MR evaluation of breast lesions obtained by diffusion-weighted imaging with background body signal suppression (DWIBS) and correlations with histological findings

Accuracy of abbreviated magnetic resonance compared to 3-dimensional mammography and ultrasound in early detection of breast cancer

BACKGROUND

The purpose of this study is to assess the usefulness of the novel abbreviated MR (AB-MR) protocol in the screening of women with an intermediate risk of breast cancer. Sixty women with a Tyrer-Cuzick model-determined intermediate risk of breast cancer underwent AB-MR, mammography, and tomosynthesis examinations; as an auxiliary procedure, ultrasound imaging was carried out. Every modality was allocated a final BI-RADS category. Time spent on acquisition and interpretation was also noted. Pathological confirmation was obtained in all cases exhibiting malignant findings. The difference in sensitivity and specificity between the two modalities was evaluated using McNemar's test.

RESULTS

When compared to traditional screening methods, AB-MR demonstrated 100% NPV, 98% specificity, 66.7% PPV, and 100% sensitivity in women with intermediate risk of breast cancer. Comparing mammography/ultrasound to positive malignancies verified by biopsy, the results indicated 100% sensitivity, 96.5% specificity, 60% PPV, and 100% NPV. Complete agreement was observed between abbreviated MR and malignant biopsies (100% sensitivity, specificity, NPV, and PPV). For AB-MR and mammography, the average reading time was 4 min and 5 min, respectively. The average acquisition time for AB-MRI was around 10 min, whereas the average time for complete MR imaging is 17 min.

CONCLUSION

AB-MR has better sensitivity, specificity, PPV, and NPV in screening of intermediate- and high-risk breast cancer. Acquisition time was shorter than full MR protocol. Reading time was decreased in respect of mammography. MRI screening ought to be more practical with the AB-MR protocol.

Long-Term Breast Cancer Risk in Hodgkin Lymphoma Survivors: Evaluating Background Parenchymal Enhancement and Radiotherapy-Induced Toxicity

Hodgkin lymphoma (HL) treatment has dramatically improved, with high survival rates in early stages. However, long-term survivors face an increased risk of secondary cancers, particularly breast cancer (BC), which emerge as a leading cause of mortality decades after therapy. Background/Objectives: This study explores the risk of BC and the toxic effects of radiation therapy (RT) in long-term HL survivors compared to age-matched high-risk women, including BRCA1 and BRCA2 mutation carriers. A prospective study was conducted on 62 women who had undergone chemotherapy and involved-field RT for HL, with MRI used to assess breast tissue changes. This study's primary endpoint was to analyze BC incidence in HL survivors, while secondary objectives focused on the analysis of background parenchymal enhancement (BPE) in irradiated areas. Results: The findings revealed a 5% incidence of BC in HL survivors, with 50% showing moderate or marked BPE, similar to that observed in high-risk BC controls. No significant differences in BPE distribution were found between the two groups. Conclusions: The study highlights the long-term risk of BC in HL survivors and suggests that advanced RT techniques and targeted therapies may help reduce the incidence of secondary tumors. Future research should focus on understanding the genetic and biological mechanisms behind treatment-induced cancers.

Predictive value of T2-weighted magnetic resonance imaging for the prognosis of patients with mass-type breast cancer with peritumoral edema

The aim of the present study was to investigate the role of edema surrounding breast cancer masses in the prognostic prediction of magnetic resonance imaging (MRI) T2-weighted fat suppression sequence. For this purpose, 80 patients with mass-type breast cancer underwent conventional plain breast MRI, dynamic contrast-enhanced (DCE)-MRI or diffusion-weighted MRI scan. The associations between edema around the mass on MRI T2 fat suppression sequence plain scan and tumor stage, pathological findings, immunohistochemical findings and axillary lymph node metastasis were analyzed. The results revealed the presence of edema around the mass on the MRI T2 fat suppression sequence plain scan in 35 patients. By contrast, there was no abnormal enhancement on the DCE-MRI, and the apparent diffusion coefficient value did not decrease in these areas. Compared with the remaining 45 patients, the 35 patients with peritumoral edema exhibited a higher tumor stage and a higher rate of axillary lymph node metastasis (all P<0.05). However, there was no significant difference in pathological classification or the expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 (as determined by immunohistochemistry) between the two groups. In total, 12 cases of tumor shrinkage during neoadjuvant chemotherapy were accompanied by an improvement in edema. Taken together, the findings of the present study indicated that the presence of edema around the mass on the MRI T2 fat suppression sequence may predict poor prognosis in patients with mass-type breast cancer. Furthermore, the improvement of the peritumoral edema post-neoadjuvant chemotherapy may also be a predictor of a more favorable prognosis.

