MRI-guided breast biopsy: a review of technique, indications, and radiological-pathological correlations.

Breast magnetic resonance imaging (MRI) is the technique of choice in detection, local staging, and monitoring of breast cancer; however, breast MRI results in the detection of more indeterminate/suspicious lesions that need to be histopathologically proven to guide patient management than any other breast imaging method. If such abnormalities are not detectable in any of the conventional imaging tools (mammography (MMG) or ultrasound) then an MRI-guided biopsy needs to be performed to obtain a diagnosis. Breast MRI-guided biopsy is a time-consuming and complex procedure that requires specific equipment and experienced, well-trained staff. This review article explores and illustrates the indications, the currently available technologies, and the technique of breast MRI-guided biopsy, and explains the importance of careful imaging review and selection of cases. We correlate the radiological-pathological findings and highlight the impact on patient management in a multidisciplinary setting.

Measuring the accuracy of diagnostic imaging in symptomatic breast patients: team and individual performance.

OBJECTIVE: The combination of mammography and/or ultrasound remains the mainstay in current breast cancer diagnosis. The aims of this study were to evaluate the reliability of standard breast imaging and individual radiologist performance and to explore ways that this can be improved. METHODS: A total of 16,603 separate assessment episodes were undertaken on 13,958 patients referred to a specialist symptomatic breast clinic over a 6 year period. Each mammogram and ultrasound was reported prospectively using a five-point reporting scale and compared with final outcome. RESULTS: Mammographic sensitivity, specificity and receiver operating curve (ROC) area were 66.6%, 99.7% and 0.83, respectively. The sensitivity of mammography improved dramatically from 47.6 to 86.7% with increasing age. Overall ultrasound sensitivity, specificity and ROC area was 82.0%, 99.3% and 0.91, respectively. The sensitivity of ultrasound also improved dramatically with increasing age from 66.7 to 97.1%. Breast density also had a profound effect on imaging performance, with mammographic sensitivity falling from 90.1 to 45.9% and ultrasound sensitivity reducing from 95.2 to 72.0% with increasing breast density. CONCLUSION: The sensitivity ranges widely between radiologists (53.1-74.1% for mammography and 67.1-87.0% for ultrasound). Reporting sensitivity was strongly correlated with radiologist experience. Those radiologists with less experience (and lower sensitivity) were relatively more likely to report a cancer as indeterminate/uncertain. To improve radiology reporting performance, the sensitivity of cancer reporting should be closely monitored; there should be regular feedback from needle biopsy results and discussion of reporting classification with colleagues.

Ultrasound of the axilla: where to look for the sentinel lymph node.

AIMS: The aim of this paper is to guide the radiologist to the most likely location of the sentinel lymph node (SLN). MATERIALS AND METHODS: Patients with invasive breast cancer underwent axillary ultrasound examination. The position and morphological appearances of the lymph nodes were noted and core biopsy (CB) was performed of the largest or most suspicious node. Those patients whose biopsy revealed no evidence of malignancy proceeded to a surgical sentinel lymph node (SLN) biopsy (SLNB) looking for histopathological evidence of previous CB. RESULTS: Of 121 patients who underwent axillary ultrasound and CB no malignancy was identified in 73, all of whom subsequently underwent SLNB. Histological evidence of CB in the SLN was identified in 47 (64%) patients. The position of all the lymph nodes identified on ultrasound and the 47 patients whose SLNs were identified were drawn on composite diagrams of the axilla. Of the 36 nodes identified as sentinel whose position relative to other nodes could be determined, 29 (81%) represented the lowest node identified in the axilla, four (11%) were the second lowest, and three (8%) were the third lowest node. None of the four patients whose CB was from the fourth lowest node had the CB site identified at subsequent SLNB. CONCLUSION: Ultrasound of the axilla should be carried out in a systematic fashion focusing on level I nodes paying particular attention to the lowest one or two lymph nodes.

One-stop diagnostic breast clinics: how often are breast cancers missed?

