Transcranial Magnetic Resonance Imaging-Guided Focused Ultrasound Treatment at 1.5 T: A Retrospective Study on Treatment- and Patient-Related Parameters Obtained From 52 Procedures

Objective: To present a retrospective analysis of patient- and sonication-related parameters of a group of patients treated with a transcranial magnetic resonance imaging (MRI)-guided focused ultrasound (tcMRgFUS) system integrated with a 1.5-T MRI unit. Methods: The data obtained from 59 patients, who underwent the tcMRgFUS procedure from January 2015 to April 2019, were retrospectively reviewed for this study. The following data, among others, were mainly collected: skull density ratio (SDR), skull area (SA), number of available transducer elements (Tx), and estimated focal power at target (FP). For each of the four different treatment stages, we calculated the number of sonication processes (S-n), user-defined sonication power (S-p), effective measured power (S-mp), sonication duration (S-d), user-defined energy (E), effective measured energy (E-m), maximum temperature (T-max), and MR thermometry plane orientation. Furthermore, the time delay between each sonication (S-t) and the total treatment time (T-t) were recorded. Results: Fifty-two patients (40 males and 12 females; age 64.51 +/- SD 11.90 years; range 26-86 years), who underwent unilateral Vim thalamotomy (left = 50, 96.15%; right = 2, 3.85%) for medication-refractory essential tremor (n = 39; 78%) or Parkinson tremor (n = 13; 22%) were considered. A total of 1,068 (95.10%) sonication processes were included in our final analysis (average S-n per treatment: 20.65 +/- 6.18; range 13-41). The energy released onto the planned target was found to decrease with the SDR for all temperature ranges. A positive correlation was observed between the slope of T-max vs. E-m plot and the SDR (R-2 = 0.765; p < 0.001). In addition, the T-max was positively correlated with SDR (R-2 = 0.398; p < 0.005). On the contrary, no significant correlation was found between SDR and SA or Tx. An analysis of the MR thermometry scanning plane indicated that, at our site, the axial and the coronal planes were used (on average) 10.4 (SD +/- 3.8) and 7.7 (SD +/- 3.0) times, respectively, whereas the sagittal plane was used only 2.5 (SD +/- 3.0) times per treatment. Conclusion: Our results confirm the factors that significantly influence the course of a tcMRgFUS procedure even when a 1.5-T MRI scanner is used for procedure guidance. The experience we gained in this study indicates that the SDR remains one of the most significant technical parameters to be considered in a tcMRgFUS procedure. The possibility of prospectively setting the sonication energy according to the presented curves of energy delivery as a function of SDR for each treatment stage could provide a further understanding and a greater awareness of this emerging technology

Utility of post mortem computed tomography in clivus fracture diagnosis. Case illustration and literature review

Clivus fractures are usually associated with head blunt trauma due to traffic accident and falls. A 23–year-old man died immediately after a smash-up while he was stopping on his motorcycle. Post-mortem Computed tomography (PMCT), performed before autopsy, revealed a complex basilar skull base fractures associated with brainstem and cranio-vertebral junction injuries, improving the diagnostic performance of conventional autopsy. Imaging data were re-assessable and PMCT offers the possibility to perform multiplanar and volume rendered reconstructions, increasing forensic medicine knowledge related to traumatic injuries

MR Imaging of Perianal Crohn Disease: The Role of Contrast-enhanced Sequences

The MR imaging protocol described by the authors includes contrast-enhanced T1-weighted imaging with fat saturation in all patients except those with poor renal function. Horsthuis et al demonstrated in 2009 the usefulness of contrast-enhanced MR imaging for determining disease activity. Contrast agent administration is also required in case of suspicion of neoplastic tissue complicating fistulas. The joint European Crohn\u2019s and Colitis Organisation\u2013European Society of Gastointestinal and Abdominal Radiology guidelines report that T2-weighted images and contrast-enhanced T1-weighted images are included in the MR imaging protocol for the evaluation of perianal CD. However, as we have demonstrated, an axial T2-weighted fast spinecho sequence with fat saturation, in particular the short inversion time inversion-recovery (STIR) sequence, is a valid alternative to postcontrast T1- weighted fat-saturated imaging, allowing the identification of the primary fistula and any secondary ramification

Imaging appearance of treated hepatocellular carcinoma.

Surgical resection and imaging guided treatments play a crucial role in the management of hepatocellular carcinoma (HCC). Although the primary end point of treatment of HCC is survival, radiological response could be a surrogate end point of survival, and has a key role in HCC decision-making process. However, radiological assessment of HCC treatment efficacy is often controversial. There are few doubts on the evaluation of surgical resection; in fact, all known tumor sites should be removed. However, an unenhancing partial linear peripheral halo, in most cases, surrounding a fluid collection reducing in size during follow-up is demonstrated in successfully resected tumor with bipolar radiofrequency electrosurgical device. Efficacy assessment of locoregional therapies is more controversial and differs between percutaneous ablation (e.g., radiofrequency ablation and percutaneous ethanol injection) and transarterial treatments (e.g., conventional transarterial chemoembolization, transarterial chemoembolization with drug eluting beads and radioembolization). Finally, a different approach should be used for new systemic agent that, though not reducing tumor mass, could have a benefit on survival by delaying tumor progression and death. The purpose of this brief article is to review HCC imaging appearance after treatment

Imaging findings of hepatic focal nodular hyperplasia in men and women: are they really different?