A Brief Review on Breast Carcinoma and Deliberation on Current Non Invasive Imaging Techniques for Detection

BACKGROUND

Breast carcinoma is a life threatening disease that accounts for 25.1% of all carcinoma among women worldwide. Early detection of the disease enhances the chance for survival.

DISCUSSION

This paper presents comprehensive report on breast carcinoma disease and its modalities available for detection and diagnosis, as it delves into the screening and detection modalities with special focus placed on the non-invasive techniques and its recent advancement work done, as well as a proposal on a novel method for the application of early breast carcinoma detection.

CONCLUSION

This paper aims to serve as a foundation guidance for the reader to attain bird's eye understanding on breast carcinoma disease and its current non-invasive modalities.

Unenhanced breast MRI: could it replace dynamic breast MRI in detecting and characterizing breast lesions?

Background

We aimed to evaluate the unenhanced MRI of the breast (UE-MRI) as an effective substitute for dynamic contrast-enhanced breast MRI (DCE-MRI) in both detecting and characterizing breast lesions. We enrolled in our retrospective study 125 females (232 breasts, as 18 patients had unilateral mastectomy) with breast mass at MRI of variable pathologies. Routine DCE-MRI protocol of the breast was conducted. We compared the conventional unenhanced images including STIR, T2, and DWIs to the DCE-MRI by two blinded radiologists, to detect and characterize breast lesions, and then we compared their results with the final reference diagnoses supplied by the histopathology or serial negative follow-ups. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy for UE-MRI and DCE-MRI were calculated. UE-MRI results of each observer were also compared with DCE- MRI.

Results

The calculated UE-MRI sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for the first observer were 95%, 80%, 83%, 94%, and 89% respectively, and for the second observer, they were 94%, 79%, 81%, 93%, and 86%. On the other hand, those for the DCE-MRI by the first observer were 98%, 82%, 84%, 98%, and 90% and were 97%, 81%, 84%, 97%, and 89% by the second observer. The intraobserver agreement between the UE-MRI and DCE-MRI results of each observer was 94% and 95%, while the interobserver agreement for each section was 97.4% for UE-MRI and 98.3% for DCE-MRI.

Conclusion

UE-MRI of the breast can be a reliable and effective substitute for breast DCE-MRI. It can be used with comparable accuracy to DCE-MRI whenever contrast administration is not feasible or contraindicated.

Lipoma of the transverse colon covered by tubulovillous adenoma: a rare indication for surgical treatment

Lipomas of the digestive tract are rare benign tumours which, in most cases, are totally asymptomatic. Because of their localization within the intestinal wall, endoscopy may be completely negative so contrast-enhanced computed tomography (CT) is very important for detecting and typing these lesions. The case of a 49-year-old man with abdominal pain is presented. Colonoscopy and biopsy of a polypoid lesion on the right colonic flexure concluded for tubulovillous adenoma. The subsequent CT showed a polylobate lesion of 5 cm in diameter with predominant fat density causing luminal sub-stenosis. Histological examination of the surgical specimen confirmed the presence of a voluminous submucosal lipoma. CT allows to diagnose lipomas of the large bowel thanks to the density measurement (between -40 and -120 Hunsfield Units) with an accurate detection of the site and nature of lumen stenosis.

A Gradient-Based Approach for Breast DCE-MRI Analysis

Breast cancer is the main cause of female malignancy worldwide. Effective early detection by imaging studies remains critical to decrease mortality rates, particularly in women at high risk for developing breast cancer. Breast Magnetic Resonance Imaging (MRI) is a common diagnostic tool in the management of breast diseases, especially for high-risk women. However, during this examination, both normal and abnormal breast tissues enhance after contrast material administration. Specifically, the normal breast tissue enhancement is known as background parenchymal enhancement: it may represent breast activity and depends on several factors, varying in degree and distribution in different patients as well as in the same patient over time. While a light degree of normal breast tissue enhancement generally causes no interpretative difficulties, a higher degree may cause difficulty to detect and classify breast lesions at Magnetic Resonance Imaging even for experienced radiologists. In this work, we intend to investigate the exploitation of some statistical measurements to automatically characterize the enhancement trend of the whole breast area in both normal and abnormal tissues independently from the presence of a background parenchymal enhancement thus to provide a diagnostic support tool for radiologists in the MRI analysis.

