Sürrenal kitlelerde dinamik manyetik rezonans ve difüzyon ağırlıklı görüntülemenin tanıya katkısı
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Tarih
2016
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Yayıncı
Trakya Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/restrictedAccess
Özet
Adrenal bezler, primer benign-malin ve metastatik kitlelerin bulunabildiği endokrin organlardır. Radyolojik yöntemler adrenal kitleleri saptamada yeterli olsa da, lezyonların karakterizasyonu ve özellikle nonfonksiyonel adenomların metastazlardan ayrımı sorun oluşturabilmektedir. Difüzyon ağırlıklı manyetik rezonans görüntüleme, dokulardaki su moleküllerinin mikroskopik hareketlerinden yola çıkarak tanısal bilgi sağlayan fonksiyonel bir görüntüleme tekniği olup, değişik abdominal organlardaki yer kaplayan lezyonların karakterizasyonunda son yıllarda giderek daha çok kullanılmaktadır. Bu çalışmada amaç, adrenal bez kitlelerinin karakterizasyonu ve benign-malign lezyonların ayrımında difüzyon ağırlıklı görüntülemenin (DAG), dinamik MR’ın ve kimyasal şift artefaktının etkinliğini non-invaziv yöntemler ile araştırmaktır. Bu çalışma ‘’helsinki bildirisi iyi klinik uygulamalar kılavuzu’’ ile uyumlu olup bizim kurumsal etik inceleme kurulu tarafından onaylandı. MR veri tabanımızda Haziran 2011 ve Haziran 2015 arasında adrenal kitleye sahip 115 hastadan 131 adrenal lezyon görüldü. 1 cm’den küçük lezyonların deneyimlerimize göre ADC haritasında zor görüldüğünden çalışmamıza 1 cm’den küçük lezyonları eledik. Çalışmamızda; adenom için en az 6 aylık izlem veya patolojik tanı ile, adrenal myelolipomlar için yağ baskılı sekanslarda baskılanıp kimyasal şift artefaktı gösteren makroskopik yağın gösterilmesi ile tanı konuldu. Adrenal kist MR da T1 sekansta düşük sinyal, T2 sekansta yüksek sinyal ve kontrastlı T1 sekansta kontrastlanma göstermemesi ile tanı konuldu. Adrenal kortikal karsinom ve nöroblastom histopatolojik verifikasyon ile tanı konuldu. Metastazlara histopatolojik tanı veya takip görüntülerinde progresyon veya PET pozitifliği ile tanı konuldu. Çalışmamızda; 131 adrenal yer kaplayan lezyonlara dinamik adrenal MRG, kimyasal şift artefaktı MRG sonrasında adrenal bezlere yönelik DAG yapılmıştı ve difüzyon ağırlıklı görüntüler üzerinden lezyonların ‘apperent diffusion coefficient’ (ADC) haritaları oluşturuldu. İki ayrı b değeri (b:50, b:200) kullanılarak lezyonların ADC değerleri ölçüldü. Radyolojik sonuçlar, klinik bulgular/laboratuar verileri, histopatolojik inceleme ve takip sonuçlarına göre 33 lezyon malign, 98 lezyon benign olarak belirlendi. Benign ve malign lezyonlarda saptanan ADC değerleri, istatistiksel olarak, her bir b değeri için ayrı ayrı karşılaştırıldı. Her iki b değerinde de benign ve malign lezyonların ortalama ADC değerleri arasında istatiksel fark saptanmadı (p>0.05). Dinamik olarak faz 1’den faz 2’ye geçişte ve faz 1’den faz 3’e geçişte istatiksel anlamlı bir fark bulundu (p<0.05). MR kimyasal şift artefaktı sinyal intensitesi indeks ölçümlerinde, lezyonların benign malign ayrımında istatiksel olarak anlamlı bulundu (p<0.05). Çalışmamızda, benign ve malign adrenal lezyonların ADC değerleri arasında istatistiksel olarak anlamlı farklılık saptanmamıştır. Bu sonuca göre, DAG adrenal kitlelerin karakterizasyonunda etkin bir yöntem olarak görülmese de, MR teknolojisinde kaydedilen teknolojik gelişmelerin difüzyon ağırlıklı görüntülerin daha kaliteli olmasını sağlayıp, ADC ölçümlerinin daha doğru yapılmasını mümkün kılabileceği unutulmamalıdır. Dinamik çalışmalarda bazı fazlar arası farklarda ve MR kimyasal şift sinyal intensite indeksi ölçümünde istatistiksel olarak anlamlı farklılık saptanmış olup daha geniş serili çalışmalar yapılması gerekmektedir.
