Advertisement

Anatomic Pitfalls

  • Alexis JacquierEmail author
Chapter
  • 541 Downloads

Abstract

A 51-year-old male was referred to our department for exploration of a hyperechogenic mass in the right atrium. The lesion was discovered on a trans-thoracic echocardiography examination performed during a routine checkup. The patient was asymptomatic and the ultrasound exploration revealed no other anomaly apart from the mass. He was explored by contrast-enhanced CMR and cardiac MDCT.

Keywords

Inferior Vena Cava Radiological Finding Interatrial Septum Suspected Pulmonary Embolus Flow Artifact 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

3.1 Deep Atrioventricular Groove

  • Philippe Germain
  • Gilles Goyault

3.1.1 Case Report

A 51-year-old male was referred to our department for exploration of a hyperechogenic mass in the right atrium. The lesion was discovered on a trans-thoracic echocardiography examination performed during a routine checkup. The patient was asymptomatic and the ultrasound exploration revealed no other anomaly apart from the mass. He was explored by contrast-enhanced CMR and cardiac MDCT.
Fig. 1

CMR, T1 SE black blood weighted image, four-chamber view, showing a deep, wide, right atrioventricular groove (arrow). The right atrioventricular groove contains epicardial fat (hypersignal) and the right coronary vessels

Fig. 2

Cardiac MDCT, four-chamber view. (a) Deep, fatty atrioventricular groove (arrow); the right coronary artery is visible (arrowhead). (b) Surface rendering: deep atrioventricular groove (arrow)

3.1.2 Diagnosis

Deep atrioventricular groove, confirmed on the cardiac MDCT and CMR; this is an anatomic pitfall yielding a hyperechogenic tumor-mimicking image in the right atrium on the transthoracic echocardiography findings.

Table summarizing the radiological findings for deep atrioventricular groove:

Age of discovery

Variable

Clinical presentation

Asymptomatic

Developing on

Right AV groove

Type

Fat and right coronary vessels

Borders

Regular

Extension

No

Calcifications

No

Density without contrast

Hypodense

T1 SE signal

Hypersignal

T2 SE signal

Hypersignal

Uptake of contrast

No

Differential diagnosis

Lipoma

Pathognomonic sign

Morphological features

3.2 Lipomatous Hypertrophy of the Interatrial Septum

  • Laurence Monnier-Cholley
  • Lionel Arrivé

3.2.1 Case Report

Ms Y. a 62-year-old female was under surveillance for ovarian cancer with peritoneal carcinosis. She had a cardiac MDCT as part of her routine follow-up during chemotherapy and the images showed a mass developing in the interatrial septum.
Fig. 3

Cardiac MDCT, axial slice through the cardiac chambers, showing a mass with regular borders located on the interatrial septum (arrows), sparing the fossa ovalis; the low density of the mass on the image suggests that it is made up of adipose tissue. There is also an increase in the adipose tissue around the heart and in the mediastinum

Fig. 4

The cardiac MDCT shows that the fossa ovalis (arrow) is not affected, thus giving the mass its typical shape

Fig. 5

Cardiac MDCT at a lower level. The adipose tissue is infiltrating along the coronary sinus into a proeminent Eustachian valve remnant (arrow)

3.2.2 Diagnosis

Lipomatous hypertrophy of the interatrial septum.

3.2.3 Background

The incidence of this disorder is around 2% and increases with age; it is mainly diagnosed in overweight patients. Lipomatous hypertrophy of the interatrial septum is a form of hypertrophy of the preexisting fatty tissue in the interatrial septum and is often associated with hypertrophy of the epicardial fat [34, 35].

Table summarizing the radiological findings in lipomatosis of the interatrial septum:

Age of discovery

Adult

Clinical features

Asymptomatic

Developing on

Interatrial septum

Tissue

Brown fat

Borders

Regular

Extension

No

Calcifications

No

Density without contrast

Hypodense

Signal T1 SE

Hypersignal

Signal T2 SE

Hypersignal

Uptake of contrast

No

Differential diagnosis

Lipoma

Pathognomonic sign

No involvement of the fossa ovalis

3.3 Flow Artifact in the Right Atrium

  • Laurence Monnier-Cholley
  • Lionel Arrivé

3.3.1 Case Report

A 54-year-old female patient was referred for a non-gated thoracic CT scan to screen for suspected pulmonary embolus; the clinical examination revealed atrial fibrillation, precordalgia and breathlessness; the patient’s case history included surgery to correct a septal defect at the age of 17.
Fig. 6

Contrast-enhanced thoracic CT scan without cardiac gating: no pulmonary embolus is visible. In the right atrium there is a round-shaped image developing against the interatrial septum; this image is hypodense in comparison to the right ventricle

Fig. 7

The CT scan acquisitions with MPR reconstruction show that the hypodense signal picked up on the right atrium is located on the terminal portion of the inferior vena cava

Fig. 8

Contrast-enhanced CT scan 5 min after injection of contrast medium showing that the contrast medium is now evenly distributed in the vena cava and the right atrium and no mass is distinguishable

Fig. 9

On CMR, the SSFP cine sequences in the four-chamber plane confirm that there is no mass in the right atrium

3.3.2 Diagnosis

Flow artifact inside the right atrium at the inferior vena cava junction, mimicking right atrial thrombus in the early enhancement phase.

