Ascites relative enhancement during hepatobiliary phase after Gd-BOPTA administration: a new promising tool for characterising abdominal free fluid of unknown origin.

OBJECTIVES: To correlate the degree of ascites enhancement during hepatobiliary phase after gadobenate dimeglumine (Gd-BOPTA) administration with ascites aetiology. METHODS: IRB-approved retrospective study, need for informed consent was waived. We included 74 consecutive ascitic patients who underwent Gd-BOPTA-enhanced liver MRI including hepatobiliary phase (HBP) images between January 2014 and December 2017. Ascites appearance on unenhanced and HBP images was classified as hypo-, iso- or hyperintense in comparison to paraspinal muscles. Ascites signal intensity on unenhanced and HBP images was measured using round ROIs and was normalised to paraspinal muscles (NSI). Normalised relative enhancement (NRE) between native phase and HBP was calculated. The results were related to ascites aetiology using Wilcoxon and Mann-Whitney tests. RESULTS: On native images, ascites appeared hypointense in 95.9% of the cases and isointense in 4.1%, whereas on HBP images, it appeared hyperintense in 59.4% of the cases, isointense in 36.5% and hypointense in 4.1%. Mean ascites NSI was 0.52 on unenhanced images and 1.50 on HBP ones (p < 0.0001). Mean ascites NRE was 201 ± 133%. Ascites of non-malignant aetiology showed mean NRE of 210 ± 134%, whereas malignant ascites showed mean NRE of 92 ± 20% (p = 0.001). ROC analysis showed that a NRE < 112.5% correlates with malignant aetiology with 100% sensitivity and 83.4% specificity (LR = 5.667). NRE did not show any significant correlation with ascites thickness, eGFR and time interval between contrast administration and HBP acquisition (p > 0.05). CONCLUSIONS: Ascites NRE in HBP after Gd-BOPTA administration is significantly lower in patients with ascites secondary to peritoneal carcinomatosis than in patients with non-malignant ascites. KEY POINTS: • Ascites enhancement in the hepatobiliary phase after Gd-BOPTA administration may determine false positive findings when looking for biliary leaks. • Ascites enhancement in the hepatobiliary phase after Gd-BOPTA administration is lower in patients with peritoneal carcinomatosis than in patients with portal hypertension or congestive heart failure. • None of the patients with peritoneal carcinomatosis showed an ascites enhancement of more than 112% as compared with unenhanced images.

Prediction of histological grade of endometrial cancer by means of MRI.

OBJECTIVES: To evaluate the ability of MRI in predicting histological grade of endometrial cancer (EC). METHODS: IRB-approved retrospective study; requirement for informed consent was waived. 90 patients with histologically proven EC who underwent preoperative MRI and surgery at our Institution between Sept2011 and Nov2016 were included. Myometrial invasion (50%) was assessed. Neoplasm and uterus volumes were estimated according to the ellipsoid formula; neoplasm/uterus volume ratio (N/U) was calculated. ADC maps were generated and histogram analysis was performed using commercially available software. MRI parameters were compared with the definitive histological grade (G1 = 28 patients, G2 = 29, G3 = 33) using ANOVA and Tukey-Kramer tests. RESULTS: Deep myometrial invasion was significantly more frequent in G2-G3 lesions than in G1 ones (p < 0,005). N/U ratio was significantly higher for high-grade neoplasms (mean 0,08 for G1, 0,16 for G2 and 0,21 in G3; P = 0,002 for G1 vs. G2-G3); a cut off value of 0,13 enabled to distinguish G1 from G2-G3 lesions with 50% sensibility and 89% specificity. ADC values didn't show any statistically significant correlation with tumour grade. CONCLUSIONS: N/U ratio >0.13 and deep myometrial invasion are significantly correlated with high grade EC, whereas ADC values are not useful for predicting EC grade.

Gallbladder adenomyomatosis: imaging findings, tricks and pitfalls.

