Computer-based self-training for CT colonography with and without CAD.

OBJECTIVES: To determine whether (1) computer-based self-training for CT colonography (CTC) improves interpretation performance of novice readers; (2) computer-aided detection (CAD) use during training affects learning. METHODS: Institutional review board approval and patients' informed consent were obtained for all cases included in this study. Twenty readers (17 radiology residents, 3 radiologists) with no experience in CTC interpretation were recruited in three centres. After an introductory course, readers performed a baseline assessment test (37 cases) using CAD as second reader. Then they were randomized (1:1) to perform either a computer-based self-training (150 cases verified at colonoscopy) with CAD as second reader or the same training without CAD. The same assessment test was repeated after completion of the training programs. Main outcome was per lesion sensitivity (≥ 6 mm). A generalized estimating equation model was applied to evaluate readers' performance and the impact of CAD use during training. RESULTS: After training, there was a significant improvement in average per lesion sensitivity in the unassisted phase, from 74% (356/480) to 83% (396/480) (p < 0.001), and in the CAD-assisted phase, from 83% (399/480) to 87% (417/480) (p = 0.021), but not in average per patient sensitivity, from 93% (390/420) to 94% (395/420) (p = 0.41), and specificity, from 81% (260/320) to 86% (276/320) (p = 0.15). No significant effect of CAD use during training was observed on per patient sensitivity and specificity, nor on per lesion sensitivity. CONCLUSIONS: A computer-based self-training program for CTC improves readers' per lesion sensitivity. CAD as second reader does not have a significant impact on learning if used during training. KEY POINTS: • Computer-based self-training for CT colonography improves per lesion sensitivity of novice readers. • Self-training program does not increase per patient specificity of novice readers. • CAD used during training does not have significant impact on learning.

Petamenophis (Padiamenemipet), an Egyptian Child Mummy Protected for Eternity: Revelation by Multidetector Computed Tomography.

OBJECTIVE: The objective of our work was to report the most recent findings obtained with multidetector computed tomography of a child mummy from the Roman period (119-123 CE) housed at the Egyptian Museum in Turin, Italy. METHODS: Multidetector computed tomography and postprocessing were applied to understand the embalming techniques, the nature of a foreign object, and anthropometrical values. The information was compared with that from other mummies that were buried in the same tomb, but today housed in different museums. RESULTS: New information regarding the embalming technique was revealed. Multidetector computed tomography allowed the identification of a knife-like metallic object, probably an amulet for the child's protection in the afterlife. CONCLUSIONS: Multidetector computed tomography and image postprocessing confirm their valuable role in noninvasive studies in ancient mummies and provided evidence of a unique cultural practice in the late history of Ancient Egypt such as placing a knife possibly as an amulet.

Comparing CT colonography and flexible sigmoidoscopy: a randomised trial within a population-based screening programme.

IMPORTANCE AND AIMS: The role of CT colonography (CTC) as a colorectal cancer (CRC) screening test is uncertain. The aim of our trial was to compare participation and detection rate (DR) with sigmoidoscopy (flexible sigmoidoscopy (FS)) and CTC in a screening setting. DESIGN SETTING AND PARTICIPANTS: We conducted two randomised clinical trials (RCTs). (1) Participation RCT: individuals, aged 58 years, living in Turin (Italy), were randomly assigned to be invited to FS or CTC screening; (2) detection RCT: residents in northern Italy, aged 58-60, giving their consent to recruitment, were randomly allocated to CTC or FS. Polyps ≥6 mm at CTC, or 'high-risk' distal lesions at FS, were referred for colonoscopy (TC). MAIN OUTCOME MEASURES: Participation rate (proportion of invitees examined); DR of advanced adenomas or CRC (advanced neoplasia (AN)). RESULTS: Participation was 30.4% (298/980) for CTC and 27.4% (267/976) for FS (relative risk (RR) 1.1; 95% CI 0.98 to 1.29). Among men, participation was higher with CTC than with FS (34.1% vs 26.5%, p=0.011). In the detection RCT, 2673 subjects had FS and 2595 had CTC: the AN DR was 4.8% (127/2673, including 9 CRCs) with FS and 5.1% (133/2595, including 10 CRCs) with CTC (RR 1.08; 95% CI 0.85 to 1.37). Distal AN DR was 3.9% (109/2673) with FS and 2.9% (76/2595) with CTC (RR 0.72; 95% CI 0.54 to 0.96); proximal AN DR was 1.2% (34/2595) for FS vs 2.7% (69/2595) for CTC (RR 2.06; 95% CI 1.37 to 3.10). CONCLUSIONS AND RELEVANCE: Participation and DR for FS and CTC were comparable. AN DR was twice as high in the proximal colon and lower in the distal colon with CTC than with FS. Men were more likely to participate in CTC screening. TRIAL REGISTRATION NUMBER: NCT01739608; Pre-results.

