Hepatic elastography in chronic liver disease

Executive summary:

Non-elastography key points:

  • Liver biopsy is the current reference standard for diagnosis of hepatic fibrosis.
  • Blood tests are valuable as an adjunct but are not the primary method of assessment.
  • The most commonly used fibrosis grading system is METAVIR.
  • Cross-sectional imaging diagnostic features: anatomic distortion, changes in parenchymal attenuation and signal intensity/echo texture, alterations of dynamic contrast enhancement.
  • Anatomic signs of cirrhosis include surface nodularity, segmental hypertrophy or atrophy.
  • Useful diagnostic signs are enlarged. Elarged portal hilar space, and large gallbladder fossa sign and posterior hepatic Notch sign. A 100 percent specific sign is the ratio of the caudate lobe width to the right hepatic width however this is prone to serious interobserver variability.

Hepatic elastography:

  • Elastography is currently only practical in the ultrasound setting. Cut offs for elastography are manufacturer specific and vary with the technique. Scoring is done using the METAVIR system ranging from F0 to F4 This is based on shear wave elastography in most cases with a single manufacturer using transient elastography.
  • MR elastography techniques have been developed but are not in widespread use and are probably impractical in the community setting.

Merlin on Asus RT-66U (from Tomato)

Guide to Moving to Merlin from Tomato for stability testing.

The biggest thing I DONT like is the having to log out of the browser interface every time.  I often flit between PCs making changes.  I know I should sit in one spot, but c’est la vie.

  1. Connect to router and change IP under LAN to your local network addresses.
    1. Under LAN, change device name, ip address, and leave subnet mask. APPLY
    2. change DHCP server addressing block and DNS servers.
  2. Steps to get DDNS up and running with freedns afraid.org:
    1. Turn on SSH Admin -> Systemmerlin_ssh_on
    2. Enable JFFS in the same Admin screen*merlin_jffs_on*If this is the first time it has been turned on, check the “Format JFFS partition at next boot” and reboot.
    3. place the public key in the box on merlin router.
    4. place your private into putty when you open it under the SSH->Auth section.
    5. Connect using putty through SSH (this isn’t really necessary for lan access, but if you want to use SSH over the WAN, it is secure.
  3. Create the startup script.
    1. Since you enabled SSH above, open putty and SSH into the IP address of your router. You can login with admin and your password.
    2. Navigate  to scripts directory by typing:
      cd /jffs/scripts
    3. open nano and create the script document (nano is built in and a lot easier to use than vi.
      nano ddns-start
    4. paste the start script into the nano document (right click pastes in putty)
      wget -q ----- HTTPS -----                                                                                                           
      curl -k "https://freedns.afraid.org/dynamic/update.php?PASTE_YOUR_KEY_HERE" >/dev/null 2>&1 &
      if [ $? -eq 0 ]; then
          /sbin/ddns_custom_updated 1
          /sbin/ddns_custom_updated 0
    5. type ctrl-x to exit nano and answer yes to write out the file.
    6. change permissions using command below:
      chmod a+x /jffs/scripts/ddns-start
    7. go back to DDNS settings and enable the client.merlin_enable_script
    8. Success Message Should appearmerlin_enable_script_successmsg

Tomato Shibby Internal Webserver

UPDATE:  Just a heads up that Tomato Shibby is not my preferred solution anymore.  I’m not sure it’s even being developed.  There was a HUGE performance discrepancy between it and Merlin, so I dropped it in favor of speed.


This page still gets a few hits so I thought I’d post a heads up.  You can install a webserver on merlin but it will require some work.



While learning bootstrap3 and developing for beadopotamus.com, I had the need to internally serve the website so we could look at it on multiple devices to allow for screen size and color variations.

Turns out that Shibby’s Tomato has NGINX internal web server!  Yay.  Setting it up was not terribly difficult but required some tinkering.

  1. Make sure your flash drive is mounted under USB support.
  2. Under file sharing,   you probably want to create a separate mount point for ease of SAMBA access to the directory.  I did and it works well.  I can use Brackets over the network to test changes in the dev environment.
    1. I created a www directory under the root and called it web.  usbwebserver
    2. This directory houses the hosted files.
  3. Enable the webserver and point it to the correct directory.  nginxconfig

I hope this helps someone.  I couldn’t really find a tutorial on it so I fiddled with it until it worked.

The good news is that this is not externally accessible so there is little security threat.

The peculiar thing is the directory did not survive a reboot.  I’m guessing that the router clears out the web server directory on reboot.  Current config here. I’ll see if this survives a reboot.


Imaging Neurologic Conditions in Pregnant Patients

Executive Summary:

  • Neurological symptoms may be exacerbations of existing problems (MS, seizure); initial manifestation of neurological disorder (tumor, stroke) or issue unique to pregnancy (eclampsia, postpartum cerebral angiopathy, Sheehan syndrome and lymphocytic adenohypophysitis.
  • ACR Guidance on safe MRI practices states pregnant patients should undergo MRI only if the information cannot be obtained any other way.
  • Autoimmune hypophysitis is a rare chronic inflammatory disorder of the pituitary stalk and gland.  It is classified by involved portions of the gland.
  • Spontaneous or postinstrumentation intracranial hypotension.
  • Source Paper

Continue reading →

Corticosteroid Choice In Epidural Injection

Executive Summary

  • Major decision branch point is particulate (DepoMedrol, Kenalog, Celestone) versus non-particulate (Decadron).
  • Serious complications have been documented with particulate steroids AND nonparticulate steroids.
  • Studies have not demonstrated the superiority of particulate or non-particulate steroid in terms of efficacy (specifically in Cervical TFESI).
  • Lumbar TFESI studies lacked statistical significance between groups using particulate and non-particulate steroids.
  • Digital subtraction should be used in transforaminal injections if available to maximize identification of aberrant or variant arterial anatomy.
  • Source Paper

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A Guide to Diagnosing Peripheral Arterial Disease

Executive Summary

  • In PAD, the level of the lesion is grouped into three categories: aortoiliac, femoropopliteal, and tibiopedal/crural.
  • An ABI less than 0.90 is diagnostic for PAD in patients with claudication or other signs of ischemia, with 95% sensitivity and 100% specificity.
  • A proximal-to-distal decrease in sequential pressures greater than 20 mm Hg or a decrease in segmental-brachial index greater than 0.15 indicates occlusive disease and correlates with the level of the lesion.
  • A normal lower extremity arterial Doppler velocity tracing is triphasic, with a sharp upstroke and peaked systolic component, an early diastolic component with reversal of flow, and a late diastolic component with forward flow. A biphasic signal is considered abnormal if there is a clear transition from triphasic signal along the vascular tree. Monophasic waveforms are always considered abnormal.
  • Abnormal PVR findings include decreased amplitude, a flat peak, and an absent dicrotic notch.
  • In symptomatic patients with normal or borderline ABI at rest, an exercise ABI should be performed. The sensitivity for the detection of PAD may be increased with postexercise measurements.
  • Source Paper
  • Handy Reference (Angiologist)

Continue reading →