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An 80-year-old woman with osteoporosis without fractures was referred with asymptomatic primary hyperparathyroidism and elevated calcitonin level. Ultrasound, 99m Tc-pertechnetate scintigraphy, 99m Tc-MIBI scintigraphy, and CT revealed a suspicious thyroid nodule and enlarged submandibular lymph nodes. However, no parathyroid adenoma was depictable. 18 F-choline PET/CT showed increased uptake of the proximal esophagus, but neither CT nor US revealed a parathyroid lesion, and only 18 F-choline PET/US fusion imaging confirmed a paraesophageal parathyroid adenoma. Resection of both medullary thyroid carcinoma and ectopic parathyroid adenoma through a single cervicotomy was conducted (thyroidectomy, neck dissection, extirpation of parathyroid adenoma); parathyroid hormone and calcitonin dropped to normal. Multiple endocrine neoplasia IIa syndrome was suspected.

Purpose: To evaluate the microsphere outflow dynamics and residual Ho-166 activity during and after transarterial radioembolization planning and treatment procedures, and to assess the distribution and predilection sites of residual activity in the proprietary delivery set and the microcatheter. Materials and Methods: Fifteen planning and 12 therapeutic radioembolization procedures were performed with poly-l-lactic acid microspheres loaded with Ho-166. The amount and distribution of residual activity was assessed by dose calibrator measurements and SPECT imaging. The activity flow profile from the microcatheter was assessed dynamically. For planning procedures, different injection methods were evaluated in order to attempt to decrease the residual activity. Results: The median residual activities for planning and treatment procedures using standard injection methods were 31.2% (range 17.3%–44.1%) and 4.3% (range 3.5%–6.9%), respectively. Planning residual activities could be decreased significantly with 2 injection methods similar to treatment procedures, to 17.5% and 10.9%, respectively ( P = 0.002). Main predilection sites of residual microspheres were the 3-way stopcock and the outflow needle connector. During treatment procedures, more than 80% of the injected activity is transferred during the first 3 injection cycles. Conclusion: After treatment procedures with holmium-loaded microspheres, mean residual activity in the delivery set is reproducibly low and between reported values for glass and resin microspheres. The majority of microspheres is transferred to the patient during the second and third injection cycle. An estimated residual waste of 3% to 4% may be included in the treatment activity calculation. For planning procedures, a modified injection technique should be used to avoid high residual activities.

A 68-year-old woman was referred with the diagnosis of symptomatic pHPT (primary hyperparathyroidism). Ultrasonography (US) and 99mTc-MIBI scintigraphy could not clearly identify a parathyroid adenoma. A primary unilateral surgical exploration remained unsuccessful to remove adenomatous parathyroid tissue and the pHPT persisted. 18F-ethylcholine PET/CT showed a left-sided retropharyngeal lesion with intense tracer uptake that could not be detected on US images at first sight. Therefore, additional 18F-ethylcholine PET/US fusion imaging was performed and revealed a poorly definable nodular structure on US that could be unambiguously correlated to the PET finding. Surgical excision confirmed an oncocytic variant of parathyroid adenoma, and parathormone and calcium levels normalized immediately.

To investigate the interobserver agreement (IA) and the impact of consensus reading using four risk stratification systems for thyroid nodules (TN). Four experienced specialists independently rated US images of 80 TN according to the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines. The cases were randomly extracted from a prospectively acquired database (n > 1500 TN). The observers were blinded to clinical data. This study was divided into two sessions (S1 and S2) with 40 image sets each. After every session, a consensus reading was carried out (C1, C2). Subsequently, the effect of C1 was tested in S2 with 40 new cases followed by C2. Fleiss’ kappa (κ) was calculated for S1 and S2 to estimate the IA and learning curves. The results of C1 and C2 were used as reference for diagnostic accuracy calculations. IA significantly increased (p