Comparison of synthetic mammography, reconstructed from digital breast tomosynthesis, and digital mammography: evaluation of lesion conspicuity and BI-RADS assessment categories.

PURPOSE: To compare the interpretive performance of synthetic mammography (SM), reconstructed from digital breast tomosynthesis (DBT), and full-field digital mammography (FFDM) in a diagnostic setting, covering different conditions of breast density and mammographic signs. METHODS: A retrospective analysis was conducted on 231 patients, who underwent FFDM and DBT (from which SM images were reconstructed) between September 2014-September 2015. The study included 250 suspicious breast lesions, all biopsy proven: 148 (59.2%) malignant and 13 (5.2%) high-risk lesions were confirmed by surgery, 89 (35.6%) benign lesions had radiological follow-up. Two breast radiologists, blinded to histology, independently reviewed all cases. Readings were performed with SM alone, then with FFDM, collecting data on: probability of malignancy for each finding, lesion conspicuity, mammographic features and dimensions of detected lesions. RESULTS: Agreement between readers was good for BI-RADS classification (Cohen's k-coefficient = 0.93 ± 0.02) and for lesion dimension (Wilcoxon's p = 0.76). Visibility scores assigned to SM and FFDM for each lesion were similar for non-dense and dense breasts, however, there were significant differences (p = 0.0009) in distribution of mammographic features subgroups. SM and FFDM had similar sensitivities in non-dense (respectively 94 vs. 91%) and dense breasts (88 vs. 80%) and for all mammographic signs (93 vs. 87% for asymmetric densities, 96 vs. 75% for distortion, 92 vs. 85% for microcalcifications, and both 94% for masses). Based on all data, there was a significant difference in sensitivity for SM (92%) vs. FFDM (87%), p = 0.02, whereas the two modalities yielded similar results for specificity (SM: 60%, FFDM: 62%, p = 0.21). CONCLUSIONS: SM alone showed similar interpretive performance to FFDM, confirming its potential role as an alternative to FFDM in women having tomosynthesis, with the added advantage of halving the patient's dose exposure.

Incidence of hepatic encephalopathy after transjugular intrahepatic portosystemic shunt (TIPS) according to its severity and temporal grading classification.

OBJECTIVES: To evaluate hepatic encephalopathy (HE) incidence after transjugular intrahepatic portosystemic shunt (TIPS) and classify by gravity and frequency. METHODS: This is a retrospective study of 75 patients with no previous episodes of HE who underwent TIPS between 2008 and 2014 with clinical follow-up after 6 and 12 months. Patient risk factors evaluated include age, INR (international normalized ratio), creatinine, bilirubin, and MELD score (Model for End-of-stage Liver Disease). HE was reported using two classifications: (1) gravity divided in moderate (West-Haven grades I-II) and severe (III-IV); (2) frequency divided in episodic and recurrent/persistent. RESULTS: Overall HE incidence was 36% at 6 months, with 12 month incidence significantly decreased to 27% (p = 0.02). 13/75 (17%) patients had one episode of moderate HE, while 3/75 (4%) patients had severe recurrent/persistent HE. Age was the only pre-TIPS risk predictor. Post-TIPS bilirubin and INR showed variations from basal values only in the presence of diagnosed HE. Bilirubin significantly increased (p = 0.03) in correlation to HE severity, whereas INR changes correlated with temporal frequency (p = 0.04). HE distribution classified for severity is similar at 6 and 12 months, whereas when classified for frequency shows significant differences (p = 0.04). CONCLUSIONS: A classification by gravity and frequency attests post-TIPS HE as a manageable risk. Monitoring of bilirubin and INR may help on clinical management risk stratification.

