Calcification-related absorption in thyroid scintigraphy.

UNLABELLED: The enhanced absorption of X-rays in calcified structures is a basic prerequisite for performing conventional bone radiography. On the other hand, nothing has been reported on possible absorption effects of 'calcifications' as frequent findings in thyroid nodules or in the sternal bone / sternoclavicular joints. This may be caused by the general opinion, that the high energy of 99mTc-photons (140 keV) do not make visible absorptions effects very likely. PATIENTS, METHODS: To prove possible absorption effects of calcifications on thyroid scintigraphy experimentally, effects of calcium absorbers were tested on a technetium flood phantom. Furthermore, absorption effects of various calcifications (discs of calcium sulphate and calcium carbonate with varying thickness) on normal thyroid tissue and autonomous nodules were simulated in a thyroid phantom. CT 130 kV-images of 46 consecutive patients were checked for presence of retrosternal or retroclavicular growth of the thyroid gland and to measure the extent and density of the sternal bone and calcified intrathyroidal nodules. In addition, clinical cases are presented in which a possible absorption by calcifications seems to be likely. RESULTS: Bony structures in front of the thyroid gland or calcified intrathyroidal nodules could be seen on CT in 24/46 patients. The mean averaged density was 219 Houndsfield units (SD: 89 HU). The quantitative measurements using a 99mTc-flood source showed a mean absorption of 4.9%. In a thyroid phantom, absorption effects were visible only in 3/20 positions of the calcium discs over the thyroid phantom. Focal effects could be better detected in situations of only moderate uptake of the surrounding tissue. A dependence of absorption and chemistry (sulphate, carbonate) could not be found. CONCLUSION: Visible absorption effects caused by sternal bone or thyroid calcifications are seldom but potentially able to diminish the visible uptake and should be taken into account when interpreting thyroid scintigrams.

Differentiation of prolonged colonic transit using scintigraphy with indium-111-labeled polystyrene pellets.

UNLABELLED: Prolonged colonic transit can be caused either by slow transit constipation or by pelvic outlet obstruction needing different therapeutic regimes. The aim of this study was to prove the value of scintigraphic assessment. METHODS: Colon scintigraphy was performed in 32 patients (28 women, 4 men; age range 8-68 yr) with idiopathic constipation at 8, 24 and 48 hr in ventral and dorsal projection after oral administration of a pH-sensitive, methacrylate-coated capsule of nonresorbable 111In-labeled polystyrene (cathion exchanger) micropellets (3.5 MBq/capsule). The geometric center (GC) as the sum of products of colon segment activity and colon segment number (1 = colon ascendens; 2 = transverse colon; 3 = colon descendens; 4 = rectosigmoid colon; and 5 = stool) dividing by the total counts was used to determine the velocity of colonic transit at least at 24 hr as the proximal colonic emptying (PCE) rates. Stool activity was evaluated indirectly as decay-corrected colon activity loss between two examinations. Results were compared with data obtained from 22 healthy subjects. RESULTS: Twenty-six patients had a significant prolongation of colonic transit after 24 and 48 hr (the 95% confidence interval of the patient's GC showed no overlap to the 95% confidence interval of GC calculated from 22 healthy controls as normal range) revealing slow transit constipation. Six patients had normal or accelerated transit (GCs and PCE rates) up to the rectum but delayed rectal emptying indicating pelvic outlet obstruction. CONCLUSION: By the help of this method it was possible to differentiate the two subtypes of colon transit prolongation by use of the reported scintigraphic technique, which leads to different therapeutic management of the patients. Compared with x-ray methods (Hinton test), this method has the capability of a continuous observation of colonic transit without increasing radiation exposure.

Cystic pelvic mass in a patient having recurrent carcinoma of the cervix.

