One-day seminar for residents for implementing abdominal pocket-sized ultrasound

Abstract

Despite its proven high utility, integration of pocked-sized portable ultrasound (US) into internal medicine residency training remains inconsistent. For 10 years, we have held a 1-d seminar biannually, consisting of lecture (half-day) and hands-on training (half-day) on pocket-sized US of the abdomen and lungs. The lecture consists of training on US physics and clinical applications of pocket-sized US, followed by a lecture covering the basic anatomy of the abdomen and lungs and introducing the systemic scanning method. Given the simple structure of pocket-sized US devices, understanding the basic physics is sufficient yet necessary to operate the pocket-sized US device. It is important to understand the selection of probes, adjustment of B mode gain, adjustment of color gain, and acoustic impedance. Basic comprehension may have a significant positive impact on the overall utilization of pocket-sized US devices. The easiest and most reliable way to observe the whole abdomen and lungs is a combination of transverse, sagittal, and oblique scanning, pursuing the main vascular system from the center to the periphery of the organ in the abdomen and systemic scanning of the pleura. There is usually a marked change in knowledge and attitudes among the program participants, although skill gaps remain among them. We discuss the limitations and problems to this education system as well.

Keywords: Abdomen; Lung; Medical education; Pocket-sized ultrasound; Resident; Ultrasound physics.

Figure 1

Lecture by a clinician who specializes in ultrasound. The lecture covers basic ultrasound physics and simple ultrasound anatomy of the abdomen.

Figure 2

Simultaneous presentation of ultrasound images of a portal thrombus. A: High-end ultrasound B mode; B: High-end ultrasound color Doppler; C: Pocket-sized ultrasound B mode; D: Pocket-sized ultrasound color Doppler. These comparisons are used to understand the difference in image quality between the two machines. It also confirms that pocket-sized ultrasound is sufficient for diagnoses. *: Thrombus in the portal vein.

Figure 3

Ultrasound image by different probes on a pocket-sized ultrasound device. A: High-frequency linear probe; B: 1.7-3.8 MHz sector probe. The linear probe is used to visualize superficial areas, and the sector probe is used for observing deep areas. In this case of a small liver tumor situated at the hepatic surface, the lesion was detected by the linear probe (→) but not the sector probe.

Figure 4

B mode gain setting (hepatic cyst). A: B mode is too high; B: B mode is well-adjusted; C: B mode is too low. The lesion anechoic mass (arrowhead) with acoustic enhancement (arrow) is clearly seen only when the B mode gain is well-adjusted.

Figure 5

Color Doppler gain setting (normal portal vein). A: Gain setting is too high; B: Gain setting is well-adjusted; C: Gain setting is too low. Portal venous flow is not detected when color gain setting is too low (C) and is covered by color noise when it is too high (A).

Figure 6

Pocket-sized ultrasound images of gallbladder stones and ascites. A: A 1-cm stone; B: A small amount of ascites. A 1-cm stone (A) and a small amount of ascites (B) is clearly visualized as a strong echo (orange arrow) with acoustic shadowing (white arrow) in the former and an echo-free space in the latter (arrowhead).

Figure 7

Schematic drawing of basic scanning planes of the abdomen. The combination of these indicated planes permits quick observation of the whole abdomen. The transverse plane of the upper abdomen is for observation of the pancreas. The right upper abdominal plane is for observation of the liver and the gallbladder. The left upper abdominal plane is for observation of the spleen and left kidney. The sagittal plane is for observation of the abdominal aorta and its branches. L: Left upper plane; R: Right upper plane; S: Sagittal plane; T: Transverse plane.

Figure 8

Representative ultrasound images of the abdominal scanning procedure. A: The right upper abdominal scanning plane permits the observation of the liver (right lobe); B: Through the transverse scanning plane, the pancreas and the neighboring vessels are clearly demonstrated.

Figure 9

Pocket-sized ultrasound image of the pleura. A: Basic scanning planes of the chest (right) by ultrasound; B: Ultrasound image of normal pleura showing a typical A line (orange arrow); C: Ultrasound image of B line (arrowhead) and consolidation of the lung (white arrow).

Figure 10

Case presentation 1 of undesirable pregnancy causing abdominal symptoms. A: At presentation, the patient denied the possibility of pregnancy. However, pocket-sized B mode performed as part of a general physical examination revealed an embryo (arrow) in her lower abdomen. B and C: Color Doppler was particularly useful for confirming the baby’s cardiac movement. Daily use of pocket-sized ultrasound can lead to a reduction in ionizing radiation and time to correct diagnosis.

Figure 11

Case presentation 2 of abdominal pain so severe that the patient could not move. The patient’s abdominal pain was so severe that she could not move from the ambulance. Pocket-sized ultrasound performed in the ambulance revealed a gallbladder stone impact (arrow), leading to the diagnosis of acute stone-impact-induced cholecystitis.

Figure 12

Case presentation 3 of asymptomatic patient with acute hepatitis. The patient was asymptomatic upon admission. A: Pocket-sized ultrasound performed as part of a physical examination during medical rounds revealed a small amount of ascites (arrow) around the liver; B: The gallbladder was collapsed (arrowhead). She was diagnosed with severe acute hepatitis, and an energic treatment began immediately.

Figure 13

Built-in volume measurement application in pocket-sized ultrasound device. This function is useful for evaluating urine volume in elderly patients. A: Scanning with pocket-sized ultrasound device; B: Urine volume display.

Figure 14

Built-in wireless function application in pocket-sized ultrasound device. This function is particularly important when sending ultrasound information from distant locations (ambulance, etc.) or infection zones.