Prostate Cancer Detection Rate with Koelis Fusion Biopsies versus Cognitive Biopsies: A Comparative Study.

OBJECTIVE: Targeted fusion biopsies have led to an improved prostate cancer (PCa) detection rate (CDR). Our aim was to assess if device-assisted fusion biopsies are superior to cognitive ones in terms of CDR. The association between multiparametric MRI parameters and PCa was also evaluated. METHODS: We retrospectively enrolled 50 patients who underwent transrectal biopsy with elastic fusion (Koelis; group KB, n = 25) or cognitive approach (group CB, n = 25). Targeted biopsies were done on targets, while a variable number of random biopsies were performed depending on the clinical case. RESULTS: The groups did not significantly differ in terms of age, prostate-specific antigen, prostate volume and previous biopsies. Mean number of random cores was significantly inferior in KB group (8.4 vs. 12.1) and mean number of targeted biopsies was significantly higher (3.6 vs. 2.6). CDR was higher in fusion biopsies (64 vs. 40%), with the gap becoming significant when considering CDR of MRI targets only (59 vs. 27%). The difference was marked for lesions ≤10 mm, where CDR was 52% in KB against 21% in CB group. CONCLUSIONS: According to our study, elastic fusion biopsies performed with Koelis achieve an increased per-patient and per-lesion CDR as compared to cognitive biopsies, especially in the case of lesions ≤10 mm.

Digital Breast Tomosynthesis (DBT) to Characterize MRI-Detected Additional Lesions Unidentified at Targeted Ultrasound in Newly Diagnosed Breast Cancer Patients.

OBJECTIVES: Preoperative breast magnetic resonance (MR) often generates additional suspicious findings needing further investigations. Targeted breast ultrasound (US) is the standard tool to characterize MR additional lesions. The purpose of this study is to evaluate the potential role of digital breast tomosynthesis (DBT) to characterize MR detected additional findings, unidentified at targeted breast US. METHODS: This prospective study included women who a) had biopsy-proven, newly diagnosed breast cancers detected at conventional 2D mammography and/or US, referred to breast MR for tumour staging; and b) had DBT if additional MR findings were not detected at targeted ('second look') US. RESULTS: In 520 patients, MR identified 164 (in 114 women, 22%) additional enhancing lesions. Targeted US identified 114/164 (69.5%) of these, whereas 50/164 (30.5%) remained unidentified. DBT identified 32/50 of these cases, increasing the overall characterization of MR detected additional findings to 89.0% (146/164). Using DBT the identified lesions were significantly more likely to be malignant than benign MR-detected additional lesions (p = 0.04). CONCLUSIONS: DBT improves the characterization of additional MR findings not identified at targeted breast US in preoperative breast cancer staging. KEY POINTS: • Targeted US identified 114 of 164 (69.5%) additional enhancing lesions at preoperative breast MRI. • DBT identified a further 32 of the 50 lesions unidentified on targeted US. • DBT improved the characterization of additional MR findings for breast cancer staging.

Multiparametric Gd-EOB-DTPA magnetic resonance in diagnosis of HCC: dynamic study, hepatobiliary phase, and diffusion-weighted imaging compared to histology after orthotopic liver transplantation.

