E-ISSN:2320-8686
P-ISSN:2321-127X

Research Article

Tomography

International Journal of Medical Research and Review

2020 Volume 8 Number 2 March-April
Publisherwww.medresearch.in

A study to assess the role of contrast-enhanced multiphasic, multidetector computed tomography in the evaluation of renal lesions

Khantal N.1, P. Ahirwar L.2*
DOI: https://doi.org/10.17511/ijmrr.2020.i02.07

1 Nitin Khantal, Associate Professor, Department of Radiodiagnosis, Chirayu Medical College and Hospital, Bhopal, Madhya Pradesh, India.

2* Laxman P. Ahirwar, Assistant Professor, Department of Radiodiagnosis, Chirayu Medical College and Hospital, Bhopal, Madhya Pradesh, India.

Aim: To assess the role of Contrast-Enhanced Multiphasic Multidetector Computed Tomography in the evaluation of renal lesions and its potential role in differentiating benign from malignant lesions. Material and Method: This prospective study was done in the Department of Radiodiagnosis Chirayu Medical College and Hospital Bhopal. A total of 100 patients to our department with strong clinical suspicion of renal lesions and those diagnosed by ultrasonography underwent Contrast-Enhanced Multiphasic Multidetector Computed Tomographic evaluation of abdomen using 64 Multislice Spiral CT scanner from August 2015 to July 2019. Results: The majority of patients presenting with renal lesions were each of the age groups <15 years and >40 years. Most of the patients were males 57%. The most common clinical complaint was renal colic 58(46%) and hematuria. The most common pathology was calculus 35(35%) second most common pathology was congenital anomalies 23(23%). The CT accuracy for detection of benign cystic lesion in this study was 94.7%, benign lesions were 92.6%and for malignant lesions was 86.6% in the present study. Conclusion: The accuracy of Contrast-Enhanced Multiphasic Multidetector Computed Tomography in detecting and characterizing renal lesions is high and it should be considered in the imaging workup of any patient with a renal complaint.

Keywords: Computed Tomography, Renal lesions Spiral CT

Corresponding Author How to Cite this Article To Browse
Laxman P. Ahirwar, Assistant Professor, Department of Radiodiagnosis, Chirayu Medical College and Hospital, Bhopal, Madhya Pradesh, India.
Email: 		Khantal N, Ahirwar LP. A study to assess the role of contrast-enhanced multiphasic, multidetector computed tomography in the evaluation of renal lesions. Int J Med Res Rev. 2020;8(2):176-182.
Available From
https://ijmrr.medresearch.in/index.php/ijmrr/article/view/1165

Manuscript Received Review Round 1 Review Round 2 Review Round 3 Accepted
2019-12-16 2019-12-27 2020-01-04 2020-01-09
Conflict of Interest Funding Ethical Approval Plagiarism X-checker Note
No Nil Yes 6%

© 2020 by Nitin Khantal, Laxman P. Ahirwar and Published by Siddharth Health Research and Social Welfare Society. This is an Open Access article licensed under a Creative Commons Attribution 4.0 International License https://creativecommons.org/licenses/by/4.0/ unported [CC BY 4.0].

International Journal of Medical Research and Review 2020;8(2)176
Khantal N. et al: A study to assess the role of contrast-enhanced

Introduction

Contrast-enhanced multiphasic Multidetector Computed tomography plays an indispensable role in the detection and characterization of renal lesions. The detection rate of renal masses has increased in the last decades owing to the widespread use of CT and MRI [1].

The aspects of the identified renal pathologies influence the clinical and surgical decision making. Benign abnormalities such as cysts and congenital anomalies like abscess, PUJ obstruction require intervention [2].

The advent of a multidetector CT scan has enabled us to delineate the mass, detect and map the extent of venous spread, lymph nodal enlargement, and diagnose local or distant spread [3]. Malignant lesions like RCC, TCC often require active treatment [4,5].

The study is done to assess the role of Contrast-Enhanced Multiphasic Multidetector Computed Tomography in the evaluation of renal lesions and its potential role in differentiating benign from malignant lesions.

Material and Method

This prospective study was done in the Department of Radiodiagnosis Chirayu Medical College and Hospital Bhopal, Madhya Pradesh, India. A total of 100 patients to our department with strong clinical suspicion of renal lesions and those diagnosed by ultrasonography underwent Contrast-Enhanced Multiphasic Multidetector Computed Tomographic evaluation of abdomen using 64 Multislice Spiral CT scanner from August 2015 to July 2019.

