The correct answer is C

A solitary pulmonary nodule, usually found unexpectedly on chest roentgenography, is a finding that cannot be ignored.Patients who have surgical resections for solitary nodules (pathological stage Ia or T1 N0, M0) have a 60–70% chance of surviving 5 years which is the reported outcome for lung cancer. It is therefore important not to miss the opportunity for surgical cures.

In current practice, the nodule proves to be a malignant tumor in about 40% of cases, most often bronchogenic carcinoma but occasionally a solitary metastasis or carcinoid tumor.

In populations where a large proportion of SPNs are benign there is a potential for greater avoidable surgical morbidity, although fear of litigation may prompt a "play safe" policy of removal of most lesions. Thoracic computed tomography (CT) and fine needle biopsy (FNB) are both advocated to improve the precision of management by increasing the confidence with which masses can be categorised as benign or malignant.

Although each case must be considered individually, there are several basic principles of management in cases of solitary pulmonary nodules:

• Every nodule must be regarded as potentially malignant until proven otherwise.
• Malignant nodules should be resected unless the procedure is contraindicated because of an unacceptably high surgical risk or evidence of metastasis.
• Resection of a benign nodule rarely benefits the patient and carries a small but significant mortality risk. Ruling out malignancy by less-invasive means than thoracotomy is desirable wherever possible.
• A management decision should be reached with reasonable promptness once a solitary pulmonary nodule has been detected. Under certain circumstances, a decision to observe the nodule for a period of time with serial chest films may be appropriate, but this must be a considered approach and not a "default" position.

The Correct Answer is C

Magnetic Resonance Imaging (MRI) is the technique of imaging body tissue properties by using nuclear magnetic resonance.

MRI images provide information about hydrogen nuclei density ("proton density"), and about the interactions of hydrogen containing molecules with their surroundings. In the body water is the most important of these molecules. A few other nuclei may be used for specialised imaging purposes (e.g. 13C, 31P).

MRI is particularly suited to imaging differences between soft tissues, such as in the head, neck and spinal regions of the body.

The technique requires the exposure of the body to steady and time-varying magnetic, and radio-frequency magnetic fields, and to the deposition of electromagnetic power in tissues.

Conventional MRI can produce an image of the bone, but this image is typically only of the specific bone tissue surface because the number of free (not in chemically bound form) water molecules within the specific bone tissue, and consequently the number of free protons, is very small

The Correct Answer is E

The Correct Answer is A

The Five Densities are

• Metal
• Bone
• Soft tissue (water)
• Fat
• Gas

Since the inflated lungs are practically gas they are the least dense.

Radiography:

• Also called “plain films” or “standard films”
• Image formed using broad beam ionizing radiation
• The image formed is related to the subjects density
• May involve the use of contrast agents - Iodinated, Barium, Air
  

The Correct answer is C

Explanation:

DVT (Deep Venous Thrombosis) and PE (Pulmonary Embolism) are one of the major common challenges in day-to-day radiology practice. There are no common censuses or guidelines in the diagnosis and management of DVT or PE. D-dimer has a high negative predictive value, i.e. excluding DVT or PE, but it lackes positive predictive value. Duplex ultrasound remains investigation of choice in most of the hospitals to exclude or confirm DVT as this investigation is highly sensitive and specific (both >90%). VQ scan still remains a very common investigation in the diagnosis of PE and is based on PIOPED trail. Although conventional angiography is traditionally considered as a gold standard, CTPA is gaining wider acceptance in diagnosing PE, despite more dose than VQ scan. MRI is being tried in the diagnosis of PE and DVT by a technique (MRI-DTI, DTI= Direct Thrombus Imaging) which detects methhaemoglobin (M-Hb) and the initial results are promising.

Reference: Scarsbrook AF et al. Diagnosis of suspected venous thromboembolic disease in pregnancy. Clin Rad 2006: 61: 1-12

The correct Answer is B

Explanation: The skeletal changes in thalassaemia are unusual before 6 months of age and the first changes are usually seen in the hands and feet. 'Hair-on-end' appearance can be seen in any form of severe anaemia. Due to extra-medullary haemopoisis, the paranasal sinuses are not developed, except ethmoid air cells due to the absence of the red marrow around them. Iron chelation also causes changes in the skeleton, in the form of meta-epiphyseal dysplasia (one third of patients) and osteoporosis. Distal ulna is one of the earliest site to show dysplastic changes.

