have sensitivity rates of 70–80% depending on the technical equipment and

ability and on the experience of the investigator. The technique of near-

infrared imaging will be mentioned in another article in this journal. Also,

the value of biopsy techniques including recently developed ultrasonog-

raphy-guided needle biopsy with molecular analysis of the cells of about

97–100% accuracy in diagnosing benign from malignant lymph nodes will

be mentioned.

Overall, the reader will get an overview of the present imaging modalities to

potentially stage correctly lymph nodes in the head and neck region to

facilitate the therapeutic procedure.

Role of diffusion-weighted MR imaging in cervical lymphadenopathy

Abdel Razek AAK, NY Soliman, Elkhamary S, Alsharaway MK, Tawfik A

(Diagnostic Radiology Department, Faculty of Medicine, Mansoura

University, Mansoura, Egypt). Eur Radiol 2006;16:1468–1477.

The role of diffusion-weighted magnetic resonance imaging (MRI) for

differentiation between various causes of cervical lymphadenopathy was

evaluated. In a prospective study, 31 untreated patients (22 males and

9 females, aged 5–70 years) with 87 cervical lymph nodes underwent

diffusion-weighted MRI before performance of neck dissection (n=14),

surgical biopsy (n=9), or core biopsy (n=8). Diffusion-weighted MR

images were acquired with a b factor of 0 and 1000 s/mm2 using single-

shot echo-planar sequence. Apparent diffusion coefficient (ADC) maps

were reconstructed for all patients. The signal intensity of the lymph

nodes was assessed on images obtained at b=0 or 1000 s/mm2 and from

the ADC maps. The ADC value of lymph nodes was also calculated. On

the ADC map, malignant nodes showed either low (n=52) or mixed

(n=20) signal intensity and benign nodes revealed high (n=13) or low

(n=2) signal intensity. The mean ADC value of metastatic

(1.09F0.11�10�3 mm2/s) and lymphomatous (0.97F0.27�10�3 mm2/s)

lymph nodes was significantly lower than that of benign (1.64F16�10�3mm2/s) cervical lymph nodes ( Pb.04). When an ADC value of

1.38�10�3 mm2/s was used as a threshold value for differentiating

malignant from benign lymph nodes, the best results were obtained with

an accuracy of 96%, a sensitivity of 98%, a specificity of 88%, a positive

predictive value of 98.5%, and a negative predictive value of 83.7%. The

smallest detected lymph node was 0.9 cm. In conclusion, diffusion-

weighted MRI with ADC mapping is a new promising technique that can

differentiate malignant from benign lymph nodes and delineate the solid

viable part of the lymph node for biopsy. This technique provides

additional useful physiological and functional information regarding

characterization of cervical lymph nodes.

Ultrasound of superficial lymph nodes

Esen G (Istanbul University, Cerrahpasa Medical School, Department of

Radiology, 34300 Istanbul, Turkey). Eur J Radiol 2006;58:345–359.

US is a powerful tool for characterization of superficial lymph nodes.

Unlike other imaging techniques like CT and MRI, which mainly depend

on size for differential diagnosis, US can evaluate important parameters

such as shape, margins, internal structure, and abnormal vascularization. It

has the advantage of showing early subtle findings of neoplastic

involvement like asymmetric thickening and focal lobulations in the

cortex, as well as late findings such as diffuse cortical thickening and

absence of hilum. It is possible to evaluate the heterogenous inner

structure due to necrosis, unsharp or irregular borders due to extracapsular

spread, and abnormal vascularization with multiple subcapsular feeding

vessels due to tumor angiogenesis. The advances in US technology like

high-resolution transducers, power Doppler function, and contrast agents

have all contributed to the well-established role of US in the evaluation of

lymph nodes. This article mainly focuses on the sonographic criteria

for differential diagnosis of normal, reactive, inflammatous, and neo-

plastic lymph nodes, as well as examination techniques in the neck,

axilla, internal mammary and inguinal regions and indications in various

clinical settings.

Abstracts / Clinical Imaging 31 (2007) 72–75 75