ROLE OF TRIPHASIC COMPUTED TOMOGRAPHY IN THE …



RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, KARNATAKA

BANGALORE

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

|1.NAME OF THE CANDIDATE AND ADDRESS | DR. FATHIMA ZOHRA |

| |81, BENSON CROSS ROAD, BENSON TOWN, BANGALORE – 560046 |

| | |

| |DR. FATHIMA ZOHRA |

| |POST-GRADUATE IN RADIODIAGNOSIS |

|ADDRESS FOR CORRESPONDENCE |M S RAMAIAH MEDICAL COLLEGE |

| |BANGALORE – 560054 |

|2.NAME OF THE INSTITUTION |M.S. RAMAIAH MEDICAL COLLEGE |

| |M.S.RAMAIAH NAGAR, |

| |BANGALORE-560054 |

|3.COURSE OF STUDY AND SUBJECT |M.D. RADIO DIAGNOSIS |

|4.DATE OF ADMISSION TO COURSE |31-05-2011 |

|5.TITLE OF THE TOPIC |ROLE OF TRIPHASIC COMPUTED |

| | |

| |TOMOGRAPHY IN THE EVALUATION |

| | |

| |OF LIVER LESIONS. |

6. Brief resume of intended work:

6.1. Introduction and need for the study:

Spiral Computed Tomography has gained acceptance as the preferred technique for the

evaluation of wide range of liver lesions, because it provides image acquisition at peak

enhancement of liver parenchyma in a single breath hold ,reducing the chances of missing

small lesions.

Triphasic Spiral computed tomography technique allows imaging of the entire liver in three

phases, from the time of administration of contrast. The first phase is the hepatic arterial

phase, which enables early identification of primary malignancy of the liver(hepatocellular

carcinoma) and benign lesions (such as haemangioma, focal nodular hyperplasia and

hepatocellular adenoma). The second phase is the portal venous phase, which is the most

sensitive phase to detect some hypervascular tumors (hepatocellular carcinoma, metastatic

melanoma, etc) and most of the hypovascular tumors of the liver such as metastatic

lung carcinoma, metastatic colon cancer and metastatic breast cancer. The third phase is the

hepatic venous phase also known as the delayed or equilibrium phase along with the hepatic

arterial phase gives information on the vascularity of the lesion, which may further help to

clarify the nature of the lesion.

Hence, the purpose of the study is to characterize wide range of liver lesions using Triphasic

Spiral Computed Tomography.

6.2. Review of literature:

Studies 1 , 2 , 3 have suggested that most metastatic lesions were hypo vascular with more

lesions being detected on portal venous phase and most of the primary malignancies were

hyper vascular and detected on hepatic arterial phase, however haemangiomas, focal nodular

hyperplasia and hepatocellular adenoma are benign lesions which are seen to enhance in the

arterial or hyper vascular phase.Some of the above illnesses may be accompanied by

cirrhosis 3,4 , which disrupts the normal liver haemodynamics. Characteristically cirrhosis is

accompanied by portal venous hypertension and hepatic artery hypertrophy, thus giving

some hyper vascular tumors an appearance of infusing in the portal venous

phase. In addition the presence of portal vein thrombosis can delay or restrict the portal

blood flow and imaging phase.

Characterization of liver lesions as benign or malignant is important for the correct triage of

patients from surgical versus non-surgical therapies 5.Spiral CT has been found to be the

imaging modality of choice for preoperative assessment of focal liver lesions.

In a study conducted by Heiken JP et al 7, Triphasic CT scans of liver

were obtained 1 week prior to surgery, which is a tumor ablation procedure in patients with

primary malignancy and metastasis, it was noticed that laparoscopic ultrasound was more

sensitive than triphasic CT for the detection of liver tumors, especially the small lesions.

Recent studies by Peter N burns et al and Heiken JP et al 6, 7 have reported that Spiral CT is

the best imaging modality for detection of liver lesions of greater than 1cm in diameter. It is

less expensive than MRI and more accurate than ultrasound. MRI with liver specific contrast

yields better detection rates especially for those lesions less than 1 cm in diameter. However

the detection rates for these lesions is still well below 70%, even with the best MR

technique.

Hypothesis:

Triphasic CT enables characterization of different kinds of focal and diffuse liver lesions.

6.3. Objective of the study:

1. To assess the enhancement characteristics in Triphasic CT scan performed in patients

with suspected focal or diffuse liver disease.

2. To correlate the lesions with clinical and other imaging and histopathological

findings.

7. Materials and methods used:

7.1.Source of data:Cases of suspected liver disease who have undergone triphasic CT

for evaluation of liver lesions in the department of Radiodiagnosis ,M.S Ramaiah

Hospitals,Bangalore ,will be included in this study. The study period is for eighteen months;

from November 2011 to June 2013.