To investigate the value of I-124 positron emission tomography (PET) / ultrasound (US) fusion imaging in comparison to conventional diagnostics (CD) of Thyroid nodules (TN) by multiple observers. Digital patient case files (PCF) of patients that received CD and I-124-PET/US in clinical routine were prepared containing cine-loops of the examinations. All physicians with nuclear medicine specialty from Germany, Austria, and Switzerland were invited to participate. 106 acquired observers completed 7.2 ± 1.8 (median: 8, range: 4-14) randomly assigned PCF (CD only or CD+PET/US). They assessed the TN function, stated their confidence in functional assessment, and suggested a treatment course for each TN. 68 PCF of 34 patients comprising 66 TN ≥ 1 cm (= 1.94 TN/patient) were created. A total of 748 (11.2/TN), and 751 ratings (11.4/TN) were recorded for CD only, and CD+PET/US, respectively. The functional assessment revealed more hyper- or hypofunctioning (524 vs. 320, p 0.0001) and less indifferent or not rateable (209 vs. 428, p 0.0001) TN in CD+PET/US vs. CD only. The observers' confidence in functional assessment was superior in CD+PET/US (p 0.0001). Furthermore, the ratings were carried out more homogeneous in CD+PET/US (p 0.0001). Fewer suggestion of follow up (p 0.0001), and more (p 0.0001) suggestion of invasive treatments (fine-needle aspirationsurgery) was observed in CD+PET/US. Radioiodine therapy was more often (p = 0.0036), and thyroid medication less often (p = 0.0167) advised in CD+PET/US. Functional assessment of equivocal TN shows frequent failures in CD, underestimating the incidence of hyper- and hypofunctioning lesions. Confidence in functional assessment significantly increases with additional PET/US. This influences the proposed treatment course.ZIEL: Multi-Observer-Untersuchung des diagnostischen Mehrwerts der I-124-Positronenemissionstomografie (PET)/Ultraschall (US) -Fusionsbildgebung im Vergleich zur konventionellen Diagnostik (CD) bei der Funktionsbeurteilung von Schilddrüsenknoten. Es erfolgte die Erstellung digitaler Patientenakten inklusive Filmsequenzen von Probanden, die im Rahmen der klinischen Routine sowohl mittels CD als auch I-124-PET/US untersucht wurden. Alle nuklearmedizinischen Ärzte aus Deutschland, Österreich und der Schweiz waren zur Teilnahme eingeladen. 106 Untersucher absolvierten jeweils 7,2 ± 1,8 (Median: 8, Bandbreite: 4–14) randomisiert zugewiesene digitale Patientenakten (CD oder CD+PET/US). Sie beurteilten die Funktion der Schilddrüsenknoten, ihre subjektive Sicherheit bei der Funktionsbeurteilung und schlugen einen Behandlungsverlauf vor. 68 digitale Patientenakten von 34 Patienten mit 66 Schilddrüsenknoten ≥ 1 cm (= 1,94 Knoten pro Patient) wurden erstellt. Insgesamt wurden 748 Bewertungen (11,2 pro Knoten) für CD und 751 Bewertungen (11,4 pro Knoten) für CD+PET/US dokumentiert. Bei CD+PET/US wurde die Funktion der Knoten im Vergleich zu CD häufiger als hyper- oder hypofunktionell (524 vs. 320; p 0,0001) und seltener als indifferent oder nicht bewertbar (209 vs. 428; p 0,0001) beurteilt. Die subjektive Sicherheit der Untersucher war bei CD+PET/US höher (p 0,0001) und die Funktionsbeurteilungen wurden mit größerer Homogenität abgegeben (p 0,0001). Bei CD+PET/US wurden im Vergleich zu CD weniger Verlaufskontrollen (p 0,0001), mehr invasive Behandlungen (FeinnadelaspirationOperation) (p 0,0001), häufiger Radioiodtherapien (p = 0,0036) und seltener medikamentöse Therapien (p = 0,0167) empfohlen. Die Funktion von Schilddrüsenknoten wird in der konventionellen Diagnostik häufig falsch beurteilt. Der Anteil hyper- oder hypofunktioneller Läsionen wird unterschätzt. Die subjektive Sicherheit bei der Funktionsbeurteilung steigt durch den Einsatz der I-124-PET/US. Diese Ergebnisse beeinflussen die vorgeschlagenen Behandlungsverläufe.

