Frequency of diagnostic dilemmas in 131I whole body scanning

Aim: The specific excretion pathways of iodine may cause several diagnostic pitfalls. Information concerning their relative frequency and possible consequences in daily routine is scarce. Methods: A total of 500 131I whole-body scans from 300 consecutive patients with differentiated thyroid cancer of two centers were analyzed. The reports were validated with other diagnostic findings during follow-up for 12 to 85 months. 126 scans (25.2%) were performed at the time of discharge after high dose 131I therapy (2960-11100 MBq). Residual activity was approximately 185 MBq 131I at the time of imaging. 374 scans (74.8%) were performed in ambulatory patients 48 h after oral administration of 74 MBq131I. All patients revealed TSH concentrations >35 U/ml. Results: A computerized literature search revealed 74 entities that may cause a false-positive whole body scan, from which 12 were present in our cohort. The uptake patterns could be epitomized into nine clinical settings. Apart from the significantly higher frequency of cervical activity in residual thyroid tissue in patients after high dose therapy no statistically significant difference was found between high and low dose patients. The most frequent combination was stomach and colon activity, which was seen in 15.3% of all scans. Additional images or diagnostic procedures were necessary in 59.3%. Only one patient with a kidney metastasis was initially misinterpreted. The major clinical problems included: contamination, superimposed intestinal retention, hot nose, isolated peripheral metastasis, unexpected breast activity and kidney metastasis. Conclusion: 131I whole-body scanning has to be performed with painstaking precision and full awareness of even the rarest pitfalls in order to remain a sensitive and specific technique for diagnosing metastases from differentiated thyroid carcinoma.

123I-mIBG scintigraphy in neuroblastoma: development of a SIOPEN semi-quantitative reporting ,method by an international panel

Purpose

A robust method is required to standardise objective reporting of diagnostic ¹²³I-mIBG images in neuroblastoma. Prerequisites for an appropriate system are low inter- and intra-observer error and reproducibility across a broad disease spectrum. We present a new reporting method, developed and tested for SIOPEN by an international expert panel.

Method

Patterns of abnormal skeletal ¹²³I-mIBG uptake were defined and assigned numerical scores [0–6] based on disease extent within 12 body segments. Uptake intensity was excluded from the analysis. Data sets from 82 patients were scored independently by six experienced specialists as unblinded pairs (pre- and post-induction chemotherapy) and in random order as a blinded study. Response was defined as ≥50 % reduction in post induction score compared with baseline.

Results

In total, 1968 image sets were reviewed individually. Response rates of 88 % and 82 % were recorded for patients with baseline skeletal scores ≤23 and 24-48 respectively, compared with 44 % response in patients with skeletal scores >48 (p = 0.02). Reducing the number of segments or extension scale had a small but statistically negative impact upon the number of responses detected. Intraclass correlation coefficients [ICCs] calculated for the unblinded and blinded study were 0.95 at diagnosis and 0.98 and 0.99 post-induction chemotherapy, respectively.

Conclusions

The SIOPEN mIBG score method is reproducible across the full spectrum of disease in high risk neuroblastoma. Numerical assessment of skeletal disease extent avoids subjective evaluation of uptake intensity. This robust approach provides a reliable means with which to examine the role of 123I mIBG scintigraphy as a prognostic indicator in neuroblastoma.

Zuweisungen in der nuklearmedizinischen Diagnostik

Aim: Written reports are the basis of collaboration between clinician and radiologist or nuclear medicine specialist. For clinicians it is important to receive useful and accurate reports that answer their questions. A thorough referral note is needed in order to choose an appropriate examination method and to write a good report. Methods: In this retrospective study we analyzed 1330 referral notes which were addressed to the Department of Nuclear Medicine at the University Clinic of Nuclear Medicine in Vienna between 2008 and 2011. Examinations were divided into 7 groups (heart, lung, bones, central nervous system, PET or PET-CT and other). The following aspects were studied: diagnosis, clinical question, overall legibility, handwritten/typed, contact information, legibility of the referring doctor’s name, internal/external referral, additional information and region to be examined. Results: 18% of the referrals per year were analyzed. A diagnosis was given in 95%, a clinical question in 73%. Additional information was found in 41%. Only 4% were typed. In nearly all of these aspects there were major differences when compared in the seven different groups. Conclusion: To generate a good report and to provide optimal conditions for examination the data in the referral note should be given as exact as possible. Our retrospective analysis demonstrated the lack of referral note related information concerning the clinical question. In order to achieve good results, intelligent computer-assisted referrals might lead to better referral notes.

Medical preparedness in radiation accidents: a matter of logistics and communication not treatment!

The currently reactor wreckage in Fukushima raised the following important questions: Is our knowledge of the possible dangers of ionizing radiation sufficient to warrant special action? What is the role of the medical community in technical radiation accidents from Windscale to Fukushima? What is the role of the medical community in terrorist radiation attacks? Are we prepared for those challenges? How can medical services communicate information in the media framework? What have we learned recently? And, what should be improved? In this review of the current literature on ionizing radiation, we try to answer these questions. Our conclusion is that medical services have to improve their communication skills and convince the public that the dangers of ionizing radiation can be quantitated within certain limits to support a qualified discussion about its risks and benefits.

[Diagnostic reference value. Critical evaluation of the term with the example of nuclear medicine studies in Austria]

The aim of this study was to collect administered activities of important nuclear medicine diagnostic examinations and to identify frequencies as well as age distributions in the light of hybrid devices in Austria. Based on the survey data a re-evaluation of dose reference levels for nuclear medicine has been published in June 2010 in the novella of the Austrian Medical Radiation Protection Regulation (MedStrSchV) (8), also an estimate of the average individual doses of the total population. Accurate data on nuclear medicine studies of 34% of all Austrian nuclear medicine units could be collected.