3.3.3 Background

The contrast medium can sometimes distribute unevenly in the right atrium immediately after injection because of the complex flow patterns and turbulence in this part of the heart. Multiple plane reconstructions and further acquisitions at a later stage can be helpful to correct the diagnosis.

Table summarizing the radiological findings in flow artifact of the right atrium:

Clinical

Asymptomatic

Developing on

Right atrium

Type

Physiological swelling

Borders

Regular

Arterial phase

The artifact is visible

Venous or later phase

Whole chamber homogenously enhanced

Pathognomonic sign

Late homogenization of contrast

3.4 Crista Terminalis

  • Arthur Varoquaux
  • Vincent Vidal
  • Jean Michel Bartoli
  • Jean-Yves Gaubert
  • Guy Moulin
  • Alexis Jacquier

3.4.1 Case Report

A 50-year-old female was referred to our department for the exploration of a mass projecting from the lateral wall of the right atrium discovered on an echocardiographic examination.
Fig. 10

Post-contrast cardiac MDCT, axial view. The mass depicted on the echocardiogram is developing from the lateral wall of the right atrium; its borders are clear and regular (arrow)

Fig. 11

SSFP cine image, four-chamber view. The mass described above is visible on the lateral wall of the right atrium; it has regular borders and sends the same signal as the myocardium (arrow)

3.4.2 Diagnosis

Crista terminalis.

3.4.3 Background

The crista terminalis is a vertical ridge of smooth myocardium that protrudes into the right atrium. It is located on the lateral wall, running from the right side of the orifice of the superior vena cava to the right side of the inferior vena cava. It marks the line where the anterior trabeculated portion of the right atrium and the smooth posterior wall of the venous sinus merge. The crista terminalis is often visualized in the right atrium in the course of a routine contrast-injected CT scan, or CMR and can sometimes be quite prominent. The sinoatrial node is located in the upper portion of the crista terminalis [36].

Table summarizing the radiological findings for crista terminalis:

Developing on

Lateral wall of the right atrium

Type

Physiological muscular swelling

Borders

Regular

Location

Between the two vena cava, in the right atrium

Calcification

No

Density without contrast

Hypodense

T1 SE signal

Isosignal/muscle

T2 SE signal

Isosignal/muscle

Uptake of contrast

No

Differential diagnosis

Tumoral mass

Pathognomonic sign

Morphological findings

3.5 Juxtacaval Fat Collection

  • Philippe Dory-Lautrec
  • Frédéric Cohen
  • Guillaume Louis
  • Jean-Yves Gaubert
  • Guy Moulin
  • Alexis Jacquier

3.5.1 Case Report

An obese female patient, age 45 years, was explored for abdominal pain and a mass was found in the retrohepatic portion of the inferior vena cava (IVC) on her CT scan. A CMR and a non-gated CT scan were ordered to explore the mass.
Fig. 12

CMR T1-weighted axial image in the upper part of the liver showing a hypersignal indicating a mass in the lumen of the IVC

Fig. 13

CT scan 60 s after contrast injection showing a fat-suppressed mass with regular borders, developing in the lumen of the retrohepatic IVC

3.5.2 Diagnosis

Juxtacaval fat collection.

3.5.3 Background

Juxtacaval fat collection is caused by part of the fatty tissue located around the retrohepatic segment of the IVC invaginating into the lumen of the vessel. The image is position-dependent and also varies according to the patient’s respiratory phase. The frequency of this anatomical variation is 0.5%. It is located in a posteromedial position on the IVC, either on or below the confluence of the SHV. It is usually round or oval in shape, clearly delineated, measuring 5–25 mm in diameter and its density varies between −140 and −30 HU. There are many possible assumptions regarding its pathophysiology: angulation due to anatomical variation, obesity, diabetes or steroid treatment [37].

Table summarizing the radiological findings for juxtacaval fat collection:

Age of discovery

Adult

Clinical

Asymptomatic

Developing on

IVC junction of the RA

Type

Fatty tissue around vena cava and esophagus

Borders

Regular

Extension

No

Calcifications

No

Density without contrast

Hypodense

T1 SE signal

Hypersignal

T2 SE signal

Hypersignal

Uptake of contrast

No

Differential diagnosis

Lipoma

Pathognomonic sign

Position-dependent and varies with breathing

References

  1. 34.
    Gaerte SC, Meyer CA, Winer-Muram HT, Tarver RD, Conces DJ Jr (2002) Fat-containing lesions of the chest. Radiographics 22(Spec No):S61–S78PubMedGoogle Scholar
  2. 35.
    Levine RA, Weyman AE, Dinsmore RE et al (1986) Noninvasive tissue characterization: diagnosis of lipomatous hypertrophy of the atrial septum by nuclear magnetic resonance imaging. J Am Coll Cardiol 7:688–692PubMedCrossRefGoogle Scholar
  3. 36.
    Broderick LS, Brooks GN, Kuhlman JE (2005) Anatomic pitfalls of the heart and pericardium. Radiographics 25:441–453PubMedCrossRefGoogle Scholar
  4. 37.
    Raju NL, Austin JH (2001) Case 37: Juxtacaval fat collection–mimic of lipoma in the subdiaphragmatic inferior vena cava. Radiology 220:471–474PubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  1. 1.Service d’imagerie Médicale Adulte CHU la TimoneMarseille, Cedex 05France
  2. 2.Centre de Résonance Magnétique Biologique et Médicale (CRMBM) Faculté de Médecine de MarseilleUniversité de la MéditerranéeMarseilleFrance

Personalised recommendations