Assessment of breast mass morphology with diffusion-weighted MRI: Beyond apparent diffusion coefficient

BACKGROUND

Diffusion-weighted imaging (DWI) is a noncontrast-enhanced MRI technique. There are new promising studies on the use of DWI as a part of the enhanced or unenhanced abbreviated breast MRI protocols.

PURPOSE

To evaluate the ability of breast DWI in the assessment of mass morphology and determine the contribution of this morphologic evaluation in their characterization.

STUDY TYPE

Retrospective.

POPULATION

In all, 213 consecutive women were breast MR imaged and had a later confirmed diagnosis.

FIELD STRENGTH/SEQUENCE

Breast dynamic contrast-enhanced-MRI (DCE-MRI) and DWI at 1.5T.

ASSESSMENT

After Institutional Review Board approval, two radiologists first independently, and later in consensus, evaluated the visibility and morphology of the 143 malignant, 70 benign masses on DWI and DCE-MRI in separate sessions, blindly. Shape, margin, and internal pattern of the masses were evaluated according to BI-RADS lexicon. Apparent diffusion coefficient (ADC) and tumor size were measured by one radiologist.

STATISTICAL TESTS

Consistency between imaging methods and readers was evaluated with Cohen's kappa statistics. Multivariate analysis was applied to find the best predictors of malignancy.

RESULTS

Tumor visibility on DWI was high to moderate in at least 88% of cases. Consistency between DWI and DCE-MRI was substantial (kappa ≥0.757) for shape and margin and moderate (kappa = 0.505) for internal pattern. Interobserver agreement was substantial to moderate for all morphologic parameters (kappa ≥0.596). Morphology evaluated on DWI provided 83-84% accuracy in discriminating malignant from benign masses. ADC alone provided 90-91% accuracy. Both morphologic parameters and ADC were significantly associated with malignancy on multivariate analysis and provided 91-93% accuracy.

DATA CONCLUSION

DWI might be used not only for ADC evaluation but also for the morphological evaluation of breast masses to characterize them.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1668-1677.

Diagnostic accuracy of diffusion-weighted whole-body imaging with background body signal suppression/T2-weighted image fusion for the detection of abdominal solid cancer

Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) images show significant contrast for cancer tissues against non-cancerous tissues. Fusion of a DWIBS and a T2-weighted image (DWIBS/T2) can be used to obtain functional, as well as anatomic, information. In the present study, the performance of DWIBS/T2 in the diagnosis of abdominal solid cancer was evaluated. The records of 14 patients were retrospectively analyzed [5 patients with hepatocellular carcinoma (HCC), 4 with metastatic liver cancer, 3 with pancreatic cancer, 1 with renal cellular carcinoma and 1 with malignant lymphoma of the para-aortic lymph node]. T1WI and T2WI scans did not detect pancreatic cancer in certain cases, whereas DWIs and DWIBS/T2 clearly demonstrated pancreatic cancer in all cases. In addition, metastatic liver cancer and HCC were successfully detected with abdominal US and CECT; however, US did not detect pancreatic cancer in 1 case, while CECT and DWIBS/T2 detected pancreatic cancer in all cases. In conclusion, the diagnostic performance of DWIBS/T2 was the same as that of abdominal US and CECT in detecting primary and metastatic liver cancer. DWIBS/T2 enabled the diagnosis of pancreatic cancer in cases where it was not detected with US, T1WI or T2WI.

Abbreviated MRI Protocols for Detecting Breast Cancer in Women with Dense Breasts

Objective

To evaluate the validity of two abbreviated protocols (AP) of MRI in breast cancer screening of dense breast tissue.