RESULTS

Extrapolated there are about 150000 nuclear medicine examinations per year performed in Austria. The median age of patients is thereby 62 years. The results of this study resulted in 65% of the dose reference values to change, whereas 48% had to be revised downwards and 17% upwards. Additionally, 5 new reference values were included in the list; three more were taken out, however. The estimation of the individual effective patient dose for each offered examination was on average 4.7 mSv. An extrapolation based on the total exposure of the population with regard to uninvolved persons and children led to 0.07 mSv per year by nuclear medicine examinations.

CONCLUSION

The published diagnostic reference values correspond to the normal investigative practice in Austria and are compliant with most international recommendations. The term "optimal value" has been removed from the text of the law, because such wording would be misleading.

Tumor-induced hypophosphatemic rickets in an adolescent boy--clinical presentation, diagnosis, and histological findings in growth plate and muscle tissue

CONTEXT

The mechanism behind disabling muscle weakness in tumor-induced hypophosphatemic rickets is obscure. Histological investigation of growth plate tissue of patients with tumor-induced osteomalacia has so far not been reported.

PATIENT

A mesenchymal tumor was detected in the left distal fibula by (68)Ga-DOTATOC in a 17-yr-old boy with adolescent onset of severe hypophosphatemic rickets. Disabling muscle weakness improved within days after surgery, and normal mobility was restored within months.

METHODS AND RESULTS

The resected tissue included part of the growth plate allowing immunohistochemical investigation. Positive staining of FGF23 was found in the tumor cells and in hypertrophic chondrocytes, osteoblasts, and osteoclasts of the adjacent growth plate. This distribution matched that found in growth plate tissue of a healthy control. We found positive staining for the somatostatin receptor not only in the tumor but also within the growth plate and adjacent bony tissue in the patient and the healthy control. Muscle tissue provided evidence for a partial defect in respiratory chain complexes I-IV. Biochemical markers were nearly or completely restored to normal 12 months after surgery.

CONCLUSIONS

Hypertrophic growth plate chondrocytes are a target or source of FGF23 in tumor-induced osteomalacia. Low serum phosphate, FGF23, or other factors produced by the tumor may interfere with mitochondrial function.

Measurement of renal function in patients with Fabry disease

Appropriate measurement of the glomerular filtration rate (GFR) is important for the assessment of renal function. This paper reviews the methods used to assess GFR in clinical trials of enzyme replacement therapy (ERT) in patients with Fabry disease, which include inulin clearance, 24-hour creatinine clearance, chromium ethylene diamine tetraacetate (51Cr-EDTA) clearance and cystatin C concentrations. GFR has also been estimated using calculations based on creatinine clearance (the Cockcroft-Gault formula) and the Modification of Diet in Renal Disease (MDRD) equation. Analysis of the results of these studies shows that there are striking discrepancies between estimated and measured GFR. For example, the MDRD equation overestimates GFR in patients with Fabry disease who have normal renal function. In addition, cystatin C has been shown to be of limited use for measuring renal function during ERT, because it is influenced by other factors such as age, gender and weight.

CONCLUSION

The use of exact methods, such as inulin clearance, 124I-iothalamate, 99mTc-DTPA, 51Cr-EDTA and iohexol, appears to be mandatory for a robust evaluation of the effects of ERT on GFR in patients with Fabry disease.

Teleradiotherapy of joints in rheumatoid arthritis: lack of efficacy

BACKGROUND

Low dose radiotherapy is commonly used for painful rheumatic conditions in clinical practice. Teleradiotherapy may be a cheap, painless procedure which is applicable to many joints at a time.

OBJECTIVE

To determine if the local application of x rays to inflamed joints in rheumatoid arthritis (RA) affects the signs and symptoms of inflammation.

METHODS

In a randomised, controlled, double blind study, roentgen irradiation was administered in a total dose of 20 Gy during 2 weeks to single joints in six patients with RA who were receiving constant and stable pharmacological treatment with DMARDs and NSAIDs. Single inflamed joints on the contralateral side of the body were used as controls and received sham irradiation. Swelling and tenderness was assessed by blinded investigators before and until 3 months after the irradiation; general disease activity and pain scales were included in the assessment.

RESULTS

No change in the scores for tenderness, swelling, pain, or disease activity was seen. The trial was stopped for ethical reasons.

CONCLUSION

Local roentgen treatment of RA at a substantial dose of 20 Gy was ineffective in this pilot trial.

Frequency of diagnostic dilemmas in 131I whole body scanning

AIM

The specific excretion pathways of iodine may cause several diagnostic pitfalls. Information concerning their relative frequency and possible consequences in daily routine is scarce.

METHODS

A total of 500 (131)I whole-body scans from 300 consecutive patients with differentiated thyroid cancer of two centers were analyzed. The reports were validated with other diagnostic findings during follow-up for 12 to 85 months. 126 scans (25.2%) were performed at the time of discharge after high dose (131)I therapy (2960-11100 MBq). Residual activity was approximately 185 MBq (131)I at the time of imaging. 374 scans (74.8%) were performed in ambulatory patients 48 h after oral administration of 74 MBq (131)I. All patients revealed TSH concentrations >35 micro U/ml.

RESULTS

A computerized literature search revealed 74 entities that may cause a false-positive whole body scan, from which 12 were present in our cohort. The uptake patterns could be epitomized into nine clinical settings. Apart from the significantly higher frequency of cervical activity in residual thyroid tissue in patients after high dose therapy no statistically significant difference was found between high and low dose patients. The most frequent combination was stomach and colon activity, which was seen in 15.3% of all scans. Additional images or diagnostic procedures were necessary in 59.3%. Only one patient with a kidney metastasis was initially misinterpreted. The major clinical problems included: contamination, superimposed intestinal retention, hot nose, isolated peripheral metastasis, unexpected breast activity and kidney metastasis.

CONCLUSION

(131)I whole-body scanning has to be performed with painstaking precision and full awareness of even the rarest pitfalls in order to remain a sensitive and specific technique for diagnosing metastases from differentiated thyroid carcinoma.

