Preoperative breast MRI positively impacts surgical outcomes of needle biopsy-diagnosed pure DCIS: a patient-matched analysis from the MIPA study.

OBJECTIVES: To investigate the influence of preoperative breast MRI on mastectomy and reoperation rates in patients with pure ductal carcinoma in situ (DCIS). METHODS: The MIPA observational study database (7245 patients) was searched for patients aged 18-80 years with pure unilateral DCIS diagnosed at core needle or vacuum-assisted biopsy (CNB/VAB) and planned for primary surgery. Patients who underwent preoperative MRI (MRI group) were matched (1:1) to those who did not receive MRI (noMRI group) according to 8 confounding covariates that drive referral to MRI (age; hormonal status; familial risk; posterior-to-nipple diameter; BI-RADS category; lesion diameter; lesion presentation; surgical planning at conventional imaging). Surgical outcomes were compared between the matched groups with nonparametric statistics after calculating odds ratios (ORs). RESULTS: Of 1005 women with pure unilateral DCIS at CNB/VAB (507 MRI group, 498 noMRI group), 309 remained in each group after matching. First-line mastectomy rate in the MRI group was 20.1% (62/309 patients, OR 2.03) compared to 11.0% in the noMRI group (34/309 patients, p = 0.003). The reoperation rate was 10.0% in the MRI group (31/309, OR for reoperation 0.40) and 22.0% in the noMRI group (68/309, p < 0.001), with a 2.53 OR of avoiding reoperation in the MRI group. The overall mastectomy rate was 23.3% in the MRI group (72/309, OR 1.40) and 17.8% in the noMRI group (55/309, p = 0.111). CONCLUSIONS: Compared to those going directly to surgery, patients with pure DCIS at CNB/VAB who underwent preoperative MRI had a higher OR for first-line mastectomy but a substantially lower OR for reoperation. CLINICAL RELEVANCE STATEMENT: When confounding factors behind MRI referral are accounted for in the comparison of patients with CNB/VAB-diagnosed pure unilateral DCIS, preoperative MRI yields a reduction of reoperations that is more than twice as high as the increase in overall mastectomies. KEY POINTS: • Confounding factors cause imbalance when investigating the influence of preoperative MRI on surgical outcomes of pure DCIS. • When patient matching is applied to women with pure unilateral DCIS, reoperation rates are significantly reduced in women who underwent preoperative MRI. • The reduction of reoperations brought about by preoperative MRI is more than double the increase in overall mastectomies.

Screening and diagnostic breast MRI: how do they impact surgical treatment? Insights from the MIPA study.

OBJECTIVES: To report mastectomy and reoperation rates in women who had breast MRI for screening (S-MRI subgroup) or diagnostic (D-MRI subgroup) purposes, using multivariable analysis for investigating the role of MRI referral/nonreferral and other covariates in driving surgical outcomes. METHODS: The MIPA observational study enrolled women aged 18-80 years with newly diagnosed breast cancer destined to have surgery as the primary treatment, in 27 centres worldwide. Mastectomy and reoperation rates were compared using non-parametric tests and multivariable analysis. RESULTS: A total of 5828 patients entered analysis, 2763 (47.4%) did not undergo MRI (noMRI subgroup) and 3065 underwent MRI (52.6%); of the latter, 2441/3065 (79.7%) underwent MRI with preoperative intent (P-MRI subgroup), 510/3065 (16.6%) D-MRI, and 114/3065 S-MRI (3.7%). The reoperation rate was 10.5% for S-MRI, 8.2% for D-MRI, and 8.5% for P-MRI, while it was 11.7% for noMRI (p ≤ 0.023 for comparisons with D-MRI and P-MRI). The overall mastectomy rate (first-line mastectomy plus conversions from conserving surgery to mastectomy) was 39.5% for S-MRI, 36.2% for P-MRI, 24.1% for D-MRI, and 18.0% for noMRI. At multivariable analysis, using noMRI as reference, the odds ratios for overall mastectomy were 2.4 (p < 0.001) for S-MRI, 1.0 (p = 0.957) for D-MRI, and 1.9 (p < 0.001) for P-MRI. CONCLUSIONS: Patients from the D-MRI subgroup had the lowest overall mastectomy rate (24.1%) among MRI subgroups and the lowest reoperation rate (8.2%) together with P-MRI (8.5%). This analysis offers an insight into how the initial indication for MRI affects the subsequent surgical treatment of breast cancer. KEY POINTS: • Of 3065 breast MRI examinations, 79.7% were performed with preoperative intent (P-MRI), 16.6% were diagnostic (D-MRI), and 3.7% were screening (S-MRI) examinations. • The D-MRI subgroup had the lowest mastectomy rate (24.1%) among MRI subgroups and the lowest reoperation rate (8.2%) together with P-MRI (8.5%). • The S-MRI subgroup had the highest mastectomy rate (39.5%) which aligns with higher-than-average risk in this subgroup, with a reoperation rate (10.5%) not significantly different to that of all other subgroups.

