scholarly journals Magnetic Resonance Imaging of the Anal Region: Clinical Applications

2020 ◽  
Vol 10 ◽  
pp. 76
Author(s):  
Giuseppe Cicero ◽  
Giorgio Ascenti ◽  
Alfredo Blandino ◽  
Socrate Pallio ◽  
Claudia Abate ◽  
...  

Over the past years, magnetic resonance imaging (MRI) has become a cornerstone in evaluating anal canal and adjacent tissues due to its safeness, the three-dimensional and comprehensive approach, and the high soft-tissue resolution. Several diseases arising in the anal canal can be assessed through MRI performance, including congenital conditions, benign pathologies, and malignancies. Good knowledge of the normal anatomy and MRI technical protocols is, therefore, mandatory for appropriate anal pathology evaluation. Radiologists and clinicians should be familiar with the different clinical scenarios and the anatomy of the structures involved. This pictorial review presents an overview of the diseases affecting the anal canal and the surrounding structures evaluated with dedicated MRI protocol.

Author(s):  
Hongzhang Zhu ◽  
Shi-Ting Feng ◽  
Xingqi Zhang ◽  
Zunfu Ke ◽  
Ruixi Zeng ◽  
...  

Background: Cutis Verticis Gyrata (CVG) is a rare skin disease caused by overgrowth of the scalp, presenting as cerebriform folds and wrinkles. CVG can be classified into two forms: primary (essential and non-essential) and secondary. The primary non-essential form is often associated with neurological and ophthalmological abnormalities, while the primary essential form occurs without associated comorbidities. Discussion: We report on a rare case of primary essential CVG with a 4-year history of normal-colored scalp skin mass in the parietal-occipital region without symptom in a 34-year-old male patient, retrospectively summarizing his pathological and Computer Tomography (CT) and magnetic resonance imaging (MRI) findings. The major clinical observations on the CT and MR sectional images include a thickened dermis and excessive growth of the scalp, forming the characteristic scalp folds. With the help of CT and MRI Three-dimensional (3D) reconstruction techniques, the characteristic skin changes could be displayed intuitively, providing more evidence for a diagnosis of CVG. At the 5-year followup, there were no obvious changes in the lesion. Conclusion: Based on our observations, we propose that not all patients with primary essential CVG need surgical intervention, and continuous clinical observation should be an appropriate therapy for those in stable condition.


2019 ◽  
Vol 70 (1) ◽  
pp. 83-95 ◽  
Author(s):  
Tatiana Mendonça Fazecas ◽  
Edward Araujo Júnior ◽  
Heron Werner ◽  
Pedro Daltro ◽  
Alberto Borges Peixoto ◽  
...  

Objective To assess the applicability of magnetic resonance imaging (MRI) to complement ultrasound in the diagnosis of fetal urinary tract anomalies. Methods This was a retrospective cohort study that included 41 women between 19 weeks and 37 weeks and 6 days of gestation carrying fetuses with malformations of the urinary tract which were initially diagnosed by ultrasound and then referred for MRI. In all cases, the diagnosis was confirmed after birth either through imaging or autopsy. A surface coil was positioned over the abdomen and T2-weighted sequences were obtained in the axial, coronal, and sagittal planes; T1 in at least one plane; and three-dimensional (3-D) TRUFI in fetuses with dilatation of the urinary tract. Results Mean gestational age at the time of MRI examination was 28.21 weeks. The rapid T2 sequences allowed all the anomalies of the fetal urinary tract to be assessed, whereas 3-D TRUFI sequencing proved very useful in evaluating anomalies involving dilatation of the urinary tract. The signs of pulmonary hypoplasia characterized by hypointense signal in the T2-weighted sequences were identified in 13 of the 41 fetuses. Conclusion MRI confirmed and added information to the ultrasound regarding fetal urinary tract anomalies, as well as information related to the other associated malformations, their progress in the prenatal period, and possible postnatal prognosis.


1989 ◽  
Vol 26 (4) ◽  
pp. 303-308 ◽  
Author(s):  
G. A. Johnson ◽  
M. B. Thompson ◽  
G. P. Cofer ◽  
D. Campen ◽  
R. R. Maronpot

Magnetic resonance imaging (MRI) at microscopic resolution was done on a live rat that had chemically induced hepatic neoplasms. Beginning at the anterior aspect of the liver, 16 contiguous transaxial slices (each 1.25 mm thick) were produced using three-dimensional Fourier transform sequences. The rat had been treated with diethylnitrosamine (200 mg/kg) at 70 days of age, and, subsequently, received periodic implants of 17a-ethynylestradiol for 60 weeks. Carr-Purcell-Meiboom-Gill (CPMG) sequences (repetition time = 2,000 and echo time = 20, 40, 60, 80 ms) were done to give quantitative measures of spin-spin relaxation times (T2). Pixel-by-pixel curve fitting from these multiple images yielded calculated T2 images. Histologic evaluation of three abnormal areas in the liver revealed solid and cystic hepatocellular adenomas. Although lesions were evident in early-echo images of the CPMG sequence, they were more apparent in the late-echo images. This was consistent with longer T2 relaxation times for the lesions. The voxels of dimensions (230 × 230 × 1,250 /μm) permitted resolution of volume elements <0.07 mm3. This in turn permitted clear delineation of focal lesions <3 mm in diameter. The potential for MRI at microscopic resolution in toxicologic research is clearly demonstrated.


2016 ◽  
Vol 18 (3) ◽  
pp. 378 ◽  
Author(s):  
Talita Micheletti Helfer ◽  
Alberto Borges Peixoto ◽  
Gabriele Tonni ◽  
Edward Araujo Júnior

Craniosynostosis is defined as the process of premature fusion of one or more of the cranial sutures.  It is a common condition that occurs in about 1 to 2,000 live births. Craniosynostosis may be classified in primary or secondary. It is also classified as nonsyndromic or syndromic. According to suture commitment, craniosynostosis may affect a single suture or multiple sutures. There is a wide range of syndromes involving craniosynostosis and the most common are Apert, Pffeifer, Crouzon, Shaethre-Chotzen and Muenke syndromes. The underlying etiology of nonsyndromic craniosynostosis is unknown. Mutations in the fibroblast growth factor (FGF) signalling pathway play a crucial role in the etiology of craniosynostosis syndromes. Prenatal ultrasound`s detection rate of craniosynostosis is low. Nowadays, different methods can be applied for prenatal diagnosis of craniosynostosis, such as two-dimensional (2D) and three-dimensional (3D) ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) scan and, finally, molecular diagnosis. The presence of craniosynostosis may affect the birthing process. Fetuses with craniosynostosis also have higher rates of perinatal complications. In order to avoid the risks of untreated craniosynostosis, children are usually treated surgically soon after postnatal diagnosis.


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