The importance of delayed images in gastrointestinal bleeding scintigraphy

Although radionuclide methods for the detection of gastrointestinal (GI) bleeding have been available for more than 20 years, the value of delayed images in GI bleeding scintigraphy is still regarded controversially. The aim of this study was to determine the value of delayed images in a group of patients with predominantly low-grade intermittent bleeding. Eighty-nine consecutive GI bleeding scintigraphies of 75 patients were analysed retrospectively. All patients were referred to our department after other diagnostic methods had failed to identify the localization of GI bleeding. After the dynamic study, delayed images were acquired for up to 24 h until a bleeding site was identified. Data on the clinical outcome were available in all but five patients. No patient with a negative scan died from GI bleeding. A positive result was found in 41 patients (55%). The scans of 11 of these 41 patients (27%) became positive during dynamic imaging. Four required immediate surgery and, in another patient, surgery was not performed because of diffuse bleeding of the entire GI tract. One patient died without surgical intervention. Thirty-three scans of 30 of these 41 patients (73%) were positive on delayed imaging only, leading to surgery in 12 individuals. Our findings demonstrate the importance of delayed images in GI bleeding scintigraphy. Many of our patients who required surgery had scans that did not become positive for several hours.

Effects of irradiation on 99m Tc sestamibi and 201Tl uptake in a human papillary thyroid carcinoma cell line

Both 99mTc sestamibi and 201Tl have been used in conjunction with 131I scintigraphy for follow-up of patients with thyroid cancer. The aim of the study was to determine if irradiation affects tracer uptake in papillary thyroid cancer cells. The human papillary carcinoma cell line (PAP/ES-1) used in this study was generated from a papillary thyroid tumour obtained after surgery. For the in vitro uptake studies cells were seeded at 2 x 105 cells/well into 12-well microtitre plates. Irradiation was performed with a 60Co source (total dose, 2 Gy and 10 Gy). After incubation at 37 degrees C the supernatants were saved for determination of the unincorporated activity. The reaction was stopped by washing the cells four times in ice cold phosphate buffered saline. Total cellular uptake was determined by measuring cell lysate radioactivity in a Compugammasystem and was expressed as per cent uptake per mg of total cellular protein. At continuous incubation 201Tl uptake was significantly (P<0.01) higher after radiation whereas no effect of irradiation was found on 99mTc sestamibi uptake. Pulsed experiments revealed that irradiated cells displayed a faster 201Tl efflux. The net tracer retention at 90 min was similar to 201Tl to that of 99mTc sestamibi. We conclude that 99mTc sestamibi kinetics in thyroid cancer are not affected by irradiation and may therefore be superior to 201Tl in the follow-up of thyroid cancer shortly after radiotherapy.

[Traumatic temporomandibular joint injuries]

Injuries of the temporomandibular joint are mostly due to injuries or fractures of the mandibular condyle. Fractures of the skull base involving the temporomandibular joint are rare. Classification of fractures refers to their anatomical positions and the presence or absence of a luxation. Further, it is important whether the fracture is intra- or extra-capsular. The primary imaging method should be orthopantomography. As for therapy planning, especially surgery, also evaluation of soft tissue is necessary, computed tomography is the imaging method of choice. For diagnosis of complications or internal derangement of the temporomandibular joint, magnetic resonance imaging is to be recommended.

Does motion analysis in postexercise gated sestamibi SPECT reflect rest left ventricular motion even in severe coronary artery disease?

PURPOSE

Evidence has suggested that postexercise gated Tc-99m sestamibi SPECT (GSPECT) provides combined information about resting wall motion and exercise perfusion. No data have been published about possible differences in wall motion analysis between postexercise and resting GSPECT.

METHODS

Fifty patients underwent postexercise (symptom-limited bicycle stress) and rest GSPECT and cardiac catheterization with contrast ventriculography. In 35 patients, additional rest planar Tc-99m RBC radionuclide ventriculography (RNV) was performed. Four observers independently performed left ventricular ejection fraction (LVEF) calculations and visual analysis of regional wall motion (graded in four stages) for all studies.

RESULTS

The LVEF calculations in GSPECT revealed a statistically significant difference between postexercise (45.8 +/- 15.7%) and rest (48.0 +/- 16.1%; P < 0.05) determination. Postrest GSPECT LVEF showed a better correlation with LVEF determination performed with contrast ventriculography and RNV than did postexercise GSPECT LVEF. The reduced postexercise wall motion could be shown in segments with exercise-induced ischemia and in those with normal regional perfusion but not in segments with irreversibly abnormal perfusion.

CONCLUSIONS

Postexercise GSPECT provides reliable information regarding global wall motion even in severe coronary artery disease, but regional wall motion is underestimated compared with rest GSPECT, because of an imprecise surface detection algorithm in ischemic wall segments and possibly postexercise stunning in severe coronary artery disease.

FDG-PET in adrenocortical carcinoma

Adrenal cortical carcinoma (ACC) is a rare malignant neoplasm with a poor prognosis. Radical surgery of the primary tumor and of local as well as of distant recurrence is the only effective treatment, and requires accurate and early localization of recurrent tumors. In this regard, we prospectively scanned 10 patients with ACC, 8 during follow-up and 2 at primary work-up. In all patients PET scans from the neck to the upper thighs were obtained 45 minutes after injection of 370 MBq [18F]FDG. Reading was done visually, with the investigator blinded to the results of other diagnostic modalities. All known sites of ACC lesions showed markedly increased FDG uptake. In 3 patients, previously unknown lesions were identified by PET in the lung (one lesion), the abdomen (3 lesions), and the skeleton (multiple), respectively. One false positive liver focus was shown by PET aside from the true positive lung metastases in the same patient. The sensitivity/specificity of PET based on different organs was 100/97%, that based on the number of PET-detected lesions (N = 23) was 100/95%. PET altered or influenced the tumor stage in 3/10 patients, modifying the subsequent therapeutic management in 2/10 patients. We conclude that FDG-PET is highly useful in ACC and should be included in the work-up for initial staging as well as for follow-up.

