Comparative study on usefulness of USG to CT in evaluating solitary focal liver lesion

 

 

Abstract              Background: Liver diseases arc known to affect mankind since the dawn of civilization and have steadily gained recognition as a major health problem principally because of their worldwide distribution. The most important diagnostic modalities of this century that have been made available to the diagnostic armamentarium arc Ultrasonography (USG) Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). CT plays a major role in detecting focal liver lesions. Such as in search of calcifications in primary and secondary tumors, visualization of hemorrhage either in subcunsular or in hepatic parenchyma. And also in the visualization of lipiodol distribution pattern following completed intraarterial embolization of liver tumors. Aim Of The Study: To correlate the USG and CT findings with Histopathology and laboratory findings. Materials And Methods: This is a prospective study was done at melmaruvathur adhiparasakthi institute of medical education and research in the Division of Radiology and Imaging sciences between august 2019 to august 2020 .and the cases were followed up to reach a confirmative diagnosis. The patients were subjected to CT, Biopsy or FNAC wherever indicated. The imaging findings were correlated with CT/surgical/histopathological/follow –up studies. These studies were done between 2 to 6 months following the initial examination. Results: Of the total 100 cases, 56 were malignant and 44 were benign. The commonest focal liver lesions are metastasis. The most common benign tumors are Abscess and Hemangioma. RIGHT LOBE incidence was observed in 73 patients and LEFT LOBE involvement in 27 cases. In this study, it played a supportive and confirmatory role in characterizing the lesions especially in patients with liver metastasis, liver primary, and liver abscesses. Conclusion: In this comparative study of USG and CT in the evaluation of Focal liver lesions concluded that USG was more sensitive than CT in detecting lesions, but CT provided more complete information than USG in the extent of the lesion. Thus USG and CT are supplementary in the evaluation of focal liver disease. Because of the higher sensitivity, USG should be first examined followed by CT for confirmation.

Key Words: Focal Liver Lesions, CT, MRI, Hemangioma.

 

INTRODUCTION

The symptoms of liver disease such as jaundice, fever, cirrhosis. abdominal enlargement and encephalopathy are striking phenomena that bring the patient to the physician. Clinical and biochemical examination provides information regarding liver size and functions but the assessment of the exact pathology is grossly inadequate.¹ The role of Conventional Radiology in liver diseases is very limited because one can detect true borders of the liver only when it is outlined by fat or fat permeated tissue. The usefulness of plain radiograph in liver pathology is in the assessment of liver enlargement, calcification (Chronic abscess, Hydatid cyst. Metastasis and Hepatoma), and localized masses if they lie against or deform the visible linear borders. But, because of its invasive nature, arteriography is ruled out as a screening procedure for focal liver disease.² Scintigraphy can demonstrate focal defects larger than 2 cm in diameter Because of its sensitivity it is well known non-invasive screening method, its accuracy is claimed to be between 72% to 90%. Hepatic scintigraphy and Hepatic arteriography play a complementary role in the evaluation of focal liver lesions.³ The most important diagnostic modalities of this century that have been made available to the diagnostic armamentarium arc Ultrasonography (USG) Computed Tomography (CT) and Magnetic Resonance Imaging (M RI). Ultrasonogram is the baseline screening investigation done for detection as well as characterization of focal liver lesions. The advent of ultrasound has revolutionized the diagnosis of liver disease and has considerably widened the diagnostic spectrum of liver examination.⁴ The current diagnostic approach with the US has made the liver almost completely accessible. Continued improvement in the grayscale display and recent advances in real-time imaging system now permits detailed and rapid examination, to watch dynamic motion and trace vessels quickly, improving its diagnostic accuracy.⁵ Computerized tomography is helpful primarily due to its excellent visualization of the anatomical relationship of the liver and its position relative to adjacent organs. The introduction of single-slice CT in the early 1990s whose rapid and continuous data acquisition has proved advantageous. Other important technologic advances over the past decade include the drastic reduction in scan times owing to significantly shorter gantry rotation times.⁶ Another advance was the development of multiple slice helical CT scanners where up to sixteen parallel CT slices per tube rotation with partial reconstructions could he acquired simultaneously. CT plays a major role in detecting focal liver lesions. Such as in search of calcifications in primary and secondary tumors, visualization of hemorrhage either in subcunsular or in hepatic parenchyma. And also in the visualization of lipiodol distribution pattern following completed intraarterial embolization of liver tumors.⁷ MRI is a non-invasive imaging modality with no risk of radiation and less risk of contrast reaction. but it is still beyond the reach of the common man and its role in liver diseases is yet to be established.⁸ now with the advent of newer imaging protocols like SPIO enhanced T2WI and gadolinium-enhanced T1W1 accurate characterization of focal lesions can be achieved in almost all patients. Because of encouraging results with hepatosonography and CT the present study is being undertaken to evaluate its comparative usefulness and accuracy in the diagnosis of focal liver lesions.⁹

 

MATERIALS AND METHODS

This is a prospective study was done at melmaruvathur adhiparasakthi institute of medical education and research in the Division of Radiology and Imaging sciences between august 2019 to august 2020 .and the cases were followed up to reach a confirmative diagnosis The patients were subjected to CT, Biopsy or FNAC wherever indicated.