The aim of this study was to estimate the number of patients discharged from a symptomatic breast clinic who subsequently develop breast cancer and to determine how many of these cancers had been 'missed' at initial assessment. Over a 3-year period, 7004 patients were discharged with a nonmalignant diagnosis. Twenty-nine patients were subsequently diagnosed with breast cancer over the next 36 months. This equates to a symptomatic 'interval' cancer rate of 4.1 per 1000 women in the 36 months after initial assessment (0.9 per 1000 women within 12 months, 2.6 per 1000 women within 24 months). The lowest sensitivity of initial assessment was seen in patients of 40-49 years of age, and these patients present the greatest imaging and diagnostic challenge. Following multidisciplinary review, a consensus was reached on whether a cancer had been missed or not. No delay occurred in 10 patients (35%) and probably no delay in 7 patients (24%). Possible delay occurred in three patients (10%) and definite delay in diagnosis (i.e., a 'missed' cancer) occurred in only nine patients (31%). The overall diagnostic accuracy of 'triple' assessment is 99.6% and the 'missed' cancer rate is 1.7 per 1000 women discharged.

Ultrasound guided percutaneous axillary lymph node core biopsy: how often is the sentinel lymph node being biopsied?

Patients with breast cancer now frequently undergo axillary ultrasound and core biopsy (CB) in an attempt to reduce the number of unnecessary sentinel lymph node (SLN) biopsies. This study aimed to establish the frequency of successful targeting of the SLN by ultrasound guided biopsy. A total of 137 patients had axillary ultrasound of which 121 underwent CB. 73 (60%) patients proceeded to SLN after negative CB. All SLNs were examined for evidence of metastases and previous CB. Of the 73 patients, 51 had no evidence of malignancy in the SLN (true negative=70%). However nodal deposits were found in the remaining 22 patients, representing a false negative rate for CB of 30%. Overall histopathological evidence of previous CB was identified in 47 (64%) of 73 patients undergoing SLN biopsy. The reason for false negative findings in the 22 (30%) patients was failure to sample the sentinel lymph node in 10 (45%) and failure to sample the metastatic disease in the sentinel node in 11 (55%). This study suggests that both better methods of identifying the sentinel lymph node and more adequate sampling are required.

Use of ultrasound-guided axillary node core biopsy in staging of early breast cancer.

The aim of this study was to see how effective ultrasound-guided needle biopsy was at detecting lymph node involvement in patients with early breast cancer. Patients with newly diagnosed invasive breast cancer underwent axillary ultrasound (US) where lymph node size and morphology were noted. A core biopsy (CB) was undertaken of any node greater than 5 mm in longitudinal section. Patients with benign CBs proceeded to sentinel lymph node (SLN) biopsy, whereas those with malignancy underwent axillary lymph node dissection (ALND). US and CB findings were correlated with final surgical histology in all cases. One hundred and thirty-nine patients were examined, of whom 52.5% had lymph node metastases on final histology. One hundred and twenty-one patients (87%) underwent axillary node CB. The overall sensitivity of CB for detecting lymph node metastases was 53.4% (60.3% for macrometastases; 26.7% for micrometastases). The US morphological characteristics most strongly associated with malignancy were absence of a hilum and a cortical thickness greater than 4 mm. However, one third of patients with normal lymph node morphology had nodal metastases, and only 12% of these were diagnosed on CB. CB of axillary lymph nodes can diagnose a substantial number of patients with lymph node metastases, allowing these patients to proceed directly to ALND, avoiding unnecessary SLN biopsy.

A simple processing method allowing comparison of renal enhancing volumes derived from standard portal venous phase contrast-enhanced multidetector CT images to derive a CT estimate of differential renal function with equivalent results to nuclear medicine quantification.

As iodinated contrast medium is cleared by glomerular filtration, it should be possible to apply the same principles utilized in radionuclide studies to derive differential renal function by comparison of enhancing renal volumes derived from contrast enhanced multidetector CT (CEMDCT). Having established a technique iteratively which appeared successful, a retrospective study was performed using 25 consecutive patients with a wide range of urological conditions who had undergone both CEMDCT, including the renal area in the portal venous phase, and nuclear medicine (NM) assessment of renal function with no urological intervention between the studies. Proprietary volume software was used to quantify the volume and attenuation of each kidney, the products of which (after subtraction of soft tissue attenuation derived from a region of interest over psoas) gave right and left enhancing renal volumes. The contribution by each kidney as a percentage of total renal enhancing tissue was derived. Comparison with NM studies resulted in excellent correlation of relative renal function by CEMDCT and NM assessments having a regression of near unity and a Pearson's correlation coefficient of 0.96. Bland Altman and Passing Bablock tests confirmed good agreement between the two methods with no bias. This is a simple, practicable processing technique using standard portal venous phase CEMDCT images to quantify differential function. This technique may allow a one-stop CT assessment of both anatomy and function.