Magnetic resonance imaging before breast cancer surgery: results of an observational multicenter international prospective analysis (MIPA).

OBJECTIVES: Preoperative breast magnetic resonance imaging (MRI) can inform surgical planning but might cause overtreatment by increasing the mastectomy rate. The Multicenter International Prospective Analysis (MIPA) study investigated this controversial issue. METHODS: This observational study enrolled women aged 18-80 years with biopsy-proven breast cancer, who underwent MRI in addition to conventional imaging (mammography and/or breast ultrasonography) or conventional imaging alone before surgery as routine practice at 27 centers. Exclusion criteria included planned neoadjuvant therapy, pregnancy, personal history of any cancer, and distant metastases. RESULTS: Of 5896 analyzed patients, 2763 (46.9%) had conventional imaging only (noMRI group), and 3133 (53.1%) underwent MRI that was performed for diagnosis, screening, or unknown purposes in 692/3133 women (22.1%), with preoperative intent in 2441/3133 women (77.9%, MRI group). Patients in the MRI group were younger, had denser breasts, more cancers ≥ 20 mm, and a higher rate of invasive lobular histology than patients who underwent conventional imaging alone (p < 0.001 for all comparisons). Mastectomy was planned based on conventional imaging in 22.4% (MRI group) versus 14.4% (noMRI group) (p < 0.001). The additional planned mastectomy rate in the MRI group was 11.3%. The overall performed first- plus second-line mastectomy rate was 36.3% (MRI group) versus 18.0% (noMRI group) (p < 0.001). In women receiving conserving surgery, MRI group had a significantly lower reoperation rate (8.5% versus 11.7%, p < 0.001). CONCLUSIONS: Clinicians requested breast MRI for women with a higher a priori probability of receiving mastectomy. MRI was associated with 11.3% more mastectomies, and with 3.2% fewer reoperations in the breast conservation subgroup. KEY POINTS: • In 19% of patients of the MIPA study, breast MRI was performed for screening or diagnostic purposes. • The current patient selection to preoperative breast MRI implies an 11% increase in mastectomies, counterbalanced by a 3% reduction of the reoperation rate. • Data from the MIPA study can support discussion in tumor boards when preoperative MRI is under consideration and should be shared with patients to achieve informed decision-making.

Solving the preoperative breast MRI conundrum: design and protocol of the MIPA study.