PURPOSE: To evaluate Gd-EOB-DTPA-enhanced magnetic resonance (MR) performance during dynamic (DYN) phases, hepatobiliary (HB) phase and diffusion-weighted imaging (DWI) compared with pathological findings in patients undergoing orthotopic liver transplantation (OLT) for hepatocellular carcinoma (HCC) associated with different conditions, such as stage of chronic liver disease, histological grading, nodule size, and occurrence of previous treatments. METHODS: Retrospective analysis of 64 nodules reported as HCC at pathological analysis on 28 explanted livers, examined about 3 months before OLT using a 1.5 T device and 16 channels array after intravenous GD-EOB-DTPA injection. Lesions features and hepatic functional values were recorded for each patient. Two radiologists performed in consensus the analysis of nodules on DYN, HB, and DWI. MR findings were compared with those of pathological anatomy. Diagnostic indicators were calculated for each technique. RESULTS: DYN and HB showed no statistically significant difference in sensitivity (88% and 98%, respectively), diagnostic accuracy (90.6% and 99.9%), and specificity (both 100%), for all Child-Pugh scores, gradings, sizes, and presence or absence of previous treatments. DWI had a statistically significant lower sensitivity compared to DYN (p = 0.001) and HB (p < 0.0001); its sensitivity was significantly inferior for Child-Pugh Class B nodules than for Child-Pugh Class A ones (p = 0.00005). DWI sensitivity presented a significant increase (p = 0.03) with grading and presence of previous treatments (p = 0.0006). ADC values showed no statistically significant changes with Child-Pugh score, grading and nodules size; statistically significant increase was instead found for treated vs. untreated nodules (p = 0.016). CONCLUSIONS: In a multiparametric HCC MRI assessment, DYN and HB play the leading role, with DWI faring acceptably well for Child-Pugh Class A nodules and treated ones.

Treatment of urological complications in more than 1,000 kidney transplantations: the role of interventional radiology.

PURPOSE: The aim of this study is to evaluate the efficacy and safety of interventional radiology procedures in the treatment of major urological complications after kidney transplantation. MATERIALS AND METHODS: Between 2000 and 2010, 1,146 kidney transplants were performed at our institution. A total of 146 major complications occurred, including 77 obstructions, 36 leaks and 33 associated perigraft fluid collections. Percutaneous treatment was carried out in 118/146 complications in 91 patients. In the case of stenosis-obstruction and fistulas (104 complications), the first therapeutic step was placement of a nephrostomy catheter, followed by balloon ureteroplasty, placement of external-internal catheters and double-J stents; 14/33 collections were drained under ultrasound guidance. RESULTS: In all 118 percutaneous interventions, we were able to place a nephrostomy or drainage catheter, with a technical success rate of 100 %. The long-term success rate was 49.6 %: in 57/115 (three patients were lost to follow-up) we obtained the complete resolution of the complication. The procedure-related mortality rate was 0 %. There was only one major complication and the rate of minor complications was 14.4 %. CONCLUSIONS: Interventional radiology is the first choice option in the treatment of urological complications after kidney transplantation.

Percutaneous treatment of Hepatocellular carcinoma exceeding 3 cm: combined therapy or microwave ablation? Preliminary results.

PURPOSE: To compare MWA and RFA combined with TACE for HCC nodules exceeding 3 cm. METHODS: 19 lesions submitted to MWA (G1) were retrospectively compared with a combined treatment group (G2) matching by tumor characteristics (mean size 43 and 45 mm in G1 and G2, respectively). Technical success, complications, complete ablation (CA), and maintained CA (mCA) were evaluated. RESULTS: Technical success was achieved in all cases. Overall mortality was zero, both in G1 and G2. No significant differences were found in complications rates (3 in G1 and 2 in G2). CA was obtained in 11 (58 %) HCC in G1 and 15 (79 %) in G2 (p = n.s.). CA was obtained in 75.5 % (G1) and 89 % (G2) nodules up to 4 cm, 45 % and 70 % nodules >4 cm, respectively. At statistical analysis, size resulted as predictor for CA only in G1 (mean diameter of CA vs non-CA 39.9 vs. 47.7 mm, p = 0.021). During follow-up (13.1 and 14.4 months in G1 and G2), mCA occurred in 6/19 (32 %) nodules in G1, 8/19 (42 %) in G2. CONCLUSION: MWA and combined therapy are comparable as for safety. No significant differences were found in terms of technique effectiveness. Larger randomized studies should be designed to confirm MWA as a valid alternative to combined therapy.

