened gastro-esophageal junction, there was no abnormality seen on the initial computerized tomography scan. Also, raiologically, there was no evidence of metastatic disease seen either in the liver or the bones. Prior to surgical intervention, which was decided in the institutional tumour board, the patient was referred to the department of nuclear medicine for somatostatin receptor scintigraphy with ^99mTc-EDDA/HYNIC-octreotate. The images demonstrated widespread metastatic disease in the liver, bones and abdominal lymph nodes. The osseous lesions correlated well with abnormal tracer foci seen on subsequent bone scintigraphy. Moreover, scanning was completed within twenty-four hours with high-quality images produced owing to the ideal physical characteristics of technetium-99m. On the basis of the findings of the somatostatin receptor scintigraphy, the management changed from curative surgery to palliative chemotherapy. The patient however was unresponsive to combination chemotherapy and eventually expired five months after the initial diagnosis due to disease progression.

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It is not infrequent for Paget's disease and osseous metastases to coexist in an elderly patient and this possibility has to be kept in mind in order to avoid mistaken diagnosis. We report a patient with multiple concurrent pathologies in the skeleton including bone metastases, traumatic rib fractures and Paget's disease causing diagnostic uncertainties.

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