Despite its high diagnostic performance, the use of breast MRI in the preoperative setting is controversial. It has the potential for personalized surgical management in breast cancer patients, but two of three randomized controlled trials did not show results in favor of its introduction for assessing the disease extent before surgery. Meta-analyses showed a higher mastectomy rate in women undergoing preoperative MRI compared to those who do not. Nevertheless, preoperative breast MRI is increasingly used and a survey from the American Society of Breast Surgeons showed that 41% of respondents ask for it in daily practice. In this context, a large-scale observational multicenter international prospective analysis (MIPA study) was proposed under the guidance of the European Network for the Assessment of Imaging in Medicine (EuroAIM). The aims were (1) to prospectively and systematically collect data on consecutive women with a newly diagnosed breast cancer, not candidates for neoadjuvant therapy, who are offered or not offered breast MRI before surgery according to local practice; (2) to compare these two groups in terms of surgical and clinical endpoints, adjusting for covariates. The underlying hypotheses are that MRI does not cause additional mastectomies compared to conventional imaging, while reducing the reoperation rate in all or in subgroups of patients. Ninety-six centers applied to a web-based call; 36 were initially selected based on volume and quality standards; 27 were active for enrollment. On November 2018, the target of 7000 enrolled patients was reached. The MIPA study is presently at the analytic phase. Key Points • Breast MRI has a high diagnostic performance but its utility in the preoperative setting is controversial. • A large-scale observational multicenter prospective study was launched to compare women receiving with those not receiving preoperative MRI. • Twenty-seven centers enrolled more than 7000 patients. The study is presently at the analytic phase.

Results of Short-Term Follow-Up in BI-RADS 3 and 4a Breast Lesions with a Histological Diagnosis of Fibroadenoma at Percutaneous Needle Biopsy.

OBJECTIVE: To evaluate the usefulness of short-term (6 months) follow-up in patients with Breast Imaging Report and Data System (BI-RADS) 3 and 4a lesions, after a diagnosis of fibroadenoma at an image-guided biopsy. PATIENTS AND METHODS: The data of 318 women with 349 biopsy-proven fibroadenomas, a 6-month follow-up, and a follow-up of ≥ 24 months were retrospectively reviewed. Information on clinical history, lesion characteristics on ultrasound (US), mammography, and magnetic resonance imaging (MRI), BI-RADS classification, and follow-up was collected. The false-negative (FN) rate and the negative predictive value (NPV) for the biopsy were calculated. RESULTS: 43 patients (13.5%) presented with a palpable nodule; 18 (5.7%) had a history of breast cancer. There were 334 lesions visible on US (95.7%), 57 on US and mammography (16.3%), and 15 on mammography only (4.3%); 37 lesions were first detected on MRI. All lesions were stable at 6 months. After an at least 1-year follow-up, 4 lesions changed their features and were excised. Histology showed 1 invasive lobular cancer, 1 ductal carcinoma in situ, 1 phyllodes tumor, and 1 papilloma. The FN rate of the needle biopsy was 1.1% and the NPV was 98.9%. CONCLUSION: For lesions initially described as BI-RADS 3 and 4a with a histological diagnosis of fibroadenoma after biopsy, short-term follow-up can be avoided.

Comparison between automated breast volume scanner (ABVS) versus hand-held ultrasound as a second look procedure after magnetic resonance imaging.

OBJECTIVES: To evaluate the agreement between automated breast volume scanner (ABVS) and conventional ultrasound (US) as a second-look (SL) tool for assessing additional findings found on MRI. METHODS: Over a 7-month period, we prospectively assigned to SL-US and SL-ABVS all patients undergoing 1.5 T breast MRI in whom additional findings were found. Five experienced breast radiologists independently interpreted SL-US and SL-ABVS in blinded sessions to evaluate the detection rate of MRI findings and assign them to BI-RADS categories. We calculated the agreement between the two methods in assessing MRI findings as significant (BI-RADS 3-5) versus not significant (BI-RADS 1-2), as well as their cancer detection rate. RESULTS: In a population of 131 patients, SL-ABVS and SL-US showed a comparable detection rate of MRI findings (69.3 vs. 71.5%) (p > 0.05; McNemar test), with an almost perfect agreement in assessing them as significant or not (k = 0.94). This translated into a comparably high cancer detection rate (83.8% for SL-ABVS vs. 87.0% for SL-US). Only 1/31 cancers was missed by SL-ABVS. CONCLUSIONS: SL-ABVS and SL-US are nearly equivalent in assessing the significance of MRI findings, leading to a comparable cancer detection rate. SL-ABVS has the potential to replace SL-US in the SL scenario. KEY POINTS: • SL-ABVS shows almost perfect agreement with SL-US in assessing MRI findings. • SL-ABVS shows a comparably high cancer detection rate with respect to SL-US. • SL-ABVS has the potential to replace SL-US in evaluating additional MRI findings.