Does (99m)Tc-Sestamibi in high-grade malignant brain tumors reflect blood-brain barrier damage only?

(99m)Tc-Sestamibi (MIBI) has been successfully applied in recurrent glioblastoma. The aim of this study was to evaluate the incremental diagnostic information of MIBI as a tumor-avid radiopharmaceutical compared with (99m)Tc-pertechnetate ((99m)Tc) as sole indicator of the integrity of the blood-brain barrier. Twenty-five patients with confirmed recurrent brain tumors were included. MIBI SPET was performed 10 min after injection of 555 MBq MIBI intravenously with a triple-headed gamma camera equipped with LE-UHR-PAR collimators over 360 degrees (3 degrees /step) and stored in a 128(2) matrix. Identical acquisition parameters were used for (99m)Tc SPET, which was acquired 3 h after injection of 740 MBq (99m)Tc. Normalized tumor uptake (NU) was calculated from attenuation-corrected transaxial slices. In addition, tumor/plexus, tumor/nasopharynx, and tumor/parotid gland ratios were assessed in both studies. No statistically significant differences were detected for the mean NU of tumor tissue with MIBI (0.26 +/- 0.10) and (99m)Tc (0.39 +/- 0. 33) and for the tumor/nasopharynx and tumor/parotid gland ratios; only the tumor/plexus ratio was significantly higher for (99m)Tc than for MIBI (p < 0.05). In conclusion, our data indicate that MIBI scintigraphy in brain tumors at 10 min postinjection reveals no additional visual information over that provided by the conventional (99m)Tc-pertechnetate brain scan, and in addition, tracer retention reflects primarily blood-brain barrier damage.

ROC analysis of three perfusion display options for ECG-gated perfusion SPECT in severe CAD

AIM

The simultaneous computation and display of wall motion and perfusion patterns in a single 3D ventricular model would considerably ease the assessment of ECG-gated Tc-99m-sestamibi SPECT, yet the effect on the accuracy of allocating regional perfusion has so far not been validated.

METHODS

3D perfusion mapping (3D Perfusion/Motion Map Software) was compared to the visual assessment of ungated tomographic slices and polar perfusion mapping (Cedars-Sinai PTQ) by correlation analysis and receiver operating characteristics (ROC) analysis at different cut-off levels for coronary stenoses in 50 patients (11 single-, 22 two-, 16 three-vessel disease). Ungated SPECT data were obtained by adding the intervals prior to reconstruction and displaying conventional tomographic slices. All display options were visually assessed in 8 ventricular segments according to a 4-point scoring system and compared to the graded results of coronary angiography.

RESULTS

All three display options showed a comparable diagnostic performance for the detection of severe stenoses. The diagnostic gain for the detection of stenoses above 59% was highest for ungated tomographic slices, followed by ungated polar mapping and 3D mapping. Regional assessment revealed a limited performance of 3D mapping in the proximal anterior and distal lateral wall. Polar mapping showed a balanced regional performance.

CONCLUSION

3D Perfusion mapping provides comparable information to conventional display options with the highest diagnostic strength in severe stenoses. Further improvement of the algorithm is needed in the definition of the valve plane.

Is there a diagnostic role for bone scanning of patients with a high pretest probability for metastatic renal cell carcinoma?

BACKGROUND

The utility of performing whole-body bone scintigraphy (BS) as part of a routine staging workup for patients with renal cell carcinoma (RCC) is currently being debated. This study investigated the diagnostic performance of BS in 36 patients with a high pretest probability for bone metastases due to abnormal laboratory tests, pain, or confirmed nonosseous metastases.

METHODS

Planar whole-body BS was performed in all patients 3 hours after the intravenous injection of 555 MBq (15 mCi) of technetium-99m-3,3-diphosphono-1,2-propane dicarboxylic acid tetrasodium salt).

RESULTS

In 14 of 36 patients, bone metastases could be confirmed either due to computed tomography or magnetic resonance imaging (n=11) or open site directed biopsy (n=3), respectively. The sensitivity ranged from 10% to 60%, depending on the applied visual threshold. The extent of the metastatic involvement was underestimated in all cases. No diagnostic pattern of tracer accumulation, clinical features, or laboratory tests was identified as enhancing the sensitivity for the detection of bone metastases in this population.

CONCLUSIONS

The authors concluded that, even among preselected patients, BS has no diagnostic role in RCC and should therefore be omitted from the clinical workup.

ROC Analysis of Three Perfusion Display Options for ECG-gated Perfusion SPECT in Severe CAD

Aim: The simultaneous computation and display of wall motion and perfusion patterns in a single 3D ventricular model would considerably ease the assessment of ECG-gated Tc-99m-sestamibi SPECT, yet the effect on the accuracy of allocating regional perfusion has so far not been validated. Methods: 3D perfusion mapping (3D Perfusion/Motion Map Software) was compared to the visual assessment of ungated tomographic slices and polar perfusion mapping (Cedars-Sinai PTQ) by correlation analysis and receiver operating characteristics (ROC) analysis at different cut-off levels for coronary stenoses in 50 patients (11 single-, 22 two-, 16 three-vessel disease). Ungated SPECT data were obtained by adding the intervals prior to reconstruction and displaying conventional tomographic slices. All display options were visually assessed in 8 ventricular segments according to a 4-point scoring system and compared to the graded results of coronary angiography. Results: All three display options showed a comparable diagnostic performance for the detection of severe stenoses. The diagnostic gain for the detection of stenoses above 59% was highest for ungated tomographic slices, followed by ungated polar mapping and 3D mapping. Regional assessment revealed a limited performance of 3D mapping in the proximal anterior and distal lateral wall. Polar mapping showed a balanced regional performance. Conclusion: 3D Perfusion mapping provides comparable information to conventional display options with the highest diagnostic strength in severe stenoses. Further improvement of the algorithm is needed in the definition of the valve plane.