Gallbladder adenomyomatosis (GA) is a benign alteration of the gallbladder wall that can be found in up to 9% of patients. GA is characterized by a gallbladder wall thickening containing small bile-filled cystic spaces (i.e., the Rokitansky-Aschoff sinuses, RAS). The bile contained in RAS may undergo a progressive concentration process leading to crystal precipitation and calcification development. A correct characterization of GA is fundamental in order to avoid unnecessary cholecystectomies. Ultrasound (US) is the imaging modality of choice for diagnosing GA; the use of high-frequency probes and a precise focal depth adjustment enable correct identification and characterization of GA in the majority of cases. Contrast-enhanced ultrasound (CEUS) can be performed if RAS cannot be clearly identified at baseline US: RAS appear avascular at CEUS, independently from their content. Magnetic resonance imaging (MRI) should be reserved for cases that are unclear on US and CEUS. At MRI, RAS can be identified with extremely high sensitivity, but their signal intensity varies widely according to their content. Positron emission tomography (PET) may be helpful for excluding malignancy in selected cases. Computed tomography (CT) and cholangiography are not routinely indicated in the suspicion of GA. TEACHING POINTS: 1. Gallbladder adenomyomatosis is a common benign lesion (1-9% of the patients). 2. Identification of Rokitansky-Aschoff sinuses is crucial for diagnosing gallbladder adenomyomatosis. 3. Sonography is the imaging modality of choice for diagnosing gallbladder adenomyomatosis. 4. Intravenous contrast material administration increases ultrasound accuracy in diagnosing gallbladder adenomyomatosis. 5. Magnetic resonance is a problem-solving technique for unclear cases.

Renal stones composition in vivo determination: comparison between 100/Sn140 kV dual-energy CT and 120 kV single-energy CT.

The objective of this study is to compare in vivo, the accuracy of single-energy CT (SECT) and dual-energy CT (DECT) in renal stone characterization. Retrospective study approved by the IRB. 30 patients with symptomatic urolithiasis who underwent CT on a second-generation dual-source scanner with a protocol that included low-dose 120 kV scan followed by 100/Sn140 kV dual-energy scan have been included. Stone composition was classified as uric acid, cystine or calcium oxalates, and phosphates according to attenuation values at 120 kV and to 100/Sn140 kV attenuation ratios and compared with the infrared spectroscopy analysis. 50 stones were detected in 30 patients. SECT correctly assessed stone composition in 52 % of the cases, DECT in 90 %. Sensitivity, specificity, positive predictive value, and negative predictive value in differentiating uric acid vs. non-uric acid stones were 0.94, 0.72, 0.64, and 0.96 for SECT and 1.00, 0.94, 1.00, and 0.96 for DECT, respectively. DECT significantly performs better than SECT in characterising renal stones in vivo, and may represent a useful tool for treatment planning.

Dual-energy CT of the brain: Comparison between DECT angiography-derived virtual unenhanced images and true unenhanced images in the detection of intracranial haemorrhage.

OBJECTIVE: To evaluate the diagnostic performance of virtual non-contrast (VNC) images in detecting intracranial haemorrhages (ICHs). METHODS: Sixty-seven consecutive patients with and 67 without ICH who underwent unenhanced brain CT and DECT angiography were included. Two radiologists independently evaluated VNC and true non-contrast (TNC) images for ICH presence and type. Inter-observer agreement for VNC and TNC image evaluation was calculated. Sensitivity and specificity of VNC images for ICH detection were calculated using Fisher's exact test. VNC and TNC images were compared for ICH extent (qualitatively and quantitatively) and conspicuity assessment. RESULTS: On TNC images 116 different haemorrhages were detected in 67 patients. Inter-observer agreement ranged from 0.98-1.00 for TNC images and from 0.86-1.00 for VNC images. VNC sensitivity ranged from 0.90-1, according to the different ICH types, and specificity from 0.97-1. Qualitatively, ICH extent was underestimated on VNC images in 11.9% of cases. Haemorrhage volume did not show statistically significant differences between VNC and TNC images. Mean haemorrhage conspicuity was significantly lower on VNC images than on TNC images for both readers (p < 0.001). CONCLUSION: VNC images are accurate for ICH detection. Haemorrhages are less conspicuous on VNC images and their extent may be underestimated. KEY POINTS: • VNC images represent a reproducible tool for detecting ICH. • ICH can be identified on VNC images with high sensitivity and specificity. • Intracranial haemorrhages are less conspicuous on VNC images than on TNC images. • Intracranial haemorrhages extent may be underestimated on VNC images.

