USG Dan CT Kontras

7/27/2019 USG Dan CT Kontras

http://slidepdf.com/reader/full/usg-dan-ct-kontras 1/8

Value of Contrast-EnhancedUltrasonography in Assessingthe Vascularity of Liver MetastasesComparison With Contrast-EnhancedComputed Tomography

Yan-Ling Zheng, MD, Xiao-Yu Yin, MD, PhD, Xiao-Yan Xie, MD, PhD,

Hui-Xiong Xu, MD, PhD, Zuo-Feng Xu, MD, PhD, Guang-Jian Liu, MD, PhD,

Jin-Yu Liang, MD, Ming-De Lu, MD, PhD

Objective. The purpose of this study was to compare the capability of contrast-enhanced ultrasonog-

raphy (CEUS) and contrast-enhanced computed tomography (CECT) in evaluating the vascularity ofliver metastases. Methods. Both CEUS and CECT examinations were performed on 70 patients with

liver metastases, which were from colon carcinoma in 31, rectal carcinoma in 17, pancreatic carcino-

ma in 5, and others in 17. In patients with multiple lesions, the most easily observed lesion was

selected as the target lesion for evaluation of vascularity. Results. Peak enhancement of the target

lesion during the arterial phase was characterized as hyperenhancement, isoenhancement, hypo-

enhancement, and nonenhancement in 61 (87.1%), 6 (8.6%), 3 (4.3%), and 0 (0%) patients on CEUS,

respectively, and in 52 (74.3%), 8 (11.4%), 8 (11.4%), and 2 (2.9%) on CECT. Contrast-enhanced

ultrasonography showed more lesions with hyperenhancement than CECT (P < .01). The enhancement

pattern during the arterial phase was homogeneous, inhomogeneous, and rimlike in 30 (42.9%), 16

(22.9%), and 24 (34.2%) patients on CEUS and in 13 (18.6%), 8 (11.4%), and 49 (70%) on CECT.

Contrast-enhanced ultrasonography revealed more lesions with homogeneous enhancement than

CECT (P < .01). Contrast-enhanced ultrasonography showed dysmorphic vessels in 33 patients(47.1%) during the arterial phase, whereas CECT showed dysmorphic vessels in 27 (38.6%; P < .01).

Contrast-enhanced ultrasonography showed hypervascular lesions in 58.6% of patients, whereas

CECT showed hypervascular lesions in 12.9% (P < .01). Conclusions. Contrast-enhanced ultrasonog-

raphy was superior to CECT in assessing the vascularity of liver metastases. Key words: contrast-

enhanced computed tomography; contrast-enhanced ultrasonography; liver metastases; vascularity.

Received February 24, 2010, from the Departments of Medical Ultrasonics (Y.-L.Z., X.-Y.X., H.-X.X., Z.-F.X.,G.-J.L., J.-Y.L., M.-D.L.) and Hepatobiliary Surgery (X.-Y.Y., M.-D.L.), First Affiliated Hospital, and Instituteof Diagnostic and Interventional Ultrasound (Y.-L.Z.,

X.-Y.X., H.-X.X., Z.-F.X., G.-J.L., J.-Y.L., M.-D.L.), Sun Yat-Sen University, Guangzhou, China. Revision requested March 16, 2010. Revised manuscript accepted for pub-lication May 17, 2010.

Address correspondence to Xiao-Yu Yin, MD, PhD,Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, 510080 Guangzhou,Guangdong, China.

E-mail: [email protected]

AbbreviationsCECT, contrast-enhanced computed tomography;CEUS, contrast-enhanced ultrasonography; CT, comput-ed tomography; MRI, magnetic resonance imaging;TACE, transcatheter arterial embolization

ssessment of the vascularity of liver malignan-

cies is of clinical importance because it is one of

the major factors affecting therapeutic out-

comes, including systemic chemotherapy andtranscatheter arterial embolization (TACE). Braga et al1

used magnetic resonance imaging (MRI) to analyze the

vascularity of liver metastases in 16 patients with breast

cancer who underwent systemic chemotherapy and

found that patients with hypervascular liver lesions were

20.5 times more likely to have disease progression than

patients without hypervascular metastases. Taniai et al2

adopted contrast-enhanced computed tomography

(CECT) to evaluate the vascularity of liver metastases in

45 patients with colorectal cancer who were treated with

© 2010 by the American Institute of Ultrasound in Medicine • J Ultrasound Med 2010; 29:1403–1410 • 0278-4297/10/$3.50

A

Article

Article includes CME test

CME

CME



TACE and found that TACE was effective in only

hypervascular colorectal liver metastases. Alba et

al3 used TACE as neoadjuvant treatment for 56

patients with hepatocellular carcinoma who had

131 nodules and were waiting for orthotopic livertransplantation. Subsequent pathologic exami-

nation confirmed that the antitumoral effect of

TACE was more remarkable in hypervascular

lesions compared with hypovascular ones.

