Six Sigma
At the Customer For
the Customer (ACFC)
The name, Six Sigma, is derived from the index of measurement used in
this method - Defects Per Million Opportunities (DPMO), which is then
translated into a Sigma Value. It indicates the frequency with which defects
are likely to occur. The higher the Sigma Value, the lesser the chance
of defects occurring.
Six Sigma is Rigorous, fact-based and statistically driven, to identify
the causes of defects, making the improvements and sustaining them.
| Zs |
DPMO |
| 2s |
308,537 |
defects |
| 3s |
66,807 |
defects |
| 4s |
6,210 |
defects |
| 5s |
233 |
defects |
| 6s |
3.4 |
defects |
Billing Process Example.
If a hospital has a billing process rating of 3 sigma, it indicates
that there will be 66,807 defects per million bills processed. A Hospital
with a 4 Sigma rating loses US $ 55,600 per month. If the rating can be
improved to Six Sigma, the losses will be as little as US $ 24 !
Wipro GE is now taking Six Sigma to customers to help them improve
their productivity and efficiency. Two of our customers who have experienced
Six Sigma spoke to IMAGES:
SIX SIGMA PROJECT: Increased Customer Productivity at Manipal Hospital:
Improved Spine MR Imaging with the Fast Recovery Fast Spin Echo pulse
sequence
ACFC projects aim to
design and implement medical diagnostic methods or work-flow processes
that improve customer productivity. Here, we describe one such project
that has resulted in an improvement in the quality of spine MR imaging
with the workhorse, T2-weighted Fast Spin Echo (FSE) pulse sequence. The
CTQ™s were:
- cerebrospinal fluid
(CSF) signal-to-noise ratio (SNR) should be increased
- the SNR of other normal
tissues should not change significantly
- as a corollary, this
should result in an increased contrast-to-noise ratio (CNR) relative
to CSF
A Fast Recovery FSEXL
(FRFSE-XL) pulse sequence that satisfied all three CTQ™s was developed
in collaboration with and delivered to the customer. Its use has resulted
in diagnostically higher quality spine images in less imaging time, thereby
directly impacting customer productivity.
The clinically significant
findings from their evaluation of the pulse sequence for T2-weighted spine
imaging were presented and received very well in an oral presentation
made at ASNR 2000 by Dr. Uday Patil.
| A Fast Recovery
FSE-XL pulse sequence designed using Six Sigma methods to achieve
a higher CSF SNR and better CSF-to- tissue CNR was evaluated for efficacy
in T2-weighted MRI of the spine on patients. |
 |
The FRFSE-XL images showed
significantly better CSF-to- disc and CSF-to-nerve root/cord contrast,
improved sharpness and less pulsation artefacts in comparison with a standard
FSE pulse sequence. An improvement in the hyperintense intradural (cystic)
lesion-to-CSF contrast was observed. Moreover, there was better delineation
of solid- cystic interface in mixed intra-medullary lesions, aiding in
delineation without the use of a contrast agent. Further, since the FRFSE-XL
images show superior fluid-to-tissue contrast as compared to FSE images
for the same TR, a lower TR can be used to get identical contrast to FSE
images in select disease processes to save on imaging time.
In my opinion, the superior
image quality in lower time, reduction in artifacts and reduced necessity
of contrast agents makes the FRFSE-XL pulse sequence the method of choice
for T2-weighted imaging of the spine as it allows for more efficient usage
of the MR scanner.
Dr.
Uday D. Patil, Consulting Radiologist
Manipal Hospital, Bangalore
|
Images Journal