References:

1. Tyler PA et al. The radiological appearances in thalassaemia. Clin Rad 2006:61:40-52.
2. Dahnert W. Radiology review manual 5th edition. Lippincott williams and Wilkins 2003: 165-166

The Correct Answer is E

Explanation:

Pivot shift injury is a non-contact, vulgus injury with femoral internal rotation commonly seen in skiers and Rugby players and the ACL is commonly disrupted. In dashboard injury, the knee is in 90° flexion with anterior force, leading to disruption of the taut PCL. In lateral patellar dislocation, the injury is on the inferomedial ascpect with injury to the inferomedial aspect of the patella, medial retinaculum, MPFL and medial patellotibial ligament. Hyperextension injuries are commonly seen in footballers, leading to kissing conutions, injury to ACL, PCL or menisci.

Reference: Timothy G. Sanders, Monica A. Medynski, John F. Feller, and Keith W. Lawhorn. Bone Contusion Patterns of the Knee at MR Imaging: Footprint of the Mechanism of Injury. RadioGraphics 2000; 20: 135.

The Correct Answer is 4

Explanation:

16% of the complete and 0.5% of the partial moles can transform into malignant forms, i.e., invasive mole, choriocarcinoma and placental site trophoblastic tumour (PSTT). GTN has excellent prognosis and are almost always curable with methotrxate or actinomycin-D. USG and MRI show 'cluster of grape' or 'sand storm' appearance. GTN shows low impedence, high velocities (low PI) in the arteries. The uterine artery PI is known to predict response to chemotherapy. With the exception of vaginal disease, it is rare to have other metastatic disease in the absence of lung disease. Liver metastasis is a marker of poor outcome. Up to 15% of GTNs develop vascular malformations and UAE has been used successfully to treat them. Hyperthyroidism is a rare complication of GTN.

Reference: Allen SD et al. Radiology of gestational trophoblastic neoplasia. Clin Rad 2006:61:301-313.

The correct Answer is B

Explanation:

Fibrous dysplasia is the most common benign rib tumour, followed by enchondroma and osteochondroma. FD usually occurs in the posterior or lateral ribs, where as EC and OC occur anteriorly at the costochondral junctions. Hyaline cartilage is not calcified and is best seen on T2WI as a bright signal. Cartilage cap of more than 2 cm in adult and 3 cm in children is highly suspicious for malignant transformation in OC. ABCs are usually seen in the posterolateral aspect of the ribs.

Reference:

1. Hughes et al. Benign primary tumours of the ribs. Clin rad (2006): 61:314-322

The correct Answer is E

Explanation:

CNs are typically located within the lateral ventricle with extension into the third ventricle. The light microscopic features are similar to oligodendroglioma (OD) and many CNs were diagnosed as ODs in the past; hence immunohistochemistry with synaptophysin should be done. Most of the CNs present between 20 and 40 years with no sex prevelance. Attachment to the spetum pellucidum is considered as characteristic for CN. CNs are typically low on T1, high on T2 with usually some enhancment. Intratumoral calcification is common, where as haemorrhage is rare. Differentials include choroid plexus paiplloma, astrocytoma, meningioma, ependymoma, subependymoma and oligodendroglioma.

Reference: Zhang et al. Central neurocytoma: clinical, pathological and neuroradiological findings. Clin Rad (2006): 61: 348-357 .

The Correct Answer is B

Overall accuracy of MRI is 83-92% and endovaginal ultrasound (77%) is more accurate than CT(61-76%) in predicting the myometrial invasion. Zonal anatomy is best seen on the T2WI and endometrial carcinoma is typically of low signal on the T2WI and enhance more slowly than myometirum on the dynamic enhancement scan. Inner myometrium is brighter than outer myometrium on dynamic MRI and maximum contrast between the two occurs at 50s. Endometrial carcinoma is of high signal compared to cervical stroma on T2WI.