The role of interventional radiology in the treatment of biliary strictures after paediatric liver transplantation.

PURPOSE: The aim of this study is to evaluate the safety and efficacy of percutaneous treatment of biliary strictures after paediatric liver transplantation. MATERIALS AND METHODS: In the period between October 1999 and October 2010, a total of 92 transplants in 86 children were performed at our Liver Transplant Centre. Eighteen patients had anastomotic biliary strictures (in four cases associated with intrahepatic bile duct stenosis). Percutaneous treatment (transhepatic biliary drainage and conventional/cutting balloon dilatation) was proposed as a first approach in 13/18 patients. Strict radiation protection precautions were taken in accordance with the ALARA (as low as reasonably achievable) principle. Mean follow-up time was 2,364 days. RESULTS: Surgical correction was required in 3/13 patients; in 8/13 cases, there was complete disappearance of clinical symptoms without bile duct dilatation; in one case, an asymptomatic persistent bile duct dilatation was detected while in the other case, the liver is currently in cirrhotic degeneration (69 % clinical success including the asymptomatic patient with biliary dilatation). Two of the five patients who were initially treated with surgery required percutaneous revision (clinical success of 100 %). There were two cases of long-term restenosis and two cases of transient haemobilia. CONCLUSIONS: Percutaneous procedures are safe and effective therapeutic options for the treatment of biliary strictures after paediatric liver transplantation.

Breast cancer risk associated with the diagnosis of a microhistological radial scar (RS): retrospective analysis in 10 years of experience.

PURPOSE: To retrospectively assess the risk of breast cancer associated with the radial scar (RS) microhistological diagnosis, also taking into consideration the percutaneous biopsy devices used, as well as the different performances of the mammographic systems (analogical, digital and tomosynthesis) in the radiological diagnosis of RS. MATERIALS AND METHODS: Between March 2002 and November 2011, 80 RSs were identified using the analogical, digital and tomosynthesis mammographic systems. Based on the microhistological examination, the patients were divided into three groups [RS without hyperplasic-proliferative lesions (HPL); RS with HPL; RS with cancer] and we assessed the risk of cancer associated with RS in the first and second group. We evaluated the mammographic features and the BI-RADS categories assigned to RSs, the biopsy devices used and the differences between the pathological examination and the microhistological diagnosis (p < 0.05). RESULTS: Based on the microhistological examination, 51/80 patients were included in the first group (9 of them not subjected to surgery), 25/80 in the second group and 4/80 in the third one. At the final histological examination, there were 7/42 (16.7%) cancers in the first group and 8/25 (32%) in the second group. The largest number of microhistological underestimation occurred in the patients who were subjected to core biopsy (15 cases) (p < 0.05). Tomosynthesis improved (p < 0.05) the identification of the RS. CONCLUSIONS: 22.3% of the RSs was associated with cancer. Given that at microhistological examination 16.7% of the RS without HPL was cancer at pathology, the surgical excision is preferred. Tomosynthesis was useful to detect parenchymal distortions.

Mammotome(®) and EnCor (®): comparison of two systems for stereotactic vacuum-assisted core biopsy in the characterisation of suspicious mammographic microcalcifications alone.