Foci on breast magnetic resonance imaging in high-risk women: cancer or not?

PURPOSE: To assess how frequently foci are identified on MRI in high-risk patients, and their association with malignancy, breast density, and background parenchymal enhancement (BPE). MATERIALS AND METHODS: In this multicentric study, two readers, in consensus, retrospectively reviewed screening breast MRI of 245 high-risk women, performed between 2009 and 2014. Eligible patients had at least two consecutive screening MRI, and a follow-up of at least 1 year after a lesion was first detected; histology was available for all suspicious findings. Breast density, BPE (both using BI-RADS lexicon), presence, and changes at follow-up for foci were evaluated. Clinical history of the patients was reviewed. Chi-square test was used to define significant correlations. RESULTS: 166 women (mean age 43 years), who underwent a median of 4 MRI (range 2-6) during the study period, were included. 68 foci were found in 58 women [34.9 %, 95 % confidence interval (CI) 28.1-42.5 %]. Foci were more frequent in dense breasts (P = 0.079) and with moderate or marked BPE (P < 0.001). During follow-up, two foci increased in size (2.9 %, 95 % CI 0.8-10.1 %) and at biopsy, a cancer was found (1 high-grade ductal carcinoma in situ, 1 tubular carcinoma). Breast cancer was diagnosed in the other three cases, not initially appearing as foci, and it was more frequent in women with dense breasts (P = 0.04); no correlation between cancer and BPE was found (P = 0.145). CONCLUSIONS: Foci are relatively frequent in screening MRI, and they are usually benign. An increase in size is the most reliable criteria to suspect malignancy.

Impact of multiparametric magnetic resonance imaging on risk group assessment of patients with prostate cancer addressed to external beam radiation therapy.

PURPOSE: To investigate the impact of multiparametric magnetic resonance imaging (mpMRI) on risk group assessment of patients with prostate cancer (PCa) initially addressed to external beam radiation therapy (EBRT). MATERIALS AND METHODS: We prospectively performed mpMRI (3.0Tsystem) in 44 patients addressed to EBRT, using a multiparametric protocol (high-resolution multiplanar T2-weighted, diffusion-weighted and dynamic contrast-enhanced imaging). Risk group was assessed in accordance with the National comprehensive cancer network (NCCN) categories, by combining prostate-specific-antigen level, Gleason score and the T-stage as established by digital rectal examination (clinical risk assessment; c-RA) versus mpMRI (mpMRI-risk assessment; mpMRI-RA). The agreement between c-RA and mpMRI-RA was investigated using Cohen's kappa. RESULTS: Patients were included in very low/low risk, intermediate risk, high risk, very high risk and metastatic NCCN categories in 10 (22.7%), 18 (40.9%), 15 (34.1%), 1 (2.3%) and 0 cases using c-RA vs. 8 (18.2%), 14 (31.8%), 14 (31.8%), 4 (9.1%) and 4 (9.1%) cases using mpMRI-RA, respectively, with only moderate agreement (k=0.43). mpMRI-RA determined risk downgrading in 2/44 patients (4.5%), and risk upgrading in 16/44 patients (36.3%). After mpMRI, EBRT remained indicated in all patients. CONCLUSION: mpMRI changed clinical risk stratification in about 41% of patients with PCa, with potential impact on EBRT planning.

Impact on the recall rate of digital breast tomosynthesis as an adjunct to digital mammography in the screening setting. A double reading experience and review of the literature.

