Assessment of bone quality with trabecular bone score in type 2 diabetes mellitus: A study from the FRISBEE cohort.

OBJECTIVE: The purpose of our study was to compare bone mineral density (BMD) and trabecular bone score (TBS) values between patients with type 2 diabetes (T2D) and control subjects with similar FRAX scores in order to evaluate TBS as an additional tool for assessing fracture risk in diabetic subjects. METHODS: A cross-sectional analysis was performed using BMD results from 260 subjects participating in the FRISBEE study (Fracture RISk Brussels Epidemiological Enquiry), an ongoing prospective epidemiological study in a population-based cohort (Brussels, Belgium) of 3560 postmenopausal women aged 60-85 years. TBS measurement was possible in 1108 subjects from the FRISBEE cohort. Among these 1108 subjects, 65 had known T2D at inclusion. For each diabetic case we selected 3 controls from our database. (n = 195). Diabetic subjects and controls were matched for age and baseline FRAX score for major osteoporotic fractures. RESULTS: BMD (g/cm2 ) tended to be higher in T2D than in control subjects, significantly so at the total hip 0.90 ± 0.13 versus 0.87 ± 0.12 (P = 0.015). On the contrary, TBS was significantly lower in the T2D group (mean = 1.19 ± 0.17) compared with the control group (mean = 1.27 ± 0.13) (P = 0.005). Mean TBS remained significantly lower in T2D (1.22 ± 0.17) compared with the control group (1.27 ± 0.13) (P = 0.02) after adjustment for body mass index. CONCLUSION: Our data suggest that TBS complements BMD at the total hip, in demonstrating the "diabetes-associated bone disease".

A surprising finding during solid-phase gastric emptying scintigraphy.

In case of repeated episodes of abdominal discomfort and vagal symptoms, especially occurring after ingestion of a rich meal, the diagnosis of intermittent volvulus could be considered. The sudden arrival of large amounts of partially digested food in the intestine after spontaneous resolution might be associated with a dumping syndrome.

A rare cause of persistent hyperparathyroidism.

In a case of patient with persistent hypercalcemia after parathyroidectomy, different imaging techniques and particularly 18F-fluorocholine PET/CT are important to localize the adenoma even in a very unusual location.

Can we safely reduce the administration of 131-iodine in patients with differentiated thyroid cancer? - experience of the Brugmann hospital in Brussels.

BACKGROUND: 131-iodine (131I) administration after surgery remains a standard practice in differentiated thyroid cancer (DTC). In 2014, the American Thyroid Association presented new guidelines for the staging and management of DTC, including no systematic 131I in patients at low-risk of recurrence and a reduced 131I activity in intermediate risk.The present study aims at evaluating the rate of response to treatment following this new therapeutic management compared to our previous treatment strategy in patients with DTC of different risks of recurrence. METHODS: Patients treated and followed up for DTC according to the 2014-ATA guidelines (Group 2) were compared to those treated between 2007 and 2014 (Group 1) in terms of general characteristics, risk of recurrence (based on the 2015-ATA recommendations), preparation to 131I administration, cumulative administered 131I activity and response to treatment. RESULTS: In total, 136 patients were included: 78 in Group 1 and 58 in Group 2. The two groups were not statistically different in terms of clinical characteristics nor risk stratification: 42.3% in Group 1 and 31% in Group 2 were classified as low risk, 38.5 and 48.3% as intermediate risk and 19.2 and 20.7% as high risk (P = 0.38). Two patients (one in each group) with distant metastases were excluded from the analysis.Preparation to 131I administration consisted in rhTSH stimulation in 23.4% of the patients in Group 1 and 100% in Group 2 (p < 0.001).131I was administered to 46/77 patients (59.7%) in Group 1 (5 at low risk of recurrence) and 38/57 patients (66.7%) in Group 2 (0 with a low risk). Among the patients treated by 131I, median cumulative activity was significantly higher in Group 1 (3.70GBq [100 mCi] range 1.11-11.1 GBq [30-300 mCi]) than in Group 2 (1.11 GBq [30 mCi], range 1.11-7.4 GBq [30-200 mCi], P < 0.001). Complete response was found in 90.9% in Group 1 vs. 96.5% in Group 2 (P = 0.20). CONCLUSIONS: Using the 2015-ATA evidence-based guidelines for the management of DTC, meaning no 131I administration in low-risk patients, a low activity in intermediate and even high risk patients, and a systematic use of rhTSH stimulation before 131I therapy allowed us to reduce significantly the median administered 131I activity, with a similar rate of complete therapeutic response.

Influence of the different biokinetics of sestamibi and tetrofosmin on the interpretation of myocardial perfusion imaging in daily practice.

