High-Resolution-MRI of the Breast Including All Locoregional Lymph Nodes: All-In-One with Additional Use of a Body Coil on the Back (Sandwich Concept)

Keywords

Breast MRI; Lymph node diagnostics; Sandwich concept; Breast carcinoma.

Abstract

• Background: Breast MRI is a valuable tool, especially for women with dense breasts, but its visualization of all local lymph nodes is limited.

• Purpose: To demonstrate a breast MRI technique using a body coil on the back in addition to a breast surface coil to improve imaging of the breast and locoregional lymph nodes.

• Materials and Methods:

  • Breast MRI performed with a dedicated surface coil AND a second coil on the back.

  • Prone position.

  • High spatial resolution ("MIO Breast MRI").

  • Total examination time: 8:32 minutes for the breast MRI portion.

  • Included T2 measurement and dynamic T1 sequences (before and twice after 5 ml gadobutrol – a first-pass technique).

  • Additional coronal fat-suppressed T1 VIBE DIXON sequence:

    • 52 slices, 3mm thickness

    • Matrix 320 x 240

    • TR 4.2ms, TE 1.34/2.57ms

    • FOV 420mm

    • Measurement time: 16 seconds

• Results: The "sandwich technique" (breast coil + body coil) enabled detection of breast carcinomas AND imaging of axillary, infra-, supraclavicular, and parasternal lymph nodes. Total measurement time was 8:48 minutes (8:32 breast MRI + 16 seconds for lymph nodes). Optional lymph node imaging before contrast agent administration could be done in an additional 16 seconds.

• Conclusion: Combining breast and body surface coils provides high-quality breast MRI and sufficient imaging of all locoregional lymph nodes in under 10 minutes. This is particularly useful for preoperative local MR staging.

Citation

Uwe F, Anja EH, Nadia M, Friedemann B, Jutta R. (2024) High Resolution-MRI of the Breast Including All Locoregional Lymph Nodes: All In-One with Additional Use of a Body Coil on the Back (Sandwich Concept). JSM Breast Cancer Res 5: 6.

INTRODUCTION

Breast MRI underwent several developments in recent years. These range from a drastic increase in spatial resolution to a reduction in the overall examination time to less than 10 minutes [1-3]. Furthermore, breast MRI is still the most sensitive method for detecting breast cancer. This applies to both, intraductal carcinomas and invasive tumors [4,5]. Breast MRI is especially important in cases of high tissue density (type ACR C and D), as mammography is drastically limited in these cases with sensitivities of 30-50% for the detection of breast cancer [6]. For this reason, the European Society for Breast Imaging EUSOBI has recommended the primary use of breast MRI in women with extremely dense breasts [7]. However, the lymph nodes can only be assessed with established breast MRI to the extent that they are also imaged. Here, MRI is usually incomplete, particularly in the axillary region. It is therefore desirable to have an option that can image the local-regional lymph nodes of the breast completely without any significant additional time and methodological effort. For this reason, a combination of a high-resolution breast coil and a body coil attached to the back is presented for the first time. In this sandwich concept, it is possible to examine all regional breast lymph nodes with little methodological effort and an additional measurement time of < 20 seconds.

MATERIALS AND METHODS

Diagnostic contrast-enhanced breast MRI has been performed for several years using high-resolution technology. This currently includes a matrix of 1024 × 1024 pixels, called MIO breast MRI with 1 million pixels [1]. The examinations were performed on a 1.5 Tesla and a 3.0 Tesla system (1.5 T Altea and 3.0T Lumina, both Siemens, Erlangen, Germany) using a dedicated 6-channel breast surface coil with integrated lateral medial compression tool (NORAS, Hoechberg, Germany). After adequate positioning of the patient, the examination protocol included the performance of a T2 inversion recovery sequence with fat suppression using the Resolve technique (50 slices 2-3 mm, TR 7230ms, TE 63ms, FOV 380-400 mm; acquisition time 3:24 min). This T2 sequence is performed before initiation of the dynamic MRI to provide the additional T2 information, but foremost to allow the patient a few minutes to relax before the CE dynamic T1wi sequences start. Subsequently, a dynamic T1 GRE measurement was performed repetitively once before and twice after IV administration of a defined dosage of 5 ml Gd-DO3A butrol (Gadobutrol, 1molar) regardless of body weight. The examination parameters were: 50 slices 2-3 mm each, TR 5.7ms, TE 2.46ms, FOV 380 400 mm; acquisition time per sequence 1:41 min. The total measurement time was 8:27 min. Image post-processing included the subtraction of both measurements after contrast agent administration minus the pre contrast sequence and the preparation of maximum intensity projections (MIP) of the T2 images and the subtraction series.