OBJECTIVES: To estimate the impact on recall rate (RR) of digital breast tomosynthesis (DBT) associated with digital mammography (DM+DBT), compared to DM alone, evaluate the impact of double reading (DR) and review the literature. METHODS: Ethics committees approved this multicenter study. Patients gave informed consent. Women recalled from population-based screening reading were included. Reference standard was histology and/or ≥ 1 year follow up. Negative multiple assessment was considered for patients lost at follow up. Two blinded readers (R1, R2) evaluated first DM and subsequently DM+DBT. RR, sensitivity, specificity, accuracy, positive and negative predictive values (PPV, NPV), were calculated for R1, R2, and DR. Cohen κ and χ(2) were used for R1-R2 agreement and RR related to breast density. RESULTS: We included 280 cases (41 malignancies, 66 benign lesions, and 173 negative examinations). The RR reduction was 43% (R1), 58% (R2), 43% (DR). Sensitivity, specificity, accuracy, PPV and NPV were: 93%, 67%, 71%, 33%, 98% for R1; 88%, 73%, 75%, 36%, 97% for R2; 98%, 55%, 61%, 27%, 99% for DR. The agreement was higher for DM+DBT (κ=0.459 versus κ=0.234). Reduction in RR was independent from breast density (p=0.992). CONCLUSION: DBT was confirmed to reduce RR, as shown by 13 of 15 previous studies (reported reduction 6-82%, median 31%). This reduction is confirmed when using DR. DBT allows an increased inter-reader agreement.

Management of atypical lobular hyperplasia, atypical ductal hyperplasia, and lobular carcinoma in situ.

Atypical hyperplasia and lobular carcinoma in situ are rare proliferative breast lesions, growing inside ducts and terminal ducto-lobular units. They represent a marker of increased risk for breast cancer and a non-obligate precursor of malignancy. Evidence available on diagnosis and management is scarce. They are frequently found incidentally associated with other lesions, but can be visible through mammography, ultrasound or magnetic resonance. Due to the risk of underestimation, surgical excision is often performed. The analysis of imaging and histopathological characteristics could help identifying low-risk cases, for which surgery is not necessary. Chemopreventive agents can be used for risk reduction. Careful imaging follow up is mandatory; the role of breast MRI as screening modality is under discussion.

Liver involvement by multiple myeloma presenting as hypervascular focal lesions in a patient with chronic hepatitis B infection.

Extramedullary myeloma refers to the infiltration of neoplastic monoclonal plasma cells in either organs or soft tissues. The disease is clinically and radiologically underestimated compared with the autopsy findings and is usually associated with a more aggressive clinical course and poorer outcome. A minority of patients with extramedullary myeloma show hepatic involvement, usually in the form of diffuse parenchymal infiltration. When focal infiltration is present, variable imaging findings have been described both on CT scan and MRI. We report the case of a 63-year-old male with hepatitis B virus-related liver disease and biopsy-proven multiple myeloma involving the liver, manifesting as hypervascular focal liver lesions on MRI. A brief review of the literature is also proposed.

Is there a systematic bias of apparent diffusion coefficient (ADC) measurements of the breast if measured on different workstations? An inter- and intra-reader agreement study.

OBJECTIVES: To evaluate the influence of post-processing systems, intra- and inter-reader agreement on the variability of apparent diffusion coefficient (ADC) measurements in breast lesions. METHODS: Forty-one patients with 41 biopsy-proven breast lesions gave their informed consent and were included in this prospective IRB-approved study. Magnetic resonance imaging (MRI) examinations were performed at 1.5 T using an EPI-DWI sequence, with b-values of 0 and 1000 s/mm(2). Two radiologists (R1, R2) reviewed the images in separate sessions and measured the ADC for lesion, using MRI-workstation (S-WS), PACS-workstation (P-WS) and a commercial DICOM viewer (O-SW). Agreement was evaluated using the intraclass correlation coefficient (ICC), Bland-Altman plots and coefficient of variation (CV). RESULTS: Thirty-one malignant, two high-risk and eight benign mass-like lesions were analysed. Intra-reader agreement was almost perfect (ICC-R1 = 0.974; ICC-R2 = 0.990) while inter-reader agreement was substantial (ICC from 0.615 to 0.682). Bland-Altman plots revealed a significant bias in ADC values measured between O-SW and S-WS (P = 0.025), no further systematic differences were identified. CV varied from 6.8 % to 7.9 %. CONCLUSION: Post-processing systems may have a significant, although minor, impact on ADC measurements in breast lesions. While intra-reader agreement is high, the main source of ADC variability seems to be caused by inter-reader variation. KEY POINTS: • ADC provides quantitative information on breast lesions independent from the system used. • ADC measurement using different workstations and software systems is generally reliable. • Systematic, but minor, differences may occur between different post-processing systems. • Inter-reader agreement of ADC measurements exceeded intra-reader agreement.

