Spot Diagnosis

Post plastic surgery changes in radiology images

This article discusses the various common plastic surgery procedures and their expected radiology appearances. Very interesting.

Mediastinal mass biopsy - transcostal approach

This is a 20-years old lady who presented with a mediastinal mass, predominantly in the aorto-pulmonary window. A CT-guided biopsy was suggested.

On the contrast-scan, it was possible to delineate the aorta and pulmonary arteries separate from the mass with a 1cm wide window between the two (Figs. 1, 2). Using a transcostal approach (Fig. 3), the cannula was slowly advanced (Fig. 4), until it lay within the centre of the mass, away from the vessels and bronchus. A biopsy was then performed (Fig. 5). This turned out to be lymphoma.

Head Injuries Lecture - Slides 10-13

Osteoblastoma

This 23-years old man presented with pain in the right hip region. A plain radiograph (not available) showed a sub-trochanteric osteolytic lesion with a narrow zone of transition and a sclerotic rim. The MRI (Figs. 1-3) showed a focal lesion with heterogeneous low signal on all sequences with minimal surrounding marrow edema. The CT showed a well-defined lesion with a sclerotic rim and subtle calcification / ossification in the matrix.

The appearance was of a benign lesion. This lesion did not fit into any obvious chondroid or fibrous lesion and the most likely possibility was of an osteoblastoma, given the morphology and the subtle calcification / ossification, as well as the marrow edema.

At surgery, the diagnosis was confirmed.

Duplex left kidney

This 25-years old man came with a history of severe left loin pain. A calculus was suspected and since the USG was normal, a CT urogram was performed.

The study showed a duplex left kidey with fusion of the ureters just proximal to the UV junction. There was no pathology. The depiction of the anatomy on the CT urogram was exquisite.

Air Crescent

"Air in a crescentic shape in a nodule or a mass, in which the air separates the outer wall of the lesion from an inner sequestrum, which most commonly is a fungal ball of Aspergillus species"

Calcifying Epithelial Odontogenic Tumor - Pindborg Tumor

This is a patient who had a gradually increasing right lower jaw mass. The OPG showed (Fig. 1) an expansile, osteolytic lesion with coarse trabeculae. The CT scan (Figs. 2, 3) showed an enhancing lesion with trabeculae with marked thinning of the buccal and lingual cortices. The 3DCT image (Fig. 4) showed the lesion in a 3D perspective.

Though the exact etiology is indeterminate, the appearances are suggestive of an odontogenic tumor and the differentials would include ameloblastoma and odontogenic myxoma. On biopsy, this turned out to be a calcifying epithelial odontogenic tumor, also called the Pindborg tumor.

This tumor is commonly seen around the age group of 40 and occurs in the pre-molar area of the manndible. It usually presents with poorly marginate borders and has mixed osteolytic and sclerotic areas.

Pyogenic liver abscess

Pyogenic abscesses can also present as an acute abdomen. As compared to amebic liver abscesses, pyogenic lesions are often multiple and confluent and seem to show less parenchymal edema than amebic lesions.

New musculoskeletal quiz

A new musculoskeletal quiz is up today at the REF site.

The answer to last week's abdominal quiz is - biliary cystadenoma.

Tranpedicular biopsy of a pedicle lesion - metastasis

This 62-years old man with local pain and tenderness was shown to have a focal L3 pedicular and body lesion on MRI. A biopsy was suggested. The lesion was well seen on the CT (Fig. 1). A COOK bone biopsy cannula was advanced into the pedicle (Fig. 2). Once in place, through the cannula, using an 18G COOK biopsy gun, multiple cores were obtained.

The patient had metastasis from adenocarcinoma, which eventually turned out to be a small lung lesion.