Radiology Picture of the Day

Nasopalatine duct cyst

Dr Laughlin Dawes — Thu, 25 Aug 2011 01:35:09 +0000

An incidental finding of a well-defined high T1 signal lesion was made on a MRI brain. CT was performed for clarification and shows a smoothly marginated expansile lesion that communicates with the nasopalatine duct. The appearances are characteristic of nasopalatine duct cyst. The T1 signal in these cysts can be variable, depending on the nature of the cyst contents.

Liver Haemangioma

Dr Laughlin Dawes — Wed, 03 Aug 2011 23:55:24 +0000

This multiphase CT shows the typical imaging features of liver haemangioma. There is peripheral nodular enhancement in the arterial phase which gradually fills in in later phases (portal venous and delayed). Haemangiomas are the most common benign tumour of the liver (78%), and the second most common liver tumour after metastases.
Reference: Dahnert W. Radiology Review Manual 5th ed. Lippincott Williams & Wilkins

Osteopoikilosis

Dr Laughlin Dawes — Thu, 28 Jul 2011 01:01:07 +0000

Osteopoikilosis is a benign autosomal dominant condition where small multiple bone islands are found predominantly in the epiphyses and metaphyses of the long bones, pevis and scapula. The low signal of the lesions on the proton-density MR shown here reflects the low water content of cancellous bone. T1 and T2-weighted MR also show low signal.

Warthin’s Tumour

Dr Laughlin Dawes — Thu, 21 Jul 2011 01:50:19 +0000

This contrast-enhanced CT shows a left parotid tail lesion with a well-circumscribed border and heterogeneous enhancement. The appearance is nonspecific but in keeping with the known diagnosis of Warthin’s tumour. The scan was performed to exclude contralateral tumour, which occurs in around 10% of cases. Warthin’s tumours may show cystic areas, and small cysts may be seen on MR that are not visualised on CT.

Reference: Valvassori’s Imaging of the Head and Neck. Mafee MF et al. Thieme 2005

Carcinoma of the Pancreatic Head

Dr Laughlin Dawes — Fri, 15 Jul 2011 02:50:08 +0000

This abdominal ultrasound shows the characteristic appearance of a pancreatic head carcinoma – a hypoechoic mass with irregular margins. Deep to the mass a biliary stent can be seen within the common bile duct.

Papillary Carcinoma of the Thyroid Gland

Dr Laughlin Dawes — Thu, 14 Jul 2011 05:49:03 +0000

This ultrasound image is of a solitary thyroid nodule. The nodule is hypoechoic, has an irregular margin and contains small calcifications. None of these features are specific for malignancy, but when occurring together are highly suspicious. This lesion was found to be papillary thyroid carcinoma.

Scaphoid Osteonecrosis

Dr Laughlin Dawes — Wed, 13 Jul 2011 03:18:28 +0000

This patient previously had a fracture of the scaphoid waist. This plain film of the scaphoid shows sclerosis of the proximal pole in keeping with osteonecrosis.

Proximal pole osteonecrosis can be classified radiographically as:
stage 1: patchy areas of radiodensity of proximal pole
stage 2: involvement of entire proximal pole
stage 3: carpal collapse

According to this classification, this case would be stage 2.

Reference: Wheeles Textbook of Orthopaedics Online

Carotid Body Tumour

Dr Laughlin Dawes — Sat, 02 Jul 2011 03:04:59 +0000

This curved reformat of a CT angiogram nicely shows an arterial-phase enhancing lesion situated between the internal and external carotid arteries. This is the typical location and appearance of a carotid body tumour. Carotid body tumour is a paraganglioma of the carotid body; this is the most common site of paraganglioma in the head & neck. Other sites include glomus jugulare / jugulotympanicum, glomus vagale, glomus tympanicum, or rarely glomus faciale (along the course of the facial nerve). Malignant features may be seen in 6% of head & neck paragangliomas, and possibly as high as 16% for glomus vagale.

Reference: Valvassori’s Imaging of the Head and Neck 2nd ed. Mafee MF et al. Thieme 2005.

Nasal Encephalocoele

Dr Laughlin Dawes — Tue, 31 May 2011 06:36:53 +0000

This patient in her 70s presents with nasal obstructive symptoms. Sagittal gadolinium-enhanced T1-weighted MR image shows a defect in the dura of the anterior cranial fossa. The frontal lobe herniates through the defect into the nasal cavity. It is important to recognise this entity as a cause of nasal obstruction, as a well-intentioned biopsy may lead to troublesome CSF leak or meningitis.

Choledocholithiasis

Dr Laughlin Dawes — Thu, 26 May 2011 05:39:07 +0000

This patient has had a cholecystectomy but presents with recurrence of biliary symptoms.

A CT cholangiogram was performed after intravenous administration of meglumine iotroxate (Biliscopin). Biliscopin is preferentially excreted by hepatocytes, opacifying the biliary tree. In the case of severe liver impairment, Biliscopin is renally excreted. CT cholangiography provides high-resolution imaging of the biliary tree and is an alternative to MRCP or ERCP for biliary imaging.

The study shows multiple calculi within a dilated biliary tree.