Study design:Hospital based prospective study.

Sample size: Sample size was estimated using N-master software. From the sited reference

‘Focal Liver lesions: Characterization with Triphasic Spiral computed tomography’1

proportion of liver lesions detected on spiral CT was considered to be 87% assuming

relative precision of 12% and desired confidence interval of 95% (Alpha error of 5%) the

minimal sample size required is 40 cases for satisfactory statistical analysis.

Statistical analysis: Descriptive statistics such as mean and standard deviations shall be

used. Chi-square test of proportion shall be used to compare the statistical significance of

difference in proportions among different groups. Level of significance shall be fixed

at 5%.

7.2. Method of data collection:

A Triphasic liver CT will be performed with a single or dual slice CT in M.S Ramaiah

Hospitals.The entire liver will be scanned successively, in arterial ,portal and equilibrium

phases. A 5mm collimation and 5mm/sec table speed will be used. All scans will be taken in

the craniocaudal direction and during single breath hold. After obtaining a digital scout

view, unenhanced scan of the liver will be obtained.100-200 ml of 65% iodinated contrast

material will be given by using a power injector at a rate of 1.5 to 2ml/sec.After 22 or 27

seconds ,the entire liver will be scanned in arterial phase.22 seconds after the end of the

arterial phase,the liver will be scanned in portal venous phase. The 20 second interscan

delay is for the patient to rebreath and reposition the scan plane cephalad to the liver. After

these two phases the third scan will be taken in the equilibrium phase ,8-10 minutes after

injection of contrast the images acquired in different phases will be evaluated in detail to

identify lesions, classify according to age, clinical background and other imaging

findings.Further the findings will be classified as benign or malignant by correlating them

with histopathological findings.

Inclusion criteria:

1. All age groups.

2. All patients with clinical suspicion of liver disease or with lesions detected on ultrasound,

conventional CT or biopsy.

Exclusion criteria:

1 .All pregnant women with suspected liver disease.

2. All patients with hypersensitivity to CT contrast agents, all restless patients and in patients in whom CT is contraindicated due to any other reason.

7.3 Does the study require any investigation or interventions to be conducted on patient, other humans or animals?

Yes. The study requires Triphasic spiral computed tomography,as well as ultrasonography,

endoscopy and biopsy when required.

7.4 Have you obtained ethical clearance from your institution?

Yes. The certificate of the same has been enclosed.

7.5. List of references:

1. Maarten S.van Leewen,Jos Noordzji,Michel A.M. Feldberg,Adrian H. Hennipman,Helen

Doorneward,Focal liver lesions: Characterization with Triphasic CT, Radiology.

1996;201 :327-336.

2. Haaga JR, Dogra VS, Forsting M, Gilkison RC, Ha H, Sundaram M. CT and MRI of the

whole body, Liver :normal anatomy , imaging techniques, and diffuse disease. and focal

hepatic mass lesions,5th edition. Philadelphia: Mosby Elsevier; 2009 .p. 1455-1566.

3. Salma Hafeez, Muhammed Shahbaz Alam, Zafar Sajjad, Zahid Anwar Khan,Waseem

Akhtar,Fatima Mubarak ,Triphasic computed tomography scans of focal tumoral

lesions, Journal of Pakistan Medical Association,2011; 61:571.

4. Joel Gibson, Spiral Computed Tomography of the liver :Is Biphasic or Triphasic

scanning the routine in your department? Advance For Imaging And Radiation

Oncology, April 14;2003

5. Freeny PC and Marks W.M. Patterns of contrast enhancement of benign and malignant

hepatic neoplasms during bolus dynamic and delayed CT,Radiology 1986;160: 613-

618.

6. Peter N Burns and Stephanie R Wilson,Focal liver masses:Enhancement patterns on

Contrast enhanced mages-Concordance of US Scans with CT Scans and MR Imaging

,Radiology 2007,volume 242, no.1, 162- 173.

7. Heiken JP , Weymen PJ, JK Lee,,D M Balfe, D Picus, E M Brunt and M W

Flyle,Detection of focal hepatic masses; Prospective evaluation with CT ,delayed CT

,CT during arterial portography and MRI imaging.Radiology 1989:171;47-51

|9.SIGNATURE OF THE CANDIDATE | |

|10.REMARKS OF THE GUIDE: | |

|11.NAME AND DESIGNATION OF | |

|(IN BLOCK LETTERS) | |

|11.1. GUIDE: | |

| | |

|11.2 SIGNATURE | |

|11.3. CO-GUIDES | |

|11.4 SIGNATURE | |

|11.5. HEAD OF THE DEPARTMENT | |

|11.6. SIGNATURE | |

|12. REMARKS OF CHAIRMAN & PRINCIPAL | |

|12.1 SIGNATURE | |

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