PURPOSE: The authors sought to compare the diagnostic performance of the Mammotome(®) and EnCor(®) vacuum-assisted breast biopsy (VABB) systems in the assessment of suspicious mammographic microcalcifications. MATERIALS AND METHODS: Between January 2011 and July 2012, a total of 169 VABB were performed by stereotactic guidance on a prone table. The Mammotome(®) 11G (S1) or EnCor(®) 10G (S2) probes were used randomly. Sampling time and the number of frustules collected were considered; sensitivity, specificity, diagnostic accuracy, positive and negative predictive value (PPV, NPV) of both procedures were evaluated, considering the final histological examination as reference (B1, B3, B5 lesions underwent surgical excision; B2 lesion were considered confirmed after a negative follow-up of at least 1 year). RESULTS: There were no statistically significant differences between the two groups of patients according to the number of procedures (S1 82/169; S2 87/169), average age, BIRADS category (4a, b), and average size of the lesions. The two systems did not differ statistically for correlation with the final histology (S1 k = 0.94 ± 0.06; S2 k = 0.92 ± 0.08) and underestimation of B3 lesions or in situ (S1 4.5%; S2 4.3%). Sensitivity, specificity, PPV, NPV, diagnostic accuracy of S1 and S2 were also not statistically different. The systems differed only in sampling time (S1 80; S2 63 s), but not in total procedure time. CONCLUSIONS: Our study confirms the effectiveness of VABB in the assessment of microcalcifications and highlights the lack of significant differences between the two systems in terms of diagnostic performance.

Use of oral gadobenate dimeglumine to visualise the oesophagus during magnetic resonance angiography in patients with atrial fibrillation prior to catheter ablation.

BACKGROUND: Atrio-oesophageal fistula was first reported as a fatal complication of surgical endocardial and percutaneous endocardial radiofrequency ablation for atrial fibrillation, with an incidence after catheter ablation between 0.03% and 0.5%. Magnetic resonance angiography (MRA) was usually performed to obtain pre-procedural 3D images, used to merging into an electro-anatomical map, guiding step-by-step ablation strategy of AF. Our aim was to find an easy, safe and cost-effective way to enhance the oesophagus during MRA. METHODS: In 105 consecutive patients, a right-left phase encoding, free breathing, 3D T1 MRA sequence was performed in the axial plane, >24 hours before catheter ablation, using an intravenous injection of gadobenate dimeglumine contrast medium. The oesophagus was enhanced using an oral gel solution of 0.7 mL gadobenate dimeglumine contrast medium mixed with approximately 40 mg thickened water gel, which was swallowed by the patients on the scanning table, immediately before the MRA sequence acquisition. RESULTS: The visualisation of the oesophagus was obtained in 104/105 patients and images were successfully merged, as left atrium and pulmonary veins, into an electro-anatomical map, during percutaneous endocardial radiofrequency ablation. All patients tolerated the study protocol and no immediate or late complication was observed with the oral contrast agent administration. The free-breathing MRA sequence used in our protocol took 7 seconds longer than MRA breath-hold conventional sequence. CONCLUSION: Oesophagus visualization with oral gadobenate dimeglumine is feasible for integration of oesophagus anatomy images into the electro-anatomical map during AF ablation, without undesirable side effects and without significantly increasing cost or examination time.

Percutaneous segmental dilatation of portal stenosis after paediatric liver transplantation to avoid or postpone surgery: two cases and literature review.

PURPOSE: The authors retrospectively reviewed the results obtained with percutaneous treatment of portal stenosis. MATERIALS AND METHODS: In November 2005 and March 2008, two patients, 15 and 32 months old, underwent portal vein angioplasty at our centre. Both procedures were performed after ultrasound-guided portal vein puncture and measurement of pre- and postanastomotic pressure gradients. The diameters of the angioplasty catheters ranged from 5 to 10 mm and no stents were used. RESULTS: In both cases, it was possible to cross the stenoses, perform angioplasty and obtain an immediate reduction of the pressure gradients. There were no major complications after the procedure. In the first patient, percutaneous treatment allowed us to postpone surgical revision of the anastomosis; in the second case, angioplasty had to be repeated twice over a period of 4 years to finally achieve regular patency of the anastomosis and function of the graft. CONCLUSIONS: Percutaneous treatment of portal stenosis after paediatric liver transplantation is a safe and feasible treatment; if balloon dilatation does not guarantee functional recovery of the organ, it allows surgical revision to be postponed to a later date when the clinical condition is more stable.

