Lymphedema-edema that results from chronic lymphatic insufficiency-is a chronic debilitating disease that is frequently misdiagnosed, treated too late, or not treated at all. There are, however, effective therapies for lymphedema that can be implemented, particularly after the disorder is properly diagnosed and characterized with lymphoscintigraphy. On the basis of the lymphoscintigraphic image pattern, it is often possible to determine whether the limb swelling is due to lymphedema and, if so, whether compression garments, massage, or surgery is indicated. Effective use of lymphoscintigraphy to plan therapy requires an understanding of the pathophysiology of lymphedema and the influence of technical factors such as selection of the radiopharmaceutical, imaging times after injection, and patient activity after injection on the images. In addition to reviewing the anatomy and physiology of the lymphatic system, we review physiologic principles of lymphatic imaging with lymphoscintigraphy, discuss different qualitative and quantitative lymphoscintigraphic techniques and their clinical applications, and present clinical cases depicting typical lymphoscintigraphic findings.

https://jnm.snmjournals.org/content/jnumed/44/1/43.full.pdf

Who is at risk for developing chronic anal fistula or recurrent anal sepsis after initial perianal abscess

Pulmonary Radiation Injury

Hypothesis The causes and management of lower limb lymphedema in the Western population are different from those in the developing world. Objective To look at the differential diagnosis, methods of investigation, and available treatments for lower limb lymphedema in the West. Data Source A PubMed search was conducted for the years 1980-2002 with the keyword "lymphedema." English language and human subject abstracts only were analyzed, and only those articles dealing with lower limb lymphedema were further reviewed. Other articles were extracted from cross-referencing. Results Four hundred twenty-five review articles pertaining to lymphedema were initially examined. This review summarizes the findings of relevant articles along with our own practice regarding the management of lymphedema. Conclusions The common differential diagnosis in Western patients with lower limb swelling is secondary lymphedema, venous disease, lipedema, and adverse reaction to ipsilateral limb surgery. Lymphedema can be confirmed by a lymphoscintigram, computed tomography, magnetic resonance imaging, or ultrasound. The lymphatic anatomy is demonstrated with lymphoscintigraphy, which is particularly indicated if surgical intervention is being considered. The treatment of choice for lymphedema is multidisciplinary. In the first instance, combined physical therapy should be commenced (complete decongestive therapy), with surgery reserved for a small number of cases.

https://jamanetwork.com/journals/jamasurgery/articlepdf/394351/ssa2105.pdf

Differential diagnosis, investigation, and current treatment of lower limb lymphedema

We describe the diagnostic contribution of [(18)F]fluoro-deoxyglucose (FDG) positron emission tomography (PET) scan in 58 consecutive cases of fever of unknown origin (FUO) and compare this new approach with gallium scintigraphy. This investigation was performed from March 1996 through October 1998 at Gasthuisberg University Hospital in Leuven, Belgium. A final diagnosis was established for 38 patients (64%). Forty-six FDG-PET scans (79%) were abnormal; 24 of these abnormal scans (41% of the total number of scans) were considered helpful in diagnosis, and 22 (38% of the total number) were considered noncontributory to the diagnosis. In a subgroup of 40 patients (69%), both FDG-PET and gallium scintigraphy were performed. FDG-PET scan and gallium scintigraphy were normal in 23% and 33% of these cases, respectively; helpful in diagnosis in 35% and 25%, respectively; and noncontributory in 42% each. All foci of abnormal gallium accumulation were also detected by use of an FDG-PET scan. We conclude that FDG-PET is a valuable second-step technique in patients with FUO because it yielded diagnostic information in 41% of the patients in whom the probability of a definite diagnosis was only 64%. FDG-PET scan compares favorably with gallium scintigraphy for this indication. Because of the quick results (within hours instead of days), FDG-PET scan may replace gallium scintigraphy as a radiopharmaceutical for the evaluation of patients with FUO.

/pdf/clinical-value-of-18f-fluoro-deoxyglucose-positron-emission-3uhnt7p018.pdf

Clinical Value of [18F]fluoro-Deoxyglucose Positron Emission Tomography for Patients with Fever of Unknown Origin

The lymphatic system is a complex network of lymph vessels, lymphatic organs and lymph nodes. Traditionally, imaging of the lymphatic system has been based on conventional imaging methods like computed tomography (CT) and magnetic resonance imaging (MRI), whereby enlargement of lymph nodes is considered the primary diagnostic criterion for disease. This is particularly true in oncology, where nodal enlargement can be indicative of nodal metastases or lymphoma. CT and MRI on their own are, however, anatomical imaging methods. Newer imaging methods such as positron emission tomography (PET), dynamic contrast-enhanced MRI (DCE-MRI) and color Doppler ultrasound (CDUS) provide a functional assessment of node status. None of these techniques is capable of detecting flow within the lymphatics and, thus, several intra-lymphatic imaging methods have been developed. Direct lymphangiography is an all-but-extinct method of visualizing the lymphatic drainage from an extremity using oil-based iodine contrast agents. More recently, interstitially injected intra-lymphatic imaging, such as lymphoscintigraphy, has been used for lymphedema assessment and sentinel node detection. Nevertheless, radionuclide-based imaging has the disadvantage of poor resolution. This has lead to the development of novel systemic and interstitial imaging techniques which are minimally invasive and have the potential to provide both structural and functional information; this is a particular advantage for cancer imaging, where anatomical depiction alone often provides insufficient information. At present the respective role each modality plays remains to be determined. Indeed, multi-modal imaging may be more appropriate for certain lymphatic disorders. The field of lymphatic imaging is ever evolving, and technological advances, combined with the development of new contrast agents, continue to improve diagnostic accuracy.

