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Tag Archives: MRI



HBV and HCV are major causes of viral hepatitis that lead to the development of cirrhosis and HCC. HBV gains entry into liver cells through a receptor mediated pathway. HBV-DNA integration into host genetic machinery causing DNA methylation resulting in oxidative stress and formation of HBx protein(1). The risk of developing HCC has been shown to be proportional to HBV-DNA level in liver cells. Chronic illness results from persistence of the virus in the host cells via various mechanisms that include infection of immune defense control centers, viral inhibition of antigen presentation,selective immune suppression, down-regulation of viral gene expression, and viral mutations that functionally incapacitate virus-specific T cells from recognizing HBV antigen(2)

HCV hijacks host cellular machinery to increase cellular proliferation, steatosis, inflammatory processes, mitochondrial dysfunction, insulin resistance, all leading to oxidative stress, genetic instability and DNA damage with cirrhosis and HCC as a likely outcome(3)


Diabetes mellitus, alcohol abuse, cardiovascular disease, liver inflammation, obesity, dyslipidemia and non-alcoholic fatty liver disease (NAFLD) are some other major contributors to HCC development(4)

Accumulation of iron in the liver of NASH and HCC patientsis correlated with progression of fibrosis and HCC. NAFLD provides the metabolic environment to induce insulin resistance a known etiological factor for HCC(4,5).

Obesity impairs metabolism, induces inflammation and is an etiological factor for NAFLD, steatosis, NASH, hepatic fibrosis, cirrhosis, and ultimately HCC.

Toxic by-products of alcohol catabolism such as accumulation of acetaldehyde and free radicals can influence oxidative stress, apoptotic cell death, necrosis and necroptosis(6).Reactive oxygen species (ROS) generation is the result of increased inflammatory cytokine. ROS-induced DNA damage, genomic vulnerability of hepatocytes and T-lymphocyte suppression contribute to HCC development. Alcohol diet have shown exacerbation of inflammation, epithelial-mesenchymal transition (EMT) andfibrosis, and consequent progression to HCC (3).

Other possible risk factors include genetic predisposition and congenital abnormalities, toxic exposures (aflatoxin or arsenic contaminated food), and autoimmune diseases of the liver. The pathogenesis of aflatoxin B1 (AFB1) – induced HCC includes several mechanisms, including the formation of mutagenic and carcinogenic intermediates and adducts. These adducts and intermediates can also directly induce a mutation at codon 249 of the p53 tumor suppressor gene. This replaces arginine with serine, a change that reverses the tumor suppressing ability of the gene. There are reports that suggest that AFB1 acts synergistically with HBV to induce HCC(7).




  • Small focal HCC appears hypoechoic compared with normal liver.
  • Larger lesions appear heterogeneous due to fibrosis, fatty change, necrosis and calcification.
  • A peripheral hypoechoic halo may be seen with focal fatty sparing
  • Contrast-enhanced ultrasound 1

o arterial phase-arterial enhancement from neovascularity

o portal venous phase

 Decreased echogenicity relative to background liver ie wash out.

 Tumour thrombus may be visible.(8)

Figure 1:Two different HCC lesions (arrows) in gray-scale ultrasound (a,c)
and in late phase of contrast-enhanced ultrasound (b,d)(9)


Imaging protocols are

  1. The patient was positioned in the supine position.
  • Technical parameters were X-ray tube current 160 to 220 mA; tube voltage 120 kV;

collimation 5mm; rotation speed 0.75 s; matrix 512×512. Iohexol (350 g/L) was used to

perform the contrast-enhanced scanning.

  • A high-pressure syringe was used to inject 1.2-2 ml/kg of contrast agent at injection rate

of 3.5- 4.0mL/s. Twenty millilitre saline were later injected at the same rate.

  • Scanning range was set to from the lower chest to the to lower abdomen level.
  • All image data were transmitted directly to our picture archiving and communication

system. Sagittal and coronal reformats of images were also obtained(10).

Imaging of FLLs in CT requires the use of a multi-phase study protocol.

  • Includes a phase prior to the intravascular administration of contrast agent.
  • Phases obtained after intravascular administration of contrast medium – Hepatic arterial

phase(HAP), Portal Venous Phase(PVP) and Equilibrium phases(EP) obtained routinely

40, 60 and 180 seconds post contrast administration respectively in a multi-row CT unit

  • EP may be also referred to as an early delay phase in comparison to the late delay phase,

obtained after 10 to 15 minutes after administration of contrast medium, acquired if the

imaging protocol is extended to detect lesions with a high content of fibrous tissue(9).

Figure 2:Multiphase CT. Native examination (a), hepatic arterial phase with contrast agent in
hepatic arteries and slight enhancement in portal vein (b), portal venous phase (c) equilibrium
phase (d).

