Benha Medical Journal

ORIGINAL ARTICLE
Year
: 2017  |  Volume : 34  |  Issue : 2  |  Page : 73--76

The role of multislice computed tomography in the differential diagnosis of retroperitoneal masses


Medhat M Reffat1, Islam M Elshazly1, Ahmed F Mohammed2,  
1 Diagnostic Radiology Department, Faculty of Medicine, Benha University, Benha, Egypt
2 Radiology Department, Faculty of Medicine, Cairo University, Cairo, Egypt

Correspondence Address:
Ahmed F Mohammed
El Qanater El Khairia, El Qualiobia, 13621
Egypt

Abstract

Background The great majority of retroperitoneal masses are found incidentally as a result of the use of computed tomography (CT), ultrasonography, and MRI. Therefore, the proper characterization of the masses is essential so that appropriate management is instituted. With modern CT imaging equipment, the diagnosis of most retroperitoneal masses is usually straightforward and accurate. Aim The aim of this study was to know the role of multidetector CT in the diagnosis and detection of retroperitoneal masses. Patients and methods The study was performed at National Cancer Institute, and approved by its ethical committee, and informed consent was given by all patients. The study was conducted on 32 patients (17 male and 15 female) presented to the National Cancer Institute with abdominal or pelvic swelling (on clinical examination or detected by previous imaging study) suspected to be of retroperitoneal origin to perform CT of the abdomen and pelvis for initial assessment or follow-up. Results At present, CT is the most reliable, effective, and efficient instrument in this context, offering sensitivity and specificity values in excess of 87%, with a diagnostic reliability of over 90% in application to retroperitoneal masses of a cystic or complex nature, with nonspecific or specific inflammatory characteristics, or of a primary or secondary neoplastic nature. Conclusion The differential diagnosis of retroperitoneal masses may be based on the predominant cross-sectional CT imaging appearance as either cystic or solid and neoplastic and non-neoplastic. Characteristic imaging findings, such as the composition (fat, calcification, and necrosis), enhancement pattern, vascularity, location, and relationship to adjacent structures, may be combined with clinical information and assisted by diagnostic scheme to help narrow the differential diagnosis.



How to cite this article:
Reffat MM, Elshazly IM, Mohammed AF. The role of multislice computed tomography in the differential diagnosis of retroperitoneal masses.Benha Med J 2017;34:73-76


How to cite this URL:
Reffat MM, Elshazly IM, Mohammed AF. The role of multislice computed tomography in the differential diagnosis of retroperitoneal masses. Benha Med J [serial online] 2017 [cited 2018 Aug 18 ];34:73-76
Available from: http://www.bmfj.eg.net/text.asp?2017/34/2/73/218821


Full Text



 Introduction



The great majority of retroperitoneal masses are found incidentally as a result of the use of computed tomography (CT), ultrasonography, and MRI [1]. Therefore, the proper characterization of the masses is essential so that appropriate management is instituted [2]. With modern CT imaging equipment, the diagnosis of most retroperitoneal masses is usually straightforward and accurate.

The evaluation usually can be accomplished if a high-quality examination is performed, if the clinical history of the patient is kept in mind, and the condition that mimics a retroperitoneal neoplasm is considered and excluded [3]. Multidetector (also known as multislice, multichannel, or multisection) computed tomography (MDCT) is the most recent advancement in CT technology. It uses a multiple-row detector array instead of the single-row detector array used in helical CT. These new CT scanners allow 2–25 times faster scan times compared with helical CT scanner with the same or better image quality [4]. These faster scan times result in decreased breath-hold times with reduced motion artifact and better diagnostic image. Increased volume coverage is combined with thinner slice thickness to obtain better quality volume data sets for workstation analysis, either in two dimensional axial, multiplanar reformatting or three-dimensional imaging. The main advantages of MDCT are faster scanning times, increased volume coverage, and improved spatial and temporal resolution [1]. Moreover, using MDCT allows imaging to be obtained from the same acquisition data set. MDCT allows images to be obtained in multiple phases of renal parenchymal enhancement and excretion in the collecting system after administration of a single bolus of intravenous contrast material. Therefore, detection and characterization of small retroperitoneal masses display the arterial and venous supply of the retroperitoneal structures similar to conventional angiography, and demonstration of the abnormalities using different three dimensional display techniques are possible with MDCT [4].