Materials and Methods

This was a retrospective study in 356 participants with dense breast tissue and negative mammography results. The study was approved by the Nanjing Medical University Ethics Committee. Patients were imaged with a full diagnostic protocol (FDP) of MRI. Two APs (AP-1 consisting of the first post-contrast subtracted [FAST] and maximum-intensity projection [MIP] images, and AP-2 consisting of AP-1 combined with diffusion-weighted imaging [DWI]) and FDP images were analyzed separately, and the sensitivities and specificities of breast cancer detection were calculated.

Results

Of the 356 women, 67 lesions were detected in 67 women (18.8%) by standard MR protocol, and histological examination revealed 14 malignant lesions and 53 benign lesions. The average interpretation time of AP-1 and AP-2 were 37 seconds and 54 seconds, respectively, while the average interpretation time of the FDP was 3 minutes and 25 seconds. The sensitivities of the AP-1, AP-2, and FDP were 92.9, 100, and 100%, respectively, and the specificities of the three MR protocols were 86.5, 95.0, and 96.8%, respectively. There was no significant difference among the three MR protocols in the diagnosis of breast cancer (p > 0.05). However, the specificity of AP-1 was significantly lower than that of AP-2 (p = 0.031) and FDP (p = 0.035), while there was no difference between AP-2 and FDP (p > 0.05).

Conclusion

The AP may be efficient in the breast cancer screening of dense breast tissue. FAST and MIP images combined with DWI of MRI are helpful to improve the specificity of breast cancer detection.

Breast US as primary imaging modality for diagnosing gynecomastia

AIM

To assess the role of breast US in diagnosing and classifying gynecomastia as the primary imaging modality and to compare US findings and classification system with the mammographic ones.

PATIENTS AND METHODS

48 patients suspected of having gynecomastia underwent mammography and US. Two radiologists in consensus retrospectively evaluated mammograms and sonograms. Both US and mammographic images were evaluated categorizing gynecomastia into non-mass, nodular and flame shaped patterns. The two category assignations were compared in order to find any difference. The reference standard for both the classification systems was represented by the cytological examination in 18 out of 44 cases (41%) and the six-month US follow-up in the remaining cases.

RESULTS

The US examination revealed pseudo-gynecomastia in 4/48 (8%) and true gynecomastia in the remaining 44 (92%). Gynecomastia was bilateral in 25/44 cases (57%) and unilateral in the remaining 19 (43%). The cases of true gynecomastia included non mass shape in 26/44 cases (59%), nodular shape in 12 (27%) and flame shape in 6 (14%). The mammographic examination revealed the same results as compared with US findings. 18/44 (41%) patients affected by nodular or dendritic gynecomastia underwent cytological examination confirming the presence of glandular tissue and the benign nature of the clinical condition.

CONCLUSIONS

US could be proposed as the primary imaging tool for diagnosing and classifying gynecomastia, avoiding unnecessary Xray examinations or invasive procedures in case of diffuse gynecomastia. In case of nodular or dendritic patterns, biopsy remains mandatory for a definitive diagnosis.

Supine breast US: how to correlate breast lesions from prone MRI

OBJECTIVE

To evaluate spatial displacement of breast lesions from prone MR to supine ultrasound positions, and to determine whether the degree of displacement may be associated with breast density and lesion histotype.

METHODS

380 patients underwent breast MR and second-look ultrasound. The MR and ultrasound lesion location within the breast gland, distances from anatomical landmarks (nipple, skin and pectoral muscle), spatial displacement (distance differences from the landmarks within the same breast region) and region displacement (breast region change) were prospectively evaluated. Differences between MR and ultrasound measurements, association between the degree of spatial displacement and both breast density and lesion histotypes were calculated.

RESULTS

In 290/380 (76%) patients, 300 MR lesions were detected. 285/300 (95%) lesions were recognized on ultrasound. By comparing MR and ultrasound, spatial displacement occurred in 183/285 (64.3%) cases while region displacement in 102/285 (35.7%) cases with a circumferential movement along an arc centred on the nipple, having supine ultrasound as the reference standard. A significant association between the degree of lesion displacement and breast density was found (p < 0.00001) with a significant higher displacement in case of fatty breasts. No significant association between the degree of displacement and lesion histotype was found (p = 0.1).

CONCLUSION

Lesion spatial displacement from MRI to ultrasound may occur especially in adipose breasts. Lesion-nipple distance and circumferential displacement from the nipple need to be considered for ultrasound lesion detection.