Imaging features in Hepatocellular carcinoma

  • HCCs enhance strongly in the HAP, depending on the size of the tumor and the presence

of regressive changes homo- or heterogeneously. Large tumors will typically present with

heterogeneous enhancement, often with so-called mosaic pattern as opposed to small,

early forms of hepatocelullar carcinomas

2. Washing-out of the contrast agent in PVP (the phase of the strongest enhancement of the

liver parenchyma) or/and EP is a sine qua non for diagnosing HCC with specificity of 95-


3. If tumor pseudo-capsule is present, it is more clearly visible in the PVP and EP than in

HAP, with delayed enhancement in EP. Tumors with pseudo-capsule show better


Figure 3: Schematic presentation of pattern of enhancement of HCC lesion with strong enhancement
in HAP and wash-out of contrast agent in subsequent PVP and EP(12)
Figure 4:CT axial images. HCC in hepatic arterial phase (a) and equilibrium phase (b). Wash-out
feature and enhancing tumor pseudo-capsule is visible in the latter(9).


Standard MRI protocol consists of

  • Patients were positioned supine head first on the MRI table, then the MRI was

performed including T2 weighted fast spin-echo (T2-FSE) and DIXON, Duel echo

sequence(TE 90 and 180 ms), chemical shift imaging (in- and opposed-phase) and

diffusion-weighted image (DWI) map was performed for using b value of 500 (with

TR 1300 ms & TE 64 ms), with corresponding ADC mapping.

  • CE-MRI was performed afterward using gadopentetate dimeglumine

(Omnivist)/gadoterate meglumine(Clariscan) injected through an antecubital

intravenous catheter at a rate of 1.2 ml/min over 15 s and a dose of 0.2 ml/kg followed

by saline chaser of 20 ml at a rate of 1–2 mL/s

  • Dynamic contrast-enhanced sequences were acquired using DIXON sequence

acquired before (pre-contrast) and after contrast injection at 15-20 s (arterial phase), 40

s (portal phase), 60s (venous phase), and 180s (delayed phase). All contrast sequences

were acquired at the axial plane(13).

Imaging features in Hepatocellular carcinoma

  • Pre-contrast MRI sequences the majority of large HCCs show decreased signal intensity

in T1-weighted and increased signal intensity in T2-weighted images.

Small lesions tend to remain isointense to the adjacent liver parenchyma in T1-weighted

images Presence of intracellular fatty components may be easily confirmed in phase and

out of phase sequences.

  • Decrease in signal intensity in T2-weighted images is seen in case of fibrous tissue,

while areas of necrosis present especially within large foci cause an increase in signal

intensity and lead to heterogenous enhancement.

  • Low signal intensity of regenerative nodules in T2-weighted images resulting from

characteristic iron deposits, facilitate differential diagnosis with usually hyperintense

HCC foci.

  • Pseudocapsule is hypointense in T2-weighted images and shows delayed enhancement

in EP, similarly to CT.

  • DCE-MRI shows a similar enhancement pattern in majority of HCCs as observed in

multiphase CT with early strong enhancement in HAP and washing-out in the following


Figure 8:

Stepwise carcinogenesis of HCC in cirrhosis

Table 1: Various imaging appearance of cirrhotic nodules to frank HCC in MRI
  • Early washout can be seen in high grade or undifferentiated hepatocellular carcinoma

since the lesion is entirely supplied by hepatic artery. So the phase of washout will

help in diffentiation the grade of hepatocellular carcinoma.

  • Hepatocellular carcinomas have fat within it where as dysplastic and regenerative

nodules do not contain fat within it.

  • HCC directly invades the vessel and enhances on arterial phase.
  • Collateral formation and prominent adjacent vessel are the additional imaging features seen in HCC.
  • Intratumoural psuedoaneurysms are common in HCC(9).
Figure 5:Large HCC with degenerative changes in coronal T1-weighted image with fat saturation

(a) and in coronal T2-weighted image (b). Dynamic contrast-enhanced sequences in axial T1-

weighted images with fat saturation after administration of hepatocyte-specific contrast agent in

hepatic arterial phase (c), portal venous phase (d) and hepatobiliary phase (e). Heterogenous

enhancement of the lesion is seen with areas of non-enhancing focal necrosis (c) with subsequent

washing out of the contrast agent (d). Lesion shows low signal intensity in comparison to adjacent

liver parenchyma in hepatobiliary phase (e) (9).


LABORTARY TESTS-Serum AFP is the most widely used tumor biomarker in

diagnosis of HCC. An increase of serum AFP levels in cirrhotic patients, however its

value is often considered insufficient(14)

HISTOPATHOLOGY- Well vascularized tumors with wide trabeculae (> 3 cells),

prominent acinar pattern, small cell changes, cytologic atypia, mitotic activity, vascular

invasion, absence of Kupffer cells and the loss of the reticulin network(12).



Musculoskeletal Disorder (MSD), includes diseases of muscles, bones, joints, and the soft tissues around it. Pain and injuries are the most common complaints of the patients reaching out to a primary care physician, and with increasing age, the risk of developing MSD increases. As per the data from the World Health Organization (WHO), disability from MSDs is second largest in number, across the globe. The symptoms of various MSDs vary and it may affect the daily activity so much so that the quality of life may get compromised. It’s very important to get muscle or bone disorders diagnosed and treated in time, to keep oneself healthy. This makes MSK, the most sought after system as far as, an accurate clinical diagnosis is concerned.