 Aim



The aim of this study was to know the role of multidetector CT in the diagnosis and detection of retroperitoneal masses.

 Patients and methods



Study design

This prospective study was performed aiming to determine the role of CT in the differential diagnosis of retroperitoneal masses.

Study population

The study was performed at National Cancer Institute (NCI) and approved by its ethical committee, and informed consent was given by all patients.

The study was conducted on 32 patients (17 male and 15 female) presented to the NCI with abdominal or pelvic swelling (on clinical examination or detected by previous imaging study) suspected to be of retroperitoneal origin to perform CT of the abdomen and pelvis for initial assessment or follow-up.

Inclusion criteria

Patients with primary retroperitoneal lesion were included.

Exclusion criteria

Presence of lesions not located at the retroperitoneal region.Unstable general condition.

Methods

CT of the abdomen and pelvis was performed.

Computed tomography examination protocol design

CT examinations were performed on a GE light speed VCT 64 multislice CT scanner (Complete Medical Services Inc., 105 Peyerk Court, Romeo, MI, USA) and Toshiba Asteion four-slice CT scanner (Toshiba, Japan). CT of the abdomen and pelvis with oral and intravenous contrast was performed using the following parameters: 350 mA, 120 kV, 0.5 s tube rotation time, slice thickness 5 mm, 8 mm table feed, and 3 mm incremental reconstruction. Noncontrast CT was performed in patients with impaired renal function (creatinine level>2 mg/dl) and/or with a history of hypersensitivity for contrast media.

Computed tomography images

On CT, confirmation of site as retroperitoneal and exclusion of organ of origin were performed first, followed by assessment of definition, consistency, components of the lesion (fat, calcium, and necrosis), pattern of enhancement (unenhanced, homogeneous, or heterogeneous), and average CT attenuation [by measuring Hounsfield unit (HU) in five different locations and calculating the average HU].

 Results



A total of 32 patients presented to the NCI with abdominal or pelvic swelling (detected by means of clinical examination or by previous imaging study suspected to be of retroperitoneal origin). Their mean±SD age was 31.75±21.48 years. Seventeen (53.1%) patients were male and 15 (46.9%) patients were female ([Table 1],[Table 2],[Table 3] and [Figure 1] and [Figure 2]).{Table 1}{Table 2}{Table 3}{Figure 1}{Figure 2}

 Discussion



The diagnostic study, analysis, and characterization of retroperitoneal masses and their behavior are one of the key elements for elaborating a surgical or therapeutic strategy, determining the prognosis, and for the follow-up of treatment efficacy in patients with benign or malignant disease. At present, CT is the most reliable, effective, and efficient instrument in this context, offering sensitivity and specificity values in excess of 87%, with a diagnostic reliability of over 90% in application to retroperitoneal masses of a cystic or complex nature, with nonspecific or specific inflammatory characteristics, or of a primary or secondary neoplastic nature [5]. MDCT is widely used for the evaluation of retroperitoneal tumors. As thin-slice images afforded by MDCT make it possible to detect smaller lesions than previously, MDCT is useful for the detection and diagnosis of small lesions. Furthermore, high-resolution multiplanar reformatted images reconstructed with the thin-slice MDCT images are helpful for evaluating perinephric spaces, as well as the tumor thrombus of retroperitoneal neoplasm. Therefore, MDCT is expected to provide accurate preoperative staging of retroperitoneal cancer. Maximum intensity projection and volume-rendering images have been used to provide the urologist with a road map for surgery. MDCT has the potential to replace traditional imaging techniques in the evaluation of pathologic processes involving the inferior vena cava. The ability to acquire near-isotropic data allows high-quality reconstructions in the sagittal and coronal planes and thus overcomes one of the major limitations of CT in evaluating the inferior vena cava [6].

These results are presented in [Figure 3],[Figure 4],[Figure 5].[7][8]{Figure 3}{Figure 4}{Figure 5}

 Conclusion



The differential diagnosis of retroperitoneal masses may be based on the predominant cross-sectional CT imaging appearance as either cystic or solid and neoplastic and non-neoplastic. Characteristic imaging findings, such as the composition (fat, calcification, and necrosis), enhancement pattern, vascularity, location, and relationship to adjacent structures, may be combined with clinical information and assisted by diagnostic scheme to help narrow the differential diagnosis.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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