Application of a protocol for magnetic resonance spectroscopy of adrenal glands: an experiment with over 100 cases.
OBJECTIVE
To evaluate a protocol for two-dimensional (2D) hydrogen proton (1H) magnetic resonance spectroscopy (MRS) (Siemens Medical Systems; Erlangen, Germany) in the detection of adrenal nodules and differentiation between benign and malignant masses (adenomas, pheochromocytomas, carcinomas and metastases).


METHODS
A total of 118 patients (36 men; 82 women) (mean age: 57.3 ± 13.3 years) presenting with 138 adrenal nodules/masses were prospectively assessed. A multivoxel system was utilized with a 2D point-resolved spectroscopy/chemical shift imaging sequence. The following ratios were calculated: choline (Cho)/creatine (Cr), 4.0-4.3/Cr, lipid (Lip)/Cr, Cho/Lip and lactate (Lac)/Cr.


RESULTS
2D-1H-MRS was successful in 123 (89.13%) lesions. Sensitivity and specificity values observed for the ratios and cutoff points were the following: Cho/Cr ≥ 1.2, 100% sensitivity, 98.2% specificity (differences between adenomas/pheochromocytomas and carcinomas/ metastases); 4.0-4.3 ppm/Cr ≥ 1.5, 92.3% sensitivity, 96.9% specificity (differences between carcinomas/pheochromocytomas and adenomas/metastases); Lac/Cr ≤ -7.449, 90.9% sensitivity and 77.8% specificity (differences between pheochromocytomas and carcinomas/adenomas).


CONCLUSIONS
Information provided by 2D-1H-MRS were effective and allowed for the differentiation between adrenal masses and nodules in most cases of lesions with > 1.0 cm in diameter.
PhD, Assistant Professor, Centro Universitário São Camilo, Collaborator, Department of Imaging Diagnosis - Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil.
Homero José de Farias E
HJ
Melo
Private Docent, Affiliate Professor, Department of Imaging Diagnosis - Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil.
Suzan M
SM
Goldman
Private Docent, Associate Professor, Department of Imaging Diagnosis - Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil.
Jacob
J
Szejnfeld
PhD, MD, Radiologist, Sociedade Paulista para o Desenvolvimento da Medicina - Hospital São Paulo (SPDM-HSP), São Paulo, SP, Brazil.
Juliano F
JF
Faria
Master, MD, Endocrinologist, Department of Endoclinology - Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil.
Martha K P
MK
Huayllas
Private Docent, Associate Professor, Department of Urology - Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil.
Cássio
C
Andreoni
Postdoc, Associate Professor, Department of Endocrinology - Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil.
Cláudio E
CE
Kater
Adrenal gland; Espectroscopia; Glândula adrenal; Magnetic resonance imaging; Ressonância magnética; Spectroscopy