Purpose

To evaluate the technical performance of two different multi-arterial phase techniques in liver MRI.

Material and methods

From February 2017 to December 2018, we enrolled 273 randomized patients who underwent liver MRI using CAIPIRINHA (Controlled Aliasing in Parallel Imaging Results in Higher Acceleration) or TWIST-VIBE (Siemens, Erlangen, Germany) before and after the administration of gadoxetic acid (Gd-EOB-DTPA) (dose: 0.025ml/kg; injection rate: 1ml/s). The acquisition time of both sequences is superimposable (<20s). The protocol includes 3 arterial phases (6.5s each for CAIPIRINHA; 9s, 4s, 4s for TWIST-VIBE) with the possibility of reducing them depending on the patient's fitness level. The images were evaluated by two dedicated radiologists, who quantify Gibbs artifacts and noise (present/absent), breath artifacts and general quality of images using a score from 1 to 5 (1 “non-diagnostic” and 5 “absence of artifacts”/“optimal exam quality”).

Results

There is no statistically significant difference between the demographic data of CAIPIRINHA and TWIST-VIBE cohort. CAIPIRINHA has always a better quality score (p>0.02) but we could not obtain a three-arterial-phase study in all patients (3%). TWIST-VIBE has worse Gibbs and breath score artifact but better noise score.

Conclusion

CAIPIRINHA always allows to obtain a diagnostic image, rarely at the expense of the three arterial phases (0% with one phase, 3% with two phases, 97% with three phases). TWIST-VIBE always allows to obtain three arterial phases. CAIPIRINHA better tolerates artifacts at the detriment of image resolution; TWIST-VIBE has a better signal-to-noise ratio but greater susceptibility to artifacts. The choice of one or the other must take into account patient's compliance and physical characteristics.

Purpose

To investigate long term results of endobiliary biopsy performed with a transluminal forceps set in metastatic biliary involvement.

Material and methods

Between September 2014 and June 2019, 25 patients (18 male (72%), mean age 65± 15 years) underwent 26 biliary forceps biopsy procedures with a dedicated set (Cook Medical, USA). All patients presented with obstructive jaundice, suspected malignant, and pre-procedural MR-cholangiopancreatography was obtained. The procedure was performed during percutaneous internal-external biliary drainage positioning, under fluoroscopic guidance. The study’s primary endpoints included technical success and complications rates. The study’s secondary endpoints were sensitivity, specificity and diagnostic accuracy for the characterization of malignancy.

Results

Technical success rate was 96% (25 cases) with histological diagnosis of phlogistic stenosis in 5 cases, 6 case of pancreatic adenocarcinoma, 8 colon rectal liver metastases, 3 hepatocellular carcinoma and 3 cases of normal biliary mucosa. In 1 case the sample was considered insufficient by the pathologist (1 pancreatic adenocarcinoma) and the procedure was successfully repeated. The 6 to 48 months follow-up showed 5 false negative cases, in particular 2 case of non colon rectal liver metastases (breast and gastric cancer) and 3 metastatic hilar lymph nodes. The statistical analysis revealed a sensitivity of 77%, specificity of 100% and overall accuracy of 80%. The complications rate was 11,5% (3 cases with transient haemobilia).

Conclusion

Transluminal biliary biopsy performed with forceps set is a safe and effective minimally invasive procedure for histological characterization in patients presenting with obstructive jaundice due to non-primary biliary tumor.

Purpose

To evaluate intra-patient and interobserver variability in patients who underwent liver MRI with Gd-EOB-DTPA using two different multi-arterial phase techniques.

Material and methods

Two radiologists retrospectively analysed 154 prospectively enrolled patients. Every patient underwent liver MRI twice from February 2017 to March 2019, using two different multi-arterial algorithm: CAIPIRINHA (Controlled Aliasing in Parallel Imaging Results in Higher Acceleration) or TWIST-VIBE (Siemens, Erlangen, Germany). For every patient, breath-holding time, BMI, sex, age were recorded before the second MRI.

The unenhanced phase and every arterial phase (after administration of Gd-EOB-DTPA; dose: 0.025ml/kg; injection rate: 1ml/s) were evaluated using different scores to quantify Gibbs artifacts and noise (present/absent), breath artifacts and general quality of images (score from 1 to 5, 1 being “non-diagnostic” and 5 “absence of artefacts”/“optimal exam quality”).