Reference: Barwick TD et al. Imaging of endometrial carcinoma. Clin Rad (2006) 61, 545-555

The Correct Answer is D

Explanation:

Endometrial carcinoma is the most common gynaecological malignancy, followed by cervical carcinoma. Most of them present early, 75-80% in stage I, and have a good prognosis. Endometrial carcinoma accounts for 7-14% of post menopausal bleeding. FIGO staging is surgical and pathological based as clinical staging is inaccurate. FIGO does not consider imaging in the staging. However, the role of MRI in the diagnosis of myometrial and cervical invasion is increasing recognised. The incidence of nodal involvement is 3% with stage IB and 40% with stage IC and MRI may play an important role in this. Lymphadenectomy is done for Grade I/II with more than 50% myometrial invasion and for all grade III disease.A large randomised ASTEC (A Study in the Treatment of Endometrial Cancer) is being carried out to address role of lymhadenectomy and post-operative radiotherapy.

Reference: Barwick TD et al. Imaging of endometrial carcinoma. Clin Rad (2006) 61, 545-555

Tags: MCQ, Radiology, Endometrial Cancer

The Correct Answer is C

Notes: Posterolateral corner injuries are less common than medial knee injuries, but more debilitating. The bone injuries include Segond fracture (indicator of ACL injury), Arcuate fracture (avulsion fracture of fibular head - indicator of PCL injury), anterior rim tibial plateau fracture (indicator of PCL injury) and Gerdy's tubercle avulsion fracture. Soft tissue injuries include lateral collateral ligament, biceps tendon, popliteus, lateral head of gastrocnemius, fabellofibular ligament, arcuate ligament and mid-third lateral capsular ligament.

Reference: Harish S et al. Imaging of the posterolateral corner of the knee. Clin Rad (2006) 61, 457-466

The correct Answer is E

Explanation: TDIs commonly occur after blunt trauma as in RTA or fall. Because of the liver, the right hemidiaphragm is ruptured less common than the left. Only about 10% of TDIs are diagnosed in acute setting. Stomach is most commonly herniated organ (32%), followed by colon (27%). CT is investigation of choice even in the acute setting. 'Dependent viscera sign' on CT is very sensitive in the diagnosis of TDI. The bowel or abdominal viscera usually do not contact the ribs due to seperation by diaphragm; contact indicates diaphragmatic injury and is known as 'dependent viscera sign'. Sagittal reconstruction is most sensitive and specific in the diagnosis of TDI.

Reference:

1. Eren S et al. Imaging of diaphragmatic rupture after trauma. Clin Rad (2006)61, 467-477
2. ABCs of blunt trauma

The Correct Answer is C

Explanation: Angiomyolipomas are benign hamratomas. Sporadic type is usually seen between 50 and 80 years, has a female preponderance and comprises 80% of Angiomyolipomas.Angiomyolipomas are commonly seen in tuberous sclerosis (wide range, 20-80%) and also has a female prediliction. Angiomyolipomas are associated with neurofibromatosis and VHL syndrome. Retroperitoneal haemorrhage is the most common and life threatening complication. The larger the tumour, the greater is the risk of haemorhage; hence Angiomyolipomas larger than 4 cm are usually treated and the rest are followed. Embolization is increasing used to treat hypervascular Angiomyolipomas.

References:

1. Rimon U et al. Larger renal angiomyolipomas: DSA grading and presentation with bleeding. Clin Rad (2006) 61, 520-526
2. Dahnert W. Radiology review manual 5th edition. Lippincott Williams & Wilkins.

The correct answer is D

Explanation:

Epidermoid cyst is a rare benign lesion of the testis (1%–2% of testicular lesions). Commonly the patients present between 2nd and 4th decades. Most of the epidermoid cysts are single and unilateral. Multiple or bilateral cysts are associated with Gardner syndrome, Klinefelter syndrome and cryptorchid testes. They are filled with laminated cheesy material. The clinical management is controversial and recently, organ-preserving surgery has been favored over traditional orchidectomy.Most patients present with painless mass, but a few complain of pain or discomfort.