Currently, the vascularity of liver lesions is main-

ly assessed by CECT, MRI, and digital subtraction

angiography. Of them, CECT and MRI have been

most commonly used because of their noninva-

siveness and convenience. However, they are not

real-time imaging modalities and easily miss the

early arterial phase, particularly in liver metas-

tases in which arterial perfusion is usually short-lasting.4 Digital subtraction angiography has

been used for arterial angiography and can clear-

ly illustrate the early arterial perfusion of lesions,

but it has disadvantages of invasiveness and radi-

ation exposure. On the other hand, both CECT

and digital subtraction angiography use iodinat-

ed contrast agents, which might be associated

with severe adverse reactions in some patients.5

Furthermore, they are contraindicated in patients

with renal insufficiency because the iodinated

contrast agents are excreted by the kidney.

Contrast-enhanced ultrasonography (CEUS) is a

recently developed technique that can depict the

blood perfusion of liver lesions in a real-time man-

ner.4,6 Because of its advantages of noninvasive-

ness, real-time scanning, and safety,7 enthusiasm

about CEUS for evaluating the vascularity of liver

lesions has grown rapidly. The aim of this study

was to compare the capability of CEUS and CECT

in assessing the vascularity of liver metastases.

Materials and Methods

Patients

From March 2004 to September 2008, CEUS

examinations were performed in 284 consecu-

tive patients with liver metastases in our hospital.

Among them, 70 patients had CECT examina-

tions in our hospital simultaneously. Seventy

patients who had both CEUS and CECT exami-

nations were included in the study. There were 39

male and 31 female patients with a mean age ±

SD of 56.6 ± 12.1 years (range, 32–75 years).

The diagnosis of liver metastases was estab-

lished by histopathologic examination in 23

patients and 2 contrast-enhanced imaging stud-

ies (CEUS, CECT, or MRI) in 47 patients. Tumor

sizes were 3.2 ± 1.8 cm (range, 0.9–8.2 cm).Twenty patients had single lesions, and the

remaining 50 had multiple lesions. The primary

malignancies consisted of colon carcinoma in 31,

rectal carcinoma in 17, pancreatic carcinoma in

5, gastric carcinoma in 3, pulmonary carcinoma

in 3, esophageal adenocarcinoma in 2, gallblad-

der carcinoma in 2, breast carcinoma in 2, blad-

der carcinoma in 1, uterine cervical cancer in 1,

renal carcinoma in 1, thyroid carcinoma in 1, and

ileal leiomyosarcoma in 1.

Informed consent was obtained from each

patient. The study was approved by the EthicsCommittee of the hospital.

Contrast-Enhanced Ultrasonographic

Technique and Image Analysis

The contrast agent used for CEUS was SonoVue

(Bracco SpA, Milan, Italy), a sulfur hexafluoride

(SF6)-filled microbubble agent that is stabi-

lized by phospholipids. Ultrasonographic

examinations were performed with an Acuson

Sequoia 512 scanner (Siemens Medical Solutions,

Mountain View, CA), which incorporated

Cadence contrast pulse sequencing software

and a 4V1 vector transducer with a frequency

range of 1 to 4 MHz. Contrast-specific contrast

harmonic imaging software was installed in the

system. A low–mechanical index real-time con-

trast-specific CEUS mode was used in the

examination, and the mechanical index value

indicated on the screen was between 0.1 and 0.2.

