Incidence of superficial abdominal organ identification is similar using high-frequency linear (transrectal) and low-frequency curvilinear (abdominal) transducers in clinically healthy horses: A pilot study

Comparison of transrectal and transabdominal transducers for use in fast localized abdominal sonography of horses presenting with colic

Abdominal ultrasonography is valuable in the diagnosis of equine colic. Fast localized abdominal sonography of horses (FLASH) enables practitioners with limited experience to perform ultrasonography in emergency settings. However, many practitioners only possess rectal format linear array transducers (RFLT). The hypotheses are: (a) A low frequency curvilinear transducer (LFCT) and RFLT will detect free abdominal fluid and abnormal small intestinal loops with similar frequency during FLASH, and (b) there will be a difference between the transducers for detection of gastric abnormalities and nephrosplenic entrapment. The objective is to compare transcutaneous abdominal ultrasonographic detection of abnormalities in horses presenting with colic using a LFCT and RFLT. Twenty-four horses requiring FLASH for investigation of colic were enrolled. Horses that were too painful to undergo transcutaneous abdominal ultrasonographic examination were excluded. A single investigator performed FLASH on all horses using a RFLT, while one of three other clinicians simultaneously performed FLASH using a LFCT. Comparison of abnormal findings between the two transducers was performed using Chi square, Fisher's exact or Wilcoxon tests. The incidence of identification of abnormal findings was similar between the two transducers for all comparisons except the visibility of the left kidney and stomach (kidney LFCT 81.25% vs. RFLT 22.92%, stomach LFCT 87.5% vs. RFLT 62.5%). While there are limitations to using a RFLT to identify nephrosplenic entrapment of the colon and detection of the stomach, it reliably detects other common abnormalities, including peritoneal effusion, lesions of the small intestine, and changes to the wall of the large colon and cecum.

Abdominal Sonographic Evaluation: In the Field, at the Hospital, and After Surgery

Abdominal sonography is currently a routine procedure in the evaluation of colic in the horse. This imaging technique is used in both the assessment of the horse presented in the emergency setting with acute colic and the assessment of the horse presented for chronic or recurrent colic in the nonemergency setting. Sonography for colic evaluation is used by specialists in different disciplines and by general practitioners in the ambulatory and hospital settings. In this review, we will focus on indications and clinical interpretation of findings as well as recent developments in abdominal sonography.