Comparison of Fetal Ultrasonography and Fetal Magnetic Resonance Imaging for the Detection of Additional Anomalies in Cases of Fetal Ventricolumegaly

Öz

Objective: To compare fetal US and fetal MRI techniques for the detection of additional findings in cases of fetal venticulomegaly diagnosed by antenatal US.

 

Material and Method: 46 Patients diagnosed with ventriculomegaly by ultrasonography between May 2009 – April 2010 have been included in the study. Gestational (FETAL age mi demek gerek, tam terimi bilmiyorum?) age (GA) was between 21 and 35 weeks. MRI examination couldn’t be performed in 4 patients due to clostrophoby and 2 patients didn’t give consent for the procedure. Those 6 patients have been excluded from the study and the examination was carried in 40 patients. The ventriculomegaly was graded in 2 groups as mild (10-14 mm) or as severe (15 mm or higher). MRI has been performed in maximum 4 days following ultrasonography with a  1,5 T MRI unit (Sympony, Siemens, Erlangen, Germany), using a “phased array” body coil. The fetal anatomy was evaluated by  the  “Half-Fourier acquisition single-shot turbo spin-echo" (HASTE) sequence (TR: 4.4, TE: 64, flip angle: 150°, slice thickness: 6 mm, gap: 0.1 mm, matriks: 160x256, FOV: 350 mm) in three planes adjusted to the fetal position. The frequency of the patients  where MRI and US results were in concordance and teh frequency of the patients where MRI provided additional diagnostic information were given  by a confidence interval of 95%. Chi-square test (Yates) was used to compare the groups. The significance was evaluated at p<0.05.

 

Findings: Mild ventirculomegaly (10-14 mm) was detected in 28 patients (Group 1), and severe ventriculomegaly (>15 mm) was detected in 12 patients (Group II). MRI detected additional findings compared to ultrasonography in 7 of the 28 patients in Group I (25% [CI 95%; 0.11-0.45]) and 5 of the 12 patients in Group II (%42 [CI 95%; 0.15-0.72]), a total of 12 patients (30% [CI 95%; 0.16-0.46]). When 2 groups were compared for the additional findings provided by MRI, MRI detected more abnormalities in severe ventriculomegaly group (42%), however the difference with mild ventriculomegaly group (25%) was not statistically significant ( x² yates: 0.459, p:0.498). MRI changed patient management in 4 patients in Group I (14% [95% CI; 0.09-0.34]) and 3 patients in Group II (25% [95% CI; 0.14-0.94]). In total, MRI changed patient management in 17% [95% CI; 0.13-0.41] of the patients.

 

Conclusion: Our study demonstrated that, while US has a high accuracy in diagnosing ventriculomegaly, fetal MRI examination can provide additional findings to US, especially in detecting co-existing CNS abnormalities.

Anahtar Kelimeler

• Fetal Ventriculomegaly,Magnetic Resonance Imaging

Fetal Ventrikülomegali Olgularında Ek Anomali Tanısında Fetal Ultrasonografiiel Manyetik Rezonans Görüntüleme Tetkiklerinin Değerlendirilmesi

Öz

Amaç: Antenatal dönemde yapılan USG’de fetal ventrikülomegali saptanan olgularda, ek bulgular açısından, fetal USG ile fetal MRG  tetkiklerini karşılaştırmaktır.

 

Materyal ve Metod: Mayıs 2009 - Nisan 2010 tarihleri arasında USG’de ventrikülomegali tanısı konan 46 hasta dahil edildi. Fetal yaş 21-35 gebelik haftası (GH), arasındaydı. 4 hastada klostrofobi nedeniyle, 2 hastada da onay vermedikleri için MRG tetkiki yapılamadı. 40 hastaya MRG tetkiki yapıldı, diğer 6 hasta çalışmadan çıkarıldı. Ventrikülomegali derecesi hafif  (10-14 mm) ve belirgin (15 mm ve üzeri) olarak 2’ye ayrılarak değerlendirildi. USG tetkiki sonrası en geç 4 gün içerisinde hastalara MRG tetkiki yapıldı. MR görüntüleme, 1.5 T MR cihazında (Sympony, Siemens, Erlangen, Almanya), "phased array" vücut sarmalı kullanılarak yapıldı. Fetal anatomiyi belirlemek için fetal pozisyona uygun başlıca 3 planda "Half-Fourier acquisition single-shot turbo spin-echo" (HASTE) sekansı (TR: 4.4, TE: 64, sapma açısı: 150°, kesit kalınlığı: 6 mm, kesitler arası boşluk: 0.1 mm, matriks: 160x256, FOV: 350 mm) kullanıldı. MRG ve USG tetkiklerinde tanısal uyumu olan hasta sıklıkları ve MRG tetkiki ile ek tanısal bilgi elde edilen hastaların sıklıkları, % 95 güven aralığı ile birlikte verildi. Grupların karşılaştırılmasında ki-kare (yates) testi kullanıldı. Anlamlılık p<0.05 düzeyinde değerlendirildi.     

                                                                                       

Bulgular:  28 hastada (Grup I) hafif ventrikülümegali (10-14mm), 12 hastada (Grup II) belirgin ventrikülomegali (>15 mm)  saptandı. I.gruptaki 28 hastanın 7’sinde (% 25 [% 95 GA; 0.11-0.45]) , II.gruptaki 12 hastanın 5’inde (% 42 [% 95 GA; 0.15-0.72]) ve tüm olgular göz önüne alındığında toplam 12 hastada (% 30 [% 95 GA; 0.16-0.46])  MRG tetkiki USG’ye ek bulgu saptadı. MRG tetkikinin sağladığı ek bulgular açısından her iki grup karşılaştırıldığında, belirgin ventrikülomegali olan grupta MRG tetkiki  daha fazla oranla ek bulgu (% 42) saptamasına rağmen istatistiksel olarak hafif ventrikülomegali olan grupla ( % 25) arasında anlamlı fark saptanmadı ( x² yates: 0.459, p:0.498). MRG tetkiki I. grupta 4 olguda (% 14  [% 95 GA; 0.09-0.34]) II.Grupta ise 3 olguda (% 25 [% 95 GA; 0.14-0.94])  hasta yönetimini değiştirdi. Tüm hasta grubu göz önüne alındığında  olguların % 17’sinde  [% 95 GA; 0.13-0.41] hasta yönetimini değiştirdi.

 

 

Sonuç:  Çalışmamız, her ne kadar USG tetkikinin ventrikülomegali olgularında yüksek oranda doğru tanı koyabilsede, fetal MRG tetkikinin özellikle eşlik edebilecek diğer SSS anomalilerini ortaya koymakta USG’ye ek bulgular saptayabileceğini ortaya koymuştur.

Anahtar Kelimeler

• Fetal Ventrikülomegali,Manyetik Rezonans Görüntüleme

Kaynakça

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