SIRT is an established treatment option for liver malignancies. Metabolic information can provide additional knowledge about tumoral characteristics and treatment response. FDG-PET/CT was shown to be advantageous for pre-/post-SIRT evaluation. However, whole-body PET/CT is an elaborate procedure. The aim of the study was to optimize clinical efficacy assessment after SIRT with a low-dose, low-cost protocol for focused diagnostic work-up. An abdomen-only minimal-activity FDG-PET/CT protocol (MA-PET) was established as an alternative for clinically indicated whole-body PET/CT scans. After administering 40 MBq of F-18-FDG one bed position was scanned for 15 minutes. Scans were acquired before (initial scan), one month after (interim scan) and three months after SIRT (follow-up scan). Metabolic tumor activity was evaluated and was compared to standard CT follow-up results. 50 lobar SIRT procedures in 37 patients were analysed. HCC (28), hepatic metastases (15) and CCC (7) were treated. In 18 liver lobes initial MA-PET did not show hypermetabolic lesions, 32 liver lobes underwent interim and follow-up MA-PET. All 114 MA-PET were technically feasible. Mean radiation dose was 1.9 mSv. 64 % of HCC presented low metabolism at baseline, whereas metastases and CCC were all clearly PET-positive. Majority of radiated liver tumors showed at least partial metabolic response. PET/CT results diverged from follow-up CT in 63 % of cases. Minimal-Activity FDG-PET/CT of the liver is a feasible tool for efficacy assessment after SIRT with low financial and radiation burden. It provides additional information to morphologic imaging modalities, which can be helpful in response appraisal and treatment planning.ZIEL: Die FDG-PET/CT erwies sich im Rahmen der SIRT als gewinnbringend für die prä- und posttherapeutische Diagnostik. Dennoch wird diese aufgrund des hohen Aufwands häufig nicht angewendet. Ziel unserer Untersuchung war die Optimierung der Therapiekontrolle nach SIRT mittels eines fokussierten, kostensparenden Niedrigdosis-PET-Protokolls. Ein Oberbauch-zentriertes, Minimal-Aktivitäts-FDG-PET/CT-Protokoll (MA-PET) wurde für klinisch indizierte Untersuchungen etabliert. Nach Injektion von 40 MBq F-18-FDG wurde eine Bettposition über 15 Minuten akquiriert. Die MA-PET wurden einen Tag vor, einen Monat nach und drei Monate nach SIRT durchgeführt. Das metabolische Therapieansprechen wurde ermittelt und mit der CT-Verlaufskontrolle verglichen. 50 lobäre SIRT-Prozeduren, darunter 28 HCC, 15 hepatische Metastasen und 7 CCC, wurden betrachtet. Von 37 eingeschlossenen Patienten erhielten 13 eine zusätzliche SIRT der Gegenseite. Alle Metastasen und CCC waren PET-positiv, 64 % der HCC hingegen initial PET-negativ. 32 Leberlappen mit initial hypermetabolen Läsionen wurden mittels MA-PET verlaufskontrolliert. Alle 114 MA-PET waren technisch durchführbar. Die mittlere Strahlenbelastung pro Untersuchung lag bei 1,9 mSv. Die Mehrheit der Lebertumoren zeigte mindestens ein partielles Therapieansprechen, wobei sich die MA-PET-Ergebnisse in 63 % der Fälle von denen der Standard-CT unterschieden. MA-PET der Leber ist ein zuverlässiges und geeignetes Verfahren zur Beurteilung der SIRT-Wirksamkeit, mit welchem Strahlenbelastung und Kosten eingespart werden können. Im Vergleich zur morphologischen Bildgebung werden auch mit dem neu etablierten Protokoll zusätzliche Informationen gewonnen, die für Verlaufskontrolle und Therapieplanung nützlich sein können.

Both, ultrasonography but also radionuclide imaging using [99mTc]Pertechnetate or radioactive iodine isotopes are essential tools used during the diagnostic workup of hyperthyroidism with or without structural alterations of the thyroid. Colour duplex sonography and ultrasound elastography may add important information in order to find the cause of the hormone excess. During the last years, also hybrid imaging using SPECT/-(CT) or PET-based methods, such as [124]Iodine-PET/CT or [124]Iodine-PET/ultrasound also have nodularbeen increasingly used and especially play a role in the context of localizing ectopic thyroid tissue or in multinodular goiter. Recently also promising data has been published on the use of [99mTc]MIBI imaging in amiodarone induced hyperthyroidism.

Short-term follow-up examinations could verify ambiguous findings in PET/CT diagnostics, but are often avoided due to radiation and financial burdens. We demonstrate the feasibility of a focused, minimal-activity PET protocol as a supplemental examination for uncertain findings after standard PET/CT. After changing conditions, e.g. patient positioning, preparation and bypassing an interval as well as a targeted tracer change, an additional examination with less than 1 mSv of additional radiation exposure was performed. Lowered administered activity of radiopharmaceuticals could be compensated by prolonged acquisition time, which was made possible by the limitation to a single body region. A sufficient visual and quantitative image quality of scans could be achieved. In all cases, the ambiguous finding could be clarified, so further diagnostic procedures or unnecessary interventions were avoided.