Imaging Modalities

Various modalities are used to reach an optimum conclusion , before starting a confirmed treatment in MSDs. These are X-Rays, ultrasound, CT scans, and magnetic resonance imaging (MRIs). Each modality offers its benefits and limitations, that also, make them specific tools for diagnosis in specific health conditions. 

 X-rays are often performed in an emergency situation such as a traumatic fall or an accident leading to fractures. Limited information can also be received in conditions like arthritis, infections, and osteoporosis while using X-rays.

Ultrasound is used to take pictures of the anatomy and function of soft tissue around bones and joints using sound waves. Ultrasound imaging is typically used to diagnose tendon tears, muscle tears, fluid collections, ligament sprains or tears, inflammation or fluid within the bursae and joints, early changes of rheumatoid arthritis, nerve entrapments such as carpal tunnel syndrome.

CT scan is a procedure, which can produce detailed pictures of the muscles, bones, joints, and the soft tissues around. This painless and non-invasive procedure helps doctors making a diagnosis in cases of, Osteoporosis, Osteopenia, Paget’s disease, Bone cancer, Bone infections, Muscular dystrophy, Muscle sprains or strains, Tendinitis, etc.

● MRI (Magnetic Resonance Imaging)

MRI is the most sensitive non-invasive imaging tool for a broad range of diseases affecting the musculoskeletal system. MRI’s edge over the other imaging tools rests primarily in obtaining better image resolution of body tissues and pathologic processes. Thus, high-resolution images of MRI, bring the excellent and discrete view of organs and diseases.

MRI uses a strong magnetic field, which is directly related to image resolution obtained. The field strength is typically between 1.5 T and 3 T, but may be lower in an open MRI scanner.

MRI is highly sensitive and specific for osseous and articular hip injuries, as well as soft tissues injuries of the hip and pelvis, and is the recommended imaging modality in most cases after a radiograph is negative.

Indications of MRI

Diagnostic imaging can be a valuable tool when used in conjunction with a thorough history and physical examination for establishing a diagnosis and treatment plan. Radiographs are the initial imaging modality in most cases of musculoskeletal injury or pain but MRI is most important and recommended imaging in following cases.


In the setting of trauma, MRI is indicated for the evaluation of those injuries of the metaphysis and epiphysis, where Xrays are found inconclusive/ undetected injuries, and to assess fracture union.

In knee injuries, When there is clinical suspicion for meniscal or ligamentous injury, MRI is the best modality to be used to detect such injuries.

MRI is useful to detect and stage acute and chronic osteomyelitis,primary bone tumors, both benign and cancerous, and undetected spread of secondaries to the bones.

2. Soft Tissues

 MRI is indicated for the evaluation of,

Muscle and tendon and ligament tears/injuries , hematomas, nerve entrapment syndromes,  tenosynovitis, bursitis, infections, abscesses and myositis  Rotator cuff injury (tendinopathy or tear), Avascular necrosis, Biceps tendon injury (tendinopathy/tear).

 It is helpful in detection, and staging of benign and malignant soft tissue tumours.

3. Joints/spinal

MRI is indicated for the diagnosis of hurt/ injuries to joints due to trauma, certain articular cartilage injuries, and inflammatory changes in the joints due to overuse, posttraumatic osteonecrosis and degenerative joint disease, joint infections, rheumatoid and the seronegative arthritis.

During traumatic spine surgeries, MRI is specifically recommended when there is a doubt for the injury to the spinal cord, nerve roots, and/or soft tissue, which are not well visualized on CT. MRI is also indicated in the cases of joint pain with clicking sounds, abnormal disc displacement, marrow abnormalities, osteonecrosis of the mandibular condyle and so on and so forth.

The list is endless……..and exhausting. Musculoskeletal health is very important to keep us going in our routine life, and in today’s day n time when the clinicians are overloaded and patients are becoming more impatient, there is a dire need for a diagnostic tool with an accurate, and in time reporting to have best results in day-to-day practice. MRI is the most recommended imaging tool in this scenario….

How do We Help….

At Cloudex, we have an entire team of certified Radiologists, Physicians, Subspeciality experts, and trained technologists, who work in association with Primary care  Physicians, Surgeons, orthopedic surgeons, and Radiation and Medical Oncologists to provide the best MRI reporting.

Our Fellowship Trained Experts from North America, provide structured reports based on the need and urgency. They are always available on call (24x7x365), for any discussion that can help managing any case, right from the simple fracture to an occult bone mass.

Urgent reporting within few hours, with upfront  information provided by the team to the referring doctor for various critical cases, has rewarded us with better patient and doctor satisfaction and immense faith of fellow clinicians.

Take Home Message from Cloudex……

We understand that the recipe to successful treatment results, is totally dependent upon the following ingredients:

The precision,

Reliability and,

In time access to an accurate, easy to understand imaging report,

At Cloudex, we ensure to help you have, that winning edge.



What is Body Imaging?

Body Imaging is a subspecialty of diagnostic radiology which deals with imaging evaluation of organs in the thorax, abdomen, and pelvis. It includes all types of radiological examinations performed using conventional X- rays, CT scan, MRI, ultrasound, mammography, and PET (positron emission tomography).