Rajul Rastogi1* and Sujeet Kumar Jain2
1Teerthanker Mahaveer Medical College and Research Center, Moradabad, U.P, 244001 India 2School of Medical Sciences & Research, Greater Noida, U.P, India
Received: 29 February, 2016;Accepted: 25 May, 2016; Published: 28 May, 2016
Dr. Rajul Rastogi, Teerthanker Mahaveer Medical College and Research Center, Moradabad, UP, India, 244001, E-mail:
Rastogi R, Jain SK (2016) Imaging in Diabetes Mellitus. Arch Clin Nephrol 2(1): 017-025.
© 2016 Rastogi R, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Diabetes mellitus [DM] is the commonest endocrine disorder encountered in the clinical practice. It in fact, comprises of multiple disorders that manifest in the form of hyperglycemia. It is a multisystem disorder with pathophysiologic changes occurring in almost all the major systems and organs of the human body resulting in serious physical and mental disturbances and also posing tremendous burden on the health care resources of the country. The common sites of involvement include cardiovascular system, nervous system (central and peripheral), eyes, gastrointestinal system, genitourinary system, nasal and paranasal sinus region, hepatopancreatobiliary system, etc. Radiological manifestations are directly proportional to the duration and severity of involvement of the various systems. Various imaging (diagnostic and invasive) techniques can be used to detect the various manifestations as well as subsequent complications occurring during the course of disease. The following imaging techniques can be utilized for the purpose of evaluating the patients of DM:
• Special investigations
• Ultrasonography (USG) and color doppler study (including echocardiography – ECHO]
• Computed tomography (CT)
• Magnetic resonance imaging (MRI)
• Radionuclide scintigraphy (including single photon emission computed tomography – SPECT)
The role of imaging in assessing the systemic involvement by DM can be well studied in the system-wise manner. However, before we proceed, let us first discuss in short, the classification of diabetes mellitus:
Type I: Insulin-dependent Diabetes Mellitus (IDDM)
Type II: Non-insulin-dependent Diabetes Mellitus or Maturity onset Diabetes (NIDDM or MODY)
Type III: Diabetes Mellitus secondary to multiple causes including chronic diabetes, hemochromatosis, pancreatic hypoplasia, etc.
Type IV: Gestational Diabetes Mellitus or Diabetes Mellitus of Pregnancy
The above classification is relevant to imaging specialists as well, the type of DM (primary or secondary) will affect manifestations and the complications including their severity. It is of equal significance for those patients undergoing some interventional radiological procedure for diagnosis or treatment.
Cardiovascular system [1-7]
Cardiac involvement in diabetes mellitus occurs in the form of coronary artery sclerosis or atherosclerosis, congestive cardiac failure, acute ischemia or infarction.
In acute ischemia or infarction, role of scintigraphy (technetium thallium scan), SPECT and cardiac MRI is well documented. These modalities are useful in detecting at-risk, ischemic, infarcted, nonviable and scarred regions of myocardium. The abnormal area appears as a region of hypoperfusion or cold spot with or without dyskinesia. 2D- echocardiography (ECHO) is very useful in assessing the status of cardiac chambers and flow through the valves. Pericardial effusion can also be detected with high sensitivity by ECHO. Radiograph of chest is very helpful in the assessment of the status of pulmonary parenchyma & vasculature and presence of pleural effusion. Pleural effusions can be detected with higher sensitivity with high resolution ultrasonography of the pleural spaces. Radiograph of chest may reveal signs of pulmonary venous hypertension in the form of Kerley B lines especially at the bases, upper lobe blood diversion, alveolar & interstitial opacities and in severe cases, hilar and perihilar pneumonic consolidation in bat-wing pattern.
In congestive cardiac failure, besides chest radiograph, ultrasonography of the abdomen is very useful in assessing the back pressure changes as depicted by the dilatation and engorgement of the hepatic veins and inferior vena cava. There may be associated hepatomegaly and fluid in the serous cavities including pleural, peritoneal and pericardial cavities.
Asymptomatic coronary artery disease (CAD) is common in NIDDM patients. Noninvasive detection of carotid intima-media thickening by ultrasound has been accepted as a surrogate marker of the increased risk of subclinical CAD in diabetic patients. Coronary arteriosclerosis and atherosclerosis can be well studied with CT angiography or invasive coronary angiography. Though, both modalities can give reliable information regarding the degree of stenosis, yet CT angiography scores over invasive angiography in revealing information regarding the walls of arteries & nature of plaque while the latter is more accurate in detecting degree of stenosis and collateral circulation. Atherosclerotic plaques appear hypodense on CT scans due to their lipid content while calcium appears hyperdense with CT – attenuation values of greater than 100 Hounsfield units (HU). Calcium scoring of the coronary arteries can be done using CT scan for the purpose of screening for coronary arteriosclerosis. CT pulmonary angiography may be used to assess the extent of pulmonary arterial hypertension especially if pulmonary thromboembolic phenomenon is suspected.
Metaiodobenzylguanidine (MIBG) imaging has proved useful in detection of the silent ischemic disease in patients with diabetes mellitus as disruption of the cardiac sympathetic innervation leads to increased threshold of pain perception in these patients. Diabetic patients show decreased uptake of MIBG as compared to normal subjects.
DM is associated with arteriosclerosis in the central and peripheral arteries with subsequent narrowing and alterations in the color and spectral flow pattern that can be well evaluated with Doppler studies. Characteristic findings of arteriosclerosis include thickening of intima-media complex (greater than 0.8 mm), irregular intimal surface, increased echogenicity and calcification in walls. There may be formation of atherosclerotic soft (cholesterol-rich, noncalcified) & calcified plaques with subsequent narrowing of the lumen and hemodynamic changes. Color Doppler may show incomplete filling of color in the lumen of arteries while spectral flow may show changes in the pattern of flow in the form of loss of triphasicity in distal arteries with widening of spectral window and decreased peak systolic velocities. Increased systolic velocities may be seen in post-stenotic areas while absence or minimal flow may be seen in the gangrenous areas. Parvus-tardus pattern is characteristic of severely compromised arterial flow usually secondary to severe atherosclerotic changes. Digital subtraction or CT angiography can be used for further assessment, if surgical treatment is being planned. Digital subtraction angiography (DSA) is the gold standard and has the advantage of being converted in to the therapeutic procedure simultaneously. Recently, MR angiography using time of flight & other newer sequences has emerged as a valuable tool in preoperative vascular assessment of patients with compromised renal functions where iodinated contrast medium may be contraindicated (Figures 1-3).