Lung scintigraphy was performed to rule out pulmonary embolism in a 37-year-old woman suffering from dyspnea and hypoxemia after routine diagnostics failed to find the underlying disease. Perfusion scans did not show tracer uptake within the lungs despite ventilation scans being unremarkable. Instead, the result suggested a complete right-to-left shunt, which was a conundrum. With the assistance of CT an uncommon congenital vessel aberration turned out to be the cause of this exceptional scintigraphy finding, as well as the yet unexplained hypoxemia.

SPECT using Tc-99m-dimercaptosuccinic acid (DMSA-camSPECT) and ultrasound (US) are useful diagnostic modalities in pediatric nephrology. Former studies proved SPECT/US fusion to be a problem-solving tool for thyroid and sentinel lymph node imaging. The purpose of this study was to demonstrate the feasibility of real-time DMSA-camSPECT/US fusion in children and to evaluate the technical implementation. Subsequent to a clinical indicated DMSA-camSPECT showing a mostly normal result, 10 children received a SPECT/US fusion. The magnetic sensor-navigated equipment allows a real-time superposition of three-dimensional SPECT data to live US images according to the position of the transducer. 100 % of still images and 90 % of cine-loops were sufficient to depict the kidney; at least one sufficient camSPECT/US fusion loop could be accomplished for every kidney examined. Limitations are mainly caused by standard difficulties of conventional US. Real-time DMSA-camSPECT/US is feasible in depiction of renal parenchyma. This newly implemented application broadens the scope of SPECT/US fusion imaging. SPECT mit Tc-99m-Dimercaptobernsteinsäure (DMSA-camSPECT) und Ultraschall (US) sind wichtige Diagnosemodalitäten in der pädiatrischen Nephrologie. Frühere Studien haben gezeigt, dass die Schilddrüsen- und Sentinel-Lymphknoten-Diagnostik von der SPECT/US-Fusionsbildgebung profitieren kann. Ziel dieser Studie war es, die Realisierbarkeit der Echtzeit-DMSA-camSPECT/US-Fusionsbildgebung kindlicher Nieren zu demonstrieren und deren technische Durchführung zu evaluieren. Nach einer klinisch indizierten DMSA-camSPECT mit weitgehend normalem Befund erhielten 10 Kinder eine SPECT/US-Fusionsbildgebung. Auf Grundlage magnetischer Koregistrierung wird die Überlagerung 3-dimensionaler SPECT-Daten mit US-Bildern in Echtzeit möglich. Bei allen Standbildern und bei 90 % aller Videoaufnahmen war eine Beurteilung der Nieren möglich, wobei mindestens 1 suffiziente Videoaufnahme für jede untersuchte Niere vorlag. Limitationen der camSPECT/US-Fusionsbildgebung wurden hauptsächlich durch die bekannten Herausforderungen der konventionellen Nierensonografie verursacht. Die Echtzeit-DMSA-camSPECT/US-Fusionsbildgebung ermöglicht die Darstellung des kindlichen Nierenparenchyms, wodurch der Anwendungsbereich der SPECT/US-Fusionsbildgebung erweitert wird.

