Role of ultrasonogram in chronic lower abdominal pain: special reference to gyenecologoical problems

Abdominal Pain is very common reason for Out Patients Department and ward visit. In Pediatric population almost more than half cases are not having anyu specific reason for that. These are classified as Functional Abdominal pain. Many times patients insist for radiographic evaluation. It is worthy to check if there is any gyenecological issues in these cases.


Introduction
Abdominal pain is a common problem & constitutes about 3% of the hospital visit among adults [1]. It may be acute or chronic. Chronic abdominal pain is defined as continuous or intermittent abdominal discomfort lasting for more than six months. It may occur due to problems of the gut, biliary tract, pancreas, gynaecological or genitourinary origin. Sometimes Chronic abdominal pain may be part of a functional syndrome [2]. The term "chronic abdominal pain" also includes "recurrent abdominal pain," which is characterised by more than 3 episodes of abdominal pain; severe pain sufficient to affect daily activities; symptoms lasting more than 3 months; and absence of any organic cause [3]. Chronic abdominal pain usually occurs beyond 5 year of age& nearly 10% of children require detailed evaluation.  [11].
An abdominal ultrasound can also be used as a diagnostic tool for conditions such as Abdominal aortic aneurysm, Hydronephrosis, Portal hypertension, Obstruction of bile ducts, Cirrhosis, blood clot/ fluid in abdominal cavity, hernia, kidney blockage or tumour. Ultrasound is useful for suspected Crohn's disease due to its high negative predictive value [12,13]. Pelvic ultrasound is the most important investigation for women of reproductive age with suspected endometriosis,ovarian or other adnexal disease [14].
Renal ultrasound is useful for ruling out renal obstruction, intra-renal calculi & renal masses [15]. Visualization of morphologic changes in chronic pancreatitis by transabdominal ultrasound has varying diagnostic accuracy with a sensitivity of 70% to 80% [16,17]. One large study reported sensitivities for Ultrasound to be around 85% for features calcifications, pancreatic duct dilations & cysts which is comparable to CT [24]. Ultrasonogram also helps in assessing the severity of disease as in chronic pancreatitis [18,19].
Here as the disease worsens, the pancreas loses its hyperechogenicity & becomes progressively heterogeneous due to focal inflammation [20,21]. This progressive inflammation & fibrosis & irreversible structural changes involving parenchyma & pancreatic duct can be evaluated using Ultrasonogram [22,23]. It also detects late stages where there is irregularly dilated Main pancreatic duct, Pseudocysts with pancreatic & intraductal calculi and pancreatic atrophy [20,24].
Though extremely useful, ultrasound is highly operator dependent. As Ultrasound waves are disrupted by air or gas it can not be used for imaging air-filled bowel or organs obscured by the bowel. Similarly for obese patients, imaging can be difficult due to greater amounts of tissue attenuating the sound waves. Though ultrasound cannot differentiate a benign or malignant tumor, it can be used during biopsy guiding the placement of the needle. It is also useful to drain fluid from a cyst or abscess & to examine blood flow inside the abdomen.
Ultrasonogram among children is different as several factors are unique including increased radiosensitivity to ionizing radiation, smaller body size & less body fat [25]. The spectrum of the Chronic Abdominal Pain is also different among Children.

Review Article
Obsgyne Review: Journal of Obstetrics and Gynecology Available online at : www.medresearch.in 23 | P a g e malformations, reduced or absent blood flow to various organs, greater than normal blood flow to different areas commonly associated with infections. Chronic pain caused by vascular conditions such as mesenteric artery stenosis ('mesenteric angina') are initially best investigated with Doppler ultrasound.
Endoscopic Ultrasonogram with characterization of ductal & parenchymal changes with or without the aid of weighted scores like Rosemont score is currently the gold standard for chronic pacreatitis imaging [26]. Its diagnostic quality is comparable to computed tomography (CT) & magnetic resonance imaging (MRI) [27,28]. Endoscopic ultrasonogram changes correlates with histopathologic findings & extent of exocrine dysfunction [27,29].
Of late modern Ultrasound probes are developed with dynamic frequencies, better depth-focusing technology, high-frequency, significantly better noise reduction & improved resolution are accessible. This helps in better characterization of lesions especially calcifications, where overall reduction of random noise features is important.
Funding: Nil, Conflict of interest: None initiated, Permission from IRB: Yes