abstract
Adrenal glands are the major endocrine organs that can be selected as target by either benign or malign processes and metastasis. Even though, adrenal masses are precisely detected by current radiological methods, differentiating non-functional adenomas from metastatic lesion could be challenging for physicians. Diffusion weighted magnetic resonance imaging technique, which increasingly become more popular in the last years for characterization of different lesions in various abdominal organs, mainly uses microscopic movement of water molecules to provide functional imaging. With this study, we try to look into current role of diffusion weighted imaging (DWI), Dynamic Magnetic Resonance Imaging and chemical shift artifact in either differentiate benign and malign lesions or further characterize adrenal masses with non-invasive radiologic technique. This study was compliant with WMA Declaration of Helsinki - Ethical Principles for Medical Research Involving Human Subjects and approved by our institutional review board. A search of the departmental MRI data base revealed 131 adrenal lesion from 115 patients who underwent MRI examinations between June 2011 and June 2015 with an adrenal mass. In our previous experience, we found that lesions smaller than 1 cm were hard to detect on ADC maps. In addition, a previous study of DWI of adrenal lesions excluded lesions smaller than 1 cm. For the purposes of this study, adenomas were diagnosed by stability on at least 6-month serial imaging and surgical pathology. Lesions that showed stability on 6-month follow-up scans were considered benign in accordance with previous reports. Adrenal myelolipomas were diagnosed by the detection of macroscopic fat, that showed chemical shift artifact, which also was suppressed on fat- suppressed sequences. The diagnosis of adrenal cysts was made on the basis of low SI on T1-weighted images, absence of enhancement on contrast-enhanced T1 images, and high SI on T2-weighted images. Adrenal cortical carcinomas and neuroblastomas were diagnosed by surgical pathology. Adrenal metastases were diagnosed by surgical pathology or by the presence of a new or enlarging adrenal mass on follow-up imaging studies or positive PET. Our study, 131 lesions were analyzed by dynamic adrenal MRI, chemical shift artifact signail intensity index and lastly DWI performed. Furthermore ‘apparent diffusion coefficient’ (ADC) mapping was constituted by using DWI of lesions. ADC values were measured by using two different b values (b:50, b:200). We classified 33 lesions into malign category while 98 lesions into benign category by using radiologic results, clinical and laboratory values, histopathological discussions and with follow up data. ADC values of benign and malign lesions were analyzed by statistical program with using two b values one by one. We could not detect any statistically significant difference between ADC values of benign and malign lesions for two b values (p>0.05). We found a statistical difference in dynamic magnetic resonance imaging while passing through phase 1 to phase 2 and phase 1 to phase 3 (p>0.05). No difference is detected while passing through the other phases. Magnetic resonance chemical shift artifact signal intensity index values were found to be useful in the differetion of benign or malign adrenal lesions (p<0.05). In conclusion, we did not detect any statistically significant difference between ADC values of benign and malign lesions. Even though, DWI is not seemed to be effective radiological technique currently to characterization of adrenal masses, we suggested that with further technological advancing in MRI can allow to us more accurate ADC measuring. We detected statistically significant difference some phases of dynamic magnetic resonance imaging and magnetic resonance chemical shift artifact signal intensity index. For this reason, we conclude that new studies with including more lesions may be more elucidative and may result different than this study.