Additional findings at preoperative breast MRI: the value of second-look digital breast tomosynthesis.

OBJECTIVES: To evaluate second-look digital breast tomosynthesis (SL-DBT) for additional findings (AFs) at preoperative MRI compared with second-look ultrasound (SL-US). METHODS: We included 135 patients with breast cancer who underwent digital mammography (DM), DBT, US, and MRI at two centres. MR images were retrospectively evaluated to find AFs, described as focus, mass, or non-mass; ≤10 mm or >10 mm in size; BI-RADS 3, 4, or 5. DM and DBT exams were reviewed looking for MRI AFs; data on SL-US were collected. Reference standard was histopathology or ≥12-month negative follow-up. Fisher exact test and McNemar test were used. RESULTS: Eighty-four AFs were detected in 53/135 patients (39%, 95%CI 31-48%). A correlate was found for 44/84 (52%, 95%CI 41-63%) at SL-US, for 20/84 (24%, 95%CI 11-28%) at SL-DM, for 42/84 (50%, 95%CI 39-61%) at SL-DBT, for 63/84 (75%, 95%CI 64-84%) at SL-DBT, and/or SL-US, the last rate being higher than for SL-US only, overall (p < 0.001), for mass or non-mass, ≤ or >10 mm, BI-RADS 4 or 5, or malignant lesions (p < 0.031). Of 21 AFs occult at both SLs, 17 were malignant (81%, 95%CI 58-94%). CONCLUSIONS: When adding SL-DBT to SL-US, AFs detection increased from 52% to 75%. MR-guided biopsy is needed for the remaining 25%. KEY POINTS: • Detection rate of MRI AFs using SL-US was 52% • Adding SL-DBT, the detection rate of MRI AFs significantly increased to 75%. • Over 80% of the remaining 25% MRI AFs were malignant. • MR-guided biopsy should be used when SL-US and SL-DBT are inconclusive.

MR mammography using diffusion-weighted imaging in evaluating breast cancer: a correlation with proliferation index.

PURPOSE: To evaluate whether the variation of the apparent diffusion coefficient (ADC) values obtained with DWI can predict elevated levels of Ki67 proliferation index and aggressive subtypes in patients with breast cancer. MATERIALS AND METHODS: Breast MRI studies of 115 patients (mean age 57.3 years, range 36-81 years) with a biopsy-proven breast cancers were evaluated in this retrospective IRB-approved study. Examinations were performed on a 1.5 T magnet and included a Single-Shot Echoplanar DWI sequence with b values of 0 and 1000 s/mm(2). For each target lesion, ADC was measured. ADC values were compared considering Ki67 status (≥20 % or <20 %), histology, grade (G1, G2 or G3) and clinical-pathological classification (Luminal A, Luminal B HER2-positive, Luminal B HER-2 negative, HER-2 enriched and Triple Negative). Mann-Whitney U test and Kruskal-Wallis test were used for comparisons and receiver operating characteristic (ROC) curves were obtained. Inter- and intra-reader variability was evaluated in a subset of 40 patients, using interclass correlation coefficient (ICC) and Bland-Altman plots. RESULTS: Of 115 lesions, 53 (46.1 %) were assessed as Ki67 positive and 62 (53.9 %) as Ki67 negative. ADC values were significantly (p < 0.0001) lower in Ki67-positive patients (median 0.86 × 10(-3) mm(2)/s; interquartile range 0.75-0.92) compared to Ki67-negative (median 1.03 × 10(-3) mm(2)/s; interquartile range 0.92-1.13). Median ADC was also lower in G2 and G3 cancer and in the Luminal B Her2-negative subtype (p = 0.0015). No differences were found when evaluating histology. ROC curve showed a sensitivity and specificity of 83.0 and 66.1 %, respectively, when using a cutoff of 0.95 s/mm(2) to differentiate Ki67-positive from Ki67-negative cancers. Inter- and intra-reader variability was moderate (ICC = 0.623; ICC = 0.548, respectively). No systematic differences were identified with Bland-Altman plots. CONCLUSIONS: Lower ADC values are associated with elevated Ki67 proliferation index and more aggressive pathologic features. Moderate agreement in ADC measurement could be a limitation.