Purpose This study was undertaken to compare the imaging findings of focal nodular hyperplasia (FNH) in men and women, as seen on multidetector computed tomography (MDCT), magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS). Materials and methods Two radiologists reviewed 195 imaging studies (17 MDCT, 81 MRI and 97 CEUS examinations) pertaining to 111 FNHs (mean size 3 cm) in 91 patients (mean age 39 years). For each lesion, the readers assessed size, location, echogenicity, attenuation, or signal intensity in comparison with adjacent liver parenchyma on both unenhanced and postcontrast images. Results Eighty-nine FNHs (mean size 3.1 cm) were observed in 73 women (mean age 37.9 years) and 22 FNHs (mean size 2.7 cm) in 18 men (mean age 41.2 years). No statistically significant differences were found between men and women in terms of age, FNH lesions per patient (1.22 and 1.21, respectively), size, baseline and enhancement pattern on MRI, CEUS and MDCT (p < 0.05). A central scar in FNHs was depicted in 4/18 (22.2 %) men and 16/63 (25.4 %) women on MRI (p < 0.05), and in 1/2 (50 %) men and 7/15 (46.7 %) women on MDCT (p < 0.05), whereas a spoke-wheel pattern, central scar, and/or feeding vessel were seen in 5/17 (29.4 %) men and 22/80 (27.5 %) women on CEUS (p < 0.05). Conclusions Our results did not show any differences in imaging features, age of occurrence and size of FNH between men and women

Perfusion MR Imaging in Differentiating High-Grade from Low-Grade Gliomas

To correlate perfusion MR imaging with histologic grade of cerebral gliomas. Materials & Methods Relative cerebral blood volume (rCBV) maps were determined in 22 patients with pathologically proved gliomas (11 glioblastomas, 8 anaplastic gliomas and 2 low-grade gliomas) by dynamic contrast-enhanced T2*-weighted MR imaging. MR examination was completed with conventional T1- and T2-weighted imaging. The rCBV maps were calculated with an independent workstation by fitting a gamma-variate function to the contrast material concentration versus time curve. Relative CBV ratios obtained between tumor and normal white matter were compared between glioblastomas, anaplastic gliomas and low-grade gliomas by means of receiver operating characteristic (ROC) analysis. Results Mean rCBV ratios were 4.85 (\ub1 1) for glioblastomas, 3.87 (\ub1 0.7) for anaplastic gliomas and 1.65 (\ub1 1.6) for low-grade gliomas. Receiver operating characteristic analysis demonstrates significant differences between glioblastomas and anaplastic gliomas (p<.05), between anaplastic gliomas and low-grade gliomas (p<.05) and between glioblastomas and low-grade gliomas (p<.01). The rCBV ratio cutoff value between highgrade gliomas and low-grade gliomas was 2.52 with a sensitivity and specificity of 100% and 75% respectively. Conclusion Perfusion MR imaging is a reliable technique for differentiating high-grade from low-grade glioma

Hippocampal and Amygdalar Volumes Changes in Drug Addicts: A Preliminary Study

Oral comunication for American Society of Neuroradiology 45th Annual Meeting. Chicago, June 9-14 200

Magnetic resonance imaging of the cirrhotic liver in the era of gadoxetic acid

Gadoxetic acid improves detection and characterization of focal liver lesions in cirrhotic patients and can estimate liver function in patients undergoing liver resection. The purpose of this article is to describe the optimal gadoxetic acid study protocol for the liver, the unique characteristics of gadoxetic acid, the differences between gadoxetic acid and extra-cellular gadolium chelates, and the differences in phases of enhancement between cirrhotic and normal liver using gadoxetic acid. We also discuss how to obtain and recognize an adequate hepatobiliary phase

Acceptance of non-invasive computed tomography coronary angiography: for a patient-friendly medicine

PURPOSE: This study was done to evaluate the psychological state and anxiety of patients undergoing computed tomography coronary angiography (CTCA), and assess their acceptance and satisfaction compared to invasive conventional coronary angiography (CCA). MATERIALS AND METHODS: A total of 442 consecutive patients (282 male; mean age 57.7 ± 9.5 years) who underwent CTCA for suspected or known coronary artery disease were evaluated with the Endler Multimodality Anxiety Scales (EMAS) before and after the scan, and a questionnaire administered after the scan. Among the 442 patients, 181 had a history of CCA. Two radiologists assessed the image quality of CTCA. RESULTS: Anxiety was more intense prior to the scan (EMAS score 51.7 vs. 46.7, p < 0.01) and in patients with a history of CCA (EMAS score 55.5 vs. 49.1, p < 0.01). Women presented more intense anxiety (EMAS score 59.5 vs. 47.3, p < 0.01), higher mean heart rate (63.5 ± 7.6 vs. 60.7 ± 7.3 beats per minute, p < 0.01) and a lower image quality than men (p < 0.0001). CTCA proved to be more acceptable than CCA because of accurate preparation, lower concern prior to the examination, negligible pain, higher comfort, and greater overall satisfaction (p < 0.0001). CONCLUSIONS: Computed tomography coronary angiography is a patient-friendly imaging method because of the minimal perceived discomfort. Anxiety may affect CTCA image quality in women