ADVANCES IN KNOWLEDGE

Second-look ultrasound breast lesion detection could be improved by calculating the lesion-nipple distance and considering that spatial displacement from MRI occurs with a circumferential movement along an arc centred on the nipple.

Breast MRI background parenchymal enhancement (BPE) correlates with the risk of breast cancer

OBJECTIVES

To investigate whether background parenchymal enhancement (BPE) and breast cancer would correlate searching for any significant difference of BPE pattern distribution in case of benign or malignant lesions.

METHODS

386 patients, including 180 pre-menopausal (group 1) and 206 post-menopausal (group 2), underwent MR examination. Two radiologists evaluated MR images classifying normal BPE as minimal, mild, moderate or marked. The two groups of patients were subdivided into 3 categories based on MRI findings (negative, benign and malignant lesions). The distribution of BPE patterns within the two groups and within the three MR categories was calculated. The χ2 test was used to evaluate BPE type distribution in the three patient categories and any statistically significant correlation of BPE with lesion type was calculated. The Student t test was applied to search for any statistically significant difference between BPE type rates in group 1 and 2.

RESULTS

The χ2 test demonstrated a statistically significant difference in the distribution of BPE types in negative patients and benign lesions as compared with malignant ones (p<0.05). A significantly higher prevalence of moderate and marked BPE was found among malignant lesions (group 1: 32% and 42%, respectively; group 2: 31% and 46%, respectively) while a predominance of minimal and mild BPE among negative patients (group 1: 60% and 36%, respectively; group 2: 68% and 32%, respectively) and benign lesions (group 1: 54% and 38%, respectively; group 2: 75% and 17%, respectively) was found. The Student t test did not show a statistically significant difference between BPE type rates in group 1 and 2 (p>0.05).

CONCLUSION

Normal BPE could correlate with the risk of breast cancer being such BPE patterns as moderate and marked associated with patients with malignant lesions in both pre and post-menopausal women.

Dynamic properties of water in breast pathology depend on the histological compounds: distinguishing tissue malignancy by water diffusion coefficients

Background

The parameters that characterize the intricate water diffusion in tumors may also reveal their distinct pathology. Specifically, characterization of breast cancer could be aided by diffusion magnetic resonance.

The present in vitro study aimed to discover connections between the NMR biexponential diffusion parameters [fast diffusion phase (D_FDP ), slow diffusion phase (D_SDP ), and spin population of fast diffusion phase (P₁)] and the histological constituents of nonmalignant (control) and malignant human breast tissue. It also investigates whether the diffusion coefficients indicate tissue status.

Methods

Post-surgical specimens of control (mastopathy and peritumoral tissues) and malignant human breast tissue were placed in an NMR spectrometer and diffusion sequences were applied. The resulting decay curves were analyzed by a biexponential model, and slow and fast diffusion parameters as well as percentage signal were identified. The same samples were also histologically examined and their percentage composition of several tissue constituents were measured: parenchyma (P), stroma (St), adipose tissue (AT), vessels (V) , pericellular edema (PCE), and perivascular edema (PVE). Correlations between the biexponential model parameters and tissue types were evaluated for different specimens. The effects of tissue composition on the biexponential model parameters, and the effects of histological and model parameters on cancer probability, were determined by non-linear regression.

Results

Meaningful relationships were found among the in vitro data. The dynamic parameters of water in breast tissue are stipulated by the histological constituents of the tissues (P, St, AT, PCE, and V). High coefficients of determination (R²) were obtained in the non-linear regression analysis: D_FDP (R² = 0.92), D_SDP (R² = 0.81), and P₁(R² = 0.93).

In the cancer probability analysis, the informative value (R²) of the obtained equations of cancer probability in distinguishing tissue malignancy depended on the parameters input to the model. In order of increasing value, these equations were: cancer probability (P, St, AT, PCE, V) (R² = 0.66), cancer probability (D_FDP, D_SDP)(R² = 0.69), cancer probability (D_FDP, D_SDP, P₁) (R² = 0.85).

Conclusion

Histological tissue components are related to the diffusion biexponential model parameters. From these parameters, the relative probability of cancer in a given specimen can be determined with some certainty.