The diagnostic difficulties encountered with atypical tumor growth are reported in a 29-year-old female with recurrent carcinoma of the uterine cervix. Following a Wertheim-Meigs procedure and resection of local tumor recurrence eight months later, a second recurrence was detected on CT as a purely cystic lesion in the left pelvic wall. Although the size of the cyst subsequently increased, the patient remained asymptomatic until slight pain developed in the left leg 28 months after initial therapy. One month later, limping was noticed; plain radiography showed a large osteolytic lesion of the left hip and on I.V.U., a dilatation of the left renal collecting system was observed. Pelvic CT showed only minimal solid tissue components within a large cyst. Multiple needle aspirations of the cyst and cytological examinations of the fluid obtained showed no evidence of tumor cells. A definitive histological diagnosis of metastasizing squamous cell carcinoma was only reached after surgery.

Surveillance of TSH-suppressive levothyroxine treatment in thyroid cancer patients: TRH testing versus basal TSH determination by a third generation assay.

OBJECTIVE, DESIGN AND METHODS: Although TRH testing has been eliminated in the diagnosis of most benign thyroid diseases, it is still controversial whether or not it can be replaced by ultrasensitive determination of basal TSH for monitoring optimal TSH suppression in thyroid cancer patients. We compared basal and TRH-stimulated TSH values measured by a 2 nd generation assay (lower detection limit 0.1 mU/l) and by a 3 rd generation assay (lower detection limit 0.005 mU/l) in 209 thyroidectomized thyroid cancer patients under suppressive levothyroxine treatment. RESULTS: In the 2 nd generation assay all patients had basal TSH values < 0.1 mU/l (criterion of admission in the study), and the TRH-stimulated TSH values were above the lower detection limit in 47% of the patients (range < 0.1-1.0 mU/l). In the 3 rd generation assay TSH was above the lower detection limit in 67% under basal conditions (range < 0.005-0.098 mU/l), and in 83% after TRH stimulation (range < 0.005-1.000 mU/l). We observed close correlations (p < 0.001) between basal and TRH-stimulated TSH in the 3 rd generation assay (r = 0.86), between TRH-stimulated TSH in the 2 nd and 3 rd generation assay (r = 0.95), and between TRH-stimulated TSH in the 2 nd generation assay and basal TSH in the 3 rd generation assay (r = 0.73). The ratio between TRH-stimulated and basal TSH values was in the average range 7-9 : 1. Subdividing the patients in three subgroups based on the TRH-stimulated TSH values from the 2 nd generation assay, the corresponding basal TSH values (median and [25.-75. percentile]) from the 3 rd generation assay were < 0.005 [< 0.005-0.010] mU/l in subgroup A (2 nd generation stim. TSH: < 0.15 mU/l), 0.032 [0.021-0.040] mU/l in subgroup B (2 nd generation stim. TSH: 0.15-0.4 mU/l), and 0.066 [0.046-0.085] mU/l in subgroup C (2 nd generation stim. TSH: > or = 0.5 mU/l). CONCLUSIONS: Even in those thyroid cancer patients where a high degree of TSH suppression is the therapeutic goal, 3 rd generation TSH assays enable a reliable adjustment of the levothyroxine dose by basal TSH determinations. In laboratories still using 2 nd generation assays, the monitoring of maximal TSH suppression in patients with high-risk thyroid cancer should be performed by TRH testing.

SPECT-evaluation of the monoamine uptake site ligand [123I](1R)-2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane ([123I]beta-CIT) in untreated patients with suspicion of Parkinson disease.