Test-retest reliability of diffusion tensor imaging of the liver at 3.0 T.

PURPOSE: This study was done to evaluate test-retest reliability of liver diffusion tensor imaging (LDTI). MATERIALS AND METHODS: Ten healthy volunteers (median age 23 years) underwent two LDTI scans on a 3.0 T magnet during two imaging sessions separated by 2 weeks (session-1/-2, respectively). Fifteen gradient directions and b values of 0-1,000 s/mm(2) were used. Two radiologists in consensus assessed liver apparent diffusion coefficient (ADC) and fraction of anisotropy (FA) values on ADC and FA maps at four reference levels, namely: right upper level (RUL), right lower level (RLL), left upper level (LUL) and left lower level (LLL). We then assessed (a) whether ADC and FA values overlapped when measured on different levels within the same imaging session or between different imaging sessions; (b) the degree of variability on an intra-session and inter-session basis, respectively, using the coefficient of variation (CV). RESULTS: In sessions 1 and 2, the ADC/FA values were significantly larger in the left liver lobe (LUL/LLL) compared to right liver lobe (RUL/RLL) (p < 0.05/6). Intra-session CVs were 9.51 % (session 1) and 9.73 % (session 2) for ADC, and 12.93 % (session 1) and 11.82 % (session 2) for FA, respectively. When comparing RUL, RLL, LUL and LLL on an inter-session basis, CVs were 6.52, 8.20, 6.52 and 11.06 % for ADC, and 15.42, 15.80, 15.42 and 6.80 % for FA, respectively. CONCLUSION: LDTI provides consistent and repeatable measurements. However, since larger left lobe ADC/FA values can be attributed to artefacts, right lobe values should be considered the most reliable measurements of water diffusivity within the liver.

Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT.

Despite advances in patient and graft management, biliary complications (BC) still represent a challenge both in the early and delayed period after orthotopic liver transplantation (OLT). Because of unspecific clinical presentation, imaging is often mandatory in order to diagnose BC. Among imaging modalities, magnetic resonance cholangiography (MRC) has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively, using both the conventional technique (based on heavily T2-weighted sequences) and contrast-enhanced MRC (based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents). On this basis, MRC is generally indicated to: (1) avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications; and (2) provide a road map for interventional procedures or surgery. As illustrated in the review, MRC is accurate in the diagnosis of different types of biliary complications, including anastomotic strictures, non-anastomotic strictures, leakage and stones.

Post-operative imaging in liver transplantation: state-of-the-art and future perspectives.

Orthotopic liver transplantation (OLT) represents a major treatment for end-stage chronic liver disease, as well as selected cases of hepatocellular carcinoma and acute liver failure. The ever-increasing development of imaging modalities significantly contributed, over the last decades, to the management of recipients both in the pre-operative and post-operative period, thus impacting on graft and patients survival. When properly used, imaging modalities such as ultrasound, multidetector computed tomography, magnetic resonance imaging (MRI) and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT. Less defined is the role for imaging in assessing primary graft dysfunction (including rejection) or chronic allograft disease after OLT, e.g., hepatitis C virus (HCV) recurrence. This paper: (1) describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice; (2) illustrates main imaging findings related to post-OLT complications in adult patients; and (3) reviews future perspectives emerging in the surveillance of recipients with HCV recurrence, with special emphasis on MRI.