First, the whole liver was thoroughly scanned

using conventional gray scale ultrasonography,

and the target lesion was determined. In patients

with multiple lesions, the most easily observedlesion was selected as the target lesion for evalu-

ation of vascularity. Then a bolus of 2.4 mL of

SonoVue was injected via the antecubital vein,

followed by 5 mL of normal saline. The contrast

program was initiated at the same time. The tar-

get lesion was observed continuously during the

arterial phase (8–30 seconds after SonoVue injec-

tion). The rest of the liver was scanned to find

other lesions during the portal phase (31–120

seconds) and late phase (121–360 seconds).8–10

1404 J Ultrasound Med 2010; 29:1403–1410

Contrast-Enhanced Ultrasonography of Liver Metastasis Vascularity



The entire process was recorded and stored on

the hard disk. The ultrasonographic examina-

tions were performed by physicians with at least

4 years of experience in CEUS.

Digital cine clips were analyzed offline in con-sensus by 2 physicians with at least 4 years of

experience in CEUS. The peak enhancement

level of the target lesion during the arterial phase

was evaluated and classified as nonenhance-

ment, hypoenhancement, isoenhancement,

and hyperenhancement by comparison with

the adjacent liver tissue.9 The enhancement pat-

tern was categorized as homogeneous (uniform

enhancement of the entire lesion), inhomoge-

neous (different levels of enhancement in differ-

ent parts of the lesion), and rimlike (a continuous

ring of enhancement seen at the periphery of thenodule). Vessels that were situated outside the

lesions and showed rapid flow of microbubbles

running into the lesions during the early arterial

phase were defined as dysmorphic vessels. The

time to the peak hyperenhancement level was

analyzed on the clips. According to the peak

enhancement level, enhancement pattern, and

enhancement area during the arterial phase, the

lesions were classified as having hypervascularity,

isovascularity, and hypovascularity. Tumors

meeting one of the following criteria were consid-

ered to have hypervascularity: (1) homogeneous

hyperenhancement and (2) an enhancement

area covering half or more of the lesion (either

ringlike or inhomogeneous). Isovascularity was

defined as homogeneous isoenhancement.

Tumors meeting one of the following criteria

were considered to have hypovascularity: (1)

hypoenhancement, (2) nonenhancement, and

(3) an enhancement area covering less than half

of the lesion (either ringlike or inhomogeneous).

Contrast-Enhanced Computed Tomographic Technique and Image Analysis

The contrast agent used for CECT was Ultravist

(Schering AG, Berlin, Germany), which contains

iopromide. It was administered via the antecubital

vein by power injection at a rate of 3 mL/s (single-

slice helical computed tomography [CT]) or 4

mL/s (64-slice helical CT) at a dose of 1.5 mL/kg.

Contrast-enhanced CT examinations were per-

formed with an Xpress SX single-slice helical CT

scanner (Toshiba Medical Systems Co, Ltd,

Tokyo, Japan) or an Aquilion 64-slice helical CT

scanner (Toshiba Medical Systems) within 14

days before or after the CEUS examinations. No

treatment was given during the interval between

the CEUS and CECT examinations. The scanning parameters were 5-mm collimation, 120 kV, and

250 mAs for single-slice helical CT and 0.5 × 64-

mm collimation, 120 kV, and 150 to 200 mAs for

64-slice helical CT. The standard dual-phase

scan procedure was used. After unenhanced

helical sequence scanning, the contrast agent

was administered. The arterial phase sequence

was obtained 25 to 30 seconds after injection,

followed by a portal venous phase sequence at 50

to 60 seconds.

Digital cine clips were analyzed offline in con-

sensus by 2 physicians with at least 5 years of experience in CECT. Contrast-enhanced CT

analysis was done on the same target lesions as

CEUS. By comparison with the adjacent liver

tissue, the peak enhancement level of the target

lesion was classified as nonenhancement, hypo-

enhancement, isoenhancement, and hyper-

enhancement during the arterial phase. Similar to

that for CEUS, the enhancement pattern on CECT

was categorized as homogeneous, inhomoge-

neous, and rimlike.11 Vessels showing blood flow

penetrating into the lesion during the arterial

phase on CECT were considered dysmorphic

vessels. The definitions of hypervascularity, iso-

vascularity, and hypovascularity on CECT were

the same as those on CEUS.

Statistical Analysis

The results are given as mean ± SD. The SPSS ver-

sion 10.0 software package (SPSS Inc, Chicago,

IL) was used for statistical analysis. A χ2 test was

used to compare the enhancement level, pattern,

dysmorphic vessels, and vascularity between

CEUS and CECT. The peak enhancement time was compared between the two groups using an

independent Student t test. Two-tailed P < .05

was considered statistically significant.