BACKGROUND: For a few years, data on SPECT-imaging of dopamine transporters with the cocaine derivate [123I](1R)-2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane ([123I] beta-CIT) have been reported mostly in healthy subjects or animals. This study reflects our preliminary results with SPECT-imaging of dopamine transporters using the cocaine analogue 123-beta-CIT in patients with untreated (de novo) parkinsonism. METHODS: In 33 patients with clinical suspicion of Parkinson disease and 5 healthy controls, SPECT-imaging of dopamine transporters was performed 1, 4, and 24 hours after injection of 180 MBq of 123I-beta-CIT, which was generated by iododestannylation. None of the patients or controls had been treated before with neuroleptical drugs or any other pharmaceuticals with known binding to the dopamine transporters. Clinical symptoms were staged by the scales Hoehn-Yahr (HYS), Unified Parkinson Disease Rating Scale (UPDRS), and the self-rating scale of Beck depression inventory (BDI). For evaluation, striatal/cerebellar ratios were calculated to every time point. RESULTS: Significant correlations of 123I-beta-CIT uptake could be stated compared to UPDRS, HYS, and BDI values (Spearman correlation, p < 0.05). The symptoms of rigor and akinesia showed a significant correlation with the beta-CIT uptake, whereas the symptom of tremor failed, which may be caused by the location of tremor symptoms out of the striatum. Comparing the controls, a significant (p < 0.01) decrease of tracer uptake in parkinsonian patients is stated on the images at 24 hours p.i. In our patients, tracer uptake does not depend significantly on duration of disease and age. CONCLUSION: 123I-beta-CIT seems to be a promising tool in imaging of untreated parkinsonian patient.

[Radiological follow-up of anastomotic insufficiency following partial esophageal resections or gastrectomies. The effects of barium-containing contrast media]. / Radiologische Kontrolle von Anastomoseninsuffizienzen nach Osophagusteilresektionen oder Gastrektomien. Effekte bariumhaltiger Kontrastmittel.

Fistulae after abdomino-thoracic operations are usually treated conservatively because of the high complication rate of repeated surgery. If the anastomoses function adequately, healing usually occurs spontaneously after four to six weeks. Amongst 271 patients with intrathoracic oesophago-gastric or oesophago-jejunal anastomoses, entero-cutaneous fistulae occurred 29 times. Extension of the fistula into the pleura or peritoneum was first excluded by using an absorbable contrast medium and then a barium contrast examination was carried out. Thoracic fistulae closed, on average, after 21.8 days and fistulae in the upper abdomen after 20.3 days. Barium sulphate stimulates granulation tissue in the fistula and therefore leads to more rapid obliteration. This improves the quality of the patient's life and reduced the time the patient has to spend in hospital. There were no local or systematic complications.

[Somatostatin receptor scintigraphy in medullary thyroid carcinomas, GEP and carcinoid tumors]. / Somatostatinrezeptor-szintigraphie bei medullären Schilddrüsenkarzinomen, GEP-Tumoren und Karzinoiden.

For this study, 24 patients with medullary thyroid cancer (MTC) and 10 with carcinoid-/GEP-tumours underwent scintigraphy with 123I-Tyr3-octreotide or 111In-DTPA-D-Phe1-octreotide (Octreoscan) or 99mTc-V-DMSA. Calcitonin and CEA were elevated in MTC patients, the other had tumour lesions on CT. Octreoscan-scintigraphy was positive in 68% of all suspicious cases. On the other hand, 123I-Tyr3-octreotide showed only rarely positive results. 99mTc-V-DMSA-scans in MTC patients were positive in 23%. Liver metastases could be seen only with Octreoscan in the non-MTC-group. These results showed better sensitivity of 111In-labelled octreotide.

Influences on evaluability of radionuclide ventriculography in chemotherapy patients.