Blunt diaphragmatic lesions: Imaging findings and pitfalls.

Blunt diaphragmatic lesions (BDL) are uncommon in trauma patients, but they should be promptly recognized as a delayed diagnosis increases morbidity and mortality. It is well known that BDL are often overlooked at initial imaging, mainly because of distracting injuries to other organs. Sonography may directly depict BDL only in a minor number of cases. Chest X-ray has low sensitivity in detecting BDL and lesions can be reliably suspected only in case of intra-thoracic herniation of abdominal viscera. Thanks to its wide availability, time-effectiveness and spatial resolution, multi-detector computed tomography (CT) is the imaging modality of choice for diagnosing BDL; several direct and indirect CT signs are associated with BDL. Given its high tissue contrast resolution, magnetic resonance imaging can accurately depict BDL, but its use in an emergency setting is limited because of longer acquisition times and need for patient's collaboration.

Incisional Hernia Following Ventriculoperitoneal Shunt Positioning.

Incisional hernia represents a rare complication after ventriculoperitoneal shunt positioning due to failure of the fascial suture in the site of abdominal entrance of ventriculoperitoneal catheter. Clinical presentation can be extremely variable, according to patient's performance status, herniated material constitution (i.e. mesenteric fat, bowel loops or both) and complication occurrence (e.g. strangulation or intestinal obstruction). Early diagnosis is fundamental in order to surgically repair the defect and prevent further complications. We present the case of a paucisymptomatic incisional hernia following ventriculoperitoneal shunt positioning. Diagnosis was made by means of ultrasound and confirmed by means of computed tomography. The patient was successfully managed by means of surgical repositioning of herniated loop and re-suture.

The Role of Transcatheter Arterial Embolization in Traumatic Pelvic Hemorrhage: Not Only Pelvic Fracture.

PURPOSE: The most common life-threatening complication of pelvic trauma is bleeding. Arterial bleedings frequently require active management, preferably with transcatheter arterial embolization (TAE). Hemodynamic instability and/or contrast extravasation at computer tomography (CT) examination are reliable indicators of arterial injury. Unstable pelvic fractures are much more hemorrhagic than stable fractures. Nevertheless, an absent or isolated pelvic fracture does not exclude pelvic hemorrhage. MATERIALS AND METHODS: A retrospective study was conducted on our institutional database by collecting data of patients who underwent pelvic angiography and/or embolization due to pelvic blunt trauma in the period between August 2010 and August 2015. RESULTS: In a period of five years, 39 patients with traumatic pelvic bleeding underwent angiography at our institution. Thirty-six of the 39 (92%) patients did show CT signs of active pelvic bleeding. Nineteen of 39 (49%) patients were hemodynamically unstable at presentation. Three of the 39 patients did not require embolization. Technical success was 35/36 (97%), and overall mortality was 3/39 (8%). Notably, 5/39 (13%) patients did not have any pelvic fracture at presentation, and 18/39 (46%) had only isolated or stable pelvic ring fracture. CONCLUSIONS: TAE is an effective technique to treat arterial pelvic bleeding after trauma. The absence of a major pelvic fracture does not exclude the risk of active bleeding requiring prompt treatment.

Sequential endovascular thrombectomy approach (SETA) to acute ischemic stroke: preliminary single-centre results and cost analysis.