Results

With respect to the enhancement level of the tar-

get lesions, there were 61 patients (87.1%) with

hyperenhancement, 6 (8.6%) with isoenhance-

ment, 3 (4.3%) with hypoenhancement, and

J Ultrasound Med 2010; 29:1403–1410 1405

Zheng et al



0 (0%) with nonenhancement on CEUS and 52

(74.3%) with hyperenhancement, 8 (11.4%) with

isoenhancement, 8 (11.4%) with hypoenhance-

ment, and 2 (2.9%) with nonenhancement on

CECT. Contrast-enhanced ultrasonography

showed more lesions with hyperenhancement

than CECT (P < .01; Table 1). As illustrated in

Figure 1, the liver metastases appeared hyperen-

hanced during the arterial phase on CEUS but

isoenhanced on CECT. With respect to the enhancement pattern,

homogeneous, inhomogeneous, and rimlike

enhancement were seen in 30 (42.9%), 16

(22.9%), and 24 (34.2%) patients, respectively, on

CEUS and in 13 (18.6%), 8 (11.4%), and 49

(70.0%) on CECT. CEUS revealed more lesions

with homogeneous enhancement (P < .01; Table

2). As illustrated in Figures 2 and 3, the liver

metastases appeared to have homogeneous

hyperenhancement during the arterial phase on

CEUS but rimlike enhancement on CECT.

J Ultrasound Med 2010; 29:1403–1410


Table 1. Peak Enhancement Level During the Arterial Phase onCEUS and CECT

CECTCEUS Hyper Iso Hypo Non Total

Hyper 49 6 6 0 61Iso 3 2 0 1 6Hypo 0 0 2 1 3Non 0 0 0 0 0Total 52 8 8 2 70

1406

Figure 1. Liver metastasis with a diameter of 1.9 cm from rectal carcinoma in a 47-year-old woman. A and B, Contrast-enhanced

ultrasonography showed that the lesion was homogeneously hyperenhanced during the arterial phase (A, arrow) and homogeneously

hypoenhanced during the portal phase (B, arrow). C and D, Contrast-enhanced CT showed that the lesion was homogeneously isoen-

hanced during the arterial phase (C, arrow) and homogeneously hypoenhanced during the portal phase (D, arrow).

A

C

B

D



(2.9%) had isovascular lesions, and 59 (84.3%)

had hypovascular lesions (P < .01). In 9 hypervas-

cular lesions on CECT, 7 (77.8%) of them were

shown to be hypervascular on CEUS, and the

remaining 2 (22.2%) were isovascular. In 59 hypo-vascular lesions on CECT, 32 (54.2%) were shown

to be hypervascular on CEUS. On the other hand,

32 of 41 hypervascular lesions (78.0%) on CEUS

were shown to be hypovascular on CECT. These

findings illustrate that CEUS was more sensitive

than CECT for detecting the vascularity of liver

metastases.

Of the 32 lesions that were hypervascular on

CEUS but hypovascular on CECT, the time to

peak hyperenhancement on CEUS ranged from

9 to 19 seconds (mean, 15.8 ± 2.5 seconds) after

injection of the contrast agent. In 7 lesions that

were hypervascular on both CEUS and CECT, the

time to peak hyperenhancement on CEUS

ranged from 18 to 30 seconds (23.1 ± 4.2 seconds;

P < .01), suggesting that when the time to peak

enhancement of a lesion was too short, CECT was likely to underassess its vascularity.

Discussion

The vascularity status of liver metastases is one of

the major factors influencing therapeutic out-

comes. Braga et al1 treated 16 patients with liver

metastases from breast cancer using systemic

chemotherapy and found that patients with

hypervascular liver lesions assessed by MRI

were 20.5 times more likely to have tumor pro-

gression compared with those without hyper-

1408 J Ultrasound Med 2010; 29:1403–1410


Figure 3. Multiple liver metastases from colon carcinoma in a 47-year-old man. A–C, Contrast-enhanced ultrasonography showed that

the target lesion with a diameter of 1.7 cm had dysmorphic vessels during the early arterial phase (A, arrows) and was homogeneously

hyperenhanced during the arterial phase (B, arrows) and homogeneously hypoenhanced during the portal phase (C, arrow).

