Detectability and structural stability of a liquid fiducial marker in fresh ex vivo pancreas tumour resection specimens on CT and 3T MRI

PURPOSE: To test the detectability of a liquid fiducial marker injected into ex vivo pancreas tumour tissue on magnetic resonance imaging (MRI) and computed tomography (CT). Furthermore, its injection performance using different needle sizes and its structural stability after fixation in formaldehyde were investigated.

METHODS: Liquid fiducial markers with a volume of 20-100 µl were injected into freshly resected pancreas specimens of three patients with suspected adenocarcinoma. X‑ray guided injection was performed using different needle sizes (18 G, 22 G, 25 G). The specimens were scanned on MRI and CT with clinical protocols. The markers were segmented on CT by signal thresholding. Marker detectability in MRI was assessed in the registered segmentations. Marker volume on CT was compared to the injected volume as a measure of backflow.

RESULTS: Markers with a volume ≥20 µl were detected as hyperintensity on X‑ray and CT. On T1- and T2-weighted 3T MRI, marker sizes ranging from 20-100 µl were visible as hypointensity. Since most markers were non-spherical, MRI detectability was poor and their differentiation from hypointensities caused by air cavities or surgical clips was only feasible with a reference CT. Marker backflow was only observed when using an 18-G needle. A volume decrease of 6.6 ± 13.0% was observed after 24 h in formaldehyde and, with the exception of one instance, no wash-out occurred.

CONCLUSIONS: The liquid fiducial marker injected in ex vivo pancreatic resection specimen was visible as hyperintensity on kV X‑ray and CT and as hypointensity on MRI. The marker's size was stable in formaldehyde. A marker volume of ≥50 µL is recommended in clinically used MRI sequences. In vivo injection is expected to improve the markers sphericity due to persisting metabolism and thereby enhance detectability on MRI.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:195

Enthalten in:

Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al - 195(2019), 8 vom: 01. Aug., Seite 756-763

Sprache:

Englisch

Weiterer Titel:

Detektierbarkeit und strukturelle Stabilität eines flüssigen Bezugsmarkers in frisch resezierten Ex-vivo-Pankreastumorpräparaten in CT und 3T-MRT

Beteiligte Personen:

Schneider, Sergej [VerfasserIn]
Aust, Daniela E [VerfasserIn]
Brückner, Stefan [VerfasserIn]
Welsch, Thilo [VerfasserIn]
Hampe, Jochen [VerfasserIn]
Troost, Esther G C [VerfasserIn]
Hoffmann, Aswin L [VerfasserIn]

Links:

Volltext

Themen:

1HG84L3525
Ex vivo
Fiducial marker
Formaldehyde
Journal Article
MRI detectability
Pancreatic adenocarcinoma

Anmerkungen:

Date Completed 12.02.2020

Date Revised 25.02.2020

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s00066-019-01474-1

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM297618571