Radionuclide ventriculography (RNV) is an established method of evaluating cardiotoxic side-effects of chemotherapy. The image quality of RNV depends on labelling yields obtained after red blood cell (RBC) labelling with 99Tc(m)-pertechnetate and has an influence on the evaluation of the left ventricular ejection fraction (LVEF). Several drugs and certain parameters of RBC labelling are known to have a detrimental effect on the labelling yield, but often the reason for poor image quality remains unclear. The aim of this study was to determine the effect of chemotherapeutic agents on LVEF evaluation. The chemotherapeutic medications and RNV data of 116 patients were noted. The patients underwent 205 RNV examinations (up to 7 RNV follow-up examinations) consisting of rest and stress studies. Ten patients with a poor labelling yield after in vivo labelling received an additional RNV study after in vitro labelling. The effects of commonly used anticoagulants and chemotherapeutic drugs on labelling yields were also investigated in experiments on in vitro RBC labelling. In vitro labelling had the advantage of better detection of pathological alterations in left ventricular motility, but often improved evaluability only slightly. The administration of corticosteroids showed an unexpected positive correlation with image quality (Spearman correlation coefficient: prednisone, 0.42403, P = 0.0013; prednisolone, 0.45629, P = 0.0286) and labelling yield (prednisolone, 0.65466, P = 0.0024), whereas idarubicin showed a negative correlation with image quality (-0.53364, P = 0.005). A slight positive correlation of prednisolone with LVEF at rest (0.45425, P = 0.0197) was also noted. Using our evaluation software, the manual contour method was found to be superior to the automatic determination of the left ventricular contour. Cycle ergometry alone caused a significant deterioration in image quality. The in vitro results suggested a negative influence of epirubicine on labelling yields at very high concentrations (10(-3) M). Our main result was that a clinically adequate study is possible in patients with moderate image quality and labelling yields. Furthermore, the administration of corticosteroids had a positive impact on image quality.

2-[123I]-iodolisuride SPET visualizes dopaminergic loss in de-novo parkinsonian patients: is it a marker of striatal pre-synaptic degeneration?

The aim of this study was to assess the correlation between the functional integrity and density of striatal dopaminergic receptors and clinical data in 15 de-novo patients with idiopathic Parkinson's disease by single photon emission tomography (SPET) using 2-[123I]-iodolisuride (ILIS), a tracer based on the D2-dopamine receptor agonist lisuride. Deficient striatal uptake of ILIS correlated with the severity of the disorder, scored by the Unified Parkinson's Disease Rating Scale (UPDRS) (n = 15; ratio of ILIS uptake: basal ganglia/cerebellum [B/C] & UPDRS I-III, Spearman R = -0.562, P = 0.013), Beck's Depression Inventory (BDI) (n = 12; B/C & BDI, Spearman R = -0.825, P = 0.0009) and the ZUNG Depression Scale (ZDS) (n = 11; B/C & ZDS, Spearman R = -0.7425, P = 0.008). Experimental data indicate that lisuride shows a higher affinity for pre-synaptic dopaminergic autoreceptors than for post-synaptic D2-dopamine receptors under conditions of low applied ILIS concentrations as in this study. From the results of this study and these experimental data, we speculate that ILIS-SPET can visualize pre-synaptic striatal dopaminergic degeneration in Parkinson's disease.

Value of diuresis renography in the post-natal period of assumed physiological renal immaturity.

The aim of this study was to determine if it is possible to exclude renal obstruction using diuresis renography in the first 6 weeks of life (the period of physiological renal immaturity), thus avoiding unnecessary invasive procedures, such as the Whitaker test or surgery. Diuresis renography with 123I-hippuran was performed in 27 patients aged less than 6 weeks and in 50 older children who acted as a reference group (age 6 weeks to 1 year, n = 28; age 1-10 years, n = 22). All 27 patients had significant dilatation of the pelvicalyceal system on ultrasonography. Renal curves were evaluated by mathematical curve characteristics (split renal function, counts, T-max, etc.) as the visual grade of obstruction. Whole-kidney regions of interest were defined on images summed over 30 min; renal parenchyma on images summed over 5 min. The renal curves of 18/27 patients indicated tracer accumulation and led to frusemide administration. Only two patients showed no significant response to frusemide and had to be further investigated by the Whitaker test. The frequency of kidneys with no response to frusemide revealed no significant differences in the three groups. Whole-kidney evaluation resulted in an overestimation of obstruction in 9/150 kidneys, which matches the lower correlation to the DMSA separation values for this method of evaluation. In contrast with the literature, significant post-renal obstruction can be excluded by diuresis renography in most cases in spite of renal immaturity and can help to avoid invasive procedures.