Inclusion Criteria: Patients referred to the Radiodiagnosis Department with strong clinical suspicion of renal lesions. Patients already diagnosed with renal lesions by ultrasonography

Exclusion Criteria: Patients primarily with extrarenal pathology

Equipment and Technique

  • CT examination was performed on a GE revolution 16 multi-slice CT scanner. This is the fourth generation rotate the only scanner with slip rings technology. The scanner has a multi-detector 64 slice configuration with a gantry rotation time of 0.33 seconds. The scanner is capable of obtaining 0.6, 1,2, 5, 8, and 10 mm

sections with a maximum range of table tilt of 0 to ± 30 degrees.

  • The automatic Medrad Vistron CT pressure injector system was employed for the IV contrast administration.

Study Protocol

  • A detailed history of the patient including signs and symptoms, detailed physical examination, biochemical investigations, and radiological investigations which included chest x-ray and ultrasonography of abdomen were recorded and tabulated as in the proforma.
  • Written consent was taken.
  • Oral contrast Telebrix (Sodium + meglumine Ioxitalamate) a water-soluble contrast agent containing iodine concentration of 350 mg/ml is given. 30 ml mixed in 1000 ml given over 1 hour. The last 200 ml is given on the gantry table.
  • The patient was then placed on the gantry table in the supine position with arms placed above the head. The patient was explained to hold his/her breath on verbal instruction and to resume breathing on reinstruction. In case the patient is dyspneic or was unable to hold the breath for a reasonably long time, he/she was advised to maintain shallow breathing.
  • A digital AP (anteroposterior) scout radiograph was taken from mid thorax to mid-thigh level. Factors used: 120 kvp and 35 mAs.
  • A non-contrast enhanced scan is taken. The images were acquired through 2mm contiguous sections in the craniocaudal direction from 2 cm above the dome of diaphragm to pubic symphysis level with suspended respiration or shallow breathing. Reconstruction was done at 2 mm intervals.
  • 100 ml water-soluble iodinated contrast (ioversol 350 mg/ml) injected IV at 3-4 ml/sec through 18-20 G i.v. cannula in the antecubital fossa using the power injector.
  • Sequential phases of multiphasic imaging are done which includes.
    • Arterial phase,
    • Corticomedullary phase
    • Nephrographic phase and
    • Delayed phase.

International Journal of Medical Research and Review 2020;8(2)177
Khantal N. et al: A study to assess the role of contrast-enhanced
  • The images were acquired through 2mm contiguous sections in the craniocaudal direction from 2 cm above the dome of diaphragm to pubic symphysis level with suspended respiration or shallow breathing. Reconstruction was done at 2 mm intervals.

Results

Table 1 represented the distribution of cases on the basis of their age. Patients in the age group of <15 and >40 years had the maximum number of patients.

Table-1: Distribution of cases on the basis of their age.

Age group (years) No. of Patients %
<15 28 28
15-25 20 20
26-40 24 24
> 40 28 28
Total 100 100

Table 2 represented the distribution of cases on the basis of the sex of patients, 57% of males and 43% of females were grouped.

Table-2: Distribution of cases on the basis of their sex.

Sex No. of cases %
Male 57 57
Female 43 43
Total 100 100

Table 3 highlighted the distribution of cases on the basis of the clinical presentation. 46% of patients were attributed to renal colic, whereas 2% of patients were attributed to hypertension.

Table-3: Classification of cases on the basis of clinical presentation.

Clinical features No. of cases %
Renal colic 58 46
Fever 19 15
Hematuria 18 14
Burning micturition 12 10
Abdominal lump 11 9
Asymptomatic/ usg +ve 4 3
Hypertension 2 2
Total 122 100

Table 4 signified the classification of cases on the basis of lesions. 35% of cases were attributed with calculi whereas only 2% of cases were attributed with vascular lesions.

Table-4: Classification of cases on the basis of lesions.

  No. of Cases %
Calculi 35 35
Congenital 23 23
Benign 13 13
Malignant 13 13
Inflammatory 9 9
Trauma 5 5
Vascular 2 2
Total 100 100

Table 5 represented the classification of cases on the basis of the congenital developmental anomalies.