D, Contrast-enhanced CT also showed that the target lesion had dysmorphic vessels (arrow), but it had rimlike isoenhancement.

A

C

B

D



vascular metastases. Another study treated 45

patients with liver metastases from colorectal

carcinoma using TACE and showed that it was

effective in only hypervascular lesions assessed

by CECT.2 Hence, accurate assessment of the

vascularity status of liver metastases is of clinical

importance.

On the basis of CECT and MRI, liver metastaseshave predominantly been thought to be hypo-

vascular.12 Recently, Murphy-Lavallee et al13 used

CEUS to evaluate the vascularity of liver metas-

tases and found that 88% of them were hyper-

vascular during the early arterial phase.

However, there is still a lack of studies comparing

CEUS and CECT/MRI for assessing the vascular-

ity of liver metastases.

In this study, we compared CEUS and CECT for

evaluating the vascularity of liver metastases in

70 patients. Contrast-enhanced ultrasonography

showed that 43% of the metastatic lesions had

homogeneous enhancement, 47% had dysmor-

phic vessels, and 58.6% were hypervascular.

On the contrary, CECT showed homogeneous

enhancement in only 19% and dysmorphic ves-

sels in 39%, and only 12.9% of them were hyper-

vascular. In the 59 hypovascular lesions on CECT,

54.2% of them were shown to be hypervascular

on CEUS. On the other hand, 78% of hypervas-cular lesions on CEUS were shown to be hypo-

vascular on CECT. Among 3 patients with liver

metastases from breast and thyroid cancers that

were “classic” potentially hypervascular, CECT

showed hypervascular liver lesions in only 2 (1 in

breast cancer and 1 in thyroid cancer), whereas

CEUS revealed hypervascular lesions in all 3

(data not shown). These results suggest that

CEUS is more sensitive and accurate than CECT

for depicting the vascularity of liver metastases.

These findings might be attributed to the

following reasons. First, CEUS is a real-timedynamic scanning modality and can continu-

ously assess the vascularity of a lesion immedi-

ately after injection of a contrast agent.14,15

The dose of SonoVue used in CEUS was only

2.4 mL and was administered by bolus injection.

Contrast-enhanced ultrasonography would not

miss any time of enhancement during the whole

arterial phase and hence could accurately assess

the vascularity of a lesion. On the contrary, CECT

is an instant scanning modality and can assess

the vascularity of a lesion only at a certain point

in time during the arterial phase. Because the

dose of Ultravist used in CECT was 1.5 mL/kg

(60–100 mL in total) and was administered by

power injection at a rate of 3 mL/s (single-slice

J Ultrasound Med 2010; 29:1403–1410 1409

Zheng et al

Figure 4. Multiple liver metastases from colon carcinoma in a 70-year-old woman. A, In the live compare mode showing CEUS on

the left and the baseline image on the right, CEUS showed dysmorphic vessels around the target lesion with a diameter of 7.2 cm

(arrow). B, Contrast-enhanced CT showed no dysmorphic vessels around the lesion (arrows).

A B

Table 3. Dysmorphic Vessels of Metastatic LesionsDetected on CEUS and CECT

CECTCEUS Present Absent Total

Present 19 14 33Absent 8 29 37Total 27 43 70



helical CT) or 4 mL/s (64-slice helical CT), CECT

started to scan after completion of contrast agent

injection3,16 and usually missed the early arterial

phase (≈15–25 seconds). If the peak enhance-

ment of a lesion falls in this period, CECT is like-ly to underestimate its vascularity. In our study, of

the 32 lesions that were hypervascular on CEUS

but hypovascular on CECT, the time to peak

hyperenhancement was between 9 and 19 sec-

onds (15.8 ± 2.5 seconds) after injection of the

contrast agent. In the 7 lesions that were hyper-

vascular on both CEUS and CECT, the time to

peak hyperenhancement was between 18 and 30

seconds (23.1 ± 4.2 seconds). This indicated that

when the time to peak enhancement of a lesion

was too short, CECT was likely to underassess its

vascularity.In summary, our results show that CEUS tends

to be superior to CECT in assessing the vascular-

ity of liver metastases. More accurate assessment

of the vascularity of liver metastases by CEUS can

help select candidates who would gain potential

benefits from treatment and predict prognosis.