SPECT imaging with [123I]-beta-CIT in Parkinsonism: comparison of SPECT images obtained by a single-headed and a three-headed gamma camera.

Single photon emission computed tomography (SPECT) imaging of dopamine transporters by using the cocaine derivative [123I]-(1R)-2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane ([123I]-beta-CIT) has been shown to be useful in patients with Parkinsonism. The aim of this study was to compare beta-CIT imaging with single-headed (SHS) and three-headed gamma camera systems (THS). In 17 patients with Parkinsonism, SPECT imaging with an SHS and a THS was performed 24 h after injection of 180 MBq of [123I]-beta-CIT. The SPECT studies were evaluated by visual assessment of the caudate nucleus (CN) and the putamen (PT) and the calculation of the striatal/cerebellar (S/C) ratios (with additional comparison to clinical symptoms measured by the Unified Parkinson's Disease Rating Scale (UPDRS)). The S/C ratios measured by the SHS and THS showed highly significant correlation (two-tailed P < 0.01) with Spearman correlation coefficients (SCCs) of 0.864 for the right side, 0.676 for the left side, and 0.761 for both sides. By the SHS, a sufficient visual differentiation between the CN and the PT could not be achieved. A significantly better distinction could be achieved by using the THS (Wilcoxon P<0.05). The S/C ratios of the THS only showed a significant (P < 0.05) SCC of -0.514 comparing to the UPDRS. Pathological alterations in the beta-CIT uptake pattern could be identified by using the SHS, but a significantly better differentiation of CN and the PT was possible by using the THS. The significant correlation of the S/C ratios measured by THS only emphasizes the value of THS in beta-CIT imaging.

Vascular Parkinsonism: a case report and review of the literature.

Vascular Parkinsonism (VP) is characterised by sudden onset and rapid progression of clinical symptoms, absent or poor response to dopamine substitution therapy, and postural instability with shuffling gait and absence of tremor, making it a clinically distinct entity from idiopathic Parkinson's disease (IPD). Furthermore, it displays certain typical findings in neurological investigations. We report on a patient presenting features of VP associated with an intracerebral lesion not ascribed to VP to date, namely an isolated ischaemic focal lesion located in the left cerebral peduncle between the substantia nigra and nucleus ruber as evidenced by magnetic resonance imaging (MRI). The pathophysiological organic correlate for contralateral extrapyramidal symptoms in this patient may be an interruption of nigro-thalamic projection, interrupting the final subcortical station in the cortic-striato-pallido-nigro-thalamico-cortical loop central to the pathophysiology of parkinsonian syndromes. Non-response t o levodopa therapy could be a consequence of disruption of the cortico-basal ganglia-cortical loop on account of ischaemic destruction of subcortico-cortical axons, the underlying pathology, therefore, not being the result of a loss of nigral dopaminergic neurons or striatal dopamine deficiency pathogonomonic of IPD. To our knowledge, this is the first case of clinically manifest VP to be described with a single lesion in the contralateral cerebral peduncle between the substantia nigra and nucleus ruber, and suggests alternative intracerebral patterns for the distribution of disease-causing lesions in VP, and possibly new pathophysiological explanations for the nature of this disease.

[Carcinoid syndrome. Recurrent upper abdominal pain, diarrhea and flush in a 15-year-old girl]. / Karzinoidsyndrom. Rezidivierende Oberbauchbeschwerden, Durchfall und Flush bei einer 15jährigen Patientin.