A maximum number of cases were observed with PUJ obstruction (27%), whereas the minimum number of cases were observed with crossed ectopia.

Table-5: Classification of cases on the basis of congenital developmental anomalies.

  No. of cases %
PUJ obstruction 7 27
Hypoplastic and Malrotated kidney 3 14
Ectopic kidney 3 14
Duplication and Ureterocoele 3 14
Horseshoe kidney 2 9
Agenesis 2 9
Primary megaureter 1 4
Multicystic dysplastic kidney 1 4
Crossed ectopia 1 5
Total 23 100

Table 6 highlighted the classification of cases on the basis of the presence of calculi.

A maximum number of cases were observed with calculus (78%), whereas non-calculus cases were 22%.

Table-6: Classification of cases on the basis of the presence of calculi.

Obstructive pathologies No. of cases %
Calculus 35 78
Non-calculus 10 22
Total 45 100

Table 7 represented the classification of cases on the basis of inflammatory lesions.

A maximum number of cases were observed with Pyelonephritis (45%), whereas 22% of cases were observed with renal TB.

International Journal of Medical Research and Review 2020;8(2)178
Khantal N. et al: A study to assess the role of contrast-enhanced

Table -7: Classification of cases on the basis of inflammatory lesions

  No. of cases %
Pyelonephritis 4 45
Renal abscess 3 33
Renal TB 2 22
Total 9 100

Table 8 represented the classification of cases on the basis of cystic lesions.

The maximum number of cases was observed with a Simple cyst (32%), whereas 10% of cases were observed with the complex cyst.

Table-8: Classification of cases on the basis of cystic lesions.

  CT Features No. of Cases %
Simple cyst Homogenous, hu 0 -20, no enhancement smooth thin wall 6 32
Abscess Thick wall, hypodense fluid collection, perinephric stranding, int contents 5 26
Urinoma Collection around kidney + pc enhancement 3 16
PCDK Multiple cysts in b/l kidneys, ±liver cysts 3 16
Complex cyst Thin wall, ± septations, ±calcification, ±enhancement, ± internal contents 2 10
Total   19 100

Table 9 highlighted the classification of cases on the basis of solid lesions.

A maximum number of cases were observed with RCC (33%) whereas 10% of cases were observed in a post-traumatic hematoma.

Table-9: Classification of cases on the basis of solid lesions

  CT Features No. of Cases %
RCC Hypodense/ mixed density, pc enhancement < n renal tissue, ±calcification, irregular margin, ±necrosis 7 33
TCC Urothelium of pelvis filling defect, 40-60 hu, 3 14
Wilm’s Hypodense to mixed mass with calcification/necrosis 3 14
Angiomyolipoma Well circumscribed solid lesions + fat of -10 hu or > 2 10
Pyelonephritis B/l enlarged kidneys, striated nephrogram 4 19
Post traumatic hematoma Kidney laceration, ±perinephric collection 2 10
Total   21 100

Table 10 highlighted the classification of cases on the basis of all benign lesions.

A maximum number of cases were observed with a simple cyst (22%), whereas angiomyolipoma was observed in 7%.

Table-10: Classification of cases on the basis of all benign lesions.

  No. of Cases %
Simple cyst 6 22
Abscess 5 19
Traumatic (+urinoma) 5 19
Pyelonephritis 4 15
PCKD 3 11
Complex cyst 2 7
Angiomyolipoma 2 7
Total 27 100

Table 11 highlighted the classification of cases on the basis of malignant lesions.

A maximum number of cases were observed in cases with RCC (54%), whereas 23% of cases of TCC were observed.

Table-11: Classification of cases on the basis of malignant lesions.

  No. of Cases %
RCC 7 54
WILM’S 3 23
TCC 3 23
Total 13 100

Discussion

In the present study, the most common age group of patients presenting with renal lesions was100 <15 years and >40 years constituting 28% of the cases. Males were the majority of patients constituting around in 57% of cases.

The most common presenting complaint was renal colic seen in 46% of the cases, followed by hematuria seen in 14% of cases.

Patients presented with overlapping symptoms in most of the cases. In the current study, the majority of patients had an abnormal size in 77 % of the cases. Normal shape, position, and contour were seen in most of the patients.