Role of paravertebral block anaesthesia during percutaneous transhepatic thermoablation.

PURPOSE: This paper discusses the technique and preliminary results of right thoracic paravertebral block (TPVB) for percutaneous thermal ablation of liver tumours. MATERIALS AND METHODS: Between October 2011 and August 2012 we treated 36 lesions (25 hepatocellular carcinoma and 11 metastases) in 30 patients aged 47-85 years (mean 67.5). Patients received ultrasound (US)-guided injection of 7 ml of naropin 0.75 % in T7, T9 and T11 levels, below the costo-vertebral ligament, until we observed an anterior displacement of the parietal pleura. For the subcapsular lesions, a cervical right phrenic nerve block was associated. The level of analgesia was evaluated during and after the percutaneous procedures with the Numerical Rating Scale. Finally, we investigated statistical correlations between pain and lesions (histological type, site, dimensions), and ablation time and technique (microwave or radiofrequency ablation). RESULTS: Technical success was achieved in all patients. Despite the correct anaesthetic diffusion during the ablation, 10 patients (33.3 %) reported medium/severe pain and intravenous sedation was required. Pain was not found to correlate with any variable. No complications were observed. CONCLUSIONS: In most cases, TPVB is a safe and effective technique for conscious anaesthesia during percutaneous thermal ablation of liver tumours. Failures probably derive from left sympathetic and parasympathetic fibre stimulation. We recommend performing a TPVB in the presence of the anaesthetist.

Radiological assessment of breast density by visual classification (BI-RADS) compared to automated volumetric digital software (Quantra): implications for clinical practice.

OBJECTIVE: This study was done to assess breast density on digital mammography and digital breast tomosynthesis according to the visual Breast Imaging Reporting and Data System (BI-RADS) classification, to compare visual assessment with Quantra software for automated density measurement, and to establish the role of the software in clinical practice. MATERIALS AND METHODS: We analysed 200 digital mammograms performed in 2D and 3D modality, 100 of which positive for breast cancer and 100 negative. Radiological density was assessed with the BI-RADS classification; a Quantra density cut-off value was sought on the 2D images only to discriminate between BI-RADS categories 1-2 and BI-RADS 3-4. Breast density was correlated with age, use of hormone therapy, and increased risk of disease. RESULTS: The agreement between the 2D and 3D assessments of BI-RADS density was high (K 0.96). A cut-off value of 21% is that which allows us to best discriminate between BI-RADS categories 1-2 and 3-4. Breast density was negatively correlated to age (r = -0.44) and positively to use of hormone therapy (p = 0.0004). Quantra density was higher in breasts with cancer than in healthy breasts. CONCLUSIONS: There is no clear difference between the visual assessments of density on 2D and 3D images. Use of the automated system requires the adoption of a cut-off value (set at 21%) to effectively discriminate BI-RADS 1-2 and 3-4, and could be useful in clinical practice.

Efficacy of computer-aided detection as a second reader for 6-9-mm lesions at CT colonography: multicenter prospective trial.

PURPOSE: To assess the effect of computer-aided detection (CAD) as a second reader on the sensitivity and specificity of computed tomographic (CT) colonography in detecting 6-9-mm colorectal cancer (CRC) lesions. MATERIALS AND METHODS: Individuals with clinical indications for colonoscopy--either for symptoms or as part of participating in a surveillance program or CRC screening--were prospectively enrolled at one of 10 academic centers between July 2007 and May 2009. Institutional review board approval was obtained at each clinical site, and all participants provided written informed consent. All participants underwent CT colonography and colonoscopy on the same day. Experienced readers interpreted the CT colonography images unassisted and then reviewed all colorectal lesion-like structures pinpointed by the CAD algorithm. Segmental unblinding of CT colonoscopy findings at colonoscopy was utilized. The sensitivity and specificity of unassisted and CAD-assisted reading in identifying individuals with 6-9-mm lesions were calculated and compared by means of pairwise analysis. RESULTS: A total of 618 participants (mean age, 57.9 years; 54.5% male) were included in the final analysis. Of these participants, 464 (75.1%) had no lesions 6 mm or larger, and 52 (8.4%) had 6-9-mm lesions. The sensitivity of CT colonography with unassisted reading and that with CAD-assisted reading in identifying individuals with 6-9-mm lesions was 65.4% (95% confidence interval [CI]: 50.9%, 78.0%) and 76.9% (95% CI: 63.2%, 87.5%; P = .016), respectively. No significant change in specificity was observed: The specificity of CT colonography with unassisted and that with CAD-assisted reading was 91.8% (95% CI: 88.9%, 94.1%) and 90.9% (95% CI: 88.0%, 93.4%; P = .063), respectively. Evaluation of CAD candidates required an additional 1.6 minutes (25th-75th percentile: 1.0 minute to 3.4 minutes). CONCLUSION: The addition of CAD to reading performed by experienced readers resulted in a significant benefit in the detection of 6-9-mm polyps at CT colonography in this cohort. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120376/-/DC1.