AIM: Digestive activity can interfere with the interpretation of myocardial perfusion single photon emission computed tomography using sestamibi or tetrofosmin. Compared with sestamibi, the liver clearance of tetrofosmin is more rapid, but its absolute cardiac uptake is lower. In this study, the activity of sestamibi and tetrofosmin was quantified after exercise or pharmacological stress and at rest to objectify the biokinetic differences and to evaluate whether there is a correlation between quantitative measurements and the visual assessment of image quality. METHODS: Left ventricular activity and five ratios (R1-R5) of cardiac to adjacent extra-cardiac activity were quantified in 204 sestamibi (68 exercise stress/56 pharmacological stress/80 rest) and 221 tetrofosmin (67 exercise stress/59 pharmacological stress/95 rest) studies. Image quality was assessed by a three-point score (1, good; 2, moderate; 3, poor) and correlated with the heart to left supra-diaphragmatic region (R1) and heart to right supra-diaphragmatic region (R2) ratios. RESULTS: The mean left ventricular activity was higher for sestamibi, especially at rest (sestamibi, 0.21+/-0.05 counts/pixel/injected MBq; tetrofosmin, 0.16+/-0.042 counts/pixel/injected MBq; P<0.001). By contrast, most ratios were higher with tetrofosmin, particularly for the exercise stress and rest studies. Using the three-point quality scoring, more sestamibi than tetrofosmin studies were scored as 3 (12.2% versus 6.3%), also particularly for the exercise stress and rest studies. A highly significant relationship was found between decreasing R1 and R2 and an increasing quality score, regardless of the radiopharmaceutical used (P values between 0.02 and <0.001). CONCLUSIONS: Despite a lower cardiac uptake, the more rapid liver clearance of tetrofosmin than sestamibi significantly improves the ratios of cardiac to digestive activity, especially after exercise or at rest. These quantitative differences in biokinetics result in less poor scans with tetrofosmin in daily practice.

Dynamic Scintigraphy With SPECT-CT of Postoperative Salivary Leak.

This 65 year-old woman, 1 month postoperative after maxillary sinus carcinoma (pT4N0cM0) excision and reconstruction, presented with significant left facial clear fluid wound leakage. A salivary or cerebrospinal leakage was suspected. Fluid analysis, CT, and MRI were noncontributory. Dynamic salivary scintigraphy with SPECT-CT allowed for the detection and localization of the leakage from the left parotid gland. Radioactive dose rate of the wound bandage was 50 µSv/h compared with 0.05 µSv/h for background and confirmed the diagnosis. Left total parotidectomy resulted in resolution.

Chronic brain hypoperfusion due to multi-vessel extracranial atherosclerotic disease: a potentially reversible cause of cognitive impairment.

A 62-year-old patient presented with persistent cognitive deficits 3 months after a right temporal ischemic stroke due to ipsilateral carotid occlusion. Work-up disclosed hemodynamically significant contralateral carotid artery stenosis and left subclavian steal phenomenon. Brain SPECT imaging revealed bihemispheric chronic brain hypoperfusion that substantially improved on repeat imaging when the subclavian steal was temporarily diminished by inflating a cuff around the left arm. Carotid endarterectomy of the asymptomatic carotid stenosis substantially ameliorated bihemispheric brain perfusion and reversed cognitive impairment. This case highlights that multi-vessel, extracranial atherosclerotic disease may cause chronic diffuse brain hypoperfusion that can be associated with cognitive impairment.

Head-to-head comparison of uncorrected and scatter corrected, summed and end diastolic myocardial perfusion SPECT in coronary artery disease.

OBJECTIVES: Compared with other non-invasive methods for diagnosing coronary artery disease (CAD), myocardial perfusion imaging (MPI) suffers from some lack of specificity, especially in patients with a small heart. Allowing the assessment of perfusion on end diastolic images instead of summed images, gated single photon emission computed tomography (SPECT) constitutes an attractive method for increasing the accuracy of MPI. Scatter correction, known to improve image contrast, might also be interesting. The present study aimed at comparing scatter corrected to uncorrected gated MPI for CAD diagnosis. METHODS: The results for 100 patients referred for gated 99mTc sestamibi SPECT were analysed. They were divided into two subgroups according to their end systolic volume (ESV) measured by QGS analysis (group A, ESV > or =30 ml, n=65; group B, ESV <30 ml, n=35). For each patient, a total defect score (TDS) was quantified on four polar maps (uncorrected and scatter corrected, summed, and uncorrected and scatter corrected, end diastolic). The optimal TDS separating non-CAD from CAD patients was calculated by analysis of the receiver operating characteristic (ROC) curve for the four data sets, using the coronary angiogram as a 'gold standard'. RESULTS: In the whole patient population, the accuracy of the uncorrected data was 67% for the end diastolic images and 71% for the summed images (sensitivity, 66% and 70%; specificity, 71% and 79%, respectively). After scatter correction, the accuracy did not change for the end diastolic data (accuracy, 67%; sensitivity, 63%; specificity, 93%) and increased to 74% for the summed data (sensitivity, 73%; specificity, 79%). In group A, the uncorrected data were 72% accurate for the end diastolic images and 78% for the summed images (sensitivity, 72% and 79%; specificity, 75% and 75%, respectively). After correction, the accuracy of end diastolic images increased to 77% (sensitivity, 77%; specificity, 75%), and did not change for the summed images (accuracy, 78%; sensitivity, 79%; specificity, 75%). In group B, the accuracy of uncorrected images amounted to 51% for both end diastolic and summed data (sensitivity, 48% and 40%; specificity, 60% and 80%, respectively). After correction, it increased to 57% for the end diastolic images and to 63% for the summed images (sensitivity, 48% and 64%; specificity, 80% and 60%, respectively). CONCLUSIONS: Despite lower blurring on end diastolic compared with summed images, non-scatter corrected end diastolic data were least accurate for the diagnosis of coronary artery disease in patients with a high prevalence of disease. Scatter correction, by improving the delineation of perfusion defects, increased the accuracy of quantitative MPI for the diagnosis of CAD in a large number of patients, more particularly in those with a small heart.