US may show an echogenic centre surrounded by a hypoechoic ring and hyperechogenic rim, causing 'bull’s-eye' or 'target' lesion; or alternating hypoechoic and hyperechoic concentric rings, causing 'onion skin appearance'. The lesions are not vascular.MR shows low signal peripheral rim on both T1- and T2-weighted images and a circumferential high signal zone surrounding a low-signal central zone, or alternating concentric rings of low and high signal on T1- and T2-weighted images. On contrast, there is no enhancement.The central echogenic center may represent keratin debris and the concentric layeers may represent lipid and water containing materials. The squamous cell capsule causes hyperechoic rim.

The 'onion ring' appearance is charecteristic for an epidermoid cyst, although not pathognomonic. Simple and tunica albuginea cysts are anechoic. Tumors, abscesses and chronic inflammatory processes may have capsule, but are likely to show hypervascularity. Neoplasms usually enhance on Gd-enhanced MR. Hemorrhage may have heterogenous appearance on ultrasound.

References:

1. Cho JH et al. Sonographic and MR Imaging Findings of Testicular Epidermoid Cysts. AJR 2002; 178:743-748
2. Loya AG et al. Epidermoid Cyst of the Testis: Radiologic-Pathologic Correlation. RadioGraphics 2004; 24: S243-S246.
3. Woodward PJ et al. From the Archives of the AFIP: Tumors and Tumorlike Lesions of the Testis: Radiologic-Pathologic Correlation. RadioGraphics 2002; 22: 189.

The correct Answer is B

Spleen is the most commonly injured solid abdominal organ. Most often due to blunt trauma and often (30-60%) associated with other organ injuries. 25% of left renal injury and 20% of left rib fractures are associated with splenic injury. 40% of splenic lacerations are associated with rib fractures. 20% of splenic injuries occur during surgical procedures.

Spontaneous rupture can occur in an abnormal spleen, like in infectious mononucleosus or malaria. Subcapsular hematoma is seen as cresentic/lentiform low attenuation. Parenchymal lacerations are seen as irregularly low attenuation areas. Fracture is seen as complete seperation. Disruption of the capsule causes intraperitoneal hemorrhage. Late complications include splenic pseudocyst.

Grading:

• Grade 1 – Minor subcapsular tear or haematoma,
  
• Grade 2 – Parenchymal injury not extending to the hilum,
  
• Grade 3 – Major parenchymal injury involving vessels and hilum,
  
• Grade 4 – Shattered spleen.

Management:

Isolated grade 1 and 2 are suitable for conservative management. The patients with cardiovascular instability need surgery, which include repair, spleen conservation surgery (at least 20% of spleen is preserved) and splenectomy. Approximately 30% fail conservative management.

References:

Roberts JL et al. CT in abdominal and pelvic trauma. RadioGraphics 1993; 13: 735

The Correct Answer is D

About 95% of isolated renal injuries are minor and are managed conservatively. Hematuria is seen in 95% of renal injuries, but absence of hematuria does not exclude renal trauma. Hematuria may be absent in severe renal trauma (25% of renal artery thrombosis may not have hematuria). Hematuria with hypotension is associated with increased risk of significant renal injury; but there is poor correlation between severity of hematuria and severity of renal injury. Complete devascularization shows absent nephrogram or cortical rim nephrogram. Early complications include urinary extravasation and urinoma formation, delayed bleeding, infection of the urinoma, perinephric abscess, sepsis, arteriovenous fistula, pseudoaneurysm and hypertension. Late complications include hydronephrosis, hypertension, calculus formation and chronic pyelonephritis.

References:

1. Fanney DR et al.CT in the diagnosis of renal trauma. RadioGraphics 1990; 10: 29.S201-214
2. Kawashima A et al.Imaging of Renal Trauma: A Comprehensive Review. RadioGraphics 2001; 21: 57

The Correct Answer is A

Explanation:

Demyelination and gliosis in HIV encephalitis affects deep white matter, preferentially involving the centrum semiovale. CMV cause meningoencephalitis with predominant involvement of periventricular white matter and brain stem, ventriculitis, infarcts, spinal cord, cranial nerves. CT may show diffuse white matter hypodensity and on contrast, may show ependymal, ring or nodular enhancement. Periventricular calcification is a sign of congenital CMV infection and not a feature of CMV infection in immunocompromised. Cryptococcus is the most common fungal infection in AIDS and typically causes meningitis. PML is caused by Gr B papovavirus and shows bilateral pathy white matter abnormality without mass effect or contrast enhancement.