Diffusion-weighted imaging and apparent diffusion coefficient values versus contrast-enhanced MR imaging in the identification and characterisation of acute pyelonephritis.

OBJECTIVE: To compare contrast-enhanced (CEMR) and diffusion-weighted (DWI) magnetic resonance imaging in diagnosing acute pyelonephritis (APN) and to assess ADC measurement reliability in differentiating among normal renal parenchyma, APN and abscesses. METHODS: Eighty-eight patients (80 women, mean age 36.5 years) with clinical suspicion of APN were retrospectively reviewed. An experienced observer quantified lesions with a score ranging from 0 to 3. DWI and CEMR were compared on the basis of the assigned score, total examination number (88) and on presence (36)/absence (52) of abscesses. ADC values, calculated at the healthy parenchyma, APN and abscessed were compared to each other. RESULTS: Agreement between CEMR and DWI was 94.3 % (83/88 patients; P < 0.05). In the APN group, DWI was awarded the highest visibility score compared to CEMR (P = 0.05), while in the abscess group CEMR had the highest score (P = 0.04). The difference between ADC values of the APN-healthy parenchyma and abscess-APN groups was significant (P < 0.05). The area under the ROC curve of ADC values of the APN-healthy and abscess-APN groups were found to be 0.94 (95 % CI; cutoff value = 2) and 0.78 (95 % CI; cutoff value = 1.2) respectively. CONCLUSIONS: Diffusion-weighted imaging appears reliable in the diagnosis and follow-up of acute pyelonephritis and could provide a reasonable alternative to contrast-enhanced magnetic resonance imaging.

Accuracy of tumour size assessment in the preoperative staging of breast cancer: comparison of digital mammography, tomosynthesis, ultrasound and MRI.

PURPOSE: Accurate measurement of breast tumour size is fundamental for treatment planning. We compared the accuracy of digital mammography (DM), digital breast tomosynthesis (DBT), ultrasound (US) and magnetic resonance imaging (MRI) for the preoperative evaluation of breast cancer size. MATERIALS AND METHODS: We retrospectively reviewed 149 breast cancers in 110 patients who underwent DM, DBT, US and MRI between January 2010 and December 2011, before definitive surgery. The lesions were measured by two radiologists, without knowledge of the final histological examination, considered the gold standard. For each imaging modality, the maximum tumour size was measured to the nearest millimetre; the measurements were considered concordant if they were within ± 5 mm. Pearson's correlation coefficient was calculated for each imaging modality. RESULTS: The median pathological tumour size was 22.3 mm. MRI and DBT had a level of concordance with pathology of 70% and 66%, respectively, which was higher than that of DM (54%). DBT and MRI measurements had a better correlation with pathological tumour size (R:0.89 and R:0.92, respectively) compared to DM (R:0.83) and US (R:0.77). CONCLUSIONS: DBT and MRI are superior to DM and US in the preoperative assessment of breast tumour size. DBT seems to improve the accuracy of DM, although MRI remains the most accurate imaging modality for breast cancer extension.