Differential diagnosis of atypically located single or double hot spots in whole bone scanning

Our study assessed the predictive value of atypically located hot spots in routine 99mTc-DPD (3,3 diphosphono-1, 2-propane dicarboxylic acid tetrasodium salt) bone scanning for osseous tumor spread in patients with a history of malignant tumor.

METHODS

Of 1286 scans in consecutive patients with a history of malignant tumor, but with no current evidence of osseous tumor spread, 172 displayed one or two hot spots in the following locations: transverse process of a single vertebra, manubriosternal junction, unilateral process of L5/S1, unilateral shoulder, costal cartilage, single rib, and unilateral sternoclavicular joint. The final diagnosis could be established by a control bone scan after at least 6 mo, biopsy and/or postmortem, respectively, in 135 patients.

RESULTS

Of the atypical hot spots, 11.1% were the first indication for osseous tumor spread. This diagnosis was most probable for single hot spots in the rib (25%) and shoulder (21%). Conversely, hot spots in the sternoclavicular joint never indicated malignancy.

CONCLUSION

The likelihood of atypically located isolated hot spots indicating osseous tumor spread is higher than expected during routine investigations in patients with a history of malignant tumor but no current evidence for malignant disease. Only hot spots in the sternoclavicular joint did not indicate metastatic disease in our study.

Diagnostic patterns for bone marrow oedema syndrome and avascular necrosis of the femoral head in dynamic bone scintigraphy

This study used logistic regression analysis to assess qualitative patterns of tracer accumulation in an attempt to improve the diagnostic utility of bone scintigraphy for the detection of the bone marrow oedema syndrome (BMOS) and avascular necrosis (AVN) of the femoral head. Forty-eight symptomatic patients aged 44 +/- 9 years (mean +/- S.D.) with a final diagnosis of AVN (n = 29 hips), BMOS (n = 22), nine other hip disorders or a normal hip were examined with dynamic bone scintigraphy and qualitatively assessed for 11 scintigraphic signs in four phases by three blinded investigators. The accuracy for a correct diagnosis based on individual experience was 60-61% for the three observers, even if different signs were emphasized. A cold spot in the femoral head in both blood pool phases and the bone phase was seen only in 24% of AVN hips. Diffuse tracer accumulation in the femoral head, neck and the intertrochanteric region in the blood pool phases was seen only in 36% of BMOS hips. The arterial phase and the finding of a normal acetabulum in the bone phase had no diagnostic utility in this study. The presence of uptake increased the accuracy of differentiating AVN and BMOS from other disorders or normal hips to 88%. AVN could be differentiated from BMOS with an accuracy of 86% if the signs of the femoral head and inter-trochanteric uptake were combined into a diagnostic pattern. The scintigraphic pattern described increases the diagnostic accuracy of planar dynamic bone scintigraphy for BMOS and AVN.

The diagnostic value of planar and SPET scintimammography in different age groups

Planar scintimammography (SMM) with 99Tcm-sestamibi (99Tcm-MIBI) has proved to be a useful method in the evaluation of breast lesions. The aim of our study was to determine the diagnostic value of planar and single photon emission tomograpic (SPET) SMM in different age group. We investigated women with breast lesions for which the surgeon recommended biopsy or careful follow-up. Seventy consecutive patients underwent supine planar SMM, while supine SPET was performed in 68 of the patients. Twenty-seven carcinomas in 23 patients and 35 benign lesions in 31 patients were confirmed histologically. In the remaining 16 patients, the findings were classified as benign at follow-up. The carcinomas and benign lesions had a mean (+/- S.D.) diameter of 25 +/- 17 and 17 +/- 11 mm respectively (P < 0.05). A sensitivity/specificity of 67/96% and 88/91% was obtained with the planar and SPET techniques respectively. The accuracy of both techniques was 90%. In patients aged 40 years or less, SPET increased the sensitivity from 50 to 100% (P < 0.01), whereas it decreased the specificity and accuracy from 94 to 81% and 91 to 81% respectively (N.S.). In patients aged 41-50 years, the sensitivity increased from 63 to 100% (P < 0.01), whereas there was a small decrease in specificity and an increase in accuracy (from 91 to 89% and 86 to 91% respectively, N.S.) We conclude that, in younger patients, a negative SPET SMM study indicates the need for careful follow-up rather than biopsy. However, the addition of SPET in supine scintimammography does-not change the overall accuracy significantly.

Comparison and histopathological correlation of three parathyroid imaging methods in a population with a high prevalence of concomitant thyroid diseases

The aim of this prospective study was to evaluate the diagnostic utility of a technetium-99m sestamibi dual-phase protocol enhanced by single-photon emission tomography (SPET) and semiquantitative analysis in comparison to established preoperative staging procedures in patients with primary hyperparathyroidism. Twenty-eight (50%) out of 56 patients had superimposed thyroid disease, and 12 patients had previously undergone neck surgery. Visual and semiquantitative analysis of planar 99mTc-sestamibi dual-phase imaging, SPET of the delayed phase, ultrasonography, and thallium-201 chloride-technetium-99m pertechnetate subtraction scintigraphy was further correlated with the histopathological examination of the surgical specimens. 99mTc-sestamibi dual-phase imaging achieved the highest sensitivity for side localization and precise localization compared with 201Tl-99mTc subtraction scintigraphy and ultrasonography, but the differences reached statistical significance only in comparison to ultrasonsography. Semiquantitative analysis did not enhance sensitivity. Adenoma detection by 99mTc-sestamibi dual-phase imaging was only correlated to serum calcium levels and osteocalcin, not to cell density or oxyphil cell count (SPET yielded additional information for the exact topographical localization of the parathyroid tumour in 22 (39%) patients with superimposed thyroid disease or previous neck surgery but did not enhance the overall detection rate.