Educational impact of discussing results among nuclear medicine physicians participating in interobserver reproducibility studies: our experience with I-123 FP-CIT SPECT.

OBJECTIVES: In nuclear medicine, reproducibility studies allow the assessment of the robustness of a technique. They could also be used in continuing education. This study evaluates this educational impact. METHODS: Two series of clinical data and I-123 fluoropropyl-carbomethoxy-iodophenyl-nortropane single photon emission tomography images from 12 patients were prepared before initiating the study. Each series covered similarly a wide spectrum of clinical situations and images. Nuclear medicine physicians having experience with I-123 fluoropropyl-carbomethoxy-iodophenyl-nortropane single photon emission tomography were recruited and assigned two similar groups regarding their level of experience and type of institutions from which they were issued. Clinical data and images were transmitted by e-mail. For each case, observers had to choose among three answers: normal, equivocal, and abnormal. Answers were returned anonymously. Before the second series was sent, observers from group A had a collegiate discussion on the results of the first series of cases. Observers from group B received the second series without any information regarding analysis of series 1. RESULTS: In group A, median agreement increased from 75% (series 1) to 100% (series 2); in group B it was 75% (series 1) and 87% (series 2). In group A, a 100% agreement was observed for four cases (series 1) and for eight cases (series 2). In group B, a 100% agreement was observed for four cases for both series. CONCLUSION: These preliminary results, obtained in a small sample of observers, suggest that participating and discussing results of interobserver reproducibility studies seems to have a positive educational impact and therefore improves interobserver reproducibility.

FP-CIT SPECT in clinically inconclusive Parkinsonian syndrome during amiodarone treatment: a study with follow-up.

OBJECTIVES: To evaluate whether dopamine transport system imaging by FP-CIT single-photon emission computed tomography (SPECT) can be helpful to differentiate idiopathic Parkinson's disease (IPD) from secondary Parkinsonism induced by amiodarone. METHODS: Twenty-two patients with Parkinsonism during amiodarone therapy were evaluated by clinical neurological examination and FP-CIT SPECT. Thereafter, amiodarone was discontinued whenever possible and antiparkinsonian treatment was modified, if required. Clinical neurological status was reevaluated within a year of the SPECT examination. RESULTS: At baseline, clinical neurological examination was quite similar in all patients. No clinical symptom was able to clearly orientate the diagnosis toward IPD or drug-induced Parkinsonism. Using SPECT, the number of normal and abnormal patients was evenly distributed. In the abnormal SPECT group, amiodarone was modified in seven patients of whom six improved at follow-up. Antiparkinsonian treatment had been modified in all the patients. In the four cases with no amiodarone changes, clinical improvement was noted if antiparkinsonian treatment was optimized (three patients). In the 11 normal SPECT patients, amiodarone was modified in five patients. All patients ameliorated (two) or even normalized (three). In the six patients with normal SPECT in whom amiodarone had not been modified, symptoms remained stable despite the absence of antiparkinsonian treatment. CONCLUSION: In patients treated with amiodarone, IPD is sometimes clinically difficult to differentiate from drug-induced Parkinsonism. Using FP-CIT, a normal scan suggests drug-induced Parkinsonism, hence, there is no need for antiparkinsonian treatment and all possible attempts to reduce or preferably stop amiodarone. An abnormal scan, on the other hand, indicates IPD. In this case, treating IPD seems to have more impact on motor changes than modifying the antiarrhythmic drug.

Interobserver reproducibility of the interpretation of I-123 FP-CIT single-photon emission computed tomography.