Similar results were seen by Sechel G., et al. In the current study, 23% cases were of congenital anomalies, of which PUJ obstruction was most common (7/23) followed by ectopic kidney and

International Journal of Medical Research and Review 2020;8(2)179
Khantal N. et al: A study to assess the role of contrast-enhanced

duplication anomaly (3/23). 2 cases were of horseshoe kidney and Renal agenesis each. Primary megaureter, multicystic dysplastic kidney, crossed ectopia were seen 1 case each.

Similar results were obtained by Elaine et al [6] and W C Lin et al 63. In the arterial phase, 2% of the cases showed narrowed and stenotic renal artery hence diagnosed as renal artery stenosis.

This was similar to the study done by G D Rubin et al [7] where CT angiography was 92% sensitive and 83% specific for the detection of stenosis.

45 % of the cases showed features of obstruction were seen, of which 35 cases had calculi, rest were the cases of PUJ obstruction and duplication anomalies leading to hydronephrosisOut of 35 cases of calculi, majority of the cases had severe hydronephrosis (58 %).

CT was 100% accurate in diagnosing calculi. Similar results were obtained by RC Smith et al [9] and J Chin et al [8] who had an accuracy of 99% and 97.5% respectively. Among the 40 renal lesions, solid lesions constituted the majority, which was 66% of the cases and cystic lesions constituting a minority of 44% of the cases. This is similar to the observation by Elaine et al [6].

Simple cysts were diagnosed by the presence of a well defined renal cortical lesion of fluid attenuation with no perceptible wall, internal contents, and no enhancement B A Birnbaum et al [10]. Using these criteria simple cysts (32%) were diagnosed with 100% specificity.

An abscess is well defined thick wall with internal contents and enhancement, with or without perinephric stranding. The present study had 26% of abscess in the current study. But one case of cystic RCC was wrongly diagnosed as a renal abscess with resultant accuracy of 80%.

Polycystic kidney disease was diagnosed on the presence of numerous cysts of varying sizes present in both the kidneys. Using this PCDK was diagnosed in 16% of cases. All the above lesions were classified according to Bosniak’s classification. Of which majority of the cases (63 %) were of category I, 32 % were of category II, and 5 % of category III.

Similar results were obtained by Israel and Bosniak et al [11]. On the evaluation of Solid lesions, the most common finding was a post-contrast-enhanced lesion in 71% of cases and a hypodense lesion

in 57% of cases.

This was followed by the presence of smooth margins in 52% of cases, necrosis was seen in 26% of cases, enlarged lymph node in 26% of cases, and calcification was seen in 20% of cases.

The renal vein or IVC thrombosis was seen in 13% of cases, pulmonary metastasis was seen in 13% of cases. Adrenal involvement was seen in 7.5% of cases. Angiomyolipoma was diagnosed by the presence of a well-defined lesion with the presence of fat. On this basis, the present study had 10 % of cases of angiomyolipoma with a specificity of 100%.

Pyelonephritis was diagnosed on the basis of bilaterally enlarged kidneys with striated nephrogram. On this basis, pyelonephritis was diagnosed in 19% of cases, with 100% accuracy. Similar results were seen in the study by Massoud Majd et al [12].

RCC was diagnosed as hypodense or mixed density lesion with post-contrast enhancement with or without calcification or necrosis. Using these criteria RCC was diagnosed. Two cases of RCC were misdiagnosed as hematoma and another as an abscess with accuracy being 77%.

Similar results were obtained by Catalano et al [13] and J Chin et al [8] who got 96% and 95% accuracy.TCC was diagnosed as a pelvicalyceal mass lesion with post-contrast enhancement. On this basis, TCC was seen in 14% of cases with 100% accuracy.

Similar results were seen by F. Millian et al [14], who got 97% accuracy in diagnosing TCC. Wilm’s tumor is seen as hypo to mixed density lesion with or without calcification or necrosis. On this basis, Wilm’s tumor was seen in 14% of cases with 100 % accuracy.

Similar results were seen by Fishman et al [15] who got CT accuracy as 94%. The post-traumatic hematoma was seen in 10% of cases diagnosed as renal hematoma without renal laceration or collection. One case diagnosed as hematoma turned out to be an RCC.

CT accuracy was 50%. The diagnostic accuracy for differentiating benign and malignant lesions using all the above CT criteria in this study was assessed for cystic lesions, solid lesions, and overall. The CT accuracy for cystic benign lesions in the present study was 94.7% with one false positive case.