Differentiation of benign and malignant breast lesions: MR imaging versus Tc-99m sestamibi scintimammography

PURPOSE

To compare the accuracies of magnetic resonance (MR) imaging and scintimammography in differentiating benign from malignant breast lesions.

MATERIALS AND METHODS

MR imaging was performed in 66 women with 75 lesions during intravenous administration of gadopentetate dimeglumine. Planar and single photon emission computed tomographic (SPECT) scintimammography were performed (with 740 MBq technetium-99m sestamibi administered intravenously) in all 66 patients with 75 lesions and in 64 patients with 73 lesions, respectively. MR imaging and scintimammographic studies were independently evaluated by using signal intensity measurements versus time or focal tracer uptake to differentiate benign from malignant lesions. Histopathologic proof was obtained in 63 lesions. Twelve lesions were monitored with follow-up.

RESULTS

MR imaging was false-negative in one and false-positive in nine lesions. Planar scintimammography was false-negative in 10 and false-positive in six lesions. SPECT scintimammography was false-negative in four and false-positive in 10 lesions. Sensitivities and specificities for malignancy were, respectively, 96% and 82% for MR imaging, 62% and 88% for planar scintimammography, and 83% and 80% for SPECT scintimammography.

CONCLUSION

Both MR imaging and scintimammography are useful in the evaluation of breast cancer. MR imaging is more sensitive and as specific as scintimammography.

Potential impact of altitude on lung function

OBJECT

The effect of altitude on lung function was evaluated in 21 healthy volunteers at 171 m and at 1580 m above sea level.

METHOD

Results were obtained using an open spirometry system.

DESIGN

The parameters analyzed were forced vital capacity (FVC), forced expiration volume after 1 s (FEV1), relative 1-s capacity (FEV1/FVC), mean expiratory flows at 75%, 50% and 25% of FVC (MEF75, MEF50, MEF25), and maximal expiratory flow (peak flow, PEF).

RESULTS

MEF75 and MEF50 revealed a positive correlation with altitude, with mean rises of 15% and 11%, respectively. The difference was statistically significant for MEF75 (P = 0.0009) and MEF50 (P = 0.0001), whereas the other parameters revealed no significant difference.

CONCLUSION

Altitude could be a variable influencing spirometric measurements.

Utility of technetium-99m-sestamibi to assess osseous tumor spread

We report the staging results and the surgical outcome of a male patient with squamous-cell carcinoma in the floor of the mouth and a bone SPECT scan suggestive of local tumor infiltration of the mandible. Additional 99mTc-sestamibi SPECT imaging of the primary tumor and superimposing of both studies excluded osseous tumor spread and less extensive surgery was performed. Pathohistological examination confirmed the scintigraphic results and indicated a nonspecific periostal reaction as the cause of the positive bone scan. Nevertheless, a high-resolution camera and careful superimposition of both studies is mandatory if the differential diagnosis of an osseous tumor spread of a malignant tumor in the floor of the mouth and possibly less extensive surgery is at stake.

Five phase bone scintigraphy supports the pathophysiological concept of a subclinical inflammatory process in reflex sympathetic dystrophy

This study evaluates quantitative and qualitative patterns of bone scintigraphy and correlates them to laboratory findings and clinical signs to reveal possible inflammatory reactions in RSD. Activity ratios between the affected hand/foot and the contralateral side were calculated in 99mTc DPD-bone scintigraphy for five phases (arterial: 0-30 sec, early blood pool: 0.5-5 min. late blood pool: 5-15 min, 3 hrs early bone, 24 hrs late bone phase) and the presence of five scintigraphic signs in the bone phases was assessed. Activity ratios of all phases correlated with ESR those in the early and late bone phase correlated with alpha 2 globulin and beta globulin concentrations and those in the arterial, the early and late blood pool phase with the gamma globulin concentrations, respectively. Clinical features such as pain, swelling, physical force, temperature differences and the duration of symptoms did not correlate to the activity ratios. However, three signs in the bone phase were negatively correlated to albumin concentrations. Positive correlations were found for alpha 2, gamma globulin concentrations, ESR, neutrophil cell counts and individual uptake patterns. We conclude that the quantitative analysis of five phase bone scintigraphy in RSD reveals different aspects of tracer kinetics and provides different pathophysiological information. Lateralization of regional hyperemia, increased micro vascular permeability and bone metabolism in RSD parallels shifts in protein concentrations and blood cell counts that are suggestive of a subacute inflammatory process, even in patients with no overt signs of inflammation.

Pattern recognition in five-phase bone scintigraphy: diagnostic patterns of reflex sympathetic dystrophy in adults

The objective of this study was to assess qualitative and quantitative patterns of tracer accumulation to increase the diagnostic utility of bone scintigraphy in reflex sympathetic dystrophy (RSD). Of 120 patients with high clinical suspicion for RSD, 96 were confirmed as having RSD during follow-up, while the remaining 24 were used as controls. Clinical parameters were measured and correlated to five activity ratios (0-30 s, 0.5-5 min, 5-15 min, 3 h, 24 h) and five scintigraphic signs. Monitoring three dynamic phases revealed different tracer kinetics of potential diagnostic utility; however, the 24-h bone phase offered no additional diagnostic contribution and can be omitted. Quantification provided objective parameters for the duration of symptoms, pain and impairment of movement but not for surface temperature differences, swelling and impairment of physical force. It is of limited use for diagnosis except for the exclusion of disease. Discriminant analysis revealed the combination of three signs (diffuse uptake in carpus/tarsus+diffuse uptake in all small joints+increased activity ratio in the late blood pool phase) to be the pattern with the highest diagnostic accuracy independent of localisation, sex, age and precipitating factors. It is concluded that the scintigraphic confirmation of RSD is based on lateralisation in the late blood pool phase and the described pattern in the early bone phase.