INTRODUCTION: We report the preliminary results of a single-centre experience in the endovascular treatment (ET) of acute ischemic stroke (AIS) with a sequential endovascular thrombectomy approach (SETA), which comprehends a direct aspiration first-pass technique (ADAPT) eventually followed by stent retriever thrombectomy. MATERIALS AND METHODS: We prospectively analyzed data from 16 patients with severe to moderate AIS and CT angiography demonstration of large intracranial vessel occlusion treated with SETA between July 2013 and March 2014. We evaluated recanalization rate, clinical outcome after 90 days as well as differential costs of aspiration and stent-assisted thrombectomy. RESULTS: A group of 16 patients met the eligibility criteria to undergo ET with a baseline NIHSS score of 22 (range 12-39). In 15/16 cases, we obtained target vessel recanalization, 11 cases with ADAPT technique alone. Modified rankin score (mRS) at 90 days follow-up was ≤2 in 9/16 patients (56%). ADAPT technique had a lower device-related cost than stent-assisted thrombectomy leading to an overall saving of -2,747.28 . CONCLUSIONS: Our preliminary data suggest that a SETA beginning with direct aspiration could be useful to optimize ET of stroke in terms of invasiveness, safety and cost-effectiveness allowing recanalization with low complication rate.

MRI for local staging of endometrial carcinoma: Is endovenous contrast medium administration still needed?

PURPOSE: To compare the diagnostic performance of T2-weighted images (T2-WI)+contrast-enhanced T1-weighted images (CE T1-WI) with the one of T2-WI+diffusion-weighted images (DWI) in the assessment of myometrial and cervical stromal infiltration by endometrial carcinoma (EC). MATERIALS AND METHODS: Institutional review board approved our retrospective study; requirement for informed consent was waived. 56 patients with histologically proven EC who underwent preoperative MRI and surgery at our Institution over a 34 months period were included. Two radiologists independently evaluated T2-WI+CE T1-WI and T2-WI+DWI of each patient. Confidence in imaging evaluation (0-3), depth of myometrial invasion (0.05) whereas both imaging sequences combinations showed the same diagnostic performance in recognizing cervical stromal infiltration (accuracy, sensitivity and specificity of 0.95, 0.98 and 0.80, p>0.05). CONCLUSION: T2-WI+DWI can reliably replace the "classical" combination T2-WI+CE T1-WI for local staging of endometrial carcinoma.

Blunt cerebrovascular injury: diagnosis at whole-body MDCT for multi-trauma.

PURPOSE: To analyse the prevalence of blunt cerebrovascular injuries (BCVIs) in multi-trauma patients by means of a post-contrast acquisition of neck vessels included into the whole-body multi-detector computed tomography (MDCT) protocol performed at admission and to correlate it with the presence of risk factors (Memphis approach). MATERIALS AND METHODS: A retrospective study was undertaken for the period January 2005 to November 2011, involving 976 multi-trauma patients. Post-contrast images of neck vessels in MDCT scan were evaluated by two experienced radiologists; carotid, vertebral and basilar arteries were rated according to the Biffl classification. The presence of clinical and/or CT risk factors for BCVI was assessed. RESULTS: BCVI were present in 32/976 (3.3 %) multi-trauma patients. Risk factors for BCVI were present in 247/976 (25.3 %) patients. The group of patients presenting risk factors showed a significantly higher prevalence of cerebrovascular injuries (8.1 %) compared with the group of patients without risk factors (1.6 %) (p = 0.009); however, 12/32 (37.5 %) patients presenting BCVI did not show any of the risk factors proposed by the Memphis group. CONCLUSION: An investigation for the presence of BCVI should be performed on all multi-trauma patients despite the absence of clinical-radiological risk factors. KEY POINTS: • BCVIs are present in 3.3 % of multi-trauma patients. • BCVIs are significantly associated to the Memphis risk factors. • Of the multi-trauma patients affected by BCVIs, 37.5 % do not show clinical-radiological risk factors. • A screening for BCVI should be performed on all multi-trauma patients.