abstract
Adrenal glands are the major endocrine organs that can be selected as target by either benign or malign processes and metastasis. Even though, adrenal masses are precisely detected by current radiological methods, differentiating non-functional adenomas from metastatic lesion could be challenging for physicians. Diffusion weighted magnetic resonance imaging technique, which increasingly become more popular in the last years for characterization of different lesions in various abdominal organs, mainly uses microscopic movement of water molecules to provide functional imaging. With this study, we try to look into current role of diffusion weighted imaging (DWI), Dynamic Magnetic Resonance Imaging and chemical shift artifact in either differentiate benign and malign lesions or further characterize adrenal masses with non-invasive radiologic technique. This study was compliant with WMA Declaration of Helsinki - Ethical Principles for Medical Research Involving Human Subjects and approved by our institutional review board. A search of the departmental MRI data base revealed 131 adrenal lesion from 115 patients who underwent MRI examinations between June 2011 and June 2015 with an adrenal mass. In our previous experience, we found that lesions smaller than 1 cm were hard to detect on ADC maps. In addition, a previous study of DWI of adrenal lesions excluded lesions smaller than 1 cm. For the purposes of this study, adenomas were diagnosed by stability on at least 6-month serial imaging and surgical pathology. Lesions that showed stability on 6-month follow-up scans were considered benign in accordance with previous reports. Adrenal myelolipomas were diagnosed by the detection of macroscopic fat, that showed chemical shift artifact, which also was suppressed on fat- suppressed sequences. The diagnosis of adrenal cysts was made on the basis of low SI on T1-weighted images, absence of enhancement on contrast-enhanced T1 images, and high SI on T2-weighted images. Adrenal cortical carcinomas and neuroblastomas were diagnosed by surgical pathology. Adrenal metastases were diagnosed by surgical pathology or by the presence of a new or enlarging adrenal mass on follow-up imaging studies or positive PET. Our study, 131 lesions were analyzed by dynamic adrenal MRI, chemical shift artifact signail intensity index and lastly DWI performed. Furthermore ‘apparent diffusion coefficient’ (ADC) mapping was constituted by using DWI of lesions. ADC values were measured by using two different b values (b:50, b:200). We classified 33 lesions into malign category while 98 lesions into benign category by using radiologic results, clinical and laboratory values, histopathological discussions and with follow up data. ADC values of benign and malign lesions were analyzed by statistical program with using two b values one by one. We could not detect any statistically significant difference between ADC values of benign and malign lesions for two b values (p>0.05). We found a statistical difference in dynamic magnetic resonance imaging while passing through phase 1 to phase 2 and phase 1 to phase 3 (p>0.05). No difference is detected while passing through the other phases. Magnetic resonance chemical shift artifact signal intensity index values were found to be useful in the differetion of benign or malign adrenal lesions (p<0.05). In conclusion, we did not detect any statistically significant difference between ADC values of benign and malign lesions. Even though, DWI is not seemed to be effective radiological technique currently to characterization of adrenal masses, we suggested that with further technological advancing in MRI can allow to us more accurate ADC measuring. We detected statistically significant difference some phases of dynamic magnetic resonance imaging and magnetic resonance chemical shift artifact signal intensity index. For this reason, we conclude that new studies with including more lesions may be more elucidative and may result different than this study.
Açıklama
Anahtar Kelimeler
Difüzyon Ağırlıklı Görüntüleme, Manyetik Rezonans Kimyasal Şift Artefaktı, Adrenal Lezyon, Apparent Diffusion Coefficient, Dinamik Manyetik Rezonans Görüntüleme, Diffusion Weighted Imaging, Magnetic Resonance Chemical Shift Artifact, Adrenal Lesion, Apparent Diffusion Coefficient, Dynamic Magnetic Resonance Iimaging