BACKGROUND: A carcinoid syndrome is typically diagnosed in elderly patients, median age at diagnosis was 60 years in two large series. We describe a patient with the carcinoid syndrome at the young age of 15 years. CASE REPORT: The 15-year-old patient's history and findings on physical examination, clinical chemistry, abdominal ultrasound and liver biopsy were typical for a carcinoid with hepatic metastases. The patient's age, however, was very unusual. Because of her youth, we discussed a potentially curative treatment with resection of the primary tumor in the upper jejunum followed by liver transplantation at a second operation. This concept had to be abandoned, when the first operation revealed a tumor in the mesenterium, close to the primary, 5 cm in diameter and around the superior mesenteric artery. This tumor could not be resected. Liver transplantation therefore did not offer this young patient a chance for cure.

Correlation of radionuclide ventriculography with roentgenological findings in chemotherapy patients.

Radionuclide ventriculography (RNV) is a common method to evaluate cardiotoxic effects of drugs applied during chemotherapeutic treatment, whereas thoracic radiographs are used to detect morphologic alterations. Aim of this study was to identify radiographic signs, which correlate with RNV parameters and with RNV image quality. For this study, RNV data of 116 patients receiving chemotherapy acquired during 205 RNV studies (some patients underwent up to 7 follow-up examinations) were correlated to roentgenologic findings assessed by 176 thoracic radiographs. Isolated thoracic radiographic signs of cardiac failure showed only slight correlations to left ventricular ejection fractions measured with radionuclide ventriculography, but the orientation of correlation (positive or negative) could be confirmed well by clinical data. This fact matches clinical experience, that radiographic signs of heart insufficiency can surely predict heart damage only when several of them coincide. By the help of this study it was possible to detect radiographic findings, which are of relevance in patients with suspicion of cardiotoxic damage as side effect of high-dose chemotherapy. The clinical value of several radiologic findings should be reassessed to diagnose cardiac failure in chemotherapy patients.

Thyroid remnant dose: 124I-PET/CT dosimetric comparison of rhTSH versus thyroid hormone withholding before radioiodine remnant ablation in differentiated thyroid cancer.

AIM: Recombinant human thyroid-stimulating hormone (rhTSH) recently was approved as an alternative to thyroid hormone withholding (THW) to elevate TSH for thyroid remnant ablation in differentiated thyroid carcinoma patients. High ablation success rates are reported with diverse rhTSH-aided (131)I activities. Improved renal function causes approximately 50% faster radioiodine clearance under euthyroidism versus hypothyroidism. Knowledge of comparative remnant radioiodine kinetics, particularly the remnant radiation dose in Gy/GBq of administered (131)I activity (RDpA), could assist in choosing rhTSH-aided ablative activities. MATERIAL AND METHODS: To compare the RDpA, determined through (124)I-positron emission tomography/computed tomography (PET/CT), under the two stimulation methods, we retrospectively divided into two groups 55 consecutive totally-thyroidectomized, radioiodine-naïve patients. The rhTSH group (n=16) received (124)I on thyroid hormone, 24 h after two consecutive daily intramuscular injections of rhTSH, 0.9 mg. The THW group (n=39) received (124)I after weeks-long THW, when serum TSH first measured > or = 25 mIU/L. We performed PET investigations 4 h, 24 h, 48 h, 72 h and 96 h and PET/CT 25 h after (124)I administration. RESULTS: Median stimulated serum thyroglobulin was 15 times higher (p=0.023) and M1 disease almost twice as prevalent (p=0.05) in rhTSH versus THW patients. Mean+/-standard deviation RDpA was statistically equivalent between the groups: rhTSH, 461+/-600 Gy/GBq, THW, 302+/-329 Gy/GBq, two-sided p=0.258. CONCLUSIONS: rhTSH or THW deliver statistically equivalent radiation doses to thyroid remnant and may be chosen based on safety, quality-of-life, convenience and pharmacoeconomic factors. Institutional fixed radioiodine activities formulated for use with THW need not be adjusted for rhTSH-aided ablation.