Reference:Offiah et al. The imaging appearances of intracranial CNS infections in adult HIV and AIDS patients. Clinical Radiology (2006) 61: 393-401

The correct answer is B

HIV encephalitis accounts for up to 60% with AIDS, where as toxoplasma encephalitis accounts for approximately 30% of cases. Toxoplamosis, being the most common opportunistic neuroinfection, may result in necrotising encephalitis, predominantly involving the basal ganglia and thalami. On Unenhcened CT, the lesions are usually isodense to grey matter, but may be hyperdense due to hemorrhage and on contrast, usually show ring or nodular enhancement. Faint or absent enhancement is seen if the CD count is less than 50 and the enhancement increases with increase in the CD count.

The Correct Answer is B

Entameoba histolytica is the most common cause in developing world, but in developed world, pyogenic is the most common cause. In pyogenic abscesses, the most common organism isolated in solitary absess is Klebsiella pneumoniae and in multiple abscess E.coli. The most common mode of spread of infection for pyogenic is ascending cholangitis; for amoebic portal; phlebitis and for fungal, hepatic artery. On ultrasound, the pyogenic abscesses are usually hypoechoic with poorly defined irregular wall and may show echogenic debris. The amoebic abscesses are typically hypoechoic with absence of significant wall. Various ultrasound signs have been described for hydatid cyst and include double contour thick wall (due to triple layer), snow storm sign (falling of sand after patient repositioning), water-lilly sign with floating membranes (detachment of endocyst) and wheel spoke sign (daughter cysts). Heptaic infection is known complications of chemoembolization and radiofrequency ablation

Reference: Doyle DJ et al. Imaging of hepatic infections. Clin Rad 61: 737-746

The Correct Answer is E

Tumours more than 3cm are unlikely to be resectable. Peripancreatic lymphadenopathy is relative contraindication for surgery. Contuguity of 25-50% is equivocal for resectability, where as more than 50% makes it irresectable. Vascular encasement, occlusion or alterationin contour or caliber makes the tumour irresectable. Involvement of gastroduodenal, celiac or superior mesenteric artery is indicator of advanced disease, where as invasion of splenic vessels or spleen is not absolute contraindication for surgery.

Reference: Smith Sl et al. Imaging of pancreatic adenocarcinoma with emphasis on multidetector CT . Clinical Radiology 59 (January 2004): 26-38

The Correct Answer is D

Cigarette smoking is thought to account for 30% of deaths from pancreatic adenocarcinoma. Diabetes and chronic pancreatitis are also associated with increased risk of pancreatic adenocarcinoma. Whipple's procedure carries a risk of 5% mortality. The survival rate, including the ones undergone Whipple's, is not more than 5%. 80% of carcinomas arise from the head. The carconomas arising from body, tail and uncinate process carry worse prognosis than those arising from the head, because of late presentation.

Reference: Smith Sl et al. Imaging of pancreatic adenocarcinoma with emphasis on multidetector CT . Clinical Radiology 59 (January 2004): 26-38

The Correct Answer is C

Most of the melanoma metastasis to brain are multiple, occur at corticomedullary junction and 85% are hyperdense on unenhanced CT scan. Hemorrhage is found in nearly 20%. On MR, they are typically high signal on T1 and low on T2. Most of the intraocular melanomas are primary and ultrasound and MRI are used in the evaluation of the lesion. 40% of lung metastasis are multiple, 20% solitory, 7% adenopathy and 28% combination of these. Bone metastasis is also relatively common and seen in 23% of ocular melanomas. The most common site is spine and most are lytic.

Reference: Kalkman E et al. Melanoma. Clin Rad 59 (2004): 313-326