The imaging findings were correlated with CT/surgical/histopathological/follow –up studies. These studies were done between 2 to 6 months following the initial examination.

METHODOLOGY: A complete evaluation of these patients was done in the following format: Detailed Clinical History, Physical Examination, Biochemical Investigation (depending on the individual case), Radiological Modalities (depending on the individual case)

INCLUSION CRITERIA: Asymptomatic/Symptomatic patients detected to have focal liver lesions on USG. Diffuse liver disease like cirrhosis, fatty liver, etc. in which focal lesions were identified.

EXCLUSION CRITERIA: Diseases that have spread to the liver through local extension (eg. Lesions in Right Kidney /Stomach/ Right adrenals).Gall bladder diseases extending to the liver.Acute Traumatic contusions or lacerations of the liver. The imaging findings were correlated with CT/surgical/histopathological/follow –up studies. Follow up studies included repeat Ultrasonography or Computed Tomography following medical or symptomatic treatment. These studies were done between 2 to 6 months following the initial examination.

 

Results

Table 1: AGE DISTRIBUTION IN 100 PATIENTS WITH FOCAL liver LESIONS

Table:1 Of the total 100 cases, 72 patients were males and 28 were females. Male: Female ratio is 2.57: 1. The incidence of focal liver lesions was high in the elderly age group. more than 50% of the lesions occurred in patients more than 50 years of age. 23% of patients belonged to the fifth decade.23% of patients belonged to the sixth decade.33% of patients were above the age of sixty.

table 2: location of lesions

Table:2 location of lesions in the right lobe was 73 cases, and in the left lobe were 27.

 Table 3: incidence of benign and malignant focal liver lesions in 100 patients

Table :3 Of the total 100 cases, 56 were malignant and 44 were benign. The commonest focal liver lesions are metastasis. The most common benign tumor is Abscess and Hemangioma.

 

table 3: sonographic appearance of simple cyst (10 cases )

 

table4: sonographic appearance of amoebic liver abscess in

 

tablE 5: sonographic appearance of pyogenic liver abscess in 14 cases

Table6: sonographic appearance of hemangioma in 12 cases

 

 

 

 

 

table 6: sonographic appearance of adenoma in 1 case

 

Table 7: SONOGRAPHIC APPEARANCE OF GRANULOMA IN 4 CASES

 

Table 8: SONOGRAPHIC APPEARANCE OF METASTASIS IN 38 CASES

 

Table 9: SONOGRAPHIC APPEARANCE OF HEPATOBLASTOMA IN 3 CASES

 

Table 10: SONOGRAPHIC APPEARANCE OF HEPATOCELLULAR CARCINOMA IN 12 CASES

 

Table 11: CT AND CECT FINDINGS

In this study, it played a complementary and confirmatory role in characterizing and in knowing the extent of the lesion.

 

Table 12: BIOPSY FINDINGS

In this study, it played a supportive and confirmatory role in characterizing the lesions especially in patients with liver metastasis, liver primary, and liver abscesses.

 

Discussion

The asymptomatic/symptomatic cases of liver disease and routine check-up patients were clinically assessed. Abdominal and right hypochondria pain were the most common presenting signs. It the present series, also it has been noticed that this improves diagnostic accuracy especially the specificity of hepatosonography.¹⁰ It is very important in distinguishing between an acute inflammatory process and neoplastic lesions. All the 15 cases of liver abscesses had significant symptoms and signs in the form of fever with chills and rigors, swelling and tenderness in right hypochondrium, intercostals tenderness, and restriction of breathing.¹¹ Of this 1 patient with an amoebic liver, the abscess had a history of diarrhea and dysentery in the recent past which gave clues to his possible amoebic etiology. A similar finding of diarrhea and dysentery was found by John K. et.al ¹² Patients with pyogenic liver abscesses were commonly adults and were found to be more toxic than ALA patients. Suhas G et al. agrees with that a thorough clinical assessment of the patient is very essential before deciding immediate interventional procedure under US guidance. Patients with suspected primary and secondary in the liver had a history of significant loss of appetite and weight.¹³ Enlargement of the liver and ascites was also seen in these patients. The majority of these patients were middle-aged or older. The clinical assessment also helped in the search for primary malignancy in cases with hepatic metastasis like in cases of bronchogenic carcinoma, carcinoma of the stomach, carcinoma of the pancreas, carcinoma of the ovary, etc.¹⁴ as these cases presented with a mass abdomen besides hepatomegaly or post-operative / treatment history. Clinical assessment was not much helpful in patients with hepatic cystic disease and hemangioma as most of these patients were asymptomatic.¹⁵ The above observations confirm that a good clinical assessment in patients with liver disease helps improve sensitivity, specificity, and accuracy of hepatosonography and CT.¹⁶ Only up to a limited extent they help characterize the disease process and indicate the probability of biliary obstruction, cholestasis, infiltration. However, the AFP test proved to be very sensitive in diagnosing and in the management of HCC. Other investigations like the serum alkaline phosphatase test, CEA test, and CA 125 test help in pointing to the specific disease process. So, biochemical tests are useful in quantitating impaired liver function and are useful in abscesses, necrotic secondary, and HCC. In diseases like simple cyst, polycystic liver disease, hemangioma they are least affected.¹⁷ Overall they have an only supportive role not affecting the accuracy of hepatosonography significantly. With the advent of high-resolution real-time US, ultrasonography has emerged as the primary method for the diagnosis of liver disease. Its role is paramount in providing a high degree of diagnostic accuracy.¹⁸ R.J. Machell Its usefulness in the diagnosis of specific liver disease is now well recognized. Grayscale ultrasonography has been reported to have an overall accuracy of 73% to 90% for the liver disease^19,20

