Impact of ultra-low dose CT acquisition on semi-automated RECIST tool in the evaluation of malignant focal liver lesions.

PURPOSE: To compare the evaluation of malignant focal liver lesions (FLLs) using a semi-automated RECIST tool with a standard and an ultra-low dose (ULD) computed tomography (CT) protocol. MATERIALS AND METHODS: Thirty-four patients with malignant FLLs underwent two abdominal-pelvic CT examinations one using a standard protocol and one using an ULD protocol. There were 23 men and 11 women with a mean age 64.3±14.4 (SD) years (range: 22-91 years). Dosimetric indicators were recorded, and effective dose was calculated for both examinations. Mean malignant FLL attenuation, image noise and contrast-to-noise-ratio (CNR) were compared. The largest malignant FLL per patient was evaluated using the semi-automated RECIST tool to determine longest axis length, longest orthogonal axis length, volume and World Health Organisation area. RESULTS: Dosimetric values were significantly reduced by -56% with ULD compared to standard protocol. No differences in mean malignant FLL attenuation values were found between the two protocols. Image noise was significantly increased for all locations (P<0.05) with ULD compared to standard protocol, and CNR was significantly reduced (P<0.05). On the 34 malignant FLLs analyzed, six semi-automated shapes non-concordant with radiologist's visual impression were highlighted with the software, including one FLL (1/34; 3%) with standard CT acquisition only, three FLLs (3/34; 9%) with ULD CT acquisition only and two FLLs (2/34; 6%) with both CT acquisitions. After manual editing, the concordance of the values of the studied criteria between both acquisitions was good and no significant difference was reported. CONCLUSION: Semi-automated RECIST tool demonstrates good performances using ULD CT protocol. It could be used in routine clinical practice with a ULD protocol for follow-up studies in patients with known malignant FLL.

Isospin Properties of Nuclear Pair Correlations from the Level Structure of the Self-Conjugate Nucleus

The low-lying energy spectrum of the extremely neutron-deficient self-conjugate (N=Z) nuclide _{44}^{88}Ru_{44} has been measured using the combination of the Advanced Gamma Tracking Array (AGATA) spectrometer, the NEDA and Neutron Wall neutron detector arrays, and the DIAMANT charged particle detector array. Excited states in ^{88}Ru were populated via the ^{54}Fe(^{36}Ar,2nγ)^{88}Ru^{*} fusion-evaporation reaction at the Grand Accélérateur National d'Ions Lourds (GANIL) accelerator complex. The observed γ-ray cascade is assigned to ^{88}Ru using clean prompt γ-γ-2-neutron coincidences in anticoincidence with the detection of charged particles, confirming and extending the previously assigned sequence of low-lying excited states. It is consistent with a moderately deformed rotating system exhibiting a band crossing at a rotational frequency that is significantly higher than standard theoretical predictions with isovector pairing, as well as observations in neighboring N>Z nuclides. The direct observation of such a "delayed" rotational alignment in a deformed N=Z nucleus is in agreement with theoretical predictions related to the presence of strong isoscalar neutron-proton pair correlations.

PICC management led by technicians: Establishment of a cooperation program with radiologists and evaluation of complications.

PURPOSE: The purpose of this study was to evaluate a cooperation program in order to compare incidence of complications after peripherally inserted central catheter (PICC) placement between radiologists and technicians. MATERIALS AND METHODS: PICC placement technique was standardized with ultrasound-guided puncture and fluoroscopic guidance. Numbers of PICC delegated to technicians, and PICC placement difficulties, were prospectively recorded for the whole study population whereas complications such as PICC infection, deep venous thrombosis and catheter occlusion were prospectively recorded until PICC removal for a subgroup of patients included during one month. RESULTS: A total of 722 patients had PICC placement. There were 382 men and 340 women with a mean age of 66.8±15.8 (SD) years (range: 18-94years); of these, 442/722 patients (61.22%) were included in the cooperation program with 433/722 patients (59.97%) who effectively had PICC placement by technicians and 289/722 (40.03%) by radiologists. Technicians needed radiologists' help for 23/442 patients (5.20%) including 6 failed PICC placement subsequently performed by radiologists. Twenty complications (20/77; 26%) were recorded in the subgroup of 77 patients studied for complications. No differences in complications rate were found between the 33 patients who underwent PICC placement by radiologists (6/33; 18%) and the 44 patients who underwent PICC placement by technicians (14/44; 32%) (P=0.296). Complications included 8 PICC-related infections (8/77; 10.4%), 3 deep venous thromboses (3/77; 3.9%) and 9 catheter occlusions (9/77; 11.7%). CONCLUSION: PICC placement led by technicians is feasible and safe without statistical difference in terms of complications compared to PICC placement made by radiologists.