OBJECTIVES: I-123 ioflupane (FP-CIT) single-photon emission computed tomography is a recognized tool in the diagnosis of Parkinsonian syndromes. In practice, data interpretation relies on visual and semiquantitative analyses. Good interobserver reproducibility is a prerequisite before claiming the robustness of a technique. This study aimed at evaluating interobserver reproducibility of this approach. METHODS: Thirty nuclear medicine physicians participated in the study. Data included FP-CIT images and semiquantitative measurements of 12 cases, covering a wide spectrum of scintigraphic patterns and for which a 'true' clinical diagnosis based on long-term follow-up was available. Interobserver agreement was defined, for each case, as the highest percentage reached among the three proposed answers with complete agreement arbitrarily set at 80% or more. Variability in an individual observer's sensitivity to assess data as normal, equivocal or abnormal was scored using a three-point scale. RESULTS: Response rate was 99.7%. Among the three possible answers,'normal' accounted for 41.2% of the total, 'abnormal' for 49.8% and 'equivocal' for 8.1%. The mean interobserver agreement was 76% (range: 37-100%), with complete agreement being reached only in five cases. The interpretation proposed by most observers accorded to clinical diagnosis in 75% of the cases. Abnormalities of the central nervous system were encountered in all the cases with disagreement between the observer's interpretation and clinical diagnoses. An important variability in the observers' sensitivity was seen. CONCLUSION: In the particular setting of this preliminary study evaluating the reproducibility of FP-CIT single-photon emission computed tomography interpretation in a group of nuclear medicine physicians with various experiences, interobserver agreement was suboptimal. Collegial discussion and standardized interpretation criteria could contribute to an improved reproducibility.

Variability of left ventricular ejection fraction and volumes with quantitative gated SPECT: influence of algorithm, pixel size and reconstruction parameters in small and normal-sized hearts.

PURPOSE: Several software packages are commercially available for quantification of left ventricular ejection fraction (LVEF) and volumes from myocardial gated single-photon emission computed tomography (SPECT), all of which display a high reproducibility. However, their accuracy has been questioned in patients with a small heart. This study aimed to evaluate the performances of different software and the influence of modifications in acquisition or reconstruction parameters on LVEF and volume measurements, depending on the heart size. METHODS: In 31 patients referred for gated SPECT, 64(2) and 128(2) matrix acquisitions were consecutively obtained. After reconstruction by filtered back-projection (Butterworth, 0.4, 0.5 or 0.6 cycles/cm cut-off, order 6), LVEF and volumes were computed with different software [three versions of Quantitative Gated SPECT (QGS), the Emory Cardiac Toolbox (ECT) and the Stanford University (SU-Segami) Medical School algorithm] and processing workstations. Depending upon their end-systolic volume (ESV), patients were classified into two groups: group I (ESV>30 ml, n=14) and group II (ESV<30 ml, n=17). Agreement between the different software packages and the influence of matrix size and sharpness of the filter on LVEF and volumes were evaluated in both groups. RESULTS: In group I, the correlation coefficients between the different methods ranged from 0.82 to 0.94 except for SU-Segami (r=0.77), and were slightly lower for volumes than for LVEF. Mean differences between the methods were not significant, except for ECT, with which LVEF values were systematically higher by more than 10%. Changes in matrix size had no significant influence on LVEF or volumes. On the other hand, a sharper filter was associated with significantly larger volume values though this did not usually result in significant changes in LVEF. In group II, many patients had an LVEF in the higher range. The correlation coefficients between the different methods ranged between 0.80 and 0.96 except for SU-Segami (r=0.49), and were slightly worse for volumes than for LVEF values. In contrast to group I, however, inter-method variability was quite large and most mean LVEF differences were significant. LVEF was systematically highest with ECT and lowest with SU-Segami. With QGS, changes in matrix size from 64(2) to 128(2) were associated with significantly larger volumes as well as lower LVEF values. Increasing the filter cut-off frequency had the same effect. With SU-Segami, a larger matrix was associated with larger end-diastolic volumes and smaller ESVs, resulting in a highly significant increase in LVEF. Increasing the filter sharpness, on the other hand, had no influence on LVEF though the measured volumes were significantly larger. CONCLUSION: In patients with a normal-sized heart, LVEF and volume estimates computed from different commercially available software packages for quantitative gated SPECT are well correlated. LVEF and volumes are only slightly sensitive to changes in matrix size. Smoothing, by contrast, is associated with significant changes in volumes but usually not in LVEF values. However, owing to the specific characteristics of each algorithm, software should not be interchanged for follow-up in an individual patient. In small hearts, on the other hand, both the used software and the matrix size or smoothing significantly influence the results of quantitative gated SPECT. LVEF values in the higher range are frequently observed with all the studied software except for SU-Segami. A larger matrix or a sharper filter could be suggested to enhance the accuracy of most commercial software, more particularly in patients with a small heart.