Differentiating small (≤1 cm) focal liver lesions as metastases or cysts by means of computed tomography: a case-study to illustrate a fuzzy logic-based method to assess the impact of diagnostic confidence on radiological diagnosis.

PURPOSE: To quantify the impact of diagnostic confidence on radiological diagnosis with a fuzzy logic-based method. MATERIALS AND METHODS: Twenty-two oncologic patients with 20 cysts and 30 metastases ≤1 cm in size found at 64-row computed tomography were included. Two readers (R1/R2) expressed diagnoses as a subjective level of confidence P(d) in malignancy within the interval [0,1] rather than on a "crisp" basis (malignant/benign); confidence in benignancy was 1 - p(d). When cross-tabulating data according to the standard of reference, 2 × 2 table cells resulted from the aggregation between p(d)/1 - p(d) and final diagnosis. We then assessed (i) readers diagnostic performance on a fuzzy and crisp basis; (ii) the "divergence" δ(F, C) (%) as a measure of how confidence impacted on crisp diagnosis. RESULTS: Diagnoses expressed with lower confidence increased fuzzy false positives compared to crisp ones (from 0 to 0.2 for R1; from 1 to 2.4 for R2). Crisp/fuzzy accuracy was 94.0%/93.6% (R1) and 94.0/91.6% (R2). δ(F, C) (%) was larger in the case of the less experienced reader (R2) (up to +7.95% for specificity). According to simulations, δ(F, C) (%) was negative/positive depending on the level of confidence in incorrect diagnoses. CONCLUSION: Fuzzy evaluation shows a measurable effect of uncertainty on radiological diagnoses.

Does diffusion-weighted imaging add diagnostic confidence in discriminating between benign and malignant solid focal liver lesions?

We investigated whether diffusion-weighted Imaging (DWI) adds diagnostic confidence in assessing focal liver lesions (FLLs). By reviewing FLLs without and with DWI at 1.5 T, two radiologists scored the confidence in diagnosing benignancy/malignancy (confidence score), and DWI usefulness (usefulness score). We showed that adding DWI significantly decreased the confidence score of the most experienced radiologist and increased his confidence in false-negative diagnoses showing atypical features on conventional magnetic resonance imaging.

Comparison between different imaging techniques in the evaluation of malignant breast lesions: can 3D ultrasound be useful?

PURPOSE: This study was done to assess the feasibility of three-dimensional ultrasonography (3D-US) for volume calculation of solid breast lesions. MATERIALS AND METHODS: The volumes of 36 malignant lesions were measured using conventional 2D-US, 3D-US and magnetic resonance imaging (MRI) and compared with that obtained with histology (standard of reference). With 2D Ultrasouns, volume was estimated by measuring three diameters and calculating volume with the mathematical formula for spheres. With 3D-US, stored images were retrieved and boundaries of masses were manually outlined; volume calculation was performed with VOCAL software. For MRI, volume measurements were obtained with special software for 3D reconstructions, after each lesion had been manually outlined. Histology measured the three main diameters and the volume was estimated using the mathematical formula for spheres. Interclass correlation coefficient (ICC) and Bland-Altman plots were used to assess agreement between the volumes measured. RESULTS: ICC indicated that a good level of concordance was identified between 3D-US and histology (0.79). According to the Bland-Altman analysis, limits of agreement of mean differences of the volumes measured with the three imaging modalities were comparable with histology: -2 ÷ 1.5 cm(3) for 3D-US; -2.3 ÷ 1.3 cm(3) for 2D-US and -2.2 ÷ 1.6 cm(3) for MRI. CONCLUSIONS: 3D-US is a reliable method for the volumetric assessment of breast lesions. 3D-US is able to provide valuable information for the preoperative evaluation of lesions.