Thyroid nodules are a common finding, especially in iodine-deficient regions. Ultrasonographic scoring systems such as the Thyroid Imaging Reporting and Data System (TIRADS) are helpful in differentiating between benign and malignant thyroid nodules by offering a risk stratification model. Depending on the constellation or number of suspicious ultrasound features, a fine-needle biopsy is recommended. However, none of the previous TIRADS publications considered the functional status of the nodules. Hyperfunctioning thyroid nodules (HTNs) were presumed to exclude malignancy with a very high negative predictive value. Particularly in regions where the iodine supply is low, most HTNs are seen in patients with normal thyroid-stimulating hormone levels. Therefore, thyroid scintigraphy is essential for the detection of HTNs. We investigated whether TIRADS identifies HTNs as nonsuspicious. Methods: We evaluated 615 HTNs (23.2 ± 10.0 mm in maximum diameter in 582 patients ([442 women, 57.7 ± 13.2 y old, and 140 men, 60.1 ± 12.7 y old) detected by 99mTc-pertechnetate or 123I scintigraphy. Before evaluating the scintigraphic appearance, all nodules were analyzed prospectively with sonography, using the TIRADS model referenced in Kwak et al., wherein fine-needle biopsy is recommended for TIRADS 4A or higher. We also investigated 2 subgroups, 42 nodules with available histology and 117 patients with subclinical or overt hyperthyroidism. Results: Whereas 15.9% of the nodules were classified as TIRADS 3 or lower and less than 0.1% as TIRADS 5, most of the nodules were classified as TIRADS 4A (29.3%), 4B (29.3%), or 4C (24.9%). Altogether, more than 80% of the autonomous thyroid nodules were classified as TIRADS 4A or higher, a grade that would result in a recommendation of fine-needle biopsy. Focusing on those 117 HTNs that were already associated with hyperthyroid laboratory values, the rates were similar: 81.2% were categorized as TIRADS 4A or higher (4A, 33.3%; 4B, 29.9%; 4C,17.1%; 5, 0.9%). In the subgroup of patients who underwent thyroid surgery, all nodules were benign, confirming the known negative predictive value of HTNs with regard to malignancy exclusion. Conclusion: Integration of thyroid scintigraphy into the TIRADS model is essential to prevent unnecessary fine-needle biopsy and thyroid surgery.

A 67-year-old woman presented with malignant struma ovarii after radical bilateral salpingo-oophorectomy. The surgery revealed a 4.4 cm papillary thyroid carcinoma (follicular variant) within a right-sided ovarian teratoma. I sodium iodide positron emission tomography / computed tomography and cervical ultrasound showed 2 slightly hyperfunctional thyroid nodules and several metastases, including bone metastases with intense iodine uptake. Thyroidectomy was necessary in preparation for radioiodine therapy and proofed the thyroid nodules to be benign. Complete remission was achieved by single radioiodine therapy (30 months of follow-up).

Gallium-68-labeled prostate-specific membrane antigen ligands are not only established radiopharmaceuticals for staging of prostate cancer but also accumulate physiologically in nonprostate organs, including the salivary glands. We show the converted application of prostate-specific membrane antigen -positron emission tomography/computed tomography (PSMA-PET/CT) as a dedicated method to depict salivary gland tissue using a region-focused, low-dose protocol. An accessory parotid gland at the right buccal region could be confirmed; therefore, further diagnostic or invasive therapeutic steps were not necessary.

The purpose of this study is to investigate I-124 positron emission tomography (PET)/ultrasound (US) fusion imaging for function assessment of thyroid nodules. In 70 patients, 201 lesions were examined with conventional diagnostics (CD) (thyroid US, laboratory findings and Tc-99m pertechnetate scintigraphy), Tc-99m pertechnetate single photon emission computed tomography (SPECT) and I-124 PET/computed tomography (CT). Subsequently, US fusion imaging (SPECT/US and PET/US) was performed by three experienced investigators. Patients referred for thyroid diagnostics in a clinical routine setting were included in this study if CD produced equivocal results. PET/US was superior to CD and SPECT/US in 96% and 86%, respectively, and ambiguous findings in CD were clarified by PET/US in 96% of the 70 patients. Regarding nodule-based function assessment, 10% (66%), 39% (14%) and 71% (4%) of the 201 lesions were rated with absolute certainty (equivocal or uncertain) using CD, SPECT/US and PET/US, respectively (p < 0.001). PET/US has the potential to improve the function assessment of thyroid nodules in comparison to CD.

Fine-needle aspiration cytology using a novel ultrasound needle guidance system on the basis of standard needle magnetization was consecutively performed in 30 (15 in-plane and 15 out-of-plane) suspicious thyroid nodules. Nondedicated, commercially available needles were used. The technical effectiveness and safety of the system were satisfying; system failures were observed in 2 cases. The needle tip could be (at least occasionally) visualized inside the thyroid nodule in 96%, and the subjective procedure ratings were excellent in 57%. The out-of-plane technique was significantly superior in both respects (P = .021 and .027, respectively). Standard needle magnetization ultrasound needle guidance was easy to apply and cost-effective and has the potential to improve fine-needle aspiration cytology performance.