Detection and characterization of focal liver lesions with ultra-low dose computed tomography in neoplastic patients.

PURPOSE: The purpose of this study was to evaluate and compare the diagnostic accuracy of ultra-low dose (ULD) computed tomography (CT) with that of standard dose (STD) CT in the detection and characterization of focal liver lesions in neoplastic patients. MATERIALS AND METHODS: A total of 177 neoplastic patients who underwent two abdominopelvic CT examinations (one with STD and one with ULD protocol) for suspected focal liver lesions were included. There were 103 men and 74 women with a mean age of 64.6±14.4 (SD) (range: 19-93 years). Raw data images were reconstructed with iterative reconstruction. Dose length product (DLP) and effective dose for both protocols were compared. Images were independently evaluated by two radiologists for image-quality, diagnostic quality, and confidence level. RESULTS: DLP for STD and ULD were respectively 215.4±92.0 (SD) mGy·cm (range: 76-599mGy·cm) and 90.7±37.2 (SD) mGy·cm (range: 32-254mGy·cm). Effective dose for STD and ULD CT were 3.2±1.4 (SD) mSv (range: 1.1-9.0mSv) and 1.4±0.6 (SD) mSv (range: 0.5 to 3.8mSv). A significant 58% dose reduction was found between the two protocols (P<0.05). Noise, signal-to-noise ratio and contrast-to-noise ratio were higher with the ULD protocol compared to the STD protocol. No differences in subjective image quality were found between the two protocols. STD CT revealed focal liver lesions in 80 patients and ULD CT in 70 patients (P<0.05). ULD protocol resulted in a sensitivity of 83.8% and a specificity of 96.9% for the diagnosis of focal liver lesions although it was not able to characterize them properly (Se 62.5%). CONCLUSION: STD CT helps detect and characterize focal liver lesions. ULD CT offers good performance to detect focal liver lesions but with lower performances for lesion characterization.

Assessment of patient's peak skin dose during abdominopelvic embolization using radiochromic (Gafchromic) films.

PURPOSE: To assess the value of the routine use of radiochromic films in abdominopelvic embolization procedures to improve patient follow-up. METHODS: A total of 55 patients who underwent transcatheter abdominopelvic embolization were prospectively included. Six types of procedures were evaluated including hepatic chemoembolization (HCE), gonadal veins embolization (GVE), uterine elective embolization (UEE), uterine urgent embolization (UUE), abdominal elective embolization (AEE), and abdominal urgent embolization (AUE). Dosimetric indicators (DIs) such as air-kerma (AK) and kerma-area-product (KAP) were collected and peak skin dose (PSD) was measured with radiochromic films. Correlations between PSD and DIs were searched for. RESULTS: The mean (±standard deviation [SD]) PSD for the various procedures were: 1033±502 mGy for HCE; 476±271 mGy for GVE; 460±171 mGy for UEE; 531±263 mGy for UUE; 708±896 mGy for AEE; 683±392 mGy for AUE. Strong correlations were observed between PSD and DIs (r=0.974 for AK and r=0.925 for KAP). PSD was>2Gy in one procedure and all procedures (7/132) procedures resulted in AK>2Gy, mostly for HCE and AEE. CONCLUSION: Dosimetry using radiochromic film is only appropriate for HCE, AEE and AUE, whereas dose-mapping systems present a more suitable solution for all embolizations including those with AK that occasionally exceed 2Gy.

[Ruptured uterine artery pseudo-aneurysm treated by embolization for post-partum bleeding: About 2 cases]. / Pseudo-anévrisme rompu de l'artère utérine traité par embolisation pour hémorragie du post-partum : à propos de deux cas.

Pseudo-aneurysms of uterine arteries are rare causes of post-partum hemorrhage. We report two cases of rupture, revealed in one case by a hemoperitoneum and in a second case by a retroperitoneal hematoma. The treatment consisted of embolization of uterine arteries with immediate clinical success, to avoid surgery.

[Chronic coronary artery occlusion: questions from the cardiologist and surgeon, answers from the radiologist]. / Occlusions coronaires chroniques: les questions du cardiologue et du chirurgien, les réponses du radiologue.

The main issue with chronic coronary artery occlusion relates to optimal treatment and cross sectional imaging is a valuable source of information. Cardiac MR imaging can identify candidates to revascularization by demonstrating viable myocardium. Coronary CTA allows evaluation of the entire coronary system and detection of factors predicting the success of revascularization, either percutaneous (angioplasty) or surgical.