For the first time, the conventional breast MRI with dedicated surface coil is now supplemented by a 4-channel body coil positioned on the patient’s back (Figure1).

Figure 1 : Sandwich concept. Positioning of the breast in the breast coil. Additional body coil positioned on the patient’s back

Both coils are combined via a suitable switch. This enables a complete visualization of all regional LN within a measurement time of 16 seconds after completion of the breast MRI using both surface coils. The measurement parameters of the fat-suppressed T1 VIBE DIXON sequence used are: 52 slices each 3mm, matrix 320 x 240, TR 4.2ms, TE 1.34/2.57 ms, FOV 420mm; measurement time 16 sec in BH mode. The total measurement time of the complete sandwich protocol is 8:48 min. If additional coronal T1 imaging of the complete LN stations is desired before contrast medium administration, this can be performed in a further 16 seconds immediately before the T1 dynamic (Figure 2). In this case, the total examination time is 9:04 minutes.

Figure 2 : Normal breast findings. Normal LN. T1VIBE DIXON prae CM, 16 sec.

RESULT

The combination of high-resolution MIO Breast MRI and supplementary MRI of all regional lymph nodes allows an all-in-one concept for early detection, but especially for local staging of breast cancer. The fat-suppressed MRI images of the upper thoracic aperture in coronal view show all LN stations: axillary, infra- and supraclavicular and the internal mammary LN. The spatial resolution, which is not in the order of magnitude of dynamic breast MRI (Figure 3), is completely sufficient for a relevant assessment of the lymph nodes. Both circumscribed cortex thickening as well as general enlargement of individual lymph nodes can be clearly diagnosed (Figure 3-5). The measurement time for this additional imaging of the lymph nodes is extremely short at 16 seconds, and it results in a total measurement time for this sandwich concept of <10 minutes.

Figure 3 : MIO breast MRI. MIP. Normal findings.

Figure 4 : Breast carcinoma on the right. Circumscribed cortex thickening of an axillary LN. LN metastasis right axilla, N1. T1 FS VIBE DIXON post KM, 16 sec.

Figure 5 : Breast carcinoma left. Conglomerate of enlarged LN left axilla. LN metastases left axillary, N2. T1 FS VIBE DIXON post KM, 16 sec.

DISCUSSION

The therapeutic approach in patients with newly detected breast cancer depends not only on the size and histologically or immunohistochemically defined prognostic factors, but also on the regional lymph node status [8]. Until the end of the last century, the removal of axillary lymph nodes in level I to II (ALND, Axillary Lymph Node Dissection) was obligatory in the presence of invasive carcinoma [9]. This procedure led to not inconsiderable side effects [10]. It was significantly optimized by the introduction of Sentinel Node Biopsy (SNL) in 2005, as many women were now spared the unnecessary removal of lymph nodes up to level II with the associated morbidity [11]. Since 2005 the American Society of Clinical Oncology has only recommended ALND for patients with early-stage breast cancer who have positive evidence of metastases in the SLN [12,13].

Surgical removal of the sentinel LN was followed by the gentler percutaneous radiotherapy approach without surgery [14]. Although the strategy for dealing with localized LN metastasis has changed over the years, axillary LN status remains one of the most important predictors of disease-free interval and long-term survival [15].

In the meantime, there are initial reports on further possible optimization with regard to the strategy for dealing with local LN metastases: In patients with stage T1 or T2 breast cancer without palpable axillary lymph nodes, Giuliano AE, et al. were able to show that the 10 year survival rate for SNB alone was not lower than for ALND, provided that a maximum of one to two lymph nodes in the SLNs were affected. The decisive boundary here is therefore no longer between N0 and N1, but between LN stage N0-N1, which are not lymphadenectomized, and LN stage N2 or higher, which undergo ALND [16].