Imaging of the lymphatic system: new horizons

The authors evaluated the ability of {sup 99m}Tc-hexamethylpropyleneamine oxime ({sup 99m}Tc-HMPAO) to serve as a sensitive marker of lung injury. Two experiment rabbit models of minimal lung injury were designed using injections of a low dose (0.05 ml/kg) of oleic acid or 50 Gy of irradiation. In addition, they clinically investigated whether patients who received chemotherapy (n = 14) or radiotherapy (n = 13) for lung cancer showed high uptake of {sup 99m}Tc-HMPAO in the lungs. Despite the minimal endothelial lesions visualized by electron microscopy (edematous changes and blebbing), in both animal models, the lungs showed high uptake of {sup 99m}Tc-HMPAO, which occurred rapidly within 1 min after injection. Clinically, the mean lung-to-liver ratio of {sup 99m}Tc-HMPAO activity in the patients who received chemotherapy (0.649{+-}0.185, p < 0.01) was significantly higher than that of the controls (n = 16; 0.387{+-}0.108), and all 12 patients who received more than 30 Gy of irradiation showed abnormal uptake in the irradiated lungs, despite the lack of abnormal opacities on chest CT. These findings suggest that {sup 99m}Tc-HMPAO has the potential to be a sensitive marker of chemical and irradiation lung injury. 53 refs., 5 figs., 3 tabs.

http://jnm.snmjournals.org/content/35/9/1520.full.pdf

Technetium-99m-HMPAO as a marker of chemical and irradiation lung injury: experimental and clinical investigations.

The difference in 201Tl-chloride (201Tl) accumulation on single photon emission computed tomography (SPECT) between 58 benign (58 cases) and 48 malignant (46 cases) thoracic lesions, each of more than 20 mm in diameter was investigated. In the 34 benign and 48 malignant lesions depicted in both early (15 min) and delayed (3 h) images there was no significant difference in the mean early and delayed uptake ratios of lesion to normal contralateral lung between benign and malignant. However, the retention index in the lesion derived from (delayed ratio--early ratio)/(early ratio) x 100% showed a significant difference (benign -4.30 +/- 13.6% versus malignant 23.3 +/- 18.9%, P < 0.01), indicating the poor 201Tl retention in the benign lesions. Using the criteria of nondepiction in the delayed image or a negative retention index, 81.1% accuracy and 95.2% predictive value for diagnosis of benign lesions were obtained. Thus, 201Tl SPECT appears to have potential usefulness in the diagnosis of benign thoracic lesions.

Difference in 201Tl accumulation on single photon emission computed tomography in benign and malignant thoracic lesions.

Lymphoscintigraphy using a test involving standing from a supine position and performed following an intradermal injection of 99Tcm-human serum albumin (HSA) was developed to evaluate the function of the lymphatic system in the lower extremities of patients who developed lymphoedema following arterial reconstructive surgery. In normal subjects, the load produced by standing tended to increase lymphatic function as indicated by the frequent appearance of a large spiking wave and a rapid stepwise increase in tracer activity and, less often, a phase of decreasing tracer activity. However, there was either no or less activation of lymph flow following standing in the group which developed leg oedema postoperatively. These findings indicate that lymphatic disruption is responsible for the leg oedema seen in these patients. Performance of this test following an intradermal injection of 99Tcm-HSA is technically simple, requires no special apparatus, and can be completed in 30 min. Lymphoscintigraphy using our new method can provide useful information on abnormalities in lymphatic function.

Lymphoscintigraphic assessment of leg oedema following arterial reconstruction using a load produced by standing.

We have assembled data from patients with fever of unknown origin who underwent gallium scintigraphy during the past 5 years in order to obtain a more current sampling of patients, and evaluated the role of gallium scintigraphy retrospectively. Of the 36 patients studied, gallium scintigraphy was positive and contributed to the detection of the foci or fever origins in 17 (47.2%). The ratio of neoplastic diseases with myeloproliferative and with lymphoproliferative disorders was relatively high compared with previous reports. However, gallium scintigraphy did not contribute to the diagnosis of collagen disease. With the ability to detect both inflammatory and neoplastic lesions, gallium scintigraphy was useful in detecting the foci of fevers of unknown origin.

The role of Gallium-67 imaging in the detection of foci in recent cases of fever of unknown origin

A 45-year-old man receiving continuous ambulatory peritoneal dialysis developed scrotal swelling and edema which was aggravated in the standing position. Physical examination failed to find inguinal hernia and although ultrasonography revealed the patent had processus vaginalias, it failed to prove its continuity to the peritesticular space of the tunica vaginalis. Peritoneal scintigraphy with intraperitoneal instillation of99mTc-Macroaggregated albumin followed by standing clearly demonstrated the connection. The use of the standing load makes possible faster visualization of a positive finding and more accurate diagnosis than examination in the supine position.

Demonstration of inguinal hernia by means of peritoneal99mTc-MAA scintigraphy with a load produced by standing in a patient treated by continuous ambulatory peritoneal dialysis

Norimasa Yamada

Papers

Technetium-99m-HMPAO as a marker of chemical and irradiation lung injury: experimental and clinical investigations.

Difference in 201Tl accumulation on single photon emission computed tomography in benign and malignant thoracic lesions.

Lymphoscintigraphic assessment of leg oedema following arterial reconstruction using a load produced by standing.

The role of Gallium-67 imaging in the detection of foci in recent cases of fever of unknown origin

Demonstration of inguinal hernia by means of peritoneal99mTc-MAA scintigraphy with a load produced by standing in a patient treated by continuous ambulatory peritoneal dialysis