 

concLUsion

a good clinical assessment helps improve sensitivity, specificity, and accuracy of h               hepatosonography or surgical procedures. USG is also very helpful in diagnosing or ruling out any other associated disease or any pathology in the gallbladder, kidneys. pancreas. spleen, lyrnphnode, and any other organ simulating liver disease. In this comparative study of USG and CT in the evaluation of Focal liver, lesions concluded that USG was more sensitive than CT in detecting lesions, but CT provided more complete information than USG in the extent of the lesion. Thus USG and CT are supplementary in the Evaluation of focal liver disease. Because of the higher sensitivity, USG should be first examined Followed by CT for confirmation.

 

References

1. Taylor, K.J.W., McCready, B.B. Clinical evaluation of grayscale ultrasonography. BJR 2009:Vol.49, 244-252,
2. Edward H. Smith et al..: USG guided percutaneous Aspiration of Abscess AJR 2010; Vol.l22:308-312,
3. P.Hochbergs: Diagnosis and Percutaneous Treatment of Pyogenic Hepatic Abscesses. Acta Radiologica 2003: 31:351-353,
4. N.Juul et al..: Ultrasonically Guided Percutaneous Treatment of Liver Abscesses. Acta Radiologica 2004:31:275-277
5. Simon C.H.Yu et al..: US-guided Percutaneous Biopsy of Small Hepatic Lesions. Radiology 2001:218,195-199,
6. John. P. McGahan and Gerald D Dodd III: Radiofrequency Ablation of the Liver: Current Status: AJR,2001: Vol. 176:3-15
7. Thierry D Baere et al..: Radiofrequency Ablation of the Liver: AJR Vol. 2001:176:187-192,
8. Schiro Shina et al..: Percutaneous Ethanol injection therapy for the treatment of hepatocellular carcinoma. AJR, 2005:154,947-951,
9. Sumito Igawa et al..: Intraoperative Sonography. Radiology 2001: 156; 473-478,
10. C.Bartolozzi et al..: Ultrasound and CT in the Evaluation of Focal Liver Disease: Acta Radiologica Diagnosis 2008 :22:544-547,
11. John K. Mukai et al..: Imaging of Surgically Relevant Hepatic Vascular and Segmental Anatomy (Part.l, Part2). AJR. 2009:149,287-292,
12. John K. Mukai et al..: Imaging of Surgically Relevant Hepatic Vascular and Segmental Anatomy (Part.l, Part2). AJR. 2010:149,293-297.
13. Suhas G. Parulekar: Ligaments and Fissures of the Liver: Sonographic Anatomy: Radiology, 2005.:30,409-411,
14. Claus Niederau et al..: Sonographic Measurements of the Normal Liver, Spleen, Pancreas, and Portal Vein. Radiology, 2006:149,537-540,.
15. Didier Mathieu et al..: Hepatic Adenomas and Focal Nodular Hyperplasia. Radiology, 2009: 60,53-58,
16. Herman Grossman et al.. -.Hepatic Ultrasonography in Type I Glycogen Storage Disease (von Gierke disease): Radiology, 2009:141,753-756,
17. James V. Rogers et al..: Hepatic Focal Nodular Hyperplasia AJR 2009.: Vol. 137:983-990,
18. Abraham H. Dachman et al..: Nodular Regenerative Hyperplasia of the Liver: AJRVol.2005.48:717-722,
19. R.J. Machell and R.Y. Calne: Solitary non-parasitic hepatic cyst presenting with jaundice. BJR. 2009:51:631-632,
20. Ralph M. Weaver et al..: Gray Scale Ultrasonographic Evaluation of Hepatic Cystic Disease. AJRVoU30:2010:849-852.

 

 

 

 

 

 

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