In the past, it was not possible to make a sufficiently precise statement about the N-stage using established imaging techniques. This applies in particular to the aspect of non-space-occupying micro metastases [17-20]. However, the significance of imaging changes at the point at which a differentiation between the N0/N1 and N2 stages is sufficient to determine the therapeutic strategy. MRI in particular is of great importance for this question [21].

In 2023, the working group led by Kuhl et al showed in a retrospective evaluation that the presence of significant lymph node metastasis (≥ pN2) could be ruled out with a negative predictive value NPV of over 98 % [22]. They used a coronal T1-weighted pulse sequence, which was recorded with the body coil integrated in the system - i.e. not with the established breast coil. This allowed the complete visualization of the parasternal, axillary, infra- and supraclavicular lymph nodes within an additional measurement time of 3 minutes. They stated out, that the use of a CE fat-suppressed sequence is not recommended due to the even longer measurement time. Comparable results for the exclusion of advanced lymph node involvement - only for the axilla - are also available from the working group of van Nijnatten TJA, et al. [23].

In conclusion, the presented sandwich concept allows for the first time the acquisition of all LN stations: axillary, infra- and supraclavicular and the internal mammary LN within an additionally time slot of 16 seconds. If T1 measurement in coronary angulation is desired before contrast agent administration, this could also be obtained at the beginning of the examination with an equivalent time expenditure of 16 sec. The HR MRI of the breast thus remains within a maximum examination time of less than 10 minutes when using this concept.

FUNDS

The authors do not have any conflict of interest or industry support of the project.

All data generated or analyzed during the study are included in the published paper.

REFERENCES

1. Fischer U. Breast MRI - The champion in the millimeter league: MIO breast MRI - The method of choice in women with dense breasts. Eur J Radiol. 2023 Oct;167:111053. doi: 10.1016/j.ejrad.2023.111053. Epub 2023 Aug 24. PMID: 37659208.

2. Kuhl CK, Schrading S, Strobel K, Schild HH, Hilgers RD, Bieling HB. Abbreviated breast Magnetic Resonance Imaging (MRI): First postcontrast subtracted images and maximum-intensity projection-a novel approach to breast cancer screening with MRI. J Clin Oncol. 2014; 32: 2304-2310.

3. Fischer U, Korthauer A, Baum F, Luftner-Nagel S, Heyden D, Marten-Engelke K. Short first-pass MRI of the breast. Acta Radiol. 2012 Apr 1;53(3):267-9. doi: 10.1258/ar.2012.110638. Epub 2012 Feb 14.PMID: 22334872.

4. Kuhl CK, Schrading S, Bieling HB, Wardelmann E, Leutner CC, Koenig R, et al. MRI for diagnosis of pure ductal carcinoma in situ: A prospective observational study. Lancet. 2007; 370: 485-492.

5. Comstock CE, Gatsonis C, Newstead GM, Snyder BS, Gareen IF, Bergin JT, et al. Comparison of abbreviated breast MRI vs digital breast tomosynthesis for breast cancer detection among women with dense breasts undergoing screening. JAMA. 2020; 323: 746-756.

6. Pisano ED, Hendrick RE, Yaffe MJ, Baum JK, Acharyya S, Cormack JB, et al. Diagnostic accuracy of digital versus film mammography: Exploratory analysis of selected population subgroups in DMIST. Radiology. 2008; 246: 376-383.

7. Mann RM, Athanasiou A, Baltzer PAT, Camps-Herrero J, Clauser P, Fallenberg EM, et al. Breast cancer screening in women with extremely dense breasts recommendations of the European Society of Breast Imaging (EUSOBI). Eur Radiol. 2022; 32: 4036-4045.

8. Humphrey KL, Saksena MA, Freer PE, Smith BL, Rafferty EA. To do or not to do: Axillary nodal evaluation after ACOSOG Z0011 trial. Radiographics. 2014; 34: 1807-1816.