Side-by-side evaluation of thyroid ultrasound (US) and 99mTcO4 scintigraphy can lead to uncertainties in the correct topographic assignment of thyroid nodules. The aim of this study was to evaluate 99mTcO4 single-photon emission computed tomography/ultrasound (SPECT/US) fusion imaging. Seventy-nine patients were prospectively investigated. If conventional diagnostics of the thyroid gland (B-mode-US, scintigraphy) produced unclear findings, SPECT was performed and transferred to a US device for real-time sensor-navigated 3-D fusion US investigation. The data sets were manually matched according to their contours. Finally, SPECT/US versus conventional diagnostics was rated using an ordinal 4-point scale (SPECT/US >> conventional diagnostics, SPECT/US > conventional diagnostics, SPECT/US = conventional diagnostics, SPECT/US >, >) in 84% and equivalent (=) in 16% of the cases, respectively. No statistically significant differences were observed for uni-, bi- and multinodular goiters (p ≥ 0.3). In 67%, the respective problem that arose after conventional diagnostics was clarified by SPECT/US. SPECT/US was feasible and was helpful for the clarification of uncertain functionality assessments of thyroid nodules.

The purpose of this study is to compare functional MR urography (MRU) with the results of ultrasound and radionuclidePediatric patients with proven congenital anomalies of the kidney and urinary tract were included (n = 112). The morphologic findings of MRU were compared with previous diagnostic ultrasound findings. For evaluation of split renal function and urinary tract obstruction, MAG3 scintigraphy was used as a reference standard.MRU provided detailed morphologic information of the whole urinary tract for all 112 patients. In 94.6% of cases (n = 106), diagnostic findings could be verified, and in 5.4% of cases (n = 6), more detailed information could be gained. Equivalent split renal function showed good concordance between functional MRU and MAG3 scintigraphy. However, in kidneys with restricted function (35%), functional MRU underestimated the remaining renal function, with a mean difference of 6.6% and an SD of 24.4%. For evaluation of relevant urinary tract obstruction, the sensitivity of functional MRU was 100%, specificity was 81.6%, positive predictive value was 70.8%, and negative predictive value was 100%.Regarding split renal function, functional MRU shows a lack of accuracy in comparison with the clinical standard MAG3 scintigraphy, especially in patients with severely diminished function of one kidney. However, functional MRU allows an adequate assessment of urinary tract obstruction and a high-resolution morphologic evaluation of the whole urinary tract. Thus, functional MRU is suitable to add diagnostic value, especially as a complementary examination for complex individual cases in the presurgical state.

A 49-year-old woman presented with a multinodular goiter, causing local symptoms and hyperthyroisdism. Besides a hypofunctioning benign nodule (TIRADS 3, benign in FNAC), the conventional diagnostic revealed another small hyperfunctioning nodule with suspicious ultrasound features (TIRADS 4C). To rule out a trapping-only nodule and topographical misalignments, a I PET/ultrasound fusion was performed and confirmed elevated iodine uptake within the suspicious nodule. Further disseminated autonomous areas are suspected to be additionally responsible for the low TSH-level. Because of the local cervical symptoms and the hyperthyroidism, the patient underwent surgery. The small hyperfunctioning nodule turned out to be a classic papillary microcarcinoma.

Unexpected inflammatory activity of tumoral calcinosis periarticular to the shoulders and hips in a man with recurrent fever of unknown origin and dialysis-dependent kidney insufficiency was revealed by FDG PET/CT. In absence of other pathologies, the calcinosis was deemed to be the cause of the fever. An infectious or malignant disease could be ruled out, so further therapeutic steps were enabled.

To assess the radiation exposure of the investigator during navigated fusion of nuclear medicine images with ultrasound after application of I-124. Dosimetry with two different types of thermoluminescent detectors (TLD) was performed in 25 patients. The dose rate at the patient's neck was measured with a calibrated dose rate meter (DRM) and served as the standard of reference. The average exposure per investigation at the patient's neck measured by LiF:Mg,Cu,P TLDs (cumulative: 212 μSv), LiF:Mg,Ti TLDs (cumulative: 112 μSv) and DRM (cumulative: 150.3 μSv). The radiation exposure of the hand during navigated fusion of nuclear medicine imaging with 124I and ultrasound with a mean duration of 13 min is low and comparable between different methods. Yearly examinations are not expected to add a relevant cumulative risk.