Parenchymal and nonparenchymal uptake of technetium-99m, indium-111, and iodine-125 low-density lipoprotein in the normal and estradiol-stimulated rat liver: tracer validation for quantitative low-density lipoprotein scintigraphy

This study quantifies the parenchymal and nonparenchymal uptake of technetium-99m (99mTc)- and indium-111 (111In)-low-density lipoprotein (LDL) in different states of hepatic LDL-receptor activity to validate quantitative LDL scintigraphy. Iodine-125 (125I)-LDL was used as reference tracer. Four Sprague-Dawley rats with 17-alpha-ethinyl estradiol (EE)-stimulated LDL-receptor activity and five controls received all three tracers simultaneously 90 minutes before collagenase liver perfusion and metrizamide gradient cell separation. Total liver uptake of 99mTc-, 111In-, and 125I-LDL was 1.8 +/- 1.0, 1.6 +/- 0.8, and 0.2 +/- 0.2% injected dose/g organ weight, respectively. The contribution of nonparenchymal cells to total hepatic tracer uptake was 5.4 +/- 4.7%, 11.6 +/- 10.3%, and 9.6 +/- 7.6% in controls. Estradiol treatment increased total liver uptake to 2.4 +/- 0.5, 2.0 +/- 0.2, and 0.5 +/- 0.3% injected dose/g and reduced nonparenchymal cell contribution to 2.3 +/- 2.6%, 4.2 +/- 4.8%, and 2.6 +/- 2.9%, respectively. Dual-isotope scintigraphy in EE-treated and control rats confirmed these data, with a lower total hepatic uptake of 111In-LDL in comparison with 99mTc-LDL but a comparative degree of increase by EE treatment. Both behave quantitatively comparable as residualizing tracers, yet 99mTc-LDL shows a higher affinity to the LDL receptor pathway of parenchymal cells. However, the nonspecific uptake of both tracers can be neglected for quantitative LDL scintigraphy, and external imaging of hepatic tracer uptake primarily reflects LDL-receptor activity of parenchymal cells.

Three-phase bone scintigraphy of hydroxyapatite ocular implants

Hydroxyapatite ocular implants are replicas of lamellar bone tissue derived from the exoskeleton of a reef-building coral by a hydrothermal chemical exchange reaction. Attached to the eye muscles, they act as a passive framework for fibrovascular ingrowth and can be drilled to hold the visible part of the artificial eye and allow synchronous eye movement. Fibrovascular ingrowth has to be confirmed by bone scintigraphy before the drilling procedure. This study monitored the vascular ingrowth into the implant in ten patients over 12 months to establish a clinically feasible imaging protocol. Tracer accumulation was monitored visually and quantitatively in dynamic and single-photon emission tomography (SPET) scans after the intravenous administration of 600 MBq of 99mTc-DPD. The implants showed no tracer accumulation in the arterial or blood pool phase. Accordingly, dynamic scintigraphy can be omitted from the imaging protocol. Delayed tracer accumulation appeared no earlier than 2 and no later than 6 months after surgery. Planar scintigraphy is not recommended as high-resolution SPET is necessary to separate the implant from the surrounding bone. We conclude that imaging can be confined to high-resolution SPET 3 h after tracer injection, no earlier than 3 months after surgery. The vascularized hydroxyapatite orbital implant is an important in vivo model for bone-seeking agents to study their uptake kinetics independently of any soft tissue and bone disease. Our results provide evidence that in normal bones the chemical absorption of 99mTc-DPD into the crystalline structure of hydroxyapatite is the only quantitatively relevant uptake mechanism.

Scintigraphic pitfalls in giant parathyroid glands

We report a case of hyperparathyroidism with surgically confirmed bilaterally enlarged parathyroid glands mimicking a normal thyroid gland. Technetium-99m-pertechnetate-201Tl chloride subtraction scintigraphy was inconclusive because of suppressed thyroidal [99mTc]pertechnetate uptake after coronary angiography. Technetium-99m-sestamibi double-phase scintigraphy showed homogeneous 99mTc-sestamibi uptake that mimicked a normal thyroid gland and no differential washout, thus leading to an erroneous visual interpretation of a normal scan. Semiquantitative assessment of tracer washout, however, can differentiate between normal thyroid tissue and symmetrical parathyroid uptake mimicking normal thyroid tissue. We conclude that semiquantitative assessment of tracer washout increases the diagnostic sensitivity of 99mTc-sestamibi double-phase scintigraphy if: (a) the interpreter is unaware of the anatomical situation, (b) the scintigraphic delineation of the thyroid is hampered by a blocked tracer uptake or (c) the visual interpretation reveals no differential washout in the neck region.

[Satisfaction of paid thrombocyte donors with instrumental thrombocytapheresis]

OBJECTIVE

The increasing need for single-donor platelet concentrates makes it necessary to motivate platelet donors to donate regularly. The authors examined the contentment of existing donors in order to create a basis for improvements and to raise the attractiveness of donation.

DESIGN

Open empirical data acquisition.

SETTING

Institute for Transfusion Medicine at the General Hospital Vienna.

PARTICIPANTS

211 platelet donors.

INTERVENTIONS

Interview with a self-developed questionnaire.

RESULTS

Whereas donors rate the work of the staff as being very good, they are less content with the surroundings in the pheresis unit. Younger and higher-educated donors as well as persons who have been donating for less than 5 years show more negative ratings than comparable groups. The financial compensation is important to ensure a high donation frequency.

CONCLUSIONS

The attractiveness of donation could be raised by improving certain aspects of donation. In order to ensure a high donation frequency donors should be granted a financial compensation, as otherwise particularly younger donors, who are more likely to be seronegative for antibodies to CMV, would not donate any more or at least not that often.