Results

Breath-holding time is the main parameter that influences the performance of multi-arterial techniques. CAIPIRINHA images have always better scores for every parameter considered, with the exception of noise score analysis. 37% fail to obtain three arterial phases: in particular, 11% have only one arterial phase, 26% have two. TWIST-VIBE images have worse score for Gibbs and breath artifacts but better noise score.

Conclusion

CAIPIRINHA always permits to obtain diagnostic images, at the expense of three arterial phase in 37% of cases. TWIST-VIBE always permits to obtain three arterial phases.

Breath-holding time is the only parameter which can influence the preliminary choice between CAIPIRINHA and TWIST-VIBE algorithm. If the patient is very compliant, TWIST-VIBE is preferable; CAIPIRINHA is more appropriate in non-compliant patients.

Purpose

To investigate long term results of endobiliary biopsy performed with a transluminal forceps set in metastatic biliary involvement.

Material and methods

Between September 2014 and June 2019, 25 patients (18 male (72%), mean age 65± 15 years) underwent 26 biliary forceps biopsy procedures with a dedicated set (Cook Medical, USA). All patients presented with obstructive jaundice, suspected malignant, and pre-procedural MR-cholangiopancreatography was obtained. The procedure was performed during percutaneous internal-external biliary drainage positioning, under fluoroscopic guidance. The study’s primary endpoints included technical success and complications rates. The study’s secondary endpoints were sensitivity, specificity and diagnostic accuracy for the characterization of malignancy.

Results

Technical success rate was 96% (25 cases) with histological diagnosis of phlogistic stenosis in 5 cases, 6 case of pancreatic adenocarcinoma, 8 colon rectal liver metastases, 3 hepatocellular carcinoma and 3 cases of normal biliary mucosa. In 1 case the sample was considered insufficient by the pathologist (1 pancreatic adenocarcinoma) and the procedure was successfully repeated. The 6 to 48 months follow-up showed 5 false negative cases, in particular 2 case of non colon rectal liver metastases (breast and gastric cancer) and 3 metastatic hilar lymph nodes. The statistical analysis revealed a sensitivity of 77%, specificity of 100% and overall accuracy of 80%. The complications rate was 11,5% (3 cases with transient haemobilia).

Conclusion

Transluminal biliary biopsy performed with forceps set is a safe and effective minimally invasive procedure for histological characterization in patients presenting with obstructive jaundice due to non-primary biliary tumor.

Purpose

To evaluate the technical performance of two different multi-arterial phase techniques in liver MRI.

Material and methods

From February 2017 to December 2018, we enrolled 273 randomized patients who underwent liver MRI using CAIPIRINHA (Controlled Aliasing in Parallel Imaging Results in Higher Acceleration) or TWIST-VIBE (Siemens, Erlangen, Germany) before and after the administration of gadoxetic acid (Gd-EOB-DTPA) (dose: 0.025ml/kg; injection rate: 1ml/s). The acquisition time of both sequences is superimposable (<20s). The protocol includes 3 arterial phases (6.5s each for CAIPIRINHA; 9s, 4s, 4s for TWIST-VIBE) with the possibility of reducing them depending on the patient's fitness level. The images were evaluated by two dedicated radiologists, who quantify Gibbs artifacts and noise (present/absent), breath artifacts and general quality of images using a score from 1 to 5 (1 “non-diagnostic” and 5 “absence of artifacts”/“optimal exam quality”).

Results

There is no statistically significant difference between the demographic data of CAIPIRINHA and TWIST-VIBE cohort. CAIPIRINHA has always a better quality score (p>0.02) but we could not obtain a three-arterial-phase study in all patients (3%). TWIST-VIBE has worse Gibbs and breath score artifact but better noise score.

Conclusion

CAIPIRINHA always allows to obtain a diagnostic image, rarely at the expense of the three arterial phases (0% with one phase, 3% with two phases, 97% with three phases). TWIST-VIBE always allows to obtain three arterial phases. CAIPIRINHA better tolerates artifacts at the detriment of image resolution; TWIST-VIBE has a better signal-to-noise ratio but greater susceptibility to artifacts. The choice of one or the other must take into account patient's compliance and physical characteristics.