The preoperative diagnosis of differentiated thyroid carcinomas (DTC) is particularly challenging in view of the high prevalence of thyroid nodules in the general population. Incidental diagnosis of DTC, on the other hand, can lead to reoperations and increased risk of morbidity. This study aimed to assess the prediction value of preoperative DTC dignity assessment and it's impact on surgical approaches.We retrospectively reviewed 107 cases of DTC and subdivided them in three groups based on the preoperative dignity assessment: suspected malignancy (SM), unclear dignity (UD), and incidental findings (IF). The group differences were investigated in terms of diagnostic methods, findings, and impact on the subsequent surgical approach.The patient groups consisted of n = 51 (SM), n = 32 (UD), and n = 24 (IF). The tumor size, T staging, and ultrasound (US) assessment had the largest impact on the dignity classification (each p0.001). Scintigraphy was performed in 80 % of the patients, fine-needle aspiration cytology (FNAC) in 28 %. Hypofunction at scintigraphy (p0.001) and cytology results (p0.01) were identified as significant predictors for group assignment. Other significant factors were the frequency of the US documentation of nodule characteristics (p0.001) and malignancy criteria (p0.01) as well as reduced thyroid-stimulating hormone (TSH) levels (p0.01). Frozen section (p0.001) and total thyroidectomy (p0.01) at initial surgery were performed significantly more often in the MV group. Reoperations were significantly more frequent in the IF group (p0.001).A relevant number of DTC cases was diagnosed incidentally, leading to significantly more frequent reoperations. A more systematic diagnostic approach with complete documentation of the findings according to current guidelines should be pursued.Die hohe Prävalenz von Schilddrüsenknoten stellt vor dem Hintergrund des geringen Anteils thyreoidaler Malignome besondere Herausforderungen an die Diagnostik. Der inzidentelle Nachweis differenzierter Schilddrüsenkarzinome (DTC) kann zu Nachoperationen mit erhöhter Morbidität führen.Auf Grundlage der präoperativen Dignitätsbeurteilung wurden 107 DTC in drei Gruppen eingeteilt: Malignitätsverdacht (MV), unklare Dignität (UD) und Zufallsbe-fund (ZB). Untersucht wurden die Unterschiede der präoperativen Diagnostik zwischen diesen Gruppen sowie die Abhängigkeit der chirurgischen Versorgung von der präoperativen Dignitätsbeurteilung.Den Gruppen wurden 51 (MV), 32 (UD) und 24 (ZB) Patienten zugeordnet. Die Tumorgröße und das T-Stadium sowie die Beurteilung der Sonographie zeigten den größten Einfluss auf die präoperative Dignitätsbeurtei-lung (jeweils p0,001). Szintigraphien und Feinnadelaspirationszytologien erfolgten bei 80 % bzw. 28 % aller Patienten, wobei der Nachweis von Hypofunktionalität (p0,001) und der Zytologiebefund (p0,01) als Prädiktoren identifiziert wurden. Weitere Einflussfaktoren waren die Häufigkeit der Dokumentation sonographischer Knotenmerkmale (p0,001) und Malignitätskriterien (p0,01) sowie ein erniedrigter TSH-Wert (p0,01). In der MV-Gruppe erfolgten häufiger Schnellschnittuntersuchungen (p0,001) und primär totale Resektionsverfahren (p0,01). Komplettierungsoperationen waren in der ZB-Gruppe öfter notwendig (p0,001).Ein relevanter Teil der DTC tritt inzidentell auf. Bei diesen Patienten finden gehäuft Komplettierungsoperationen statt. Daher sollte auf den konsequenten Einsatz und die vollständige Dokumentation der in den Leitlinien empfohlenen Diagnostikverfahren hingewirkt werden.

Evaluation of thyroid ultrasound and Tc-pertechnetate scintigraphy side by side frequently produces ambiguous results regarding the correct assignment of anatomy and functionality of a nodule. We describe the usefulness of Tc-pertechnetate-SPECT/US-fusion imaging. A 75-year-old woman was referred for exclusion of cold nodules. After conventional diagnostics (in vitro thyroid parameters, B mode-US, planar Tc-pertechnetate-thyroid scintigraphy), a SPECT was performed using a conventional gamma camera. The SPECT data set was transferred to an ultrasound device (LOGIQ E9), and sensor-navigated 3D ultrasound was performed. Both data sets (SPECT/US) were fused in real time, revealing the exact functional state of multiple nodules.