Heterogeneity of myocardial perfusion provides the physiological basis of perfusable tissue index

Assessment of viable from nonviable myocardium is critical for the care of patients being considered for revascularization procedures. Recently, the perfusable tissue index (PTI) has been proposed as an index of myocardial viability.

METHODS

Computer simulations were performed for homogeneously and heterogeneously perfused tissue over a wide range of flows (0.04-6.4 ml/g/min) using both bolus and infusion inputs.

RESULTS

PTI estimated from simulated homogeneously perfused tissue did reflect the amount of tissue being perfused independent of absolute level of flow, type of input or model configuration, whereas PTI obtained from simulated heterogeneously perfused tissue was consistently lower than the simulated "true" PTI and varied with flow, type of input function and model configuration. Flow estimated with 15O-water was not significantly different from that measured with radio labeled microspheres.

CONCLUSION

Oxygen-15-water can diffuse into both acutely and chronically ischemic myocardium irrespective of its functional status. The results suggest that PTI is most likely an index of the heterogeneity of myocardial flow rather than an index of the amount of tissue being perfused. Its utility for delineating myocardial viability is thus related to the amount of tissue perfused that has low absolute levels of perfusion or high degrees of flow heterogeneity.

Zufriedenheit bezahlter Thrombozytenspender bei apparativen Thrombapheresen

<i>Ziel: </i>Der steigende Bedarf an Einzelspender-Thrombozytenkonzentraten (TK) macht es notwendig, Spender zu einer kontinuierlichen Spendentätigkeit zu motivieren. Die Autoren ermittelten die Zufriedenheit von bestehenden Spendern, um damit eine Basis für Verbesserungen zu schaffen und die Attraktivität des Spendens zu erhöhen. <i>Design: </i>Offene, empirische Datenerhebung. <i>Rahmen: </i>Abteilung für Transfusionsmedizin im Allgemeinen Krankenhaus Wien. <i>Teilnehmer: </i>211 Spender (Zufallsstichprobe) von TK. <i>Interventionen: </i>Befragung durch selbstkonstruierten Fragebogen. <i>Ergebnisse: </i>Sehr positiv bewertet wurde die Betreuung durch das Personal, weniger zufrieden sind Personen mit dem Umfeld in der Phereseeinheit. Jüngere und höher-gebildete Spender sowie Personen, die seit höchstens 5 Jahren zur Spende gehen, sind unzufriedener als vergleichbare Gruppen. Die finanzielle Entschädigung ist wichtig für die Gewährleistung einer hohen Spenderfrequenz. <i>Schluβfolgerungen: </i>Die Attraktivität des Spendens könnte durch Verbesserungen der weniger positiv bewerteten Bereiche erhöht werden. Um eine hohe Spendenfre-quenz zu gewährleisten, sollten Spender eine finanzielle Entschädigung erhalten, da sonst vor allem jüngere Spender, die mit höherer Wahrscheinlichkeit CMV-Antikör-per-seronegativ sind, gar nicht mehr oder nicht mehr so häufig TK spenden würden.

Effectiveness of coronary heart disease risk management in high-risk patients

The purpose of this study was to investigate the efficacy of the patient-based coronary heart disease (CHD) risk management strategy in general practice by analyzing patients who were sent to a specialized center as refractory to conventional treatment. Of the 452 patients studied, 152 were excluded because of secondary hyperlipidemia. The effects of a food protocol-monitored dietary/drug treatment on lipid profiles and CHD risk indices and the compliance to this approach were monitored for 12 months in 300 of 452 patients. CHD risk classification was performed according to NIH criteria by the referring physicians, but secondary hyperlipidemia was not identified and treated appropriately. Physicians did not fully utilize dietary and drug treatment and referred the patients to a specialized center too early. The initiated food protocol-controlled treatment was more efficient than pretreatment in general practice, with a compliance of 80.3% by patients selected according to their CHD risk. Long-term CHD risk reduction was persistent for 12 months in compliant patients; however, a cumulative dropout rate of 43% after 6 months and of 68% after 12 months was noted. Statistical analysis failed to reveal consistent prognostic factors of long-term compliance.

Technetium-99m labelled LDL as a tracer for quantitative LDL scintigraphy. II. In vivo validation, LDL receptor-dependent and unspecific hepatic uptake and scintigraphic results

The purpose of this study was to determine whether the hepatic uptake of dialysed technetium-99m labelled low-density lipoprotein (99mTc-LDL) reflects the hepatic LDL receptor activity and to what extent the non-LDL receptor-dependent 99mTc-LDL uptake by non-parenchymal cells relates to the diagnostic utility of quantitative 99mTc-LDL scintigraphy of the liver. New Zealand White rabbits and Watanabe Heritable Hyperlipidaemic rabbits, which were sacrificed 24 h after simultaneous injection of 99mTc-LDL and iodine-125 labelled LDL, were clearly discriminated by their hepatic 99mTc-LDL uptake according to their genetically different hepatic LDL receptor activity. Yet the hepatic 99mTc-LDL uptake exceeded the 125I-LDL uptake in all animals. The different hepatic uptake of the tracers was elucidated in the isolated perfused rat liver and was due to rapid intracellular degradation and the release of low molecular catabolites of 125I-LDL. In contrast, 99mTc activity was trapped in the liver. Analysis of biliary 99mTc activity provided evidence for the excretion of 99mTc-labelled apolipoprotein B. The amount of biliary excreted protein-bound 99mTc was linked to total hepatic 99mTc-LDL uptake and presumably reflected LDL receptor-mediated apolipoprotein excretion. Collagenase liver perfusion in Sprague-Dawley rats 90 min following simultaneous injection of 99mTc- and 125I-LDL and subsequent cell separation by gradient centrifugation revealed that 99mTc-LDL and 125I-LDL had a comparably low uptake into non-parenchymal cells; thus its contribution can be neglected for scintigraphic purposes. Planar scintigraphy was performed in New Zealand White and Watanabe Heritable Hyperlipidaemic rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)