9. Fisher B, Anderson S, Bryant J, Margolese RG, Deutsch M, Fisher ER, et al. Twenty-year follow-up of a randomized trial comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation for the treatment of invasive breast cancer. N Engl J Med. 2002; 347: 1233-1241.

10. Fleissig A, Fallowfield LJ, Langridge CI, Johnson L, Newcombe RG, Dixon JM, et al. Post-operative arm morbidity and quality of life. Results of the ALMANAC randomised trial comparing sentinel node biopsy with standard axillary treatment in the management of patients with early breast cancer. Breast Cancer Res Treat. 2006; 95: 279-293.

11. Krag DN, Weaver DL, Alex JC, Fairbank JT. Surgical resection and radiolocalization of the sentinel lymph node in breast cancer using a gamma probe. Surg Oncol. 1993; 2: 335-340.

12. George R, Quan ML, McCready D, McLeod R, Rumble RB, Expert panel on SLNB in breast cancer. Sentinel lymph node biopsy in early-stage breast cancer. toronto (on): Cancer care ontario. Program in Evidence-based Care. 2009.

13. Lyman GH, Giuliano AE, Somerfield MR, Bodurka DC, Burstein HJ, Cochran AJ, et al. American society of clinical oncology guideline recommendations for sentinel lymph node biopsy in early-stage breast cancer. J Clin Oncol. 2005; 23: 7703-7720.

14. Donker M, van Tienhoven G, Straver ME, Meijnen P, van de Velde CJ, Mansel RE, et al. Radiotherapy or surgery of the axilla after a positive sentinel node in breast cancer (EORTC 10981-22023 AMAROS): A randomized, multicentre, open-label, phase 3 non-inferiority trial. Lancet Oncol. 2014; 15: 1303-1310.

15. Galea MH, Blamey RW, Elston CE, Ellis IO. The nottingham prognostic index in primary breast cancer. Breast Cancer Res Tr. 1992; 22: 207-219.

16. Giuliano AE, Ballman KV, McCall L, Beitsch PD, Brennan MB, Brennan MB, et al. Effect of axillary dissection vs no axillary dissection on 10-year overall survival among women with invasive breast cancer and sentinel node metastasis: The ACOSOG Z0011 (Alliance) randomized clinical trial. JAMA. 2017; 318: 918-926.

17. Yun SJ, Sohn YM, Seo M. Risk factors for false-negative and false-positive results of magnetic resonance computer-aided evaluation in axillary lymph node staging. J. Comput. Assist. Tomogr. 2016: 40: 928-936.

18. Park SH, Kim EK, Park BW, Kim SI, Moon HJ, et al. False negative results in axillary lymph nodes by ultrasonography and ultrasonography-guided fine-needle aspiration in patients with invasive ductal carcinoma. Ultraschall Med. 2013; 34: 559-567.

19. Baltzer PA, Dietzel M, Burmeister HP, Zoubi R, Gajda M, et al. Application of MR mammography beyond local staging: Is there a potential to accurately assess axillary lymph nodes? Evaluation of an extended protocol in an initial prospective study. Am J Roentgenol. 2011; 196: 641-647.

20. Scaranelo AM, Eiada R, Jacks LM, Kulkarni SR, Crystal P. Accuracy of unenhanced MR imaging in the detection of axillary lymph node metastasis: Study of reproducibility and reliability. Radiology. 2012; 262: 425-434.

21. Marino MA, Avendano D, Zapata P, Riedl CC, Pinker K. Lymph node imaging in patients with primary breast cancer: Concurrent diagnostic tools. Oncologist. 2020; 25: 231-242.

22. Bode M, Schrading S, Masoumi A, Morscheid S, Morscheid S, Dirrichs T, et al.. Abbreviated MRI for comprehensive regional lymph node staging during pre-operative breast MRI. Cancers. 2023; 15: 1859-1871.

23. van Nijnatten TJA, Ploumen EH, Schipper RJ, Goorts B, Andriessen EH, Vanwetswinkel S, et al. Routine use of standard breast MRI compared to axillary ultrasound for differentiating between no, limited and advanced axillary nodal disease in newly diagnosed breast cancer patients. Eur. J. Radiol. 2016; 85: 2288-2294.