Ultrasound examinations are useful for diagnosing varicose veins, and can reveal pathological conditions such as the presence of venous valve insufficiency, the extent of venous lesions, and the presence of blood clots. In order to perform ultrasound examinations efficiently for varicose veins in the lower extremities, it is important to check the patient’s medical history and physical findings and understand the purpose of the examination. The examination is mainly performed in the sitting position, but some areas of deep veins may be observed in the standing position. When a vein distal to the observation site is compressed with sufficient pressure, antegrade blood flow occurs in normal subjects, and the flow stops after the compression is released. In patients with venous valve insufficiency, long-lasting retrograde blood flow occurs after compression is released. Retrograde blood flow that lasts more than 0.5 seconds for superficial veins, 1.0 seconds for femoral to popliteal veins, and 0.5 seconds for femoral and lower leg deep veins is considered significant. Because the diameter of the vein is subject to change, probe compression should be performed under uniform conditions. Endovenous heat-induced thrombosis (EHIT), a complication of endovascular ablation for varicose veins, requires special attention.

A 3-year-old boy was referred to our hospital with the complaint of fever, redness on the left thigh, and difficulty walking. History-taking revealed that he had injured his left knee 1 week prior to presentation. On presentation, clinical examination revealed linear erythema on the left thigh. Ultrasonography revealed lymphatic dilation in the same area, beaded enlarged lymph nodes, and increased echogenicity of the surrounding adipose tissue. A left inguinal lymph node was also enlarged, with slightly irregular margins. Blood flow to the lymph node was not obviously increased, in the absence of an abscess. Blood tests showed a white blood cell count of 13,000/μL and a C-reactive protein level of 3.7 mg/dL. Intravenous cefazolin 120 mg/kg/day was initiated, but the response was poor. Because cutaneous nocardiosis was suspected based on the clinical findings, the antibiotic was switched to oral trimethoprim-sulfamethoxazole (TMP-SMX) on day 3 of hospitalization. The patient was discharged on the 5th day of hospitalization with improved clinical and hematological findings. Subsequently, culture of the fluid previously drained from the knee was positive for Nocardia brasiliensis sensitive to TMP-SMX. There was no relapse during follow-up and TMP-SMX was discontinued after 4 weeks. Cutaneous nocardiosis is rare but possibly underdiagnosed. Ultrasonography is a useful noninvasive method of diagnosis in children, who are difficult to examine physically. Ultrasonography should be performed if soft tissue infection is suspected following trauma. Cutaneous nocardiosis should be considered in cases of lymphangitis with beaded enlarged lymph nodes on ultrasonography.

Brachiocephalic artery plaque may be an embolic source as a cause of cerebral infarction. We report a case in which a movable brachiocephalic artery plaque was diagnosed using ultrasound and in which a movable lesion was clearly visualized using superb microvascular imaging (SMI). A 77-year-old woman presented to our hospital with dysarthria and ataxia of the right upper extremity, scoring 2 on the National Institute of Health Stroke Scale. Head magnetic resonance imaging showed multiple cerebral emboli in the right cerebellar hemisphere, pons, and left temporal lobe. Transesophageal echocardiography performed to search for the source of the embolus revealed a mobile plaque in the brachiocephalic artery, which was scanned from the body surface with a sector-type probe. The depth of the plaque was so deep that it was necessary to differentiate it from artifacts, so SMI was used. The patient was diagnosed as having an embolic source at the same site and was treated medically with antiplatelet agents. The patient has since been followed up via ultrasound to monitor the morphology of the plaque. SMI can be used to analyze the characteristics of tissue motion and separate slow blood flow from tissue motion. The mechanisms by which mobile plaques become apparent with SMI include clutter motion with hypermobility due to motion artifacts and strong reflection intensity. In the present case, SMI was useful in the evaluation of mobile brachiocephalic artery plaques using a sector-type probe.