For example, for liver metastases from colorectal

carcinoma, TACE is indicated for patients with

hypervascular lesions because it is effective for

only hypervascular lesions and not hypovascular

lesions. Contrast-enhanced CT may neglect

some patients who are potential candidates for

TACE because it underestimates the vascularity

of liver lesions. Comparatively, CEUS can identi-

fy more patients suitable for TACE by showing

more hypervascular lesions. Admittedly, a large-

scale clinical trial is still needed to assess the

clinical importance of CEUS in assessing the vas-

cularity of liver metastases.

References

1. Braga L, Semelka RC, Pietrobon R, Martin D, de Barros N,

Guller U. Does hypervascularity of liver metastases as

detected on MRI predict disease progression in breast can-

cer patients? AJR Am J Roentgenol 2004; 182:1207–1213.

2. Taniai N, Onda M, Tajiri T, et al. Good embolization response

for colorectal liver metastases with hypervascularity.

Hepatogastroenterology 2002; 49:1531–1534.

3. Alba E, Valls C, Dominguez J, et al. Transcatheter arterial

chemoembolization in patients with hepatocellular carci-

noma on the waiting list for orthotopic liver transplanta-

tion. AJR Am J Roentgenol 2008; 190:1341–1348.

4. Krix M, Kiessling F, Essig M, et al. Low mechanical index

contrast-enhanced ultrasound better reflects high arterial

perfusion of liver metastases than arterial phase computed

tomography. Invest Radiol 2004; 39:216–222.

5. Singh J, Daftary A. Iodinated contrast media and their

adverse reactions. J Nucl Med Technol 2008; 36:69–74.

6. Bhayana D, Kim TK, Jang HJ, Burns PN, Wilson SR.

Hypervascular liver masses on contrast-enhanced ultra-

sound: the importance of washout. AJR Am J Roentgenol

2010; 194:977–983.

7. Schneider M. SonoVue, a new ultrasound contrast agent.

Eur Radiol 1999; 9(suppl 3):S347–S348.

8. Quaia E, Calliada F, Bertolotto M, et al. Characterization of

focal liver lesions with contrast-specific US modes and a

sulfur hexafluoride-filled microbubble contrast agent: diag-

nostic performance and confidence. Radiology 2004;

232:420–430.

9. Albrecht T, Blomley M, Bolondi L, et al; EFSUMB StudyGroup. Guidelines for the use of contrast agents in ultra-

sound: January 2004. Ultraschall Med 2004; 25:249–256.

10. Xu HX, Liu GJ, Lu MD, et al. Characterization of focal liver

lesions using contrast-enhanced sonography with a low

mechanical index mode and a sulfur hexafluoride-filled

microbubble contrast agent. J Clin Ultrasound 2006; 34:

261–272.

11. Nino-Murcia M, Olcott EW, Jeffrey RB Jr, Lamm RL, Beaulieu

CF, Jain KA. Focal liver lesions: pattern-based classification

scheme for enhancement at arterial phase CT. Radiology

2000; 215:746–751.

12. Kanematsu M, Kondo H, Goshima S, et al. Imaging liver

metastases: review and update. Eur J Radiol 2006; 58:217–228.

13. Murphy-Lavallee J, Jang HJ, Kim TK, Burns PN, Wilson SR.

Are metastases really hypovascular in the arterial phase?

The perspective based on contrast-enhanced ultrasonogra-

phy. J Ultrasound Med 2007; 26:1545–1556.

14. Dietrich CF. Characterisation of focal liver lesions with con-

trast enhanced ultrasonography. Eur J Radiol 2004;

51(suppl):S9–S17.

15. von Herbay A, Vogt C, Willers R, Häussinger D. Real-time

imaging with the sonographic contrast agent SonoVue:

differentiation between benign and malignant hepatic

lesions. J Ultrasound Med 2004; 23:1557–1568.

16. Park Y, Choi D, Lim HK, et al. Growth rate of new hepato-cellular carcinoma after percutaneous radiofrequency abla-

tion: evaluation with multiphase CT. AJR Am J Roentgenol

2008; 191:215–220.

1410 J Ultrasound Med 2010; 29:1403–1410


USG Dan CT Kontras

Documents

Transcript of USG Dan CT Kontras