Magnetic Resonance Imaging Planimetry As A Quantitative Imaging Tool To Measure Pancreas Volume In

Type II Diabetes Mellitus

Nishigandha Burute, Errol Colak, David Jenkins,

Shalini Anthwal, Anish Kirpalani

St. Michael’s Hospital and University of Toronto

Toronto, Canada

Disclosure

The authors have no disclosures

Target audience

•  Abdominal imaging specialists

•  Researchers in metabolic imaging

•  Clinicians

Pancreatic atrophy in diabetes

•  Pancreatic atrophy is present in diabetes

•  Atrophy progresses with duration and severity of diabetes

•  Atrophy can be measured by pancreas volume estimation with

routine imaging modalities

Background

Background

Previous studies have measured pancreatic volume with CT/US

•  CT involves ionizing radiation, making it less feasible to measure

volumes temporally in the same individual

•  US provides only a rough estimation and cannot provide accurate

volumes

It would be beneficial to have an imaging modality that could measure

volumes accurately and without ionizing radiation

Background

Only a few studies to date have measured pancreatic volume in diabetes

with MRI

However these have specifically focused on:

•  Type 1 diabetes1 (type 1 diabetics form < 5% of the diabetic population)

•  Cystic fibrosis related diabetes2 (which is even more rare)

1.Williamsetal.JClinEndocrinolMetab,2012,97(10):E2109–E21132.Sequeirosetal.BJR2010;83:921-926

No study until now has measured pancreas volumes in Type 2 diabetes

with MRI though type 2 diabetics form > 95% of the diabetic population

Rationale

Purpose

To compare pancreas volume (PV) in patients with Type II diabetes

mellitus (DM) to PV in normoglycemic individuals, measured with MRI-

based planimetry.

Methods

Our institutional review board approved this retrospective study with a

waiver of informed consent.

Data collection

32 consecutive patients with Type II DM and 50 consecutive

normoglycemic patients were reviewed from consecutive

abdominal MRIs done for non-pancreas related

pathologies.

Inclusion criteria diabetes cohort

Documented evidence of diabetes within 6 months of the date of

MRI: FPG > 7 mmol/l / HBA1c > 6.5%

Methods

Inclusion criteria normoglycemic cohort

Documented normoglycemic status within 6 months of the date of

MRI: FPG < 5.6 mmol/l or HBA1c < 5.7%

Demographic characteristics for the normoglycemic

and Type II DM cohorts.

Demographic characteristics

Technique for volume estimation

Pancreatic contours in these 82 MRIs were traced manually on non-

gadolinium T1W 3D FS GRE images with post-processing software to

generate PVs

Volume = Cross sectional area x slice thickness

Methods

Manually traced pancreatic contour

Methods

Methods

Manually traced pancreatic contour

Methods

Manually traced pancreatic contour

Volume calculation with a post processing software

Methods

Results

Regression models showed that given the same age, weight and

gender, PV in a patient with Type II DM was

17.89 mL (19.9%)

lower compared to a normoglycemic individual.

Diabetes Normoglycemia

Results

Examples of pancreas volumes generated in a normoglycemic

and in a diabetic patient in this study

Patients with Type II DM had

significantly lower PV compared to

normoglycemic individuals

(p < 0.001)

Type II DM: 72.66 ± 20.7 cm3

Normoglycemic: 89.58 ± 20.6 cm3

Correcting for age and gender, overall mean PV in 82 patients increased with

increasing weight. PV both in the Type II DM cohort (p=0.0399) and in the

normoglycemic cohort (p<0.0001) increased with increasing weight.

Results

Pancreatic volume index (PVI) was

calculated as PV/weight (kg)

Patients with Type II DM also had

significantly lower PVIs compared

to normoglycemic individuals

(p < 0.0001)

Type II DM: 1.02 ± 0.27 cm3/kg

Normoglycemic: 1.27 ± 0.26 cm3/kg

Comparison of our study to other published human studies reporting PV measurements (in mL) using planimetry derived from cross-sectional imaging studies.

Results

This study demonstrates that pancreas volume in Type II diabetes is

significantly reduced as compared to volume in normoglycemic

individuals (19.9%)

Discussion

•  To our knowledge, this is the first study measuring pancreas volume

in Type II diabetics with MRI

•  We successfully used a routine T1W FS GRE sequence without

Gadolinium to measure pancreas volume

•  Our volume measurements in normoglycemic individuals (89.58 +/-

22.71, n=50) compared well with volume measurements

in previous studies using CT and MRI

Discussion

•  We show that MRI can be of use as an accurate and reliable method

to estimate pancreatic volume without radiation exposure

•  Potential applications of this technique include use of MRI-derived PV

as an outcome measure in clinical trials evaluating nutritional or

pharmacologic interventions in DM

Conclusion

PV is reduced in Type II DM compared to normoglycemic individuals

and can be measured using MRI without contrast injection

•  Statistical evaluation: Rosane Nisenbaum and Sidharth Saini

•  Lab medicine: Dr. Hilde Vandenberghe

•  MRI Technologists and the Research department at St. Michael’s

Hospital

Acknowledgements

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