This high accuracy was due to the presence of a

International Journal of Medical Research and Review 2020;8(2)180
Khantal N. et al: A study to assess the role of contrast-enhanced

large number of simple renal cysts. The CT accuracy for solid benign lesion detection was 87.5 %, with one false-negative case.

The CT accuracy for solid malignant lesion detection was 92.8%, due to one false positive case.

The overall accuracy of this study for benign lesions was 92.6% and for malignant lesions were 86.6% of cases.

Conclusion

The differentiation of cystic and solid lesions, benign and malignant lesions using contrast-enhanced multiphasic multidetector computed tomography in this study shows high accuracy.

What does the study add to the existing knowledge

The current study further helps in the characterization of the lesions based on morphological and enhancement characteristics.

Author’s contribution

Dr. Nitin Khantal: Study design, concept, manuscript preparation

Dr. Laxman P. Ahirwar: Statistical analysis, manuscript preparation

Reference

  1. Srougi V, Kato RB, Salvatore FA, Ayres PP, Dall'Oglio MF, Srougi M. Incidence of benign lesions according to tumor size in solid renal masses. Int Braz J Urol. 2009;35(4)427-431.
  2. Israel GM, Bosniak MA. How I do it- evaluating renal masses. Radiol. 2005;236(2)441–450.
  3. Ng CS, Wood CG, Silverman PM, Tannir NM, Tamboli P, Sandler CM. Renal cell carcinoma: diagnosis, staging, and surveillance. Am J Roentgenol. 2008;191(4)1220-1232.
  4. Coll DM, Smith RC. Update on radiological imaging of renal cell carcinoma. BJU Int. 2007;99(5 Pt B)1217-1222.
  1. Pahernik S, Ziegler S, Roos F, Melchior SW, Thüroff JW. Small renal tumors correlation of clinical and pathological features with tumor size. J Urol. 2007;178(2)414-417.
  2. Caoili EM, Cohan RH, Korobkin M, Platt JF, Francis IR, Faerber GJ, et al. Urinary tract abnormalities initial experience with multi–detector row CT urography. Radiol. 2002;222(2)353-360.
  3. Lin WC, Wang JH, Wei CJ, Chang CY. Assessment of CT urography in the diagnosis of urinary tract abnormalities. J Chi Med Assoc. 2004;67(2)73-78.
  4. Smith RC, Verga M, Dalrymple N, McCarthy S, Rosenfield AT. Acute ureteral obstruction value of secondary signs of helical unenhanced CT. AJR- Am J Roentgenol. 1996;167(5)1109-1113.
  5. Birnbaum BA, Jacobs JE, Ramchandani P. Multiphasic renal CT- comparison of renal mass enhancement during the corticomedullary and nephrographic phases. Radiol. 1996;200(3)753-758.
  6. Bosniak MA. Diagnosis and management of patients with complicated cystic lesions of the kidney. AJR- Am J Roentgenol. 1997;169(3)819-821.
  7. Majd M, Nussbaum Blask AR, Markle BM, Shalaby-Rana E, Pohl HG, Park JS, et al. Acute pyelonephritis comparison of diagnosis with 99 mTc- DMSA SPECT, spiral CT, MR imaging, and power Doppler US in an experimental pig model. Radiol. 2001;218(1)101-108.
  8. Catalano C, Fraioli F, Laghi A, Napoli A, Pediconi F, Danti M, et al. High-resolution multidetector CT in the preoperative evaluation of patients with renal cell carcinoma. Am J Roentgenol. 2003;180(5)1271-1277.
  9. Millan-Rodriguez F, Palou J, De la Torre-Holguera P, Vayreda-Martija JM, Villavicencio-Mavrich H, Vicente-Rodriguez J. Conventional CT signs in staging transitional cell tumors of the upper urinary tract. Europe Urol. 1999;35(4)318-322.

International Journal of Medical Research and Review 2020;8(2)181
Khantal N. et al: A study to assess the role of contrast-enhanced
  1. Fishman EK, Hartman DS, Goldman SM, Siegelman SS. The CT appearance of Wilms tumor. J Comput Assist Tomogr. 1983;7(4)659-665.

International Journal of Medical Research and Review 2020;8(2)182