Sunday, July 24, 2011

Congenital diaphragmatic hernia- perils and pitfalls

   It may initially appear that Congenital diaphragmatic hernia or CDH is a simple straightforward diagnosis on ultrasound imaging. But is it? I have come across many cases where the sonologist can miss this diagnosis in late 2nd trimester or early 3rd trimester fetuses. The reason is because many small diaphragmatic defects may cause only partial or intermittent fetal diaphragmatic hernia. Thus the sonographer or sonologist may not see any herniation of bowel or stomach in left sided diaphragmatic hernias or right lobe of liver in right sided hernias.                                                                                                


The ultrasound video clip shows one typical case of left sided congenital diaphragmatic hernia (CDH), with classic midline shift of heart to the right, literally pushed to a corner in the wrong side of the chest. In this case the ultrasound diagnosis of CDH was made late into 34 weeks of gestation.This can be a disaster for the mother, who might not have wished to continue the pregnancy.
What are the differential diagnoses of left sided congenital diaphragmatic hernia?
Almost any cystic lesion occupying the left hemithorax can be confused with CDH in fetal ultrasound. Among these conditions are- cystic adenomatoid malformation, bronchogenic cysts and pulmonary sequestration. Also, not to be ignored are intrathoracic teratomas, as the cystic components of this tumor can mimic a CDH. Even more ominously, these lesions mentioned above can co-exist with CDH, making a diagnosis of CDH even more complicated.
You may want to read more at:
What is the prognosis in such cases?
The earlier the diagnosis of congenital defects in the diaphragm are observed on ultrasound, the worse is the prognosis for the fetus. In fact, the detection of congenital hernia in 2nd trimester means that the severity of the congenital anomaly is more severe. Most cases are also associated with other fetal anomalies, notably involving the fetal heart. Also, invariably, the pressure from the herniated bowel and stomach, in this case means there would be severe hypoplasia of the lungs. In fact, despite surgery in the neonatal period, many such babies have pulmonary hypertension and respiratory difficulties. Also present in many neonates is the danger of mental retardation, trisomy 18 and trisomy 21 as well as neural tube defects. The fetus in this case showed no other major anomaly, but the severe midline shift is evidence of a large hernia with resultant pulmonary hypoplasia.

Wednesday, July 20, 2011

Seroma following lumpectomy in breast cancer:

The ultrasound video clip of the breast above, shows a typical seroma of the breast following lumpectomy (removal of breast lump) and is a common sequel to such breast surgeries. The presence of particulate matter in the cystic collection (fluid) in the dead space left following breast lump removal, is an indicator of the presence of hemorrhage into the cavity. Most surgeons are of the opinion that larger seromas are formed following removal of large breast lumps and particularly following axillary lymph node dissection.
    In the ultrasound video clip above note the motion of significant particles within the serous fluid. Presence of particles, mural nodules, septae are all evidence of hemorrhage following breast lumpectomy. The color Doppler ultrasound image below shows the absence of significant vascularity around the walls of the seroma, implying lack of wound/ wall infection or inflammation.

In the absence of history of breast surgery, such cystic lesions can confound the sonologist and lead to error in the diagnosis of breast seroma.
More information and ultrasound images of this case can be had at:

Breast ultrasound (google books)
(an excellent description of sonography of breast seroma)

Study of breast seroma

Friday, July 15, 2011

Ultrasound of suprapatellar hematoma

The knee joint is an excellent example of superb ultrasound imaging using the newer high resolution sonographic probes in the market. Perhaps, ultrasound offers better resolution than MRI in studying certain aspects of knee joint pathology, the only hitch being the user dependence. This case study of suprapatellar hematoma or hemorrhagic effusion is a typical example. With the opportunity to image joints on both sides and actually study the effect of probe compression, sonography is in certain ways both cost effective and complementary to an MRI study of the knee joint. The extent of muscle, tendon and ligament detail that high resolution sonography of the knee joint offers, is at par if not better than MR imaging.
Visit: a case of knee injury with hemorrhagic effusion extending into the suprapatellar bursa.

Wednesday, July 13, 2011

Schwannoma of parotid- a rare tumor

The parotid salivary gland can sometimes yield surprises in the form of rare tumors. One such instance is a Schwannoma of the parotid gland. This tumor arises from the facial nerve as it courses through the salivary gland. Visit:
This site shows ultrasound images of this well defined facial nerve mass in the parotid. This tumor has not much literature published both online or in print, pertaining to its sonography. However, the case above of Schwannoma of the right parotid was confirmed histo-pathologically after biopsy.
On ultrasound this tumor has all the appearances of a benign well defined mass with nothing to point to its exact diagnosis, making precise diagnosis of Schwannoma of the parotid, difficult, on sonography.