Friday, December 23, 2011

Mesial temporal sclerosis

MRI:
Small volume hippocampus on coronal volumeteric T1
Increased signal on coronal FLAIR
Small mamillary body
Small fornix
Temporal lobe atrophy
Ipsilateral white matter atrophy
Increased signal/ loss of volume of anterior thalamic nucleus
Increased signal/ loss of volume of amygdala
Loss of volume of sibiculum
Loss of grey-white in the anterior temporal lobe
Higher signal on ADC (but may have restricted diffusion following seizure)
Temporal horn dilatation - least sensitive sign
Ipsilateral cerebral hypertrophy
Contralateral cerebellar atrophy

Rememeber:
10% are bilateral, hence comparison with other side is not always useful

MRS:
Decreased NAA
Decreased NAA / Cho ratio
Decreased NAA / Cr ratio
Decreased MI
Increased lipid and lactate soon after as seizure

protocol: CT angiography for GI bleed

No oral contrast

Section thickness 1 mm
Reconstruction interval 0.8 mm

Unenhanced low dose CT (to show pre-existing intraluminal hyperattenuation)

100–125 mL I.V contrast 4 mL/sec, followed by 50 mL of saline solution at 4 mL/sec

Arterial phase - triggering at proximal abdominal aorta (150 HU)

Portal venous phase at 70 seconds

Reference:
Marti M et al. Acute Lower Intestinal Bleeding: Feasibility and Diagnostic Performance of CT Angiography, January 2012 Radiology, 262, 109-116.

Wednesday, November 09, 2011

Understanding Intestinal rotation, non-rotation and malrotation

Nonrotation:  
Prone for midgut volvulus  
Duodenojejunal junction does not lie inferior and left of SMA
Cecum does not lie in the right lower quadrant. 
 
Incomplete rotation:   
Prone for duodenal obstruction, midgut volvulus, internal herniation (right mesocolic i.e. paraduodenal hernia.)
Peritoneal bands from misplaced cecum to mesentery compress D3.

Incomplete fixation: 
Mesentery of right and left colon and duodenum do not get fixed retroperitoneally
If descending mesocolon (between IMV & posterior parietal attachment) remains unfixed, small intestine migrates to left upper quadrant = left mesocolic hernia 
If the cecum remains unfixed, it may lead to volulus of terminal ileum, cecum, or proximal ascending colon 
 
CT:
Large bowel predominantly on left side and small bowel predominantly on right side
SMA on right and SMV on left, or SMV anterior to SMA

Friday, September 30, 2011

Radiology reporting

My reporting format

How is the format of my radiology report and why?

My radiology report slightly deviates from suggested guidelines, and I will try explain it

Radiology 'standard' report format:
  1. Title of examination 
  2. History/indication 
  3. Technique 
  4. Comparison 
  5. Findings 
  6. Conclusion
The electronic system, which I use, automatically generates the type of examination, date and time of the exam, clinical details given by the clinicians, and the time of signing of the report.

1. Title of the examination:
I do start with the title of the examination, not because of habit or guidelines. Many a times, the details generated by the system is inadequate.

Example 1: 
The system generates 'right wrist radiograph', but is not clear whether it is AP and lateral radiograph, or scaphoid views, or views for foreign bodies. So, I start my report with title of the examination, such as 'Right wrist: AP and lateral views'.

Example 2:
The system generates, 'MRI craniofacial', when in fact, TMJ MRI is performed. I have to write my title as 'MRI TMJs'

2. History/ indication:
I usually do not write this in my report as this is electronically generated. However, I do occasionally write history, if there are further details available (either from clinic letters or conversation with the referring team) which would add to my radiological conclusion.

Example: 
I would write, 'Further clinical details: I note the patient was diagnosed with carcinoma breast 10 years ago for which she was treated with chemoradiation.'

3. Technique:
I do not write details of the technique in plain radiograph, fluoroscopy and ultrasound.

In CT, I write a brief technical detail.


Example: 
In 'CT abdomen and pelvis', I write, non-enhanced CT KUB followed by split dose CT IVU - standard departmental protocol.

In MR, I write all the sequences used. I also mention what sequences were not used, but would have added to the radiological diagnosis.

Example: 
In 'MRI brain', I write, 'axial PD and T2 supplemented by sagittal FLAIR and coronal T1 sequences. Please note DWI and ADC mapping was not performed.

If the radiographers have a difficulty in getting the scans right or are unable to perform all sequences, they usually write the details on the request form for the radiologist's attention. I always write 'radiographer's note' soon after the technique, if there is one. This will assist the clinician and reviewing radiologist not to start a blame game.

Example:
'Radiographer's note': Too large patient. Used body coils. Unable to perfom coronal STIR because patient started moving.

4. Comparison
I do not put this as a 'heading'. I usually start my 'Report' with comparison, if available.

Example:
'Comparison is made with the CT dated 1/1/11 and MRI dated 2/2/11' at the beginning of the report.

5. Findings: 
I give heading of 'Report'  for 'Findings' section.

When I was a radiology resident and registrar, the teaching was to keep radiology description separate from pathological terms. The 'findings' contained clear descriptive radiology terms and signs, avoiding clinical or pathological 'impressions' until one reached the heading of 'conclusion' or 'impression'. This holds good when you are learning the grammer and language of radiology and trying to correlate them clinically.

As we gain more experience, the 'Findings' part of the report will be filled with more of 'impressions' rather than 'radiological discriptions or signs'.

Example 1:
I am yet to see a radiologist who reports, 'A few, thin, band like, linear, nearly horizontal opacities are shown in the both lower zones of the lungs, close to the diaphragms' in 'Findings', and writes, 'Minor atelectasis in both lung bases' in 'Conclusion'. it would be simple to write, 'bibasal atelectasis is noted', not to cause any unnecessary alarm to the clinician.


Example 2:
I would not write the following paragraph to keep my 'Findings' to be 'radiologically descriptive' and to avoid 'clinical conclusion'. 
'A large area of homogeneous hyperdensity, measuring 4 x 3 cm, is seen in the right basal ganglion, with mean attenuation of 54 HU. A small area of low attenuation is seen around the hyperdensity. Similar hyperdesnity is seen in the occipital horn of the right lateral ventricle with further hyperdensities in the third and fourth ventricles. The right sylvian fissure is effaced. Overlying gyri and sulci are also effaced. Midline shift is seen, measuring 3 mm to the left. Mild dilatation of the left lateral ventricle is seen' 
I would rather write, 'Acute hemorrhage is shown in the right basal ganglia with intraventricular extension, leading to mild dilatation of the left lateral ventricle'. 
I think this makes sense to the referring tea.


The above two examples to justify me why I do not use the heading of 'Findings'. 'Findings' heading will contain my clinical impressions also. So I call this 'Findings' heading as 'Report'.

In 'Report', I use descriptive radiology terms only if this has differentials; otherwise, I use clinical/ pathological terms.

Example: 
In an elderly person, I would write, 'multiple typical simple cysts are shown in the kidneys', rather than, 'mutliple, rounded, low attenuation lesions of varying sizes are shown in both kidneys with mean attenuation of 3 HU with hardly measurable thin margins'. and then in 'Conclusion', write them again as 'most likely simple cysts'.

I always use present tense, although there are few exceptions during ultrasound and interventions. I start with the most important finding first, write relevant positive findings and then important negative findings. 

I give measurement only if it makes sense clinically.

Example:
I would definitely measure the lung cancer, but will not bother to measure renal cysts in the same patient.

I do mention all incidental findings in my report. But I will under play them.

Example 1:
Incidental note is made of a few typical simple cysts in the kidneys.

Example 2:
Note is made of mucosal thickening in the left maxillary sinus.

I try my best to keep my language simple, to use correct medial terminology, and to avoid abbreviations.


6. Conclusion: 
I use the heading of  'Comments' for 'Conclusion'. I use 'comment', instead of 'conclusion', because I want the referring clinician to read my 'Report'. Unless he/she reads the report, my 'Comment' section will not make any sense to the referring clinician. I try to keep my 'Report' section as breif as possible and as clinically relevent as possible.

Most of my plain film and ultrasound reports do not have 'Comment' heading. Many of my CT/MR brains, CT of paranasal sinuses, CT petrous, MRI lumbosacral spine and MRI extremities also do not have 'Comment' section.

Examples where I use 'Comment' section:
To answer the clinical question if not done in my 'report',
When my report is too long and contains too many clinically relevant findings.
When I need to combine more than one finding to arrive to a single diagnosis
When I need to advise the clinician regarding further tests
When I need to discuss with the clinician for further clinical details and previous imaging
When I want the case to be reviewed and discussed in the MDT
When I could not arrive to a single diagnosis and want to discuss the differentials in order
When the findings are equivocal or indeterminate, I try to give my reasoning for my clinical conclusion
When the radiological finding does not correlate with the clinical suspicion or diagnosis

I also use 'Comment' section to record my communication with the referring team.

Example:
'The report was faxed to concerned GP